-1-

1. Overview 2

2. Typical Waste Water Treatment Flow 3

3. Types and Actions of Coagulants, Classification of

Coagulants, Coagulating Model 6

4. Types and Characteristics of Inorganic Coagulants 8

5. Types and Applications of Polymer Coagulants for Waste Water

Composition (Structural Formula) and applicable targets

Effect by molecular weight

Effect of ionic polymer 9

6. Types and Characteristics of Organic Coagulants 12

7. Problems in Coagulation Treatment and Countermeasures Thereto 14

8. Emulsion Polymer for Automated System 21

Contents

Report on

Energy and Environmental Technology Diffusion and Cooperation

1999

Indonesia

March 2000

Technology Exchange Dept.

Japan External Trade Organization

-2-

1. Overview

A coagulant is a chemical used to effectively separatefine suspended particles that cause pollution from water.Minute particles that do not readily separate from watercan be separated by coagulating them into easilyseparated flocs.Coagulants are roughly divided into inorganic coagulantsand polymer coagulants. Inorganic coagulants date as farback as ancient Egypt when alum (double salt made withaluminum sulfate, alkaline metal, etc.) was used to makewater drinkable. Even today, aluminum salt s a popularinorganic coagulant.On the other hand, polymer coagulants were developedin the 1950s. At first, they were used in industrialprocessing, for example, to concentrate mining slurry.Later, in the 1960s, when environmental problemsstemming from industrial waste water became a socialissue, anionic and nonionic polymer coagulants becamewidely used to treat waste water. Then, in the 1970s,cationic polymer coagulants became used in largequantities as dehydrating agents in treating urban wastewater such as raw sewerage and night soil. Current annual use of polymer coagulants in Japan isestimated at about 11,000 ton of anionic and nonionictypes such as polyacrylamide, and about 16,000 ton ofcationic types such as polyamino alkylacrylate. Polymercoagulants are absolutely indispensable as a chemicalagent for environmental conservation.This paper reports on the characteristics and effectiveapplications of polymer coagulants in water and sludgetreatment. It cites types of organic coagulants andpolymer coagulants as well as important topics andrecent trends seen with some actual cases of use.

-3-

2. Waste Water Treatment Flow

Fig. 1 Basic flow of waste water treatment

(1) Water treatment (Inorganic suspended substances: SS and heavy metals)　 Construction, civil engineering, iron and steel, metals, mining, etc

(2) Soluble organic substances treatment (COD and BOD) Sewerage, night soil, iron and steel (ammonia water), petrochemicals, dyes, food products (beverages and meat)

(3) Soluble organic substances + Suspended substances treatment (COD, BOD, n-hex and SS) Paper and pulp, machinery and automobiles, petroleum and petrochemicals, textiles and dyes, food products, etc.

Raw water

Raw water

Raw water

Inorganic coagulant Polymer coagulant

Discharge

Dehydrator

Natural precipitation

Raw water pit

Raw water pit

Aeration tank

Aeration tank

Sedimentation pond

Sedimentation pond

Return sludge

Return sludge

Surplus sludgeDehydrator

Polymer coagulant

Dehydrator

Polymer coagulant

Coagulating sedimentation

Polymer coagulant Disposal

Dehydrated cake

Discharge

Discharge

Surplus sludge

Dehydrated cake

Dehydrated cake

Incineration

Inorganic coagulantPolymer coagulant

Coagulatingsedimentation

IncinerationDisposalAgricultural fertilizer

-4-

1 10

1 10 100μm 10mm 1mm 100nm 10nm 1nm

-1 10-2 10-3 10-4 10-5 10-6 10 (cm)-7

Particle size

Large particle SS Molecule

Suspended substancesPlastic waste fiber waste

Sand

Bacteria

Bentonite

Protein Dye

Surface active agentPigment

Screen

Ordinary filtration

Micro filtration (MF)

Ultra filtration (UF)

Reverse osmosis (RO)

Activated carbon adsorption

Ion exchange

Biological treatment (Activated sludge treatment)

Natural precipitationNatural floatation(API, PPI, CPI)

Coagulating sedimentationCoagulating floatationElectrolytic coagulation

Treatment method

Applicable range of coagulation treatment

-5-

Estimated water level after 1 hr (Treated water is actually discharged from the system, but this estimate adds it on top of the water surface.)

Water surface rise (H)

Treated water Current water level

Coagulant-added water (Raw water)

Because water level rises only by H in 1 hour time, flocs must precipitate a distance equal to or greater than H during that time.

With a raw water flow rate of 100 m3/hr and a sedimentation pond radius of a 4 m,water surface loading is as follows.

Water surface loading Treated water flow rate (m3/hr)Sedimentation pond surface area (m2)

2.0m2/m2・h 2.0m・h4×4×3.14

100=

=

= = =

Particle diameter(cm)

Size approximation Precipitation speed

By Stokes' equation

cm/sec Time required to precipitate one meter

0.05

0.01

0.001

0.0001(1m m)

0.00001

Sand 10.4 10 sec

4 min

28 day

8 year

7 hr

0.42

0.0042

0.000042

0.00000042

Fine sand

Sludge (silt, clay)

Bacteria

Colloid

Conditions: Particle density ... 2.0 g/cm3

Water temperature ... 20_C (Viscosity: 1.31 g/cm3 sec)

Stokes' equation Vg: Precipitation speedr : Solid particle densityro: Liquid densityd : Solid particle diameterg : Gravitational acceleration m : Viscosity coefficient of liquid

Vg (　　　)18 m1 d2

The relationship between particle size and precipitation

An example of water surface loading calculation

gr ro

-6-

3. Types and Actions of Coagulants

Coagulation processes are roughly divided into thosethat:

Destabilize suspended particles by electric chargeneutralization (to facilitate coagulation).

Perform flocculation by cross-linking.Those chemicals which are collectively called"coagulants" today can be categorized as follows bythese aforementioned actions.

Types and actions of coagulants

Coagulant Common name Action

Aluminum sulfatePolyalminium chloride (PAC)Iron chloride (Ⅲ)Iron (Ⅱ) sulfate

Slaked lime

Inorganic coagulantCoagulant

Polyvalent cations such as AL3+, Fe3+ and Fe2+ neutralize electric charge of suspended particles. At the same time, hydroxides such as Al(OH)3 adsorb particles, thus having slight flocculation effect.

Mostly used as neutralizer, Ca2+ has electric charge-neutralizingeffect (effective as inorganic coagulant)

Mg2+ and Ca2+ in seawater act as inorganic coagulants. Actually used to treat pulp waste water.

Seawater

Anionic/Nonionic polymer coagulant

Cross-links and flocculates particles that readily coagulate after contact with inorganic coagulant.

CoagulantPolymerFlocculant

Cationic polymer coagulant Flocculation effect by particle electric charge neutralization and cross-linking. Normally used to dehydrate biologically-treated sludge.

DehydratorCationic polymerCoagulant

Low molecular weight cationic polymer coagulant

Flocculation effect by particle electric charge neutralization and cross-linking though flocculation effect is not strong. Used as dehydrating agent with special types of dehydrators (vacuum or SL separator) and as alternative inorganic coagulant.

Polycation, Low molecular weight cationic polymer

-7-

Aluminum hydroxide floc

Electric charge neutralization (Coagulation) Cross-linking (Flocculation)

Fine suspended particle

Waste waterSuspended particle

Primary floc

Aluminum ion polymer

Nonionic/Anionic polymer

Nonionic/Anionic polymer

Coagulated floc (High sludge generation)

Inorganic coagulant treatmentOrganic coagulant treatment

Inorganic coagulant

Electric charge neutralization (Coagulation)

Organic coagulant

Primary floc

Cross-linking (Flocculation)

Coagulated floc

Low sludge generation

Model of coagulation mechanism

CoagulantClarifying agent

Inorganic coagulant

Low molecular weight cationic polymer coagulant (Polycation)

Aluminum sulfate

Iron chloride (Ⅲ)

Iron chloride (Ⅱ)

Polyiron sulfate (Ⅲ)

Polyalminium chloride (PAC)

Organic coagulant

Molecular weight Applicable pH

Several100 - 1,000

Several 1,000 - Several 100,000

5~8

5~8

4~7

4 or higher

4 or higher

9 or higher

Types of coagulants

Nonionic polymer coagulant

Anionic polymer coagulant

Cationic polymer coagulant (Cationic dehydrating agent)

Polymer coagulantCoagulantPrecipitant

Several 1,000,000- 10,000,000

4~8

6~12

10 or higher

-8-

4. Types and Characteristics of Inorganic Coagulants

4 5 6 7 8 9 10 11 12Coagulant

Aluminum sulfate (Al2[SO4]3)Liquid product: Al2O3 8%Solid product: Al2O3 16%

Polyalminium chloride (PAC)Al2O3 10 - 11%

Iron chloride (FeCl3)FeCl3 38%

iron sulfate Fe(SO4)・7H2O

UseEffective pH

Working pH range

Effective pH range

Characteristics

Merits Demerits

General waste water treatment

Amount of NaOH required to neutralize (g/kg)

Metal hydroxides generated (g/kg)

™Inexpensive™High substance 　removal rate™Low corrosion and　stimulation

™More coagulating than　aluminum sulfate™Requires little or no　neutralizer (alkali).™Effective at low　water temperature

™Heavy flocs 　(Good compression point)™Effective ever at　alkaline range

™Inexpensive™Heavy flocs

™Effective in narrow 　range of alkaline area™Less substance　removal rate

™Lightweight flocs™Less effective　at pH 8 or higher

™More expensive than 　aluminum sulfate™Lightweight flocs™Less effective at　pH 8 or higher

™Requires large quantity　of neutralizer (alkali)™Highly corrosive™Slightly expensive

To increase floc sizewhen polymers are notpractical (drinking watertreatment, neutralizercannot be used, etc.)

High pH waste watertreatmentSludge dehydratingagent aid

Some waste watertreatment (Dye waste water, etc.)

190 122

380 245

60 153

280 250

280 323

Table: Types and characteristics of inorganic coagulants

Change to iron chloride

An example for automobile factory waste water

PAC+NaOH+Anionic polymer coagulant Sludge SS 1.4%, VSS 86%

Cationic polymer coagulant

Belt-press dewatering Water content 88%

300ppm

38%+NaOH+Anionic polymer coagulant Sludge SS 1.5%, VSS 74%

Cationic polymer coagulant

Belt-press dewatering Water content 84.5%

Fecl3

300ppm

-9-

5. Types and Applications of Polymer Coagulants forWaste Water

Types and Applications of Polymer Coagulants forWaste Water

Characteristic

Structural Formula

Applicable pH range

Floc strength

Floc forming speed

–

–

–Treated water clarity

Applicable waste water

–

–

–

– –

Solution viscosityand dissolving concentration

Strong anionic polymer Anionic polymer Weak anionic polymer Nonionic polymer Anionic (Sulfonic group charged) polymer

n:m 15 or more　85 or less

n:m 15~5　85~95

n:m 5~0　95~100

n:m is mole fraction

High viscosity0.05~0.10%

High viscosity0.05~0.10%

Medium viscosity0.05~0.15%

Medium viscosity0.05~0.15%

Low viscosity0.05~0.30%

High (in low pH)

Fast

Good Good Good

Fast

High

4 6 8 10 12 14 4 6 8 10 12 14 4 6 8 10 12 2 4 6 8 10 12 2 4 6 8 10 12

Manufacturing process (Soda production, paper and pulp, aluminum)Protein recovery (Fish meat recovery)

Slurry and turbid waste water (grit, construction, civil engineering lime, dredging) Waste water containing metal oxides or hydroxides (Excluding aluminum surface treatment and galvanizing processes)Other high pH waste water

Colored waste water (pulp, textiles, dyeing, night soil, etc.)Other low pH waste water (aluminum surface treatment, emulsion, oil)

Colored waste waterOther low to medium pH waste water (effective with waste water of highlyfluctuating pH)

General mediumpH waste water

-CH2-CH-COONa n

-CH2-CH-COONa n

n

-CH2-CH-CONH2 m

-CH2-CH-

NH-C-CH2SO3Na

C = OCH3

CH3

™Polymer coagulant production flow

CH3CH=CH2 Propylene

AcrylonitrileCH2=CHCN

CH2=CHCONH2 Acrylamide

PolyacrylamideCH2–CH

CONH2n

-10-

Values: Estimated molecular weight

120

100

80

60

40

20

0 0.5 1.0

1200×104

900×104

600×104

Sup

erna

tant

turb

idity

(p

pm

)

Coagulant amount added (ppm)

Reference: Molecular weight of polymer coagulant and its amount added

-11-

Coa

gul

atio

n ef

fect

(P

reci

pita

tion

spee

d)

Coa

gul

atio

n ef

fect

(P

reci

pita

tion

spee

d)

4 5 6 7 8

Constant aluminum sulfate Constant pH (= 6.5)

Nonionic polymer Nonionic polymer

Sulfonic group chargedAnionic polymer

Anionic polymer

pH Aluminum sulfate amount added

Polymer coagulant use by pH

Low pHExcessive aluminum sulfate added

High pHInsufficient aluminum sulfate added

Polymer diffusion EffectAdsorption to particles Polymer diffusion EffectAdsorption to particles

Nonionic polymer

Anionic polymer

Anionic (Sulfonic group charged)

copolymer

Less adsorption point

Excessive adsorption

-12-

6. Types and Characteristics of Organic Coagulants

Types and characteristics of organic coagulants

Composition Estimated structural formula

Dimethyl dialuricammonium chloride

Ethyleneimine

Alkylamine epichlorohydrincondensation product

Dicyandiamide formalincondensation product

Alkylene dichloride and Polyaklylene polyaminecondensation product

CH2

N

R

R

–N

–CH –CH2–

CH2

CH

CI-CH2

CH3 CH3

–CH3–CH–CH3–

–NH2–R–NH2–R–

–O–CH2–NH–C–N–CONH2–CH2–

(–CH2–CH3–NH–)

OHCI-

CI- CI-

n

n

n

n

NH

CH2CO

Raw water

Organic coagulant CAluminum sulfate Polymer coagulant

Pressure flotation equipment

Dischargeable if COD is 20 mg/l or less

Slaked lime

Reaction tank Scum pit Sludge thickener

Polymer coagulant

Discharge

¡Mixed waste water　pH　　7.5　SS　　150 mg/l　COD　40 mg/l¡Drainage volume　6,000 m3/day

Dehydrated cake transportand disposal

Vacuum dehydratorSludge storage tank

Coagulant amount added Treated water quality

Organiccoagulant (mg/l)

Slaked lime (mg/l)

Aluminumsulfate 8%Al2O3 (mg/l)

Anionicpolymercoagulant(mg/l)

Dehydrated cakeamount generated (t/day)pH SS

(mg/l)COD(mg/l)

T–P(mg/l)

Inorganic coagulant treatment

Organic coagulant treatment

– 800~1000 12~20 100.14~0.25160 0.5 7.4 < 5

– 150~200 11~21 50.6~2.70 0.5 7.0 < 5

Fig. Improved effectiveness by organic coagulant (Automobile factory waste water)

An example of improved effectiveness by organic coagulant

-13-

pot

entia

l (m

v)

0

-5

-10

-15

100 200 300

Liquid aluminum sulfate (mg/l)

Liquid aluminum sulfate alone

sed with 5 mg/l organic coagulant

400 500

Trea

ted

wat

er tu

rbid

ity (

deg

ree)

0

5

10

100 200 300

Liquid aluminum sulfate (mg/l)

Liquid aluminum sulfate alone

Used with 5 mg/l organic coagulant

400 500

Fig. ( potential and treatment effect when inorganic coagulant used alone and when used in conjunction with polycation　　 (Specimen: Automobile factory mixed waste water)

-14-

7. Problems In Inferior Coagulation Treatment andCountermeasures Thereto

Problem waterquality item

Floc size: SmallClarity: Good

S S(Heavy metals)

Phenomenon

Unsuitable pH after inorganiccoagulant addition

S SColorCODBODn-hex

Insufficient polymer amount added Increase polymer amount added

Polymer solution deterioration

Cause Countermeasure

Change solution or dissolving conditions.

Yes

No

Clarity: NG Adjust to suitable pH.Yes

Increase inorganic coagulant addition.Yes

No

Select new inorganic coagulant byjar test.

Yes

No

CODBODn-hex

Floc size: LargeClarity: Good COD, BOD, n-hex

Increase inorganic coagulant addition.

Consideration of addition of chemical other than inorganic coagulant

Yes

Adsorbent (Activated carbon, bentonite)Application of COD decreasing agent etc.

Yes

Jar test

No

[1] Reconsideration of pollutants in waste water Ex. Change to low COD chemicals used in process.[2] Consideration of other treatment method. Ex. Biological treatment

Yes

No

No

Yes

Unsuitable type of polymer

Insufficient inorganic coagulant addition

Unsuitable type of inorganic coagulant

Insufficient inorganic coagulant addition

Limitations of coagulation treatment

Select new polymer by jar test.Yes

Low solution viscosity [1] Bad solution[2] Used for long time after dissolving.[3] Long dissolving time Over-stirring[4] Unsuitable chemical addition method (pump)

* To investigate floc size and clarity, sample suspended water in coagulating reaction tank and treated water, judging their appearance.

-15-

Phenomenon Cause Countermeasure Situation

Poor treated water quality

Scum generation

Flow rate too high Adjust flow rate as necessary. Large SS discharge. SS dischargefrom all circumference.

Improve coagulation. Fine and cottony floc discharge

Yes

YesSlow SS sedimentation speed

No

Improve problem at source.Break up scum with water spray.

Scum floatingYes

Scum generation

No

Sufficient sludge discharge (poor sludge discharge)

Large SS discharge from allcircumference

YesRising sludge interface

No

Improve inflow part. Localized SS dischargeYes

No

Improve sludge collector. Installscum skimmer. Break up andprecipitate scum with water spray.

Scum floatingYes

Install air separator oncoagulation tank outlet.

Scum floatingYesAir inclusion because of

high inflow head

Gas generation becauseof poor sludge collection

Channeling in sedimentationtank

No

Ref.: Causes of poor sedimentation and countermeasures thereto

-16-

Main ingredient in waste water by types of dye

Type of dye Main ingredient in waste water

Direct dye

Reactive dye

Acidic dye

Acidic mordant dye

Metal complex salt dye

Cationic dye

Sulfide dye

Vat dye

Naphthol dye

Disperse dye

Pigment

Dye, mirabilite, salt, sodium carbonate, surface active agent

Dye, sodium hydroxide, sodium phosphate, sodium hydrogencarbonate, mirabilite, urea, surface active agent

Dye, mirabilite, ammonium sulfate, acetic acid, sulfuric acid, surface active agent

Dye, acetic acid, mirabilite, sodium bichromate, surface active agent

Dye, sulfuric acid, sodium acetate, ammonium sulfate, mirabilite, surface active agent

Dye, sodium acetate, sodium carbonate, ammonium acetate, surface active agent

Dye, sodium sulfide, sodium carbonate, mirabilite

Dye, sodium hydroxide, sodium hydrosulfite, mirabilite, Turkey red oil

Dye, sodium hydroxide, hydrochloric acid, sodium nitrite, sodium acetate, surface active agent

Dye, carrier (various), hydrosulfite, surface active agent

Pigment, ammonia, sodium alginate, resin, mineral oil

NaO3S

SO3Na Cl

ClNH2

NH

O

O

N NNN

N

NH Cl

NHCOCH3

NH

N

O Cu O

NH2

NaO3S NaO3S

N

NN

SO3Na

N N

N

Cl

NH Cl

N N

N

SO3Na HO

NaO3S

SO3Na

SO2CH2CH2O SO3Na

Yellow 3

Red 6

Orange 1

Blue 19

-17-

Dye structure

Dye waste water treatment method

Dye ingredient separationSeparation by fi ltration: Membrane filtration,

coagulating sedimentation/floatationSeparation by adsorption: Activated carbon, ion

exchange

Dye ingredient decompositionOxidative decomposition: Chlorination, Fenton's

reagent, ozone, UVBiological decomposition: Aerobic bacteria, anaerobic

bacteria

NH

O3

Basic Violet 14

Ingigo Trisulfonate(Blue)

H

C

NH2H2N

CH3

O3

CO

NH2H2N

CH3

NHH

O

HSO3 C

O

NH

NH

CC C

SO3H

SO3H

O

NH

CO C

SO3H

SO3H

O

HSO3 C

O

NH

C O

Oxidative decomposition of dye by O3

-18-

Dye molecule

Electric charge neutralization

Colloidal insoluble substance

Decoloring agent addition

Polymer coagulant addition

Separation

Coagulation separation

Large floc generation

Coagulation separation(Sedimentation/Floatation)

Concept of large floc generation by cationic decoloring agent

SO3Na

SO3Na

NaSO3

OHOHN N

SO3(R2N(CH3)2)

SO3(R2N(CH3)2)

(R2N(CH3)2)SO3

3(R2N(CH3)2)Cl

OHOHN N

NaCl

Dye coagulation by cationic decoloring agent

-19-

010

10

100

1000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Comparison of decolorizing performance by cationic decoloring agent

-20-

Alizarin Rubinol R

Electric charge neutralization

max=530mm

Colloidal insoluble substance

Large floc generation

Large floc generation

Sedimentation separation/filtration

Separation

Absorbance measurement

Kuriflock PA365

150rpm for 60sec50rpm for 60sec

PACPoly-Cation APoly-Cation B

150rpm for 60sec

Procedure for Jar Test

NN

NNN

O O O

O

OOO

O

O

OO O

N

NN

N

N N NN

NN

NNNN

NN

N N N

Cucurbituril structure

-21-

8. Emulsion Polymer for Automated System

1) Features

Compared to conventional powder polymers, theEmulsion Polymer has the following features.Fine particles like that seen with conventional powderpolymers do not occur, which improves the workenvironment.

Highly soluble, it can be dissolved and ready to use ina few (5 - 10) minutes.As a liquid, it is very fluid, which makes it easier toadapt to automated systems and reduce labor.The chemical feeding unit is small in size.

2) Soluble behavior comparison between powderpolymer and EP (Emulsion Polymer)

Original state

High concentration liquid polymer

Water, Solvent

Polymer particle size: 0.005 mm (Approx. 5 _m)

Particle size: 1 - 0.1 mm

Dissolution startsimmediately.

Completelydissolved

Dispersed only.No major changesobserved

Small particle:Dissolves.

Large particle:Swells.

Large particle:Dissolution starts.

Completelydissolved

Powder

EmulsionPolymerEC/EN/EA

Powder

Dissolution process

After 10 min After 30 min After 60 minImmediately after

dispersion

Powder polymer requires about 1 hour to dissolve because of large particle. But, Emulsion Polymer is made of particles just a few microns in diameter, so it readily dissolves and can be used in about 5 - 10 minutes.

10

50

100

200 30

Dis

solu

tion

rate

(%

)

40 50 60

Emulsion Polymer(EC/EN/EA)

Powder polymer (Anionic polymer)

Conditions: Stirrer ... 300 rpmWater temperature: 20˚C

Time (min)

-22-

Merits of Emulsion Polymer

Emulsion Polymer

0.7 ~ 0.8 1.0 0.9

Kurifloc EN/EA Series,Kurifix EC Series

Powder polymerLiquid polymer

conventional polymer, high molecular weight

Bat

ch (

inte

rmitt

ent)

dis

solu

tion

Dissolution equipment • Dissolution tank• Stirrer• Deconcentrator• Deconcentrator incidentalequipment

• Dissolution tank• Stirrer

• Dissolution tank• Stirrer

Equipment cost ratio(Reference only)

Equipment cost ratio(Reference only)

0.2 1.0 1.8

Dissolution work After filling water• Weighing 2 - 3 min• Adding 5 - 10 sec• Dissolution stirring 5 - 10 minTotal 7 - 13 min

Time ratio (Reference only)

After filling water• Weighing and adding in hopper 2 - 3 min• Deconcentrator monitoring 5 - 10 sec• Dissolution stirring 30 - 60 min

37 - 73 min

After filling water• Weighing and adding 5 - 10 min

• Dissolution stirring 60 - 120 minTotal 65 - 130 min

Work environment • No scattered dust• simple scaffolding• Easily performed outdoors(in rain)

• Dusty• Requires slip prevention.• Not easily performedoutdoors (in rain)

Maintenance • Not required • Deconcentrator cleaning• Removal of coagulantscattered on scaffolding.

• No scattered dust• Requires scaffolding becauseof carrying about twenty timesas much as weight of powderpolymer.• Easily performed outdoors(in rain)

0.2 1.0 1.8

Dissolution equipment

Con

tinuo

us d

isso

lutio

n

• Stock solution storage tank• Stock solution stirrer• Stock solution feed pump• Dissolution tank• Chemicals feeding pump• Control panel

• Powder storage hopper• Powder feed conveyor• Weighing feeder• Automatic dissolutionequipment• Chemicals feeding pump• Control panel

• Stock solution storage tank• Stock solution feed pump• Dissolution tank• Storage tank• Chemicals feeding pump• Control panel

Work environment • Can be used outdoors. • Basically, designed forindoor use.

• Can be used outdoors.

-23-

3) Continuous dissolution equipment

Control systemThe equipment is designed to do the following whensolution surface level in the dissolution tank reaches Mlevel.

Feed constant amount of stock solution under timercontrol.

Add dissolving water until reaching level H.Run the stirrer for a set period of time.

Because of its good dispersability, the Emulsion Polymerdissolves in a short amount of time and dissolved

concentration changes little if any.Ensure a 3m3 stock solution storage tank for a 2ton

delivery. It should be made of either stainless steel orFRP. The stock solution can separate out, thereforeintermittent stirring is needed.

Note: If let still standing for a long period of time, theEmulsion Polymer particles will slowly precipitate out.Therefore, it is necessary to stir it periodically (approx.60 min/day) with a stirrer when storing. Also, theEmulsion Polymer remains chemically stable for 6months from the date of manufacture.

M LS

L LLL

M

H

LS

P P

Dissolving water

Stock solutionstorage tank

(3 m3) (1 m3)Dissolution-Storage tank

Stock solutionfeed pump(Mainly a kindof screw pump)

Feeding pump

-24-

4) Handling and cleaning

Avoid contact with water. Inclusion of a small quantityof water makes clods of polymer. Viscosity will riseextremely and the Emulsion Polymer will solidify.

CleaningPipes in stock solution can be flushed with kerosene tosome extent, but keep away from flames. If spilled,absorb it with sand or sawdust.

Wipe test equipments with paper or rag. Washing withwarm water or chlorine oxidizer is effective to cleanthem.

5) Applicable materials (Corrosion resistance)

Do not to use natural rubber, polyethylene,polypropylene or other similar materials in stocksolution circuit.

Material EP stocksolution

EPsolution

Powder polymersolution

EP stocksolution

EPsolution

Powder polymersolution

Material

EPDM, EPT(Ethylene, propylene rubber)NBR(Acrylonitrile-butadiene rubber)

Hyperon (CSM)

Polyethylene

SS41

BC-2 (Bronze)

SUS304

Hastelloy C

Polypropylene

Byton

Dylite

Hard polyvinyl chloride

FRP

Can be used. Cannot be used.

Plastic and rubber Metal

-25-

6) An example of application (1)

Application for slate factory1. Treatment flow

2. Results

3. Merits

Settling tankor

conical tankSupernatant tank

Raw material recovery

Raw materialsAsbestosCementPulp

Beater

Temperature controlling water

Wet machineWaste water

Coagulant Kurifix EA333

Waste water pit

VacuumProduct

Raw water quality Applicable coagulant

1.0

2.0 - 2.5

50 - 100

50 - 100

123

150Kurifloc EA333

Amount added(mg/l)

Anionic powder polymer ofCompany KWet machine waste water

pH 11 - 12SS 1000 - 3000 mg/l

Treated water turbidity(degree)

Chemicals cost (¥1,000/month)

[1] Greatly improved dissolution work

[2] Decrease of impurities (clods)in products

• Dissolution work: once every hour, 20 to 24 times a day(Dissolution tank: 100 l, storage tank: 200 l, no deconcentrator)• In case of anionic powder polymer of Company KWeighing and adding: 10 min/cycle (200 min/day), stirring: 1 hr/cycle (24 hr/day)• In case of Kurifloc EA333Weighing (Ladle) and adding: 0.5 min/cycle (10 min/day), stirring: 10 min/cycle (4 hr/day)

Some clods of approx. 1 mm in size, believed to be undissolved coagulant, had been found inproducts. After changing to Kurifloc EA333, most impurities were eliminated

Kurifloc EA333: Anionic EP (Emulsion Polymer)

-26-

An example of application (2)

Application to surplus sludge dewatering1. Results

2. MeritsDissolution work improvement Labor reductionBefore, 5 kg of a conventional powder polymer wasprepared from a 15 kg bag in a 3m3 tank 2 to 3 times aday. It took 2 hours to dissolve the polymer using adeconcetrator. However, the dissolution tank was locatedin a humid room and the deconcetrator sometimesclogged, requiring frequent maintenance and checks.Also, because the dissolution tank stirrer performedpoorly, it took time (5 to 10 min/cycle) to carefullydissolve all undissolved clods.With Kurifix EC153, a deconcentrator is unnecessaryand the polymer was dissolved in about 10 min withoutclods even just after adding it, which improved the workenvironment.

* Kurifix EC153: Cationic EP (Emulsion Polymer)

Chemicals cost(¥1,000/month)Cake water

content (%)Treatment amount

(kg-ds/m/hr)

Addition rate(%/SS)

Applicabledehydrating agent *

Kurifix EC153

cationic powder polymerof Company I

DehydratorTarget sludgeTreatment effect

90 - 100

100

320 - 350

380 - 420

1.0BP

2.0 - 2.5

85

85

* In addition to a polymer coagulant, 25%/SS polyiron sulfate (III) is used.

Surplus sludgeSS 0.7 to 0.8%VSS 70 to 75%Sludge amount ... 120 m3/day

-27-

An example of application (3)

Labor -savings through equipment improvements1. Results

2. Merits

1.5　450

3.0　900

7.5

7.5

83

83

7　25

7　25

1,300

850

590

1,180Before use

After use

Kurifix EC253

Various cationic powder polymers (Various manufactures)

Amount usedPrice￥/kg

Operating scheduleH/D D/M

Water content %

Treatment rate m3/hr

Chemicals addingrate %/SS ppmCoagulant

New equipments delivered by KWI ---3 m3 stainless steel stock solution tank (stirrer), 　　　　　　　　　　　　　　　　　　stock solution feed pump: a kind of screw pump, stator: synthetic rubberExisting equipments used --- Dissolution tank (stirrer), solution feed pump

* Kurifix EC253 = Cationic EP (Emulsion Polymer)

Dissolving water(Ground water)

Sludge feed

3 m3 stock solution tank

4 m3 stock solution tank

PPP P

P

P

Container loading

Dehydrator A Cake

Dehydrator B Cake

Dehydrator C Cake

Added part Existing equipments

Centrifugal dehydrator

P