particle size separation implications on cod removal ... · particle size separation implications...
TRANSCRIPT
![Page 1: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/1.jpg)
Particle Size Separation Implications on COD Removal before BNR:
A Case Study at Heyburn, Idaho
Co-Authors:Remy Newcombe, Mark LoppTravis Higby, Ralph MartiniBjorn Rusten
![Page 2: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/2.jpg)
• The Heyburn, Idaho WWTP had: screening, grit removal, oxidation ditches, clarifiers, UV, & aerobic digesters
• New requirements: phosphorus discharge to the Snake River, capacity increase from 0.39 to 0.563 MGD
Heyburn WWTP
![Page 3: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/3.jpg)
• Stipulations: no precipitating chemical addition for P removal• Heyburn added: headworks, anaerobic bio-selector tank, new
oxidation ditch, effluent filters• Plant was complete by the end of 2009
Heyburn WWTP
![Page 4: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/4.jpg)
• Rotating belt, primary filter (Salsnes Filter)
• 40–70% TSS reduction• Up to 35% BOD reduction• Produces 25-40% solids cake
Headworks: Rotating Belt Sieve
![Page 5: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/5.jpg)
Salsnes Filter
Dual SF-2000
• TSS and BOD removal creates aerobic treatment capacity
• Flexibility for varying flows, CSO, multiple models available
![Page 6: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/6.jpg)
Fine-Sieve Mesh Belt
• Nylon with Kevlar supports• Patented, self-aligning belt
• Multiple sieve sizes available
• Belt life is 1-5 years
![Page 7: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/7.jpg)
Mat Forms on Screen Cloth
![Page 8: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/8.jpg)
Mat Filters Water
![Page 9: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/9.jpg)
Belt Lifts Solids Away
![Page 10: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/10.jpg)
Solids Drop into Hopper
![Page 11: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/11.jpg)
Air Cleans the Screen Cloth
Direction of Belt
Air Knife Action
![Page 12: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/12.jpg)
Intermittent Hot Water Degreasing
Spray Nozzles
![Page 13: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/13.jpg)
Solids in Auger, Prior to Extruder
![Page 14: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/14.jpg)
40% Solids Exiting Extruder
![Page 15: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/15.jpg)
Filter Mat Principle
40%
200 µm
80%
20 µm
60%
100 µm
50%
150 µm
350 µm mesh
350 µm mesh yields 35-100 µm effective filtration
Belt direction
70%
50 µm
![Page 16: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/16.jpg)
• Recent work (Tas et al., 2009) suggested removal of particulate matter before BNR may impede denitrification potential
Question for BNR Operations?
With 35-100 µm filtration, is too much particulate removed by a RBS?
![Page 17: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/17.jpg)
• COD: suggested as more useful than BOD for determining biological conversion rates in modeling (Orhon and Cokgor, 1997)
• Only 21% of COD is “settleable” (>63 micron), and 27% of COD is “suspended” (5-63 micron) (Nieuwenhuijzen, 2000)
• Significant amount of settleable COD found to be biodegradable (Tas et al., 2009)
• This led to assumption that removal of too much particulate matter could impede BNR
Review of COD
![Page 18: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/18.jpg)
• Removal of particulate matter may be possible while maintaining critical COD/N ratios for efficient pre- denitrification
• Experiment: Sample before and after a RBS install Analyze for COD with filtered and unfiltered samples Confirm nitrogen removal at plant
…but maybe not
![Page 19: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/19.jpg)
• “Settleable COD” might capture more of the readily biodegradable particulate range than simple size exclusion
• Therefore RBS devices might be able to remove a large amount of solids, but allow more biodegradable COD to pass than primary clarifiers
Theory
![Page 20: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/20.jpg)
• RBS (Salsnes Filter) removing solids & BOD as expected
Results: TSS & BOD
(mg/L) RBS Influent RBS Effluent % Removal
TSSst. dev.
155+/- 36, n=3
85+/- 36 , n=3
45%
BODst. dev.
177+/- 25 , n=3
121+/- 55 , n=3
32%
![Page 21: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/21.jpg)
• Unfortunately the COD data quality is poor• Sample 1 appears erroneous – the COD is too high in
relation to BOD (182 mg/L influent)• Removals in Samples 2-3 do not coordinate with the
observed BOD & TSS removals
Results: COD(mg/L) RBS Influent RBS Effluent RemovalCOD-1 1860 1600 14%COD-2 475 520 -9.5%COD-3 280 330 -18%Average 872 817 6%St. dev. 861 685 NA
![Page 22: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/22.jpg)
• Filtered COD data have similar quality issues
Results: COD Fractions
Fractions(microns)
Influent(mg/L)
% of Total
Total COD 872+/- 861
100%
>29 236+/- 139
27%
>0.45 270+/- 26
31%
0.45-29 34+/- 121
4%
<0.45 602+/- 836
69%
<0.45 um
>29 um
![Page 23: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/23.jpg)
• Grab sampling was used in this study, composite sampling may provide better data quality
• Sampling method may not have pulled proper representative samples, particularly for influent
• Laboratory method may not have properly homogenized samples before analysis
• Filtering of samples may have been difficult – filtering primary influent through 0.45 micron is not easy
Sampling & Analysis
![Page 24: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/24.jpg)
• Heyburn is achieving effluent nitrogen <10 mg/L
Results: Nitrogen Removal
(mg/L) RBS Influent
RBS Effluent
Plant Effluent
Removal (whole plant)
TN 29 24 9.2 68%
TKN 28 24 5.6 80%
NO2 <0.2 <0.2 <0.2 NA
NO3 0.6 0.5 3.6 NA
![Page 25: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/25.jpg)
• COD/N ratios are critical to efficient BNR operation
• Influent COD*/N ratio: 377 g COD / 29 g N = 13
• Effluent COD*/N ratio: 425 g COD / 24 g N = 18
• COD/N ratios may be maintained, but better data are needed (*Sample 1 data are excluded as outliers)
• Influent BOD/N ratio: 177 g BOD / 29 g N = 6.1
• Effluent BOD/N ratio: 121 g BOD / 24 g N = 5.1
• BOD data suggest the ratio is only lowered by 16%, since N is also lowered across the RBS
Results: COD or BOD/N Ratios
![Page 26: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/26.jpg)
• Collect more data! Need statistically significant data for COD.
• Collect composite samples and reexamine influent sampling location.
• Use more filter sizes for samples, before and after RBS installs, to better understand COD particle size distribution.
• Examine laboratory methods for sample preparation and analysis of COD.
Future Work
![Page 27: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/27.jpg)
• Rotating belt sieves (Salsnes Filter) remove significant TSS and BOD, increasing treatment capacity in a plant
• Heyburn is achieving <10 mg/L total nitrogen• Data show the BOD/N ratio is only lowered a
small amount across the RBS• The majority of readily biodegradable COD may
pass the RBS, allowing efficient BNR, but more data are needed to understand this in detail
Conclusions
![Page 28: Particle Size Separation Implications on COD Removal ... · Particle Size Separation Implications on COD Removal before BNR: A Case Study at Heyburn, Idaho Co-Authors: Remy Newcombe,](https://reader036.vdocuments.net/reader036/viewer/2022062414/5f04a00f7e708231d40ee611/html5/thumbnails/28.jpg)