-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
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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
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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
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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
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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
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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
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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.
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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
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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
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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