applications cement kiln dust - p2 infohouse
TRANSCRIPT
Applications of Cement Kiln Dust in
Wastewater Sludge Management
J u n e 1986
.
June 13, 1986 ADDENDUM
A t the onset of this study, the only plant tested appl icat ions of cement k i l n d u s t (CKD) were for use as a cond i t ioner in con junc t ion w i th vacuum f i l t e r press dewatering and as a thickening agent for c leaning out s i udge 1 agoons. While i t was bel ieved that CKD would f a c i l i t a t e f l o c c u l a t i o n and s e t t l i n g of wastewater sludge, no t even laboratory documentation was ava i lab le to subs tan t ia te th is be l ie f .
Several laboratory scale invest igat ions had been conducted documenting CKDs a b i l i t y as a s t a b i l i z i n g agent; most o f these studies looked a t adding CKD t o a dewatered sludge cake. By and la rge , t he f eas ib i l i t y o f u t i l i z i n g CKD as a s t a b i l i z i n g agent under typical operat ional condit ions had not been demonstrated.
Since N-Vir0 was granted a patent (and the process approved by EPA) i n November 1985, aggressive marketing of the product has generated increased interest and consequently increased research and data on a wider var iety of potent ia l appl icat ions.
A recen t p i l o t sca le s tudy i n Houston showed tha t by mixing CKD w i t h a mixed (waste activated, raw) wastewater sludge (1.3% t o ta l so l i ds ) on a 1:l dry weight basis, and al lowing the mixture t o set t le, they were ab le t o pump o f f 64% of the o r ig ina l water a f te r 20 hours s e t t l i n g t ime. This confirms the laboratory results reported i n t h i s study.
The r e c e n t p i l o t p r o j e c t a t San Antonio was so successful that they are expanding the o r ig ina l p ro jec t and are get t ing set up t o pump CKD d i rec t l y t o t he l i nes t ha t f eed t he i r d ry ing beds. They hope t o use CKD t o speed up the drying process' and s t a b i l i z e t h e sludge a t t h e same time.
On June 24, severa l p i lo t s tud ies will begin at the Jef ferson Par ish Department of Sewerage i n Metair ie, LA. A t l e a s t two of the p i l o t p r o j e c t s i n v o l v e d i r e c t s t a b i l i z a t i o n o f a 1-2 % to ta l so l i ds sludge. The anaerobic digestors will be used as - mixing/sett l ing tanks for the sludge/CKD mixture. A s i m i l i a r approach could be employed a t
June 10, 1986
* J .B. Lowry - Cement K i l n Dust. Report
The attached report documents a research project undertaken while on assignment a t t h e Southside Wastewater Treatment Plant. The pro jec t was in i t ia ted to eva lua te the po ten t ia l fo r us ing Cement Ki.1 n Dust (CKD) to increase ef f ic iency of our current waste- water sludge i n j e c t i o n process. The o r ig ina l ob jec t i ve was expanded and the p ro jec t was continued under the auspices o f t h e Research and Central Labs Divis ion.
While c r i t e r i a f o r e v a l u a t i o n i n i t i a l l y appeared simple and s t ra igh t - forward, t h i s was not the case. A substant ia l amount o f time was devoted t o developing and adapting laboratory prgcedures, i n an attempt to obtain meaningful data. While this was a long and of ten f rust ra t ing proposi t ion, i t provided excel lent "on the job" t ra in ing.
This project al lowed me the oppor tun i t y . to i n te rac t w i th a diverse group o f indiv iduals, both i n and outside Dal las Water U t i l i t i e s . The cooperation I received from DWU employees confirmed my i n i t i a l impression that a t r u e team s p i r i t pervades t h i s department.
I s incere ly hope that th is repor t prov ides in format ion that can be u t i l i z e d by those ind iv iduals responsib le for eva luat ing and implementing i n te r im and future sludge management plans f o r DWU.
KaFen Bick Technical Assistant
DWU i n an emergency s i tuat ion (d igestors down , hydraul ic overf low) t o produce .s tab i l i zed sludge. It may be valuable to have someone
observe th is operat ion to evaluate the potent ia l for such use. Comprehensive Mater ia ls Management would l i k e l y cover the costs fo r a DWU representa t ive to v is i t th is p ro jec t .
Results o f t h e Ohio College o f Medicine study investigating the potent ia l for us ing CKD amendment t o achieve PFRP designation are due short ly. I f the resul ts are pos i t ive, we need t o give serious consideration to re-evaluating the proposed composting a l ternat ive, as wel l as any fu tu re expansion o f anaerobic d i g e s t i o n f a c i l i t i e s .
TABLE OF CONTENTS
SUMMARY
INTRODUCTION Concerns About Current Sludge Handling Background: Cement Kiln Dust Scope Objectives
METHODS Sampling Efficiency Parameters Stabilization Parameters Quality Control of C K D
DISCUSSION O F RESULTS Efficiency Parameters Stabilization Parameters Quality Control of CKD
SUMMARY O F RESULTS POTENTIAL USE OF CKD RECOMMENDATIONS
Interim Sludge Yanagement Long Term Sludge Management
LITERATTJRE CITED ACKNOWLEDGMENTS APPENDICES
Appendix A - EPA Yemo: November 6, 1985 Appendix B - DWU Wastewater Sludge Policy Appendix C - N-Vir0 S a l e s Literature Appendix D - CKD Chemical Analysis and Conlments Appendix E - Recovery of 10 grams C K D Powder Appendix F - Sludge/CKD pH Readings Appendix G - Ohio Medical College Study
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Applications of Cement Kiln Dust in
Wastewater Sludge Management.
BY
Karen Bick
Dallas Water Utilities
Southside Wastewater Treatment Division Research and Development Division
June 1986
SUMMARY
PURPOSE
The purpose of this report is to evaluate\.the potential for incorporating cement kiln dust (CKD) into the wastewater sludge processing at Dallas Water Utilities (DWU) .
BACKGROUND: Wastewater Sludge Processing at DWU
Current wastewater sludge processing consists of consolidating sludges and scums generated at both treatment plants, into a single lag0011 at the Southside WaStewater Treatment Plant (SWT). The sludge is allowed to settle and the bottom sediments are dredged from the lagoon. Sludge fs disposed of by subsurface injection on dedicated land disposal fields located at SWT.
Several concerns exist with regards to the efficiency of the process as well as to the quality of sludge that is currently being injected.
BACKGROUND: Cement Kiln Dust
CKD, a by-product of cement manufacturing processes, has many potential applications in the wastewater treatment field. CKD is locally marketed through Comprehensive Materials Management, Inc. (CMM), a representative for N-Vir0 Energy Systems, Ltd {N-Viro). N-Viro pioneered the research and development of CKD technology and'holds patent rights on auch of the technology.
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LIST OF ILLUSTRATIONS
FIGURES
1. Histogram of settled volumes of 1 liter sludge recorded @ 1 hr. settling time in Imhoff cone.
2. Settled volume of 1 liter of control and CKD-amended sludge 81 hr. settling time in Imhoff cone.
3 . Histogram of percent settled volume reduction in 10 g/l CKD-amended sludges @ 1 hr.in Imhoff cone.
4. Mean percent total solids of control and CKD-amended sludges; weight/volume basis.
5 . Breakdown of percent total solids composition; Percent total solids of control sludge is conlparcd t o percent total solids of CKD-amended sludge and to the portion due to sludge solids.
6 . Unit processes available for treating and disposing sludge.
7. CDM's recommended long term sludge mnnagement scheme.
T A B L E S
1. Potential uses for CKD in wsstewater sludge processes.
2. C K D oxide analysis.
3 . Settled volume of CKD-amended water 9 1 hr. settling time in Imhoff cone.
4 . Solids in supernatant.
5 . Range and mean of f total solids computed on a weight/volume basis.
6 . Breakdown of average % total solids: Sludge solids and CKD powder contributions.
7. Range of f vo.latilcs in various substrates.
8 . Range and mean pH values of CKD-amended sludge after 2-4 hrs. contact,' time.
9 . Range of log reductions of indicator organisms in CKD-amended sludge.
10. L O 1 values fur three distinct sources of CKD.
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reduction of fecal and total coliforms. The EPA has recent-ly established a Task Force to evaluate the equivalency-of alternative technologies. It is possible that CKD amendment could qualify as a PSRP at this level.
At 15 g/L, CKD amendment of sludge qualifies as a PSRP according to established EPA criteria for lime stabilization. . This finding is consistent with results previously reported by Eitel Institute for Silicate Research, Bowser Morner Testing Laboratories and Jones &
Henry Engineers, Ltd. (2,3,6).
RECOMMENDATIONS
The results were evaluated with regards to the concerns and recommendations presented in the latest Sludge Wastewater Master Plan by Camp Dresser s( HcKee ( 8 ) .
Recommendations for incorporating CKD into the DWU system are offered in terms of interim and long term sludge management schemes:
Interim Sludge Yanagement
Suggestions for incorporating CKD into the current wastewater sludge handling process are offered; implementation will result in increased efficiency and improved sludge quality, without any large changes or capital expense.
Long Term Sludge Management
Several CKD alternatives, compatible with CDMs recommended overall framework are suggested. These alternatives merit consideration in current evaluations because they represent considerable savings in capital and operational costs.
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SCOPE
N-Vir0 and CMM claim that CKD amendment is a cost effective means of improving sludge settling characteristics which will result in increased efficiency of the injection process. Concomitant sludge stabilization is also possible. To test these claims, experiments were conducted at D W U facilities. Laboratory procedures consisted of modified jar and 60-minute settleability testing and standard membrane filter techniques for pathogens.
OBJECTIVES
The primary objective of this study was to determine if CKJ) could increase the efficiency of the current sludge injection process. Criteria used to evaluate efficiency were sludge settling characteristics and settled sludge solids concentration. The second objective was to determine if CKD could be used t o stabilize the sludge in accordance with Environmental Protection Agency (EPA) criteria for P S R P .
RESULTS
Laboratory scale investigations ascertained that a dosage of 1Og/L CKD significantly enhanced sludge settling characteristics, resulting in substantial sludge volume reductions. The volume reduction was accompanied by a 400% increase in dry weight. Approximately half of this increase i s directly attributable t o CKD material, the other half represents an increased concentration of settled sludge solids. .
Concomitant effects include t h e elimination of rising sludge, reduction of n o x i o u s odors, and at least a 2 log
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Presently, the sludge in the lagoon exhibits poor settling characteristics, resulting in low (3 -4%) solids content of the injected sludge and a thick, crusty layer of risen sludge covering the surface of the lagoon. The low solids content constitutes a waste of resources since the sludge injection equipment is designed to handle a higher (6-83) solids content. The concentrated sludge solids contained.in the top crust are essentially lost to the disposal process. Aside from decreasing the capacity of the lagoon, this thick layer severely restricts mobility of the dredges and is responsible for aesthetic problems around the lagoon.
11. Sludge Quality
The sludge that is currently injected is not stabilized in accordance with federal regulations. A U . S .
Environmental Protection Agency (EPA) memo issued November 6, 1085 states: (Appendix A )
"The regulations ( 4 0 CFR Part 257.3-6) require treatment by a Process to Significantly Reduce Pathogens (PSRP) of sewage sludge applied to land or incorporated iilto the soil. '*
Due to the uncertainty that exists concerning which agency (Texas Department of Health or Tesas Water Commission) has jurisdiction over SWT's dedicated land disposal operation, current state regulations are not clear. However,new sludge management regulations are scheduled to be finalized in September 1987. It i s likely
that the PSRP stabilization requirement will be enforced at that time.
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I N T R O D U C T I O N
The purpose of this report is to evaluate the potential for incorporating cement kiln dust (CKD) into the wastewater sludge processing at Dallas Water Utilities (DWU). Alot of attention is currently being focused on
improving this process, both on an interim and long term basis. This study was originally initiated to determine if CKD could b e used advantageously in conjunction with the current operating procedures. As a result of the extensive literature review conducted, long term sludge management options are also addressed.
Current sludge handling procedures consist o f
consolidating the sludges and scums generated at the Ce'ntral Wastewater Treatment Plant (CWT) into a sludge holding tank and pumping this mixture (transfer sludge) approximately 15 miles, through an 18" transfer line to the Southside Wastewater Treatment Plant (SWT) where it is deposited into Lagoon A . Solids generated at SWT are also deposited into this lagoon. The sludge is allowed to settle in the lagoon, theoretically producing bottom sediments of 4-6% total solids. These solids are dredged from the lagoon and transferred by high pressure pumps to dedicated land disposal fields on SWT property.
CONCERNS ABOUT CURRENT SLUDGE HANDLING
I . E f f i c i e n c y
While sludge is generated each day, the time available for injection is limited by weather related conditions. Therefore, it is critical to maximize the efficiency of the injection process to take full advantage of each available "inject i a n Ilour".
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Table 1. Summary list of potential uses of CKD in wastewater sludge treatment processes.
Coagulation pH adjustment (provides alkalinity) Conditioning
a. Thickening b. Dewatering
a. Pathogen reduction b. Odor control c. Heavy metal immobilization
Stabilization
Solidification Disinfection
A 1982 Bureau of Mines report!lj concludes:
"Cement K i l n Dust is a large volume material and a potential resource... Any environmental considerations are minor...U.S. CKD is not a hazardous waste ilS defined b y current regulations.. . "
C K D is readily available, being generated at a rate of 20 million tons/year, nationwide.
N-Vir0 Energy Systems, Ltd. (N- Viro) pioneered the research and development of CKD technology and holds patent rights on much of the technology. Quot.ing their sales literature (Appendix C ) , "N-VIR0 SOIL is 3
propietary process which involves the use of kiln dust.. .to stabilize, disinfect, deodorize, dewater, and if desired, granulate municipal wastewater sludge."
CKD technology is versatile with many potential applications in the wastewater treatment field. It's effectiveness as 3
sludge conditioner and stabilizer is well documented (2-6)
CKD technology is currently employed on some basis at
treatment plants throughout the country (Monroe, MI.; Toledo, OH.; York, PA.; Jupiter, FLA.). In Texas, the city of Fort Worth recently began incorporating CKD into their wastewater sludge dewatering and stabilization processes. Pilot studies are also underway in Houston, Pasadena, and San Antonio.
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Concern also exists regarding the heavy metals content of the sludge. Metals can be a problem in terms of soil and groundwater contamination that may result from long term land disposal. They also impose constraints on utilization and marketability of a stabilized end-product.
Producing an environmentally safe, stabilized sludge is both prudent and consistent with DHU’s stated sludge policy to pursue strategies that emphasize beneficial utilization of sludge (Appendix B).
BACKGROUND: Sludge Composition
.The composition of the influent sludge is variable. Depending on operating conditions at the treatment plants, the sludge mixture may contain any or all of the following, i n varying proportions:
Raw s 1 utlge Trickling filter sludge Partially digested sludge Aerobically digested sludge Anaerobically digested sludge Waste activated sludge Various scums
The influent sludge has an average total solids of 0.8%.
BACKGROUND: Cement Kiln Dust
General C K D , a by-product of cement manufacturing processes, is a versatile material with many potential applications in the wastewater treatment field (Table 1). It is a very fine material, usually with a Blaine fineness which exceeds 5,000 c m 2 1 9 .
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Unlike lime, CKD possesses significant quantities of reactive calcium in addition to its free lime portion. Dehydroxylated clays, unstable potassium constituents, and various other components contribute to . C K D
reactivity. The actual chemical reactions are complex; it took six years for N-Vir0 to illucidate the mechanisms involved. N-Vir0 was granted patent rights on November 19, 1985. Loss on Ignition ( L O I ) at 1000°C is considered to be the key indicator of a kiln dusts’ reactivity (P. Nicholson, personal communication). This characteristic can be exploited as a
parameter.
SCOPB
Comprehensive Haterials regional representative
quick and easy quality control
Management,Inc.(CMM), the for N-Vir0 who- generously
provided the CKD for this study, claims that C K D
amendment is a cost effective means of improving our current sludge processing operation. To test these claims , experiments were conducted at DWU facilities.
Laboratory procedures consisted of modified jar and 6 0
minute. settleability testings as well as standard membrane filter techniques f o r pathogens. The findings of
this investigation were evaluated with regards to the concerns and recommendations presented .in the latest Sludge Wastewater Master Plan ( 8 ) .
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Chemistry An. - extenmive investigation by the Department of Transportation ( 7 ) pointed out that the chemical composition of CKD varies from plant to plant due to differences in raw' materials, as well as in the specifics of the manufacturing process or collection procedures. While each source of CKD is unique, analyses indicate that dust collected from a specific kiln in a specified manner, under normal conditions, will exhibit consistent physical and chemical properties.
CKD is generally analyzed by totally oxidizing a sample and expressing each component as an oxide. A typical CKD oxide analysis is illustrated for the dust used in this investigation (Table 2 ) .
Table 2 . Oxide analysis of CKD as provided by Comprehensive Materials Management, Inc.(CMM). Values are percentages based on weight.
S i O a A1203 Fez 0 3 CaO MgO so3 P r Os K2 0
T io2 Mn2 0 2
N32 0
11.8 2 . 8 2 . 5
4 3 . !3* . 5 9
12.8- 25.33 ** .12
5.80 .87 .15 . 2 7
*Total Calcium, Free Lime being 6 . 9 % ** Two values correspond to two separate analyses; so3 typically shows this variation.
Although the calcium is reported as calcium oxide (CaO> in the analysis, it is normally present as calcium carbonate (CaC03) with only small quantities of ''Free
Lime" or available calcium oxide (Appendix D).
METEQDS
I . SAMPLING
Sludge samples were collected at the "pig-catcher'' at SWT or at the holding tank at CWT each morning. When collected at CWT, the line was opened and allowed to flow for one minute before the sample was taken to avoid "stale sludge". The sample was taken immediately to the laboratory.
11. E F F I C I E N C Y P A R A M E T E R S
A . SLUDGE SETTLING CHARACTERISTICS
1. Settled Volume One liter samples o f sludge were amended with different quantities of C K D . The C K D was thoroughly mixed with the sludge. This mixture was transferred to a I liter Imhoff cone and a.llowed t o settle undisturbed for 45 minutes. At 45 minutes, the supernatant was gently stirred and the mixt.ure settled for an additional 15 minutes. The settled volume was read at 1 hour settling time. Where possible, a 2 hour reading was also taken. All samples were run in duplicate. Settled volumes of control and CKD-amended sludges were recorded a t 1 and 2 hours settling time. Percent volume reduction w a s calculated from these values:
Settled Volume of - Settled Volume of Control CKD-amended
Settled Volume of Control
f . 100 """"""""""~"""""""""""--
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OBJBCTIVES
The primary objective of this study was to determine if CKD could increase the efficiency of the current sludge injection process. Criteria used to evaluate efficiency :
1. Sludge Settling Characteristics 2. Settled Sludge Solids Concentration
A second objective w 3 s to determine if CKD could be used to stabilize the sludge in accordance with EPA criteria for PSRP.
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C. SETTLED SOLIDS
1. Percent Total Solids (t TS) Sludge was collected and allowed to settle as previously described. A t two hours settling time, several representative aliquots of the settled solids were transferred to previously prepared ceramic dishes. Samples were dried overnight or until constant weight at 105OC. Samples were cooled in desiccator and promptly reweighed. % TS w 3 s calculated on a weight/volume basis according to Standard Methods(9).
2. Composition of Percent Total Solids Samples and data were collected as outlined earlier. Us*ing the settled volume and the t TS at two hours, an absolute weight of solids was determined:
Y Total Solids * Settled Volume =Weight of Solids (as decimal) (mls) (gms 1
To estimate the relative contributions of sludge solids and CKD material to the overall Y TS of the CKD/sludge settled solids, the grams of solids in the CKD amended
sludge were calculated as above. The percentage of total solids attributable to CKD material alone was estimated as:
A = CKD added /Total solids t 100 ( gms) (gms)
Conversely, the percentage of total solids attributable to actual sludge solids was estimated as :
(100-A) or
B =Total solids - CKD added * 100 Total solids
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2. Tendency Rise Several series of 500 ml. beakers of control and CKD-amended sludge were allowed to sit out undisturbed over two week periods of time. Daily observations were recorded.
3. Settling Surface Laver A single trial was conducted to see if CKD could settle the concentrated solids that make up the surface layer covering A lagoon. After breaking through the hard crust, samples were taken frnm the top 6" of the surface layer. Weighed portions of the sludge were placed in beakers and thoroughly mixed with varying amounts of CKD. Water was added to each beaker to aid in mixing and simulate the supernatant. present in the lagoon. Percent Total Solids ( % TS! and Volatile Solids (t VS) were determined f o r the sludge sample according to Standard Methods( 9).
B. SOLIDS REMOVIL FROM SUPERNATANT
1. Suspended Solids Standard Methods ( 9 ) . procedures were employed to analyze supernatant for suspended and total sol.ids.
2. Percent. Transmittance Percent transmittance @ 940 nm. was measured on aliquots of the supernatant. Tap water and tap wa.ter amended with CKD were used as standards.
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B. PATHOGENS
Indicator organism reduction experiments were run using standard membrane filter techniques. Log reduction data were obtained for total and fecal coliforms, as well as fecal streptococcus.
C. HEAVY METALS It was beyond the scope of this investigation to experimentally verify the heavy metal stabilization abilities of CKD that were claimed in the sales literature (Appendix C ) .
IV. QUALITY CONTROL OF CKD
A.' LOSS IGNITION (LO11 Carefully weighed samples of CKD were transferred to ceramic dishes and burned at l O O O O C in a muffle furnace for 1 h o u r . Samples were cooled in a desiccator and reweighed immediately. L O 1 ( % I was calculated as :
weight Loss % 100 Original Weight
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To determine if additional sludge solids were removed from the supernatant portion due to reactions with CKD, the weight of "CKD added" was subtracted from the weight of solids in CKD-amended sludge. Any differnence represents the weight of sludge solids in the CKD-amended sludge. Subtracting the weight of solids in the control from this value, a positive number theoretically represents an increased solids removal from the supernatant.
3 . Volatile Solids Oven dried samples were transferred to a muffle furnace (550OC) and ignited for 30 minutes or until constant weight was obtained. Calculations similiar to those discussed above were applied to the volatile solids component. The only complication was that the weight of volatiles attributable to experimentally determined.
111. STABILIZATION PARAMETERS
A. pH After 2 hours, aliquots of transferred to small beakers.
the CKD had to be
the settled solids were All samples were run in
pairs. One of each pair was stirred while pH was taken to 'determine if there w3s any difference in magnitude or stability of readings between the stirred and unstirred samples. pH readings were taken at one minute after insertion of probe. Samples remained in beakers and pH readings were repeated after two hours. Several samples were monitored for a full week to determine the extent of pH decay over time.
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Figure 1. Hi8togram of 8ettled volume8 of 1-liter control sludge recorded 8 1 hr. in Imhoff cone.
1 0
SElTLED VOLUME (ml>
Figure 2. Settled volume of 1-liter of control and CKD-amended sludge 8 1 h i . mettling tire in I n h o f f cone.
a m
700
600
SO0
4QO
306
203
100
0 1 2 3 4 5
COMR9L 1% C K D mIA&& 2% C K D 5% C K D
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DISCUSSIOIY OF RESULTS
I . EFFICIENCY PARAMETERS
A.SLUDGE SETTLING CHARACTERISTICS
1. Settled Volume Sludge samples were amended with 0, 10, 20, and 30 g/L CKD to determine the dosage which maximizes the improved settling effect.
The variability observed in the settling characteristics of the control sludge is illustrated in Figure 1. Overall results are presented in Figure 2. CKD amendment resulted in a substantial reduction of settled solids volume. This effect is due to the highly absorptive and adsorptive nature of the dust.
A 10 S/L CKD amendment affected the greatest reduction in settled sludge volume. Additional CKD resulted in little, if any, further reduction. In fact at 30 g/L, a slight increase in settled volume was sometimes observed. This increase is attributed to the added volume of the CKD material itself once i t has reacted with all available sludge solids.
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Figure 3. HiStOgra8 of % settled voluye reduction observed in 10 g/L CRD-amended sludges! 8 1 hr. in Irhoff cone.
L
* Each of the 26 trials is based on duplicate samples. In a single case where the duplicates differed, an average of the two is reported.
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An attempt to isolate the contribution of the CKD material itself was made b y mixing CKD with water and allowing this mixture to settle in Imhoff cones for 1 hour. Results of this investigation are presented in
Table 3.
Table 3. Settled Volume of CKD amended water 0 1 hr. settling time in Imhoff cone.
LO 20 20 38 30 5 5 40 70
Values based on a minimum of six replicated samples.
While it is theoretically possible to subtract a value
for the CKD material (Table 3 ) when computing % settled volume reduction, this would be of no practical significance since the added CKD becomes an integral component of the solids handling process.
In order to calculate Percent Settled Volume Reduction ( %
SVL) , a series of control and 10 g/L CKD amended sludges was run to confirm the improved settling characteristics
observed in the last section. .Figure 3 summarizes the settled volume reduction due to 10 g/L CKD amendment.
Settled volume reductions ranged from 9-53%. This is
consistent with the large variation that was observed in the control sludge (Figure 1 ) . The mean f SVL was 43% as measured at 1 hr. settling time. These data are valid as experimental parameters, but the magnitude of- the effect is probably exaggerated b y the geometry of the I'mhoff cones.
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2. Percent Transmittance Percent transmittance was higher in the supernatants of
the CKD-amended samples. This confirmed the subjective observation that those supernatants looked clearer.
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Table 4 . Solids in Supernatant.
CONTROL Suspended Solids
! 8 / L ) 0.11 0.41 0.17 0.21 0.11 0.08 0.04 0.13 0 . 0 4
T o t a l Solids ( p ; / L ) 0.47
0.41 0.51
1% CKD
0.16 $1 hr. 0.31 @1 hr. 0 . 3 3 @1 hr. 0.12 @1 hr. 0.17 @1 hr. 0.19 @2 hr. 0.16 @2 hr. 0.21 ($2 hr. 0.11 92 hr.
1.46 8 2 hr. 1.67 @ 2 hr. 1 . 5 2 82 h r .
C. SETTLED S L U D G E SOLIDS
After verifying that CKD actually did improve sludge settling, the next step was to quantify that effect on the settled salids.
1 . Percent Tot31 Solids A series of trials was run to determine the relationship between the weight of CKD amendment and t h e resultant %
TS. Figure 4 and Table 5 summarize the data.
I t is of interest t o note that the total solids of the settled controls averaged 2 . 2 - t and was never more than 2.7%. These values are consistent with the 3-3.5% average that is currently being injected a t SWT and may represent the m a s i n t u r n s i o l i d s concentration attainable by settling alone. Tn fact, in the Evaluation of Treatment Alternatives it states: "Gravity thickening of secondary sludge h a s mat w i t h very limited success . . . p roducing a solids concentration of o n l y two or three percent."(lO).
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p'
2. Rising Sludge In the- course of the previous experiments, there was not a single instance of rising sludge in the CKD-amended sludges while many of the controls began to rise after 2 - 4 hrs. settling time. During the two week observation period, the control sludge rose within 2 4 hours, while the 10 g/L CKD-amended sludges exhibited no such tendencies. It is assumed that rising sludge is a major factor in the occurence of the thick surface layer covering A lagoon I S . Dugger, Sludge Injection Supervisor, S W T , personal communication). By eliminating the rising sludge component, the surface layer should be greatly reduced if not eliminated altogether.
A subjective, offshoot observation was that the amended sludge produced less noxious odors than the controls.
3. Settling A Larroon Surface Layer Samples of the surface solids were analyzed for % TS and 3; VS which were determined to be 27% and 55?s,
respectively. With very thorough mixing and addition of
water, CKD was able to settle the solid mass at a dose of 1:1 CKD/sludge on a dry weight basis. While this settling is theoretically possible, the 1ogis.tics o f providing the necessary mixing of CKD with the surface layer presents a challenge.
B, SOLIDS REMOVAL F R O M S U P E R N A T =
1. Suspended Solids Serious difficulties were encountered trying t o run suspended solids. The major problem was getting the samples t o completely filter. It was decided t o run total solids instead but this also presented difficulties due to the very d i l u t e concentration of solids in the supernatant. Although they are considered inconclusive, results are presented in T a b l e 4 .
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E
.
An estimate of "CKD recovery" in the settled solids
portion was determined by duplicating the experimental procedures with a control consist'ing of CKD and tap water. Results of this determination are presented in Appendix E.
"CKD added" was experimentally determined to be 8 and 9 grams respectively for computations involving Batch tl and Batch t3 CKD.** Calculations were performed as outlined earlier in Methods. Results are summarized in Table 6 and Figure 5.
Table 6. Breakdown of Average. ly Total Solids: Sludge Solids and CKD Powder Contributions.
S Total Solids Increase of
Trial P Control CKD-amend CKD Sludge Sludge Total S l u d & L " - S luclge Solids Solids Solids Solids
1 1.4 5.9 2.6 3.3 2.4 4.2 1.5 6.3 3.1 3.2 2.1
3 1.6 7.1 4.1 3.0 1.9 4.4 4.2
4 1.8 7.2 4.3 2.9 1.6 5
4.0 1.3 6.8 3.7 3.1 2.4 5.2
6 2.3 7.1 3.5 3.6 1.6 3.1 I 1.3 6.6 3.5 3.1 2.2 8
4.7 2.3 8.6 ./I . 6 4.0 1.7 3.7
9 2.1 6.9 2.7 4.2 2 . 0 3 . 3 10 2.0 6.0 2.3 3.7 1.9 3.0 11 12
2
"
1.7 6.8 3.1 3.7 2.2 4.0 1.7 7.1 3.6 3.6 2.1 4.2
Mean Values 1.8 6.9 3.4 3 . 5 2.0 4.0
*Averages based on a minimum of three replicates.
* * During the course nf this study, three batches of CKD powder were received. Rntch. *2 x a s discarded because i t w3s obviously from a different source and of a different quality. Batches tt i and 3 were supposedly from the same plant.
24
. Figure 5. Breakdown of percent total solids corpoaition.
Percent total solids of control sludge is compared to percent total solids of CKD amended sludge and to the portion due to sludge aolids only.
L
The 10 g/L amendment resulted in an overall 400 3 dry weight increase of settled solids. Approximately half of this increase is attributable to the CKD material itself, the other half represents an increased concentration of
settled sludge aolids.
This compositional analysis is an estimate. It relies on the
asrumption that we are able to separate out the CKD
component. Since the CKD is actually re(acting with the sludge, forming sludge/CKD complexes, the ability to isolate the CKD component remains purely theoretical. Nonetheless, this represents a legitimate approxfration.
If it is assumed that the total increase in sludge solids concentration is due to the settling (compaction) effect,
25
the % total solids attributable to sludge solids in the CKD/sludge mixture can be calculated as follows:
Settled volume of control t t Total Solids Settled volume of CKD/sludge of control
Using a mean settled volume reduction of 43% and a mean !%
total solids of control as 1.8 as an example , the calculated f total solids attributed to sludge solids is:
1000 1.8 570
= 3.2
Values calculated in this manner appear to show slightly lower values than those figured by weight (Table 6 ) .
This difference may indicate a real increased solids removal from the supernatant or i t may be an artifact caused b y water trapped in the CKD/sludge complexes. In any case, either of these two approaches ran be used to approximate the compositional make-up o f the percent total solids.
3 . Volatile Solids Concern arose as to what effect, i f any, CKD amendment had on the volatile solids component. Percent volatiles
was determined. The results are summarized i n Table 7 .
Table 7 . Range of t v o l a t i k s in various substrates.
SUBSTRATE f VOLATILES Control Sludge 71-80 Sludge + 10 g/L CKD 28-40 CKD only 1.7-2.4
Since these results did not appear t o have much siyni.ficance, an n t t ~ m p t was made to use a mass balance approach to quantif]. the effect. The results were inconclusive but suggest that CKD amendment has no effect on the volatile solids component.
26 .o
11. STABILIZATION PARAMETERS
At the onset of this investigation, EPA recommended following 1,ime stabilization criteria to evaluate CKD performance. Since that time, a special equivalence committee has been formed to evaluate alternative technologies for achieving PSRP stabilization. In order to qualify as PSRP, minimum performance criteria for lime is to maintain a pH > 12.0 f o r two hours. It is assumed that environmental conditions associated with this pH result in substantial pathogen reduction. Preliminary results indicate that the lime stabilization criteria may be a conservative measurement of CKD effectiveness.
A . ‘pH
A series of trials was run to determine the dosage of CKD required to reach and maintain pH > 12.0 for two hours. The results are summarized in T a b l e 8 . :\ctual readings are presented in Appendix F.
Table 8 . Range and mean pH values of CKD-amended sludge at 2-4 hours.
S 1 udge Composition Range Yean
Cont, Set t 6.0-7.5 6.8 +10 g/L 11.4-12.5 11.9 +15 g/L 11.8-12.7 12.3 +20 g/L 11.7-12.7 12.3 +25 g/L 11.8-12.7 12.4 +30 g/L 11.9-12.7 12.4 +35 g/L 11.7-12.8 12.3
* Values b a s e d on minimum of 10 samples, each run in duplicate.
27
The dosage of CKD necessary to stabilize sludge is affected by the chemical composition and solids concentration of the sludge. Assuming a meter accuracy of +0.1, of the twelve, sludges tested, four met EPA lime stabilization criteria at 10 g/L CKD-amendment. The others required a dose of 15 g/L to meet the criteria. These results are consistent with N-Viro's claims and other reports of CKD stabilization of municipal sludges
(2,3).
Stable p H readings could not be obtained at two hours contact time. It appears that reactions between the CKD and sludge are still taking place at this time. Glen Fitkin, a chemist with Bowscr Morner Testing La.boratories in Tolcdo, Ohio, who worked extensively with sludge/CKD mixtures, confirmed this suspicion. Once the pH readings stabilized, no difference was observed between the stirred and unstirred samples. Four sludges were monitored over a period of 5-7 days in an attempt to assess the rate o f pH decay. Basically, once enough CKD was added to bring pH ? 12.1, the mixture remained at 3
pH > 12.0 throughout the 5-7 day period. These results are consistent with those observed by Bowser Morner Testing Labs and Jones & Henry (2,3).
B. PATHOGENS Current EPA criteria for PSRP designation specify a 2 log ,reduction in total and fecal coliforms. Although fecal streptococcus is not included in the criteria, it is recognized by those working in the field to be more resistant to h i g h pH and therefore ' 'a more conservative indicator of eilterovirus inactivation in high pH environments."[ll). Laboratory results are summarized in Table 9 .
28
A dose - o f 10 g/L CKD resulted in a minimum of a 2 log reduction of total and fecal coliforms in every case, meeting EPA stabilization criteria.
C. HEAVY METALS Although no laboratory verification was conducted, N-Vir0 claims that CKD amendment actually binds and immobilizes any heavy metals present in the sludge. Meryl Hendrickson, of H & H Enterprises, an independent contractor who routinely uses CKD to manage hazardous wastes, confirmed this claim (personal communication).. A recent article addressing leaching of heavy metals, co'ncluded: "Substantial amounts of heavy metals remained in the silicon rich solids after alkalinity had been neutralized.. . . " ( 1 2 ) .
T a b l e 9. Hange of log reductions of indicator organisms in CKD amended sludge.
CKD Total Fecal Fecal Amendment Coliforms Coliforms Streptococcus
+10 g/L +20 g/L +30 g/L
2 -5 4-6 4-9
2-5 2-8 7-8
0-2 1-3 2-7
111. QUALITY CONTROL OF CED
Loss on ignition at lOOOOC ( L O X ) is considered to be the key characteristic of a kiln dust's reactivity.(J.P. Nicholson, C.E.O., N-Viro, personal communication) Having access to three different CKD's, LOX analyses were run. Results based on s i x replicates are presented in T a b l e
10.
,
29 "
Table 10. L O 1 values for three distinct sources of CKD.
CKD LO1 ( % )
Batch #l Batch X 2 Batch 93
16.6 5.5 13.4
Essentially no variation existed among replicates.
During the course of this study, three batches of CKD powder were received. Batch #2 was discarded because i t was obviously from a different source than Batch #l . Batch X 1 and Batch X3 were supposed to be from the same facility. The difference in LO1 percentages betwe,en the two batches surprised CMM representatives who provided the CKD. They claim there should not be that much variablity in a single source of dust. Unfortunately, due to an omission in the original shipping paperwork, we were unable to determine definitively whether or not they came from the sane source.
Even with the differences observed in LOI, no significant differences in effectiveness (settling ability, solids c o ~ t e n t , pH) were observed. However, the small sample size coupled with the large variability of the control sludge, may mask any differences 'that do exist. In any case, LO1 can be employed as a quick and effective quality control parameter.
30
SUMMARY Op R E S U L T S
1. CKD amendment resulted i n significant reduction of ~ e t t l e d volumes; 10 g/L was determined to be the optimal dose.
2. CKD-amended sludges produced less noxious odors than controls.
3. No rising sludge was observed over a two week period with CKD-amended sludges; all control sludges rose within 2 4 hours.
4 . Total solids of settled controls ranged between 2-3%.
> > Total solids of 1 0 g/L CKD-amended sludge ranged .between 5.5-9.0 % . Approximately half of those solids are attributed to CKD powder and half to sludge solids:
400% increase (dry weight) of TOTAL settled solids
* 200% increase (dry weight) of settl(.d S L U D G E solids * 200% increase (dry weight) due to CKD powder
5 . To consistently reach. and maintain a pH 12.0 for a two hour period, CKD amendment of 15 g/L was required.
> > pH > 12.0 was maintained for a one week period in several samples.
6 . A 10 g/L dose of CKD resulted in a minimum o f 2 log reduction for total and fecal coliforms; smaller reductions of fecal streptococcus were observed.
7 . CKD amendment on a 1:l dry weight basis, with thorough mixing, was able to facilitate settling of the thick crusty sludge layer obtained from A lagoon.
8 . Loss on Ignition (Lor! :.4 lOOOOC proved t o be a simple, reliable quality control parameter for)CKD.
31
POTENTIAL USE OF CKD
CDM developed and evaluated sludge managenmen t alternatives for DWU based on the unit processes illustrated in Figure 6 . Their recommendations were evaluated and incorporated into Alternative Treatments Evaluation prepared by Black & Veatch (B&V) (10).
In late 1985, CKD was brought to DWUs attention. It was felt that this product warranted further investigation since i t had not been considered in the previous evaluations. Using the scheme from Figure 6 as a guide, potential use of CKD at DWU is discussed below.
A . THICKENING
Of the four alternatives investigated (Figure 6 ) , gravity thickening is by far the simplest and most cost effective. Unfor%unately, this method often 'fails to achieve greater than 2-3% solids concentration with secondary sludge (10). Therefore, centrifugation was recommended. There is evidence to suggest that desired solids concentration can be ohtained through gravity thickening of CKD conditioned secondary sludge. This option offers tremendous savings on capital, as well as 0
& M costs. It is also flexible as CKD dosage rates can easily be adjusted to correspond to variations in sludge composition and/or to obtain varying solids concentrations.
32
FIGURE 6. Unit processes available for treatment and disposal of wastewater sludge.
1 )rUDQ1 1
** Adopted from CDMs, Wastewater Sludge Master - Plan (8).
33
B. STABILIZATION
C D k selected anaerobic digestion as the stabilization method of choice. B & V concurred with this recommendation. The advantages and disadvantages of this alternative with respect to D W U s system are presented in the CDM and B&V reports (8,lO). One potential disadvantage of anaerobic digestion that was not mentioned is an increased concentration of heavy metals in the resultant sludge (due to the reduction of organic matter).
Although CDM acknowledged that lime stabilization results in a readily dewaterable sludge that is suitable for land application, they eliminated this alternative from ser.ious consideration for the following reasons:
1) Difficult and expensive handling requirements; 2 ) Production of increased quantity of sludge; 3 ) No potential for energy recovery.
When C K D is substituted for lime in a lime stabilization
process, Some of the negative features associated with this process are eliminated:
1) C K D is used in powder form, thereby eliminating the difficult handling requirments of slaking lime.
2 ) Due to thickening, sludge volume is reduced. This reduction in volume may be a more significant measurement of sludge quantity than dry weight of solids which increases with CKD (or lime) treatment.
34
3 ) - Due to chemical and’physical properties of CKD, volumetric increases (displacement of liquid by powder), are much less than those associated with lime treatment ( M . Hendrickson, H&H Enterprises, personal communication).
While energy recovery is not possible with this alternative, i t should be noted that it is a far less energy intensive option than mesophilic anaerobic digestion and therefore represents an energy conservation
option.
C. CONDITIONING
CKD is an inorganic chemical addition. It has been used successfully in conjunction with vacuum filter dewatering, producing sludge cakes with low moisture content and good soil conditioning properties ( 4 , s ) . CMM
has.-experience enhancing drying bed dewatering with CKD amendment. They state that natural dewatering is
doubled; drying time is accelerated and final solids concentration is increased.
D. DEWATERING
CDM recommends centrifuge dewatering of stabilized sludge. Centrifuges are not only high capital cost items, but operational and maintenance expenses are also
considerable. Because polymer conditioning of the sludge is usually required, centrifuge dewatering is very
35
sensitive to feed characteristics and requires constant monitoring. Any dewatering process needs to be integrated into the overall treatment scheme. Since CKD conditioned sludge is easily dewatered, a more cost effective method may be available.
E. DISINFECTION A S an "additional treatment prior to final disposal", CDM recommends composting the stabilized sludge in order to produce a product which can be used as a fertilizer and soil conditioner. N-Vir0 claims that CKD- amended sludge produces an equivalent or superior product at much lower costs. A study is currently underway at the Ohio College of- Medicine to determine if CKD amendment at dosages which result in granulation of sludge, qualifies as a
"Process to Further Reduce Pathogens'' (PFRP) according to the latest EPA criteria (Appendix GI. A FFRP designation permits unrestricted utilization of sludge. There has been recent debate concerning PFRP classification of some composting processes (Water Pollution Control Federation 1985 Annual Conference, Sludge Disinfection Committee, personal communication) so at, this point, neither option guarantees a PFRP classified product.
F . ODOR CONTROL
A concomitant effect of CKD amendment is some degree of
odor control. While this is an important concern today, i t will become more critical as "i t is anticipated the
concentration of sulfides will increase significantly ... and c a n be expected to increase potential for odor release at Southside."(lO).
36
RECOMMENDATIONS
It is apparent th overall wastewater
otential us Potential
at CKD has many p
management schemes. es in
for incorporating CKD into the DWU system is addressed in the following recommendations. Many of these can be implemented in conjunction with the SWT Sludge Dewatering and Disposal Facilit.ies Contract awarded to Lockwood, Andrews and Newnam.
Interim Sludge Management
1. Laboratory results indicate that CKD amendment is effective in improving the efficiency of the current sludge injection system by improving settling characteristics of the sludge in A lagoon. Depending on t h e dosage of CKD, concomitant odor control and PSRP stabilization are possible. I recommend a pilot study be instituted t o confirm the results on a plant scale, operational basis. Concerns to be addressed in this study should .include:
3. The logistics of CKD application - We will need some type of mechanical mixing or air sparaging system to provide sufficient mixing of the powdered CKD at the pig-catcher.
b. Associated cost saving benefits - CKD amendment may lessen or alleviate the need for potassium permanganate (KMn04) or odor masking agents currently used.
c. Analysis of supernatant characteristics (BOD, TOC, pH, TSS) - These may have an impact on plant operations because the sidestream is recycled to the head of the plant.
d. Evaluation of the -ability of current sludge injection equipment to handle solids concentration of sludge/CKD mixtures 7 f .
37
2 . CKD can be used as a conditioner in conjunction with a drying bed dewatering process. CMM claims greatly enhanced drying efficiency with CKD amendment. They have offered to set up a demonstration plot at SWT. I recommend that we accept their offer, as this is in accordance with CDMs recommendation to evaluate various dewatering methods to establish actual performance levels.
3. Contingent upon confirmation of the laboratory results by the pilot study, I recommend incorporatipg CKD-amendment into the current wastewater sludge processing at a dosage level that wi1.l satisfy PSRP requirements. This can be achieved in a one step application (similiar to the laboratory procedure used in this study) or a two-step process combining a CKD amendment to improve settling in the lagoon followed by a second CKD application in conjunction with a dewatering process.
4. To gain maximum benefit from CKD treatment, I recommend that prior to or concurrent with implementation of CKD amendment in the lagoon , the thick surface layer covering A lagoon be removed. Once removed, CKD amendment should prevent a recurrence of such a layer which is responsible for aesthetic problems around the lagoon.
Incorporating CKD into the current wastewater sludge handling process as described above, will result in increased efficiency and improved sludge, quality, without any large changes or capital expense. This is compatible with any future long term sludge management plan that may
be adopted.
38
Long Term Sludge Management
CDMs recommended long term sludge management scheme is illustrated in Figure 7 . It calls for both gravity and centrifuge thickening of sludges before anaerobic digestion. After digestion, the sludge is dewatered by centrifugation and then disposed of and/or composted for product distribution. Several CKD alternatives, compatible with the overall scheme, are presented in the following recommendations.
1.
2 .
3 .
The decision to utilize centrifuges for sludge thickening should be re-evaluated in light of CKDs ability to facilitate thickening using a simple gravity thickening option.
Although i t appears that DWU is committed to anaerobic digestion, - a CKD-substituted 1 ime stabilization alternative warrants consideration.
While CKD stabilization may not be considered the most at.tractive option for DWU at this time, it is ideally suited as an emergency or back-up stabilization method. It can be brought "on-line" almost immediately if a digester is down or the treatment process is overloaded. CKD can effectively stabilize raw and/ or digested sludge. I recommend th-at CKD stabilization be incorporated into the long term sludge management plan on an emergency or back-up basis. It is a cost effective insurance policy.
39
4 . C K D -is a versatile material. Potential exists for using C K D as a conditioning agent in conjunction with most of the dewatering processes under consideration. I recommend that the use of CKD as a conditioning agent be incorporated into the evaluation of different dewatering options. (see recommendation 2 in previous section)
5 . The greatest potential f o r incorporating CKD into DWUs long term sludge management plan, exists for utilizing CKD as an alternative post-digestion, disinfection process to composting. This option appears to offer substantial economic advantages and deserves serious consideration. A study should be set up to compare the market value of the final end-products produced by composting and CKD-amendment.
The potential concern with the CKD material is its high pH. A greenhouse study can readily determine the significance of this concern. I also recommend a greenhouse o r small scale field study to compare the potential for beneficial utilization of the final end-products produced by composting and CKD-amendment. This project migilt best be accomplished as a cooperative venture with the Parks and Recreation Department.
6. The proposal to produce our own kiln dust material from incineration of water purification sludge warrants further consideration in the long term sludge management plan.
40
I I I I I I I I I I I I 1 I
n
I I I I I I I I I I
I ! I I I
LITERATURE CITED
1. Haynes,B. and G.Kramer, "Characterization of U.S. Cement Kiln Dust." Bureau of Mines Information Circular 8885 (1982).
2. "Evaluation of Sludge Stabilization Alternatives for the Bay View Wastewater Reclamation Plant." Jones & Henry Engineers, Ltd. (1984).
3. "Modification Test Results-Job # 38497." Bowser Morner Testing Laboratories (1984).
4. "Sludge Conditioning by Cement Kiln Dust at the Kennebec Sanitary Treatment Plant, Waterville, Maine." Environmental Center and Cement Technical Center ; Martin Marietta Corp. (1980).
5 . "Sludge Conditioning by Cement Kiln Dust at the Blue Plains Advanced Wastewater Treatment Plant in . Washington, D.C." Environmental Center and Cement Technical Center; Martin Marietta Corp. (1981).
6 .
7.
a.
9.
10.
11.
12.
"N-Vir0 Soil." N-Vir0 Energy Systems, Ltd.
"Kiln Dust-Fly Ash Systems for Highway Bases and S u b b a s e s . " U . S . Dept. of Transportation (1983).
Wastewater Sludge Master Plan for the City of Dallas. Camp Dresser & McKee, Inc. (1985).
Standard Methods for the Examination of Water Wastewatay. 1.5'.h ed. , American Public Health Association (198.1 j .
Evaluation of Treatment Alternatives for Phase I11
Center . Black & Veatch and Gutierrez, Smouse, Wilmut & Associates, Inc. (1984).
" and Phase E of Southside Water Resources Management
Westphal, P. and C. L. Christensen, "Lime stabilization: effectiveness of two process modifications." J. Water Pollut. Control Fed., 5 5 , 1381 (1983).
Shively, W. et. al. "Leaching tests of heavy metals stabilized with Portland cement." J. Water Pollut. Control Fed . , .58, 234 (1986):
42
h
ACKNOWLEDGMENTS
Where to begin to acknowledge all those that lent a helping hand . . . . First there was J.B. Lowry and the Southside gang who admirably took up the. challenge of initiating me into the world of wastewater sludge.
Then came the Research and Central Labs crew who stoically endured the sweet stench of burning sludge and the " j o y s " of having another person constantly underfoot . . . and constantly asking questions. (Thanks Malcolm and Hilda!)
I turned to the Central Wastewater Lab folks with ._
questions of procedure, puzzling results or when I needed a working pH meter. They always came through!
Along the way I enlisted the help and advice of m y fellow Technical Assistants, R. Cook and D. Malas. The Planning Division even got in the act when I solicited comments from J. Puckett and 9 . Gabbai. I also turned to t h e "graphics gang" up there to help me piece this report together . . . liter.-+lly. Then there was "The Kiln Dust Crew" (Y-Vir0 and CMM) who kept m e supplied with CKD and hard to find CKD literature.
All these people.deserve a sincere TIJANK YOU ! ! !
Then there are those who deserve SPECIAL RECOGNITION:
Dolores Castillo . . . her speedy fingers helped enormously. Margarett Williams...she taught me everything I know
about those little microscopic critters..,coliforms & strept. Thanks for a11 your help!
Chris Way . . . he taught me that LOTUS is not a native plant and Easywriter is not one of those New Wave bands.:,he also never let on t h a t . h e was starving 3s I hat1 him work o n through. lunch.
Ahmed Kadry. .more than once hc sat me down and i l t ? l p e d me make sense out of all I had y;athered.. . he was the one who assured m e not only that there was an end to the tunnel, but there was also light there.
43
SUBJECT: A ~ p l i c a t i o n o f 30 CFR P a r t 2 5 7 R e g u l a t i o n s t o P a t h o g e n R e d u c t i o n P r e c e d i n g L a n d A p p l i c a t i o n o f
T a n k P u m p i n g s
FROM:
I E d w i n J o h n s o n , D i r e c t o r
TO : W a t e r D i v i s i o n D i r e c t o r s R e g i o n s I - X
1 I T h i s memorandum a n d i t s a t t a c h m e n t s e x p l a i n t h e a p p l i c a t i o n 0 :
4 0 CFR P a r t 257 r e g u l a t i o n s t o t h e r e d u c t i o n o f p a t h o g e n s p r e c e d i n g l a n d a p p l i c a t i o n o f s e w a g e s l u d g e o r s e p t i c t a n k p u m p i n g s . T h i s i n f o r m a t i o n s h o u l d b e s e n t t o y o u r R e g i o n a l s l u d g a c o o r d i n a t o r s : c o n s t r u c t i o n g r a n t s , e n f o r c e m e n t a n d s o l i d w a s t e o f f i c e s : S t a t e s l u d g e m a n a g e m e n t a g e n c i e s a n d o t h e r s conc,c;ned w i t h s l u d g e or s e p t a g e m a n a g e m e n t .
T h e 40 CFR Pa r t 257 r e n u l a t i o m w e r e i s s u e d o n S e p t e m b e r 1 3 , 1 9 7 9 , (44 FR 5 3 4 3 8 - 53468) under the joint a u t h o r i t y o f S u b t i t l e D o f t h e R e s o u r c e C o n s e r v a t i o n a n d R e c o v e r y A c t ( R C R A ) a n d s e c t i o n 4 0 5 ( d ) o f t h e C l e a n W a t e r A c t . T h e r e g u l a t i o n s e s t a b l i s h a c c e p t a b l e p r a c t i c q s f o r t h e d i s p o s a l o f s o l i d w a s t e s , w h i c h i n c l u d e s e w a g e s l u d g e a n d s e p t i c t a n k p u m p i n g s , on or into the land. Any n o n - c o n f o r m i n g l a n d a lication practice is c1assifi;d as an o p e n d u m p t h a t i s p r o h i b i t e d by=. "-
""- . .."_. -"
T h e r e g u l a t i o n s ( 4 0 CFR Part 257.3-6) require treatment by e n s ( P S K P I o t s e w a g e - corporated into the soil.
Also requlred are c.ontrol of public access for at least twelve m o n t h s a f t e r a p p l i c a t i o n s a n d - p r e v e n t i n g g r a z i n g by a n i m a l s w h o s e p r o d u c t s a r e c o n s u m e d by humans for at least one month after a p p l i c a t i o n . S e p t i c t a n k p u m p i n g s d o not r e q u i r e a PSRP if publi a c c e s s is c o n t r o l l e d f o r t w e l v e m o n t h s and i f g r a z i n g b y animals w h o s e p r o d u c t s a r e c o n s u m e d by humans is prevented for a t least
Appendix A.
- 2 -
one month. - Treatment by Procesres t o Further Reduce Pathogens (PFRP) i~ required f o r s e w a g e sludge o r s e p t i c tank pumpings applied to the land surface or incorporated icto t h e soil i f c : o ? s for direat human consumption a r e g r o w n w i t h i n e ighteen monchs after application.
The technology based regulation (Appendix I 1 o f 4 0 CFR Pat: 2 5 7 ) describes, and s e t s numerical requirements for. u n i t processes and operating condition3 that qualify a s PSRP a n d P F R P ( e . g . , criteria for time and tzffiperature and for volatile s o l i d s reduction from digestion proiesues) to achieve the pathogen rrduction objectives rather t h a n requiring o specific reduccioa 1 1 :
concenttation €or given pathogens. A?pendir 1 1 a l l o w s n e thods o r operating conditions o t h e r t h a n t h o s e listed under PSRP or PFRP i f p a t h o g e n s a n d v e c t o r a t t r a c t i o n a r e r e d u c e d c o ~ e n s u r a t e w i t h the reductions attainable from listed methods. Appendir I 1 d o e s not prescribe the operation mocle ( i . e . , batch or continuous) €or digesters os. p a r t o f PSRP/PFRP.
T h e attachm:nts: (1 ) describe PSRP and PFPIP requiremcnts. ( 1 ) reco,mnead steps t o ensure t h a t projects provids PSR? or PFRP a s required, and ( 3 ) outline procedures for determining whether processes other than those l i s t e d i n the regulations qualify as PSRP or PFRP. A t t a c h c a t A answers questions that have arise3 concerning pathogen raduction requirements. Attachment B provides information on procedures to determine whether processes not specified in the regulation qualify a s PSRP o r PFRP. Attacbmtnt C contains an erample of a data collection program designed t o support a demonstration that a p r o c e s s m e c t s t h e PSRP/PFR? requirements.
Attachments
Appendix A.
City o f Dallas
POLICY: To pursue strategies that enphasite use o f a ~SOUFCC_, rather than disposal of a waste.
CURRENT: A t Southside Wastewater Treatmnt Plant, City i s reclaiming mined out gravel pits by leveling, f i l l i n g and plawlng-in shdge. With present land and equipment, able t o accomnodate approximately 50% of sludge production. Additional land Is being acquired. Excess sludge i s being held i n lagoons.
RESEARCH: Planting winter crops (wheat, oats, etc.) t o determine effectiveness for nutrient removal from s o i l ang. rdvfsa- b i 1 j t y o f future agriculture operations. Crops being furnished t o Park Department and Zoo.
OTHER USES: Near term plans f o r use o f sludge as a nu t r i en t for developing nursery stock and wildflower seed for Park Department.
LONG TERM: A proposed Master Plan will be presented t o City Council i n a few weeks that will r e c ~ n d - : o n t ~ u e d enghasis-gn ben-a use o m , spec i f i ca l l y o r use by agricul- tu re and 5 inc uding cornposting and marketing o f the product.
UNCERTAINTY: Unsure what EPA and State final regulations will allow and under what conditions, or wi th what possible penalties for unforeseen problems.
Appendix B
N-VIR0 SOIL is a proprietary process which involve? the use of kiln dust or kiln dust/fly ash technology to stabilize, disinfect, deodorize, dewater and, if desired, granulate municlpie wastewater sludge. The resultant product can be easily stored for air drying, improved pathogen reduction, and seasonal land application. fhe sludge and kiln dust combine to provide significant soil conditioning and nutrient values. The N-VIR0 Soil process is a proven, lower cost stabilization altemattve than competitive options1 The N-Vir0 Soil product has higher agricultural value than competitive alternatives and reduces or etimlnates public and enviKKwnental concam
N-Vir0 Energy Systems Ltd.
3450 West Central Avenue Toledo, Ohio (41 9) 535-6374
Appemdix C
N-VIR0 SOIL
BACKGROUND The recently pubilshed Sandia Report on pathogens in sludge (SAND83-0557) states “Section 201 oi the Clean Water
A C ~ , the Resource Conservation and Recovery Act (PL94-580), and a general national interest In resource conservation and recycling have encouraged a new prospective in sludge management options. Sludge has been shown to be an excel- lent source of macronutrient and trace minerals for soils, and its organic matter can Improve the physical characteristics of soil”. “Beneficial use of sludge by land application accounts fot.8 significant and steadily increasing percentage of sludge produced in the US.”.
The alternatives to effective and efflcient land application sludge management are not attractive. Sandia further states “The energy costs and air pollution associated with sludge incineration generally make this disposal option undesirable and uneconomical. Increasing population pressures have also reduced the land available for landfills and prohibitive1 expensive transportation costs have decreased the popularity of this sludge management option”.
interests or the Resource Conservation and Recovery Act. We would add that the concept of burning or burying Important resources is not consistent with either our national
LIME STABILIZATION: EPA 62511-79-011, Process Design Manual for Sludge Treatment and Disposal says it all very concisely: “Lime Stabili-
zation is a very simple process. It’s principal advantages over other stabilization processes are low cost and slmplklty of o(#n#on”. EPA 625 further states “Farreil and others reported that lime Stabilization of a primary sludge reduced bacterial hazards to a negligible value, improved vacuum filter performance, and provided a satisfactory means of stabilizing sludge prior to ultimate disposal ”.
EPA 60012-78-171, Full Scale Demonstration of Lime Stabilization (Burgess (L Niple, Ltd.) reports: “Lime stabilized sludges had negligible odor, minimum potential for pathogen regrowth, and were suitable for application to farmland. Pathogen concentrations in lime stabilized sludges were 10 - 1,OOO times lowr than for comparable anaerobically digested sludges”. EPA 600 also states “Lime stabilization facilities can be constructed and operated at lowor crpltrl and rnnwloprntkn and malntonrnco costs than comparable anaerobic digestion facilities, and present an attractive alterna- tive either as a new process or to upgrade existing sludge handling facilities”.
UTILIZATION OF LIME-TREATED SLUDGE In the forward to €PA 67012-75.012, Lime Stabilized Sludge: Its Stability and Effect on Agricultural Land (Battelle
Memorial Institute), A. W. Breidenback, PhD., Director of the National Environmental Research Center states, “Slnce sludge handling and disposal represents a significant part of the total wastewater treatment cost, a new stabilization technique which promises elimination of obnoxious odors and essentially all pathogenic bacteria at a high treatment rate and mducod cost is very welcome”.
EPA 670 also reports, “Continuous processing of sludge to pH greater than 12.0 reduced pathogenic bacteria indicator organism populations by greater than 99.0 percent.. .” “Lime treatment significantly increased the alkalinity of the sludge.. .” “Appllcation of lime treated sludge to cropland did increase the concentrations of nutrients available to Plants.. .” “AppllCatiOn of the proper amount of limetreated sludge appeared to improve soil productivity as indicated by mass of plant material produced . . .” “In a silt-loam type soil, application of sludge appeared to increase permeability with water; whereas sludge application to a sandy soil appeared to decrease permeability”.
In their excellent recent article, Social Institutions Influencing Land Application of Wastewater and Sludges, D. L Forster and D. D. Southgate state “Unless treatment plant odor problems are resolved, a land application program is Probably doomed”. We concur!
0. Lee Christensen, PhD., In his recently published article, Dealing With That Never-Ending Sludge Output, reports “Lime addition to sludge provides odor control during handling and storage and substantial alkalinity to help maintain high soil pH . . .’I “Maintaining soil alkalinity with a minimum pH of 6.5 is required for agricultural utilization programs in Order to minimize plant uptake of heavy metals”.
CHARACTERISTICS OF KILN DUST Kiln dust is a by-product of the production of portland cement or lime. Cement kiln dust (CKD) and high Calcium lime
kiln dust are more effective than dolomitic lime kiln dust In pH management. CKD has the additional advantage Of PoWSSing substantial quantities of potassium, a primary macronutrient, which balances with the nitrogen and PhoSPho~uS available in wastewater sludge.
Appendix C.
Kiln dust is a very fine product - usually having a Blaine fineness in excess of 5,000 square centimeters per gram. It is both absorbent and adsorbent. Approximately 40% of the dust has been calcined in the kiln (carbon dioxide volatil- ized) thus, it possesses Significant quantities of reactive calcium. In addition, the clays have been dehydroxilated - increasing their reactivity.
Dust is collected by a variety Of systems such as cyclones, bag houses and.precipitators. Cement and lime producers are all supportive of the view that a realistic management program will oryiure the availability of conrlrtmt dust from a given system. Approximately 50% of all cement kiln dust is now recycled into the kiln as feed stock for portland cement. The consistency is obviously important. A recently completed large scale study of kiln dust by the Department of Transportation and the Department of Energy (FHWA/RD82/167) reported “The dust collected from a particular kiln, if obtained during normal operating periods, will exhibit relatively consistent physical and chemical characteristics”.
Kiln dust is readily available throughout the nation as over 20,000,000 tons are generated annually and approximately 200,000,000 tons are available for reclamation.
KiLN DUST AS A SUBSTITUTE FOR LIME: A recently published Bureau of Mines report, IC 8885, Characterization of U.S. Cement Kiln Dust, reports “Cement kiln
dust is largavolume material and a potential resource as a sutistitute for lime. Any environmental consideration are minor”.
A recent DOTlDOE study concluded “It is evident that most kiln dusts sampled and tested during this research program can be successfuily substituted for hydrated lime in conventional limelfly ash/ aggregate road base systems”.
Significant tresting at Bowser Morner Laboratories, the Eitel Institute for Silicate Research at the University of Toledo, and Jones 8 Henry Laboratories (see Professional Comments) has provided substantial evidence that kiln dust substitution for lime in sludgestabilization is both effective and economical.
Numerous states are now using kiln dust as a substitute for lime in soil stabilization and soil modification.
The Martln Marietta Environmental Center has studied the substitution of kiln dust for lime at both Waterville, Maine and Washington, D.C. They state “The results demonstrate that cement kiln dust is a low cost, effective sludge conditioner for dewatering. Sludge cakes produced with cement kiln dust rather than lime had a lower moisture content and greater value as an agricultural.resource (i.e., more plant nutrients, better soil conditioning properties)”.
N-VIR0 SOIL: An Effective and Economical Lime Stabilization Process. The use of kiln dust in wastewater treatment is an exciting technological and economic development. In research, devel-
opment and demonstration work cited earlier, the effectiveness of kiln dust in lime Stabilization and other treatment pro- cesses has been welldocumented. Copies of these reports are available from N-Vir0 Energy Systems, Ltd. or our agents. Jones and Henry Engineers, Ltd., is now completing a largescale review of N-Vir0 Soil technology for the City of Toledo. Copies of this report will also be available soon.
For almost four years, the City of Detroit has beneficiated municipal sludge with kiln dust. Over 1,OOO,OOO tons of sludge has been solidified and pH elevated. The EPA in the Federal Register of May 19, 1980, identifies cement kiln dust as an example of a good solidification material.
Monroe, Michigan is now utilizing the N-Vir0 Soil process and numerous cities including Toledo, Ohio and York, Pennsyl- vania are giving full consideration to the concept. The Monroe plant Is a postliming operation that has been operative for over one year using either lime or kiln dust. Kiln dust is now being utillzed and is added to dewatered sludge cake in a con- tinuous feed mixer. Video tapes and pathogenic test results of this sludge treatment facility are available upon request.
The N-Vlro Soil process is new. The concept, however, is proven technology. It Is a simple, reliable, low cost system. Depending on the source of sludge, the source of the kiln dust, the climate M d the desired by-product, a percentage of kiln dust Is added to either wet or dewatered sludge to elevate the pH above 12.0 for at least two hours. This process signifi- cantly reduces pathogens and offensive odors. It minimizes heavy metal uptake by providing an alkaline environment. For stabilization purposes, approximately 10% of the mixture should be kiln dust.
Mixture of the kiln dust and sludges can be accomplished mechanically or with an air sparging system. The capital in- vestment is minimal compared to alternatives such as digestion and compostlng, and the operating costs are competitive with even the most efficient digestion system.
The N-Viro Soil process is ideally suited for post-liming operations. The recent Sandia Report (SAND83.0557) suggests that “Dewatering prior to disinfection would produce conditions within the sludge that prevent postdisinfectlon regrowth (of pathogens)”.
Append i x C.
PROFESSIONAL COMMENTS: Jim p m , p~sizhnt, S & L Fertilizers, inc., Whitehouse, OH, “WastcMater sludge stabilized by kiln dust is a of
substantid vdue to our customers because it significantly reduces crop fertilizer costs. in addition, the N-Viro soil pro- cess produce a product which is SOCiOiiy acceptable in the agricultural community. We believe that N.Viro soil is mom valuable than COmPO8t.”
Jim Rlchenderfor, PhD., Tethys Geotechnical COnSUitanfS, Harrisburg, PA, “The N-Viro Soil process resuits in a signif- ,cult reduction of offensive odors for a realistic period of time. The high, long term sludge stabilization decreeses the soluabiiity of heavy metals”.
G . L ~ Christensen, PhD., Associate Professor of Environmental Engineering, Vlilanova University, “Lime stabilization, with lime or kiln dust, is an effective process to significantly reduce pathogens. it Is a simple, reliable process that is
8. 0. Lenderman, 111, P.E., Administrative Engineer, Public Work Department, city of Memphis, TN, *‘The T.E. Maxim Plant is a lime stabilized sludge facility designed by Black and Veatch. The plant is exceeding design projections. It is a good, economicel operation - ch0ap.r than any o lhr rtrbillutlm pl0c.u that we .vduat.d, and we are producing an acceptable land application product”.
Dan Stefmski, Assistant Director, Metropolitan Wastewater Treatment Facility, Monroe, Mi, “Lime stabilization with either lime 01 kiln dust Offers an excellent, low capital and low operating cost method for stabilizing and utilizing munici- p.1 sludge. Utilization Of a by-product serves two goals - cost reduction and provides us with a viable recycling process”.
Tom.Kovacik, Director of Public Utilities, City of Toledo, OH, “The City of Toledo has a welldeserved reputation for effoctiV0 and efficient land application of limetreated municipal sludge. We believe the utilization of these resources is both cost effective and is totally consistent with our objectives of energy and resource Consewation, and improvement of tho environment. The use of kiln dust in sludge stabilization and land application appears to represent a significant economic opportunity”.
Bob Bmtian, U. S. Environmental Protection Agency, Technical Branch, Weshington, D.C., “Lime Stabillzation of wmtowater sludge using a kiln dust reactant is a practical concept in that it effectively provides for the utilization of two by-products”.
Robert J. Collins, P.E., Valley Forge Laboratories, Devon, PA, “The Department of Transportation-Department of Energy study showed that managed kiln dust is a consistent and dependable substitute for lime”.
Paul Munn, PE Chief, Environmental Enforcement and Engineering, City of Toledo, “In my opinion, the use of kiln dust for sludge stabilization has the potential for being economically advantageous for the City of Toledo. My experience indi- cates that kiln dust is an effective substitute for lime in many wastewater treatment processes”.
oxtnmdy coat .ttocM”’.
Terry J. Logan, et ai., quote from Ohio Guide for Land Application of Sewage Sludge: “With a $31 (1976 dollars) per dry ton disposal cost and a $25 per dry ton nutrient value, the community at large (farmers and the urban population) has averaged net disposal costs of only $6 per dry ton. Viewing landspreading from the perspective of the community at large implie8 that communities can not afford to uso landfilling or incineratlon.”
0. F. Wiles, Environmental Operations, Westminster, MD, “The N-Viro Soil process offers an excellent low cost stabili- zation and dispoaal method without requiring a high degree of capitalization and technical expertise”.
CMlp, Drossor & McKw, Inc. quoto from EPA600/S241476, Ume Stabilization and Ultimate Disposal of Municipal Wmtow8tw Sludges, “In New England, partlcularly where farmen routinely add lime to agricultural soils to maintain pH. UH of limestabilized sludge reduces or eliminates the farm&s need to purchase lime”.
William A. Kndlw, PhD, Director of the Eitel institute for Silicate Research, University of Toledo, “The Eitel Institute conductod oxtonrlve twting with different types of both kiln duats and wastewater studges. We find that we were able to att8in pH levels of 1200r greater for extended periods of time even though the free lime content of most cement kiln dust8 would not Indicate that such results were po88ible.”
Richard Hopponjans, P.E., Bowser Morner Testing Laboratories, “Bowser Morner, inc. has tested over 100 different mixtur08 of wsatewater sludge and kiln dust.;um many different sources. We have been able to economically achieve pH IOvel8 of 12.0 or greater with these mixtures at varying temperature conditions. In most cases we were testing a post-iim- ing method (I.O., adding kiln dust to a dewatered sludge cake). Pathogen testing done for us by Jones & Henry @ora- tori08 showed significant pathogen reduction (i.e., Log 3). The results were comparable to stabilization with CaO.”
Stwon Wordelman, PE, Environmental Engineer, Jones & Henry Engineers, Ltd., “Preliminary investigation on the use Of cement kiln dusr for sludge stabilization has indicated that the reduction in indicator pathogens using cement kiln dust is ~UivalWlt to the reduction achieved utilizing pebble lime.”
Appendix C .
N-VIRO SOIL: A Socially Acceptable, Marketable Product. m e combination of kiln dust and sludge (wet or dewatered) results in a product of significant nutdent and sol1 c o n d l t b
Ing value. For stabilizatlon purposes, sufficient kiln dust can be added to sludge (i.e., 10%) without affecting the physical characteristics of the sludge. In a wet sludge, the dust will go into suspension. A cake will remain a cake. The addition of kiln dust does not adverseiy affect existing Utilization methods. Kiln dust increases the value of the sludge by-product by reducing odor, increasing nutrients and soil conditioning properties, and by raising the pH of the sludgelsoil mixture.
The addition of kiln dust to non-stabilized sludges allows wastewater facilities to utilize their sludge in land applica- tions approved by the EPA for ‘‘Processes to Significantly Reduce Pathogens”. Such use reduces disposal costs and pro- vides significant value to the farm community. The environmental benefits of the kiln dust on the sludge will dramatically reduce public concerns.
A greater percentage of kiln dust (i.e., 25%) can be added to wastewater sludge to significantly reduce the moisture content and develop a granulated by-product. This technology offers many advantages. The granulation-dewatering pro- cess aids disinfection. The product will maintain its alkaline characteristics for an even greater period of time. Odor is more completely reduced. There is less concern about ground water and surface water contamination. The granulated product is easily stored and handled. This reduces soil compaction and other seasonal concerns.
The granulated N-Vir0 soil product opens the door to many marketing and utilization opportunities which have been rejected in the past because of public concern and opposition.
N-Vlro Soil Technology Versus Competitive Alternatives:
A. Digestion 1. SbblliuHen. The initial cost of digesters is enormous - at least five times more than kiln dust stabilization.
Operating costs are comparable.
2. Utll lut ion. Digestion reduces odor, but does not affect pH. Digested sludges have higher concentrations of heavy metals due to loss of Organics from volatile solids reduction activity. Value of digested sludge is far less than N-Viro Soil.
B. Compost 1. Strblllzatkn. Composting systems are very capital intense and expensive to operate. N-Vir0 Soil offers substantial
advantages in both intiai cost and operating costs.
2. Utlllutton. In urban markets, compost may have a small advantage over N-Vir0 Soil due to its neutral pH and organic value. In most geographic areas, N-Vir0 Soil is more valuable to the agricultural buyer because of its higher nutrient value, particularly potassium and calcium.
C. Limo Stablllzatlon (with lime) 1. Stablllutlon: Where lime fines or granulated lime is available, the economics are comparable. Pebble lime is not
suitable for post-liming.
2. Utll lut ion. The nutrient value, calcium carbonate, and ability to dewater, particularly in a post-liming process, are advantages of kiln dust. Additional material (by weight) will be moved but the mixture has increased value.
3. Avrllrblllty. With a chemical treatment system, availability is a key concern. Kiln dust is readily available through- out the U.S. at by-product prices.
NATIONAL INTERESTS: In the past fifteen years, our nation has awakened to the realizations that our resources are not unlimited, we must
reduce our dependence on foreign oil, and we must preserve the environment. One concept that is totally consistent with ail three natlonal objectives is the safe land application of municipal wastewater sludge. The alternatives to land appli- cation are totally inconsistent with these objectives.
The N-Vir0 Soil process represents “innovative and alternative technology”
Throughout the United States, wastewater sludge management is a realistic issue and concern. Environmental and economical technology is required.
N-Vir0 Soil Is a treatment and utilization answer for wastewater facilities of all sizes.
N-VIR0 ENERGY SYSTEMS, LTD.
In 1974 Nicholson Industries, Inc., an Ohlo ready-mixed concrete firm began research, development and demonstration efforts on cement and lime kiln dust and kiln dustlfly ash systems technology. These development efforts led to the establishment of N-Viro Energy Systems, Ltd., an Ohio limlted partnership, created to pioneer effective energy and resource conservation through economical environmental and energy conserving utilization of industrial, utility and municipal waste products - particularly cement and lime kiln dust, fly ash and municipal wastewater sludge. J. Patrick Nicholson, Chief Executive Officer of Nicholson Industrles, resigned that position to become Chief Executive Offlcer of N-Vir0 Energy Systems, Ltd.
N-Vir0 Is the recognized leader in the development of kiln dust and kiln dust technology. N-Viro patents have been issued in the United States and over ten foreign countries. N-Viro Soil technology is discussed elsewhere in this brochure. In addition, N-Vir0 has developed and patented technology to beneficlate conditioned, marginal and reclaimed kiln dust; to understand, predict and manage the chemistry of kiln dustlfly ash reactions; and to utilize kiln dustlfly ash systems in construction and waste management.
N-VIR0 AGENTS by State
STATE Alabama Arkansas (NE) Arkansas (W) Arkansas (E) Colorado ConnecUcut Delaware District of Columbia Florida Georgia Illinois (N) Illinois (S) * Indiana (N) Indiana (S) Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri (E) Missouri (W) Nebraska New Hampshire New Jersey New York New York Clty No. Carolina North Dakota Ohio (N) Ohio (S) Oklahoma Pennsylvanla (Eastern) Pennsylvanla (So. Central) Pennsylvania (Western) Rhodr Island So. Carolina So. Dakota Tennessee Texas Vermont Virginia Wisconsin
AGENT W. E. Blah a Son Delta Asphalt Inc. Ritchie Resource Mgt. W. E. Blain (L Son Power Plant Aggregates of Iowa Heede Industries Westgate Quarry, Inc. N-Viro South, Inc. N-Viro South, Inc. N-Viro South, Inc. Material Services Corp. Maclair Energy Materials May Stone N-Vir0 Great Lakes Power Plant Aggr's Ritchie Resource Mgt. Carey Construction W. E. Blain (L Son Heede Industries Westgate Quarry, Inc. Heede Industrim N-Viro Great Lakes Power Plant Aggr's W. E. Blain (L Son Maclair Energy Materiala Ritchie Resource Mgt. Constructors Heede Industries Gen'l. Crushed Stone Gen'l. Crushed Stone Heede Industries Pozzolanic Contr'g. a Supply Power Plant Aggr's N-Viro Great Lakes Anderson Concrete Ritchie Resource Mgt. General Crushed Stone Westgate Quarry Inc. Trumbuii C o n s t r a n Heede Industries Pozzolanic Contr'g. a Supply Power Piant Aggr's Pozzolanic Contr'g. a Supply Ritchie Resource Mgt. Heede Industries N-Viro South. Inc Maclair Energy Mat'ls.
CONTACT Gerald Beard Leo Hindman Drew Reynolds Gerald Beard Walt Morris Bob Sur Geo. Cramer, Jr. Mike Marinelli Mike Marinelll Mike Marinelll Ralph Vencill Jim Spagna Dave Davis Pat Nicholson Walt Morris Drew Reynolds Tom Matthews Gerald Beard Bob Sur Geo. Cramer, Jr. Bob Sur Pat Nlcholson Walt Morris Gerald Beard Jim Spagna Drew Reynolds Tax Leber Bob Sur Ron Bryan Ron Bryan Bob Sur Bob Carroll Walt Morris Pat Nicholson Doug Anderson Drew Reynolds Ron Bryan Geo. Cramer, Jr. Millard Stewart Bob Sur Bob Carroll Walt Morris Bob Carroll Drew Reynolds Bob Sur Mike Marinelli Jim Spagna
PHONE (601) 352-7063 (314) 334-5261 (316) 838-9301 (601) 352-7063 (712) 252-1891 (203) 622-0830 (717) 843-0981 (305) 5834291 (305) 563-4291 (305) 583-4291 (31 2) 372-3600 (618) 271-7470 (219) 747-3105 (419) 5356374 (712) 252-1891 (316) 836-9301 (606) 260-2131 (601) 352-7083 (203) 622-0830 (717) 843.0981 (203) 622-0830 (419) 5356374 (712) 252-1891 (601) 352-7063 (618) 271-7470
(402) 476-1212 (316) 838-9301
(203) 622.0830 (215) 459-2492 (215) 459-2492 (203) 622.0830 (615) 690-4111
(419) 535-6374 (61 4) 44341 23 (316) 838-9301 (21 5) 459-2492 (717) 643-0981
(203) 622-0830 (615) 690-41 11 (712) 252-1891 (615) 690-41 11 (316) 838-9301 (203) 6224830 (305) 563-4291 (61 8) 271 -7470
(712) 252-1891
(412) 461-9300
Appendix C .
(j) WiEnergySystemsUd SOIL
Cement Kiln Dust Stabilization and Utilization of Wastewater Sludge A Revolutionary Technological Development in Wastewater Sludge Management
and Resource Recovery
Background: N-VIR0 SOIL is a process and a marketable product involving the use of kiln dust or kiln dust/fiy ash technology to stabilize, deodorize, disinfect, dewater, and if desired, granulate wastewater sludge. Pathogen reduction is 10 to 1,000 times greater than digestion, heavy metals are stabilized, and community concerns dramatically minimized.
The kiln dust stabilization process is less costly and requires less investment than any alternative. The combination of kiln dust and wastewater sludge provides significant soil conditioning and nutrient values. The agricultural value of the N-VIR0 SOIL product significantly exceeds that of any alternative sludge treatment process.
FACTS ABOUT N-VIR0 SOIL! 1. Kiln dust stabilization is the “most cost effective” (Clean Water Act, Sec. 218) method of sludge
treatment. Stabilization costs less than $30 per dry ton. 2. N-Viro Soil is a marketable (recycled) agricultural product, totally consistent with Clean Water Act,
Section 201 (dxl), “Purpose-grants for construction of treatment works”. High agricultural value will reduce utilization costs as odor control increases community acceptance.
3 . Kiln dust adds calcium, potassium, sulphur, and magnesium to the value of the sludge product. No other alternative provides such value. Additional nutrients to achieve minimum N-P-K fertilizer per- centages can readily be added in stabilization facility to ensure market value.
4. Capital investment is less than 25% of amount required for new composting or digestion facilities. 5. Cement kiln dust chemically stabilizes heavy metals in sludge. Cement kiln dust, today, is the number
one (#l) chemical used in hazardous waste stabilization in the U. S. A. 6. Kiln dust can dewater, solidify, and even granulate sludge-reducing fears of surface and ground
water contamination. 7. The kiln dust process is particularly environmentally effective with digested sludges. Concentrations
of heavy metals are diluted and stabilized: natural dewatering is doubled; storage is a realistic option, thus minimizing trucking costs, farmer objections, and community concerns about odor and other undesirable sludge characteristics.
8. Soil liming requirements (greater than 6.5 pH) are minimized (EPA 600/S2-81-076). Calcium is provided by the process.
9. Chemical stabilization results in pathogen reduction 10 to 1,000 times greater than anaerobic digestion
10. Kiln dust is easier to handle than lime (no slaking required), far less costly, and readily available throughout the United States. The nutrients, dewatering, and metals stabilization values of kiln dust far exceed those of lime.
11. Federal studies (Bureau of Mines Information Circular 8885 and DOT/DOE FHWA/RD-82/167) have confirmed that “cement kiln dust is a large voume material having potential utilization as a substitute for lime”, “any environmental considerations are minor”, and “properly managed, kiln dust is a consistent by-product”.
(EPA 600/2-78-171).
Please Vi8it N-Viro’s Booth #700 during the 1985 Water Pollution Control Federation Annual Conference in Kansas City and/or write to N-Vir0 Energy Systems, Ltd., 3450 West Central Avenue, Suite 250. Toledo, Ohio 43606 for detailed information.
COMPREHENSIVE MATERIAIS MANAGEMENT, INC. 2656 SOlm u x ) P U", S1117F 140 HOLhTDN, TEXkS 7 0 % Telephone: (713) 669.1122 m: Telephone: (504) 254.0007 LA:
November 18, 1985
City o f Da l las Waste Water Treatment, Southside D iv i s ion 10011 Log Cabin Road Dallas, Texas 75253
ATTM: KAREN BICK
Dear Karen:
I have enclosed a chemical analysis which was supplied t o us by t h e f h c i l i t y from which the CKD for your t reatment p lant will be used.
I also ta lked to the Chief Cheaist and asked him the d i f ference between the CAO and free l ime. 'Free Lime' as described i n t h e chemical d i c t i o n a r y i s Calcium Oxide. - However, the cement plants use the t e r n CAO t o d i s t i ngu ish t he t o ta l ca l c ium componets from the other ingredients.
They then run a f r e e l i m e t e s t which actual ly determines the % of f r e e l i m e t h a t i s i n the product. In the ana lys is I have enclosed, the CAO i s shown as 43.92. Howver, only about 72, i s f r e e l i m e with the remaining 36.9% being varying forms o f Calcium, i n what form I am not sure a t t h i s time.
To breakdown the Calcium corponets i n each form requires an X-Ray defractomitry (?) t e s t which none of the plants are capable o f doing. But chemistry being an inexact science and many react ions are not completely understood, it i s bel ieved by the un i ve rs i t i es tha t d id the s tud ies , tha t the complex n i x o f oxides, not just the f ree l ime, are responsible for the react ion obtained using CKD. This complex m i x o f oxides including the total calc ium compounds, the M60 and the K,O, seem t o work together to get these resul ts.
I hope th i s i n fo rma t ion i s use fu l and I will forward anymore t h a t I can get. I will also forward the k t a l s breakdown as soon as I have received one from our lab. Call i f I can be o f service.
Sincerely,
/ ' I ". ' I
H.B. BERRY, JR. /
Appendix D.
~ ~ 0 COMPREHENSIVE MAERIAIS MANAGEMENT, INC.
CKD - Faci l i ty: 853 C h a i c a l Analysis
11 .8 2 -8 2-5 43-9+
59 12.6 - 15-33 8-16/10-4
-12 5 -80
-87 15
-27
+Total Calcirn. Free Lime k i n g 6.9%
Appendix D.
Wkmorandum
MTE November 13, 1985 CrrY OF DAUAS
TO Karen Bick
SUMCT Analysis of Cement K i I n Dust
This laboratory received a sample o f Cement K i l n Lime Dust submitted by Karen Bick on November 7, 1985. ?he container which the sample was taken was labeled from Comprehensive Management Company, 2656 South Loop West, %140, Houston, Texas.
The sample was analyzed f o r avai lable l ime using the AWWA .Standard T e s t f o r Quickl ime (6 202-65) or ASTM Chemical Analys is o f Lime (C- 25:72). This method i s r e f e r r e d as the rap id sugar t e s t .
The o n l y v a r i a t i o n i n method was t h e f i l t e r i n g o f the dissolved l ime through a g l a s s f i b e r f i l t e r t o remove iron hydroxides that obscure the phenolphthalein end point .
The actual analysis was performed by Robert Randolph a t t h e Elm Fork WTP i n Car ro l l t on , Texas. The analysis resul ts obtained showed only 7.0% availa.ble calcium oxide as received.
&&& $L- Malcolm Baker Laboratory Supervisor Research & Central Laboratories
dc
c: Joe Brown Robert Randolph Hi lda Carr igan F i l e
Append i x D.
Recovery of 10 gms C R D / L water and t Volatiles of recovered p o r t i o n .
i . 9
Ratch $ 3 C K D
9 . 1 I1 . 2 9 . 2 9 . 1 9 . 0 9 . 1 9.0 9 . 0 9 . 1
v 0 1 .- 2 . 5 2 . 5 2 . 6 2 . 5 2 . 4 2 . 5 2.1 2 . 2 2 . 3
9 . 1 2 . 3
Appendix E.
pH v a l u e s o f Sludge/CKD p r e c i p i t a t e o v e r t w o hour i n t e r v a l s .
2 h r 5 h r
3 h r 5 h r
3 h r 5 h r
4 h r G h r
4 hr 6 h r
7 . 0 1 1 . 7 6 . 8 11.8
7.5 11.9 7 . 0 11 .5
6 . 6 11.!1 6 . 5 1 1 . 7
7 . 1 1 2 . 0 6 . 9 1 2 . 0
7.0 2 1 . 9 7 . 0 1 1 . 8 .
1"'. -1 1 2 . 3
1 2 . 6 1 2 . 3
2 2 . 1 1 2 . 4
2 2 . 6 1 2 . 3
1 2 . G 1 2 . 1
1 2 . 7 1 2 . 4
1 2 . 5 1 2 . 7
1 2 . 5 12.7
Fihr 6 . 6 1 2 . 0 12.5 1 2 . 5 1 2 . 4 2 2 . 5 7 h r 6 . 6 11.9 1 2 . 5 1 2 . 3 1 2 . 7 1 2 . 6
3hr 6 .8 1 1 . 7 12-1 1 2 . 2 12. C 1 2 . 0 1 2 . 9 5 h r 6.0 11.5 12.0 11.7 11.3 11.7
6 h r 8 h r
pH V a l u e s o f Sludge/CKD p e r c i p i t a t e , o v e r severa l d a y s .
3hr 7 . 5 11.9 2 4 h r 6 . 6 11. 3 4Hhr 6 . 4 11.1 7 2 h r 6.4 1 1 . 0 9 6 h r 6 . I 1 0 . 8
12Ohr 6.3 1 0 . 8 1 4 4 h r 6 . 3 1 0 . 4 ZfiShr 6 . 9 1 0 . 0
1 2 . 6 12.2 1 2 . 3 1 2 . 0 1 2 . 1 1 2 . 0 11.9 11 .9
CKD B a t c h t l
2hr 7.0 11.4 1 2 . 1 2 4 h r 6 . 8 11.3 1 2 . 4 48hr 6.3 1 1 . 3 1 2 . 3 7 2 h r 6 . 4 11.6 1 2 . 4 9 6 h r 6 . .1 11.5 1 2 . 5
120hr 6.1 11.3 1 2 . 5
2 h r 2 4 h r i18hr 7 2 h r 36hr
1 2 0 h r 1 4 4 h r l6Rhr
7 . 0 11.3 6 . 5 11 .3 6 . 3 11 .3 6.4 11.6 6 . 7 11.1 6 . 9 1 0 . 8 6 . 7 1 1 . 0 6 . 7 10.2
1 2 . 1 1 2 . 1 1 2 . 1 1 2 . 5 1 2 . 3 1 2 . 3 1 2 . 1 1 2 . 1
C K D Batch e3
6 h r 6 . 9 1 2 . 0 '12.5 1 2 . 6 2 4 h r 6 . 4 12.3 1 2 . 5 1 2 . 2 -1EcI1r 6 . 5 11 .9 1 2 . 1 1 2 . 2 7?hr 6 . 4 11.6 1 2 . 1 11.8 9 6 h r 6 . 2 1 1 . 4 11 .9 1 2 . 1 120hr 6 . 2 1 1 . 5 11.8 1 1 . 7
Append i x F.
Treacsd
Jeffrey C. Burnham, Ph.b. Professor
tfedical Collage of Ohfo
Toledo, Ohio 43699 C. S o 10008
419-381-5423
Funding Provided by the City of Toledo i n consulta~ion wlth N-Viro Errergy Systems, Ltd.
Approved by
Jaf frcy C. Burnham, Ph-?D. DATE Principal Investigator
C. Kenneth Ptoefrock DATE Senior Vice President, Cranes and Research Administration
Appendix G .
In t roduct ion
The b e n e f i c i a l u s e of v f 8 b i l i t Y of d i sease caus
2
municipal wastewater s ludge r equ i r e s t ha t i n g microorganism i n t h i s n u t r i t i v e mater
the t a l be
sfgnificantly reduced. The-use of cement k l l n d u s t (CIU)) and lime k i l n d u s t (LKD) ha8 been developed as an advan tageous subs t i t u t e fo r lime i n t h e s t a b i l i z a t i o n of sludge. This treatment not on ly s ign i f i can t ly dewa te r s t he s ludge bu t i t a l s o raises the pH of t h e t r e a t e d s l u d g e t o o v e r 12 which causes a s i g n i f i c a n t r e d u c t i o n i n t h e v i a b i l i t y of pathogenic and o t h e r microorganisma contafned within the sludge.
A recent memorandum (November 6, 1985) addressfng t h e EPA 40 CFR 257 Regula t ions ind ica ted the l eve ls of pathogen reduction that must occur for t h e s ludge t o k u t i l i z e d i n l a n d a p p l i c a t i o n s . In summary, f o r a PSRP (Processes t o S i g n i f i c a n t l y Reduce P a t h o g e n s ) c l a s s i f i c a t i o n t h e f e c a l and t o t a l c o l i f o r m bacterial counts aust be reduced by 2 logs (eg., as from lo5 to 10 cells per 100 ol) while a 1 l og r educ t ion i n an ima l v f ruses must be achieved. . For a PFRP (Processes t o F u r t h e r Reduce Pa thogens ) c l a s s l f i ca t ion t he s t anda rd is auch stxicter requfr lng tha t Sa lmonel la be present a t no g r e a t e r c o n c e n t r a t i o n th8n 3 organ is^^ (colony forming uni ts) per 100 m l of sludge. The l e v e l of animal v i rus r equ i r ed fs 1 v i r u s per 100 m l of sludge or less. The helminth egg s t anda rd r equ i r e s t ha t on ly 1 egg per 100 ml sludge may r e t a i n i ts v i a b i l i t y . P r e v i o u s b a c t e r i a l t e s t i n g f o r N-Viro Energy Systems of sludge s t a b i l i z e d w i t h cement k i ln dus t has i nd ica t ed a r e d u c t i o n i n f e c a l c o l i f o r m b 8 c t e r i a c o n s i s t e n t w i t h t h e PSRP c l a s s i f i c a t i o n . This proposal is designed t o provide 8 more accurate assessment of t h e e f f e c t t h a t cement k i l n d u s t h a s on f e c a l c o l i f o r m s , f e c a l s t r e p t o c o c c i , S a l m o n e l l a s p e c i e s p a r a s i t i c Ascaris ova and en te rov i rw as recommended by the USEPA f o r a PFRP c l a s s i f i c a t i o n .
3
Study Plan
n e fol lowing plan is designed to provide important data on t he r educ t ion of p a t h o g e n v i a b i l i t y d u e t o t h e t r e a t s e n t of Toledo municipal sewage sludge with cement k i l n d u s t . The proposa l ob jec t ives are:
I ) To r e p r o v e t h a t CKD and LlCD t reatment of combined s ludge a long wi th ox ida t ive t u rnove r will met PSRP c l a s s i C i c a t i o n ;
2) To examine the degree o f microbia l v iab i l i ty reduct ion caused by C' iD and LKD t rea tment d s ludge a long wi th ox ida t ive tu rnover in comparison wlth USEPA PFRP c l a s s i f i ca t i t , y gu ide l ines .
The plan uses a con t ro l , un t r ea t ed s ludge of each type, i . e . , combined raw sludge and waste act ivated s ludge for comparison purposes .
Dr. Stanley Sawickl o t t he Department oC #lcrobfo logy .a t the Medica l College of Ohio will c o l l a b o r a t e by conduct ing the en te rovi rus assay . Dr. horge J. bgeage , Jr. of t h e Department of Mfcrobiology a t MCO a n d M r e c t o r Of Clinical Hicrobiology at St. Vincent 's Hospital , Toledo, dl1 c o l l a b o r a t e by conduct ing the helminth ova assay.
Appendix G .
3
STUDY PLAN OUTLINE
A. Toledo Sludge Types
a. Toledo conblned - raw s ludge b. Toledo waste - ac t iva t ed s ludge
8. Types o f Sludge Treaemant
a. 0% Cement Ktln bust (CKD) in sewage sludge b. 10% CKD In sludge C. 15% CKD In s ludge d. 25% CKD in s ludge e. 5Z f r e e lime + 15% CIU) In sludge f . 5% f r e e liau In sludge
D. Times for assaying pa thogen v iab i l i ty In u n t r e r t e d and treated samples
. See at tached schedule
E. Types of bac te r i a a s sayed (216 a r r a y s )
a. Fecal coliforms b. Feca l s t r ep tococc i C. Salmonella (enteric pathogen)
P. Types of virus assayed (6 assays only)
a. Enterovirus
a. Helminth ( fecal obtained Ascaris) ova
H. pH (each sludge sample a t each assay time)
I* X S o l i d s
Append i x G.
,
