Anionic Polyelectrolyte, Anionic Poly Electrolite, Anionic Polyacrylamide, Polyacrylamide, Anionic Flocculant, PAM, APAM, 9003-05-8

Anionic Polyelectrolyte, Anionic Poly Electrolite, Anionic Polyacrylamide, Polyacrylamide, Anionic Flocculant, PAM, APAM, 9003-05-8

ANIONIC POLYELECTROLYTE (ANIONIC POLYACRYLAMIDE - APAM)
PRODUCT IDENTIFICATION INFORMATION

CHEMICAL STRUCTURE

Anionic Polyacrylamide (APAM)

—(CH₂—CH)—(CH₂—CH)—
| |
C=O C=O
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NH₂ O⁻Na⁺
(Amide) (Carboxylate)

Molecular Formula: (C₃H₅NO)ₙ (with carboxylate groups on some monomers)
SMILES: Not applicable (polymer)
InChI: Not applicable (polymer)
Structure: Polyacrylamide chain with anionic groups (carboxylate -COO⁻, sulfonate -SO₃⁻) attached; High molecular weight linear polymer; Anionic charge density can be adjusted during production.

SECTION 1: CHEMICAL IDENTITY AND DESCRIPTION

SECTION 2: PHYSICAL AND CHEMICAL PROPERTIES

SECTION 3: POLYELECTROLYTE TYPES AND COMPARISON

SECTION 4: FORMS AND CHARACTERISTICS

SECTION 5: CHEMICAL PROPERTIES AND REACTIVITY

SECTION 6: PRODUCTION METHODS

Method 1: Solution Polymerization

Reaction: n(CH₂=CHCONH₂) → (CH₂-CHCONH₂)ₙ

Description: Acrylamide monomer is dissolved in water; Initiator (persulfate, AIBN, redox system) is added; Polymerization proceeds at controlled temperature (30-60°C); Partial hydrolysis introduces carboxylate groups; The polymer solution is dried and ground to powder form. Most common industrial method.

Method 2: Emulsion Polymerization

Process: Acrylamide monomer (aqueous) + Oil phase + Emulsifier → Polymerization → Emulsion product

Description: Acrylamide monomer solution is emulsified in oil phase with surfactant; Polymerization initiated in the aqueous droplets; Produces high molecular weight polymers with rapid dissolution; Used to produce emulsion form products.

Method 3: Bulk Polymerization

Process: Monomer + Initiator → Bulk polymerization → Grinding

Description: Acrylamide is polymerized in bulk (without solvent); Produces very high molecular weight polymers; Product is ground to powder; Requires careful temperature control.

Method 4: Hydrolysis and Modification

Process: Polyacrylamide + NaOH → Hydrolyzed polyacrylamide (anionic)

Description: Polyacrylamide is treated with sodium hydroxide to introduce carboxylate groups; Degree of hydrolysis (charge density) is controlled by NaOH concentration and reaction conditions; Produces anionic products with tailored charge density.

SECTION 7: FUNCTIONAL PROPERTIES AND MECHANISM OF ACTION

SECTION 8: APPLICATION PROCESS - STEP BY STEP

8.1 Wastewater Treatment (Municipal & Industrial)

Application Type: Post-Coagulation Flocculation + Sludge Dewatering

Process Flow:

1. Pre-Coagulation (Chemical): Cationic coagulant added to wastewater (FeCl₃, Al₂(SO₄)₃, PAC); Rapid mixing (1-3 min, 200-400 rpm) neutralizes charges; pH adjusted to 6-8 (depending on coagulant type).

2. Anionic Polyelectrolyte Preparation: Powder: Prepare 0.1-0.2% solution; Sprinkle powder slowly onto water surface; Mix at low speed for 30-60 minutes (to prevent lumps). Emulsion: Direct dilution to 0.1-0.5% solution; 5-10 minutes mixing is sufficient.

3. Dosing to Flocculation Unit: Dosage: 1-10 ppm (mg/L) active polymer (depending on wastewater characteristics); Injection point: Immediately after coagulant addition, into slow mixing zone (flocculator); Slow mixing (20-40 rpm, 10-20 minutes) to grow flocs.

4. Sedimentation (Lamella or DAF): Formed flocs settle by gravity or float with DAF (Dissolved Air Flotation); Settling time: 1-4 hours (lamella reduces time).

5. Sludge Dewatering: Settled sludge (2-5% solids) sent to belt press, centrifuge, or filter press; Additional anionic polyelectrolyte added to sludge (2-8 kg/ton dry solids); Dewatering increases cake solids to 15-40%.

Critical Points: Overdosing causes floc dispersion; Temperature <10°C increases dissolution time; Centrifuge speed must match floc strength.

8.2 Drinking Water Treatment

Application Type: Low Turbidity Water - Coagulation Aid

Process Flow:

1. Coagulation: Aluminum sulfate or ferric chloride added (10-50 ppm).

2. pH Adjustment: Adjust to 6.5-7.5 (optimal for anionic polymer).

3. Anionic Polyelectrolyte Preparation: Low dosage (0.1-1 ppm); Prepare dilute solution (0.05-0.1%); Powder requires ≥45 minutes dissolution.

4. Injection: 1-2 minutes after coagulant, into flocculation tank.

5. Slow Mixing: 10-15 minutes; Floc size reaches 1-5 mm.

6. Sedimentation and Filtration: Settling basin (30-60 min) before sand filter or membrane.

7. Disinfection: Chlorine/UV.

Note: Polymer residue must be <0.5 ppm; Acrylamide monomer residue must be <0.01% for drinking water grade products.

8.3 Paper and Pulp Industry

Application 1: Fiber Recovery from White Water

Process: White water (0.1-0.5% fiber) from paper machine collected; Anionic polyelectrolyte solution (0.1%) prepared; Dosage: 0.5-2 ppm (by water volume); DAF unit floats and skims flocs from surface; Recovered fiber returned to pulp.

Application 2: Filler Retention Improvement

Process: Filler suspension (Kaolin, CaCO₃) treated with anionic polyelectrolyte (50-200 g/ton filler); Polymer holds filler particles on fiber surface; Improves paper opacity and strength; Equipment: Static mixer or low-shear dynamic mixer.

8.4 Oil and Gas Industry

Application: Produced Water Treatment (Oil-Water Separation)

Problem: Produced water from well (10-90% water + oil + solids) is emulsified.

Solution:

1. Pre-Separation: Free water and gas removed in three-phase separator.

2. Chemical Dosing: Anionic polyelectrolyte solution (0.05-0.1%) injected; Dosage: 5-50 ppm (depending on emulsion stability); Usually used with demulsifier.

3. Mixing: Static mixer or in-line mixer for 1-2 seconds contact.

4. Settling Tank (Gunbarrel or API separator): Hold-up time 30-120 minutes; Oil floats to top; Water and flocculated solids removed from bottom.

5. Water Treatment: Separated water undergoes additional flocculation or filtration before discharge.

Drilling Fluid Application: Anionic polyelectrolyte (100-500 ppm) added to drilling mud; Viscosity increases; Solid particles (rock cuttings) stabilized; Performance decreases at high salinity; Salt-tolerant grades required.

8.5 Mining Industry

Application: Tailing Flocculation and Dewatering

Example: Copper, Gold, Coal

1. Flotation: Ore ground; Valuable mineral separated by froth flotation.

2. Tailing Suspension: Flotation tailing contains 10-40% solids.

3. Anionic Polyelectrolyte Preparation: Very high molecular weight product (>15 million Da); 0.05-0.1% solution; 45-60 minutes dissolution.

4. Dosage: 20-200 g/ton dry solids (optimized by jar test).

5. Injection: Into thickener feed pipe with static mixer.

6. Thickener (Conical or Inclined Plate): Slow rotating agitator (0.1-1 rpm) supports floc formation; Clear water overflows (recovered); Sludge removed from bottom.

7. Tailings Dam Pumping: Dewatered tailing pumped to dam.

Coal Washing Specific: Fine coal particles (<0.5 mm) flocculated after flotation; Dewatered with filter press or centrifuge.

8.6 Textile Industry

Application: Dye Bath Wastewater Treatment

Process:

1. Equalization Tank: Colored wastewater (pH 8-12, high COD) collected.

2. pH Adjustment: Reduced to 6-8 with acid or base.

3. Coagulation (Optional): FeCl₃ or Al₂(SO₄)₃ added for high color removal (100-500 ppm).

4. Anionic Polyelectrolyte Dosage: 0.1% solution; Dosage 2-10 ppm.

5. Slow Mixing: Floc formation (10-15 min).

6. Sedimentation or DAF: Colored flocs settle.

7. Dewatering: Sludge pressed into cake with filter press.

Note: Reactive dyes are anionic; Direct flocculation with anionic polymer is weak; Cationic coagulant is required first.

8.7 Agriculture and Irrigation

Application: Suspended Solids Removal for Irrigation (Filter Protection)

Process (Especially Drip Irrigation):

1. Water Source: River, pond, or well water (turbidity 10-500 NTU).

2. Anionic Polyelectrolyte Preparation: Low molecular weight grade (5-8 million Da); 0.05% solution connected to injection pump.

3. Dosage: 0.5-2 ppm (depending on turbidity).

4. Injection Point: After pump outlet, before disk or sand filter.

5. Flocculation Pipe: 10-20 meter straight pipe allows floc growth.

6. Filtration: Disk filter (130 micron) or sand filter traps flocs.

7. Backwash: Filter automatically backwashed for cleaning.

8. Benefit: Reduced dripper clogging; Lower filter washing frequency.

8.8 Sugar Industry (Beet/Cane)

Application: Raw Syrup Purification (After Carbonation)

Process (Beet Sugar Example):

1. Diffusion: Raw syrup extracted from beets (cloudy, contains calcium, pectin).

2. Liming and Carbonation: Lime (CaO) added; CO₂ precipitates CaCO₃.

3. Anionic Polyelectrolyte Dosage: 0.05-0.1% solution prepared; Dosage: 5-20 ppm (based on syrup volume); Injection after carbonation tank outlet.

4. Flocculation: CaCO₃ and impurities form flocs.

5. Filtration: Pressure filter (or vacuum drum filter) clarifies syrup.

6. Decolorization and Crystallization: Clear syrup proceeds to further processing.

Note: Temperature is 70-85°C; Polymer thermal stability must be monitored.

8.9 Metal Recovery (Electrolytic Precipitation)

Application: Particle Flocculation in Metal-Containing Wastewater

Example: Copper Recovery

1. Wastewater: pH 2-5, Cu²⁺ 100-1000 ppm.

2. pH Raise: Lime or NaOH raises pH to 6-7; Copper hydroxide precipitates (fine particles).

3. Anionic Polyelectrolyte Dosage: 5-20 ppm; 0.05% solution.

4. Flocculation: Slow mixing in flocculation tank.

5. Sedimentation: Large flocs settle rapidly.

6. Filtration: Filter press produces cake; Cake sent to metal recovery facility.

8.10 Coal Washing (Thickening)

Application: Flotation Tailings Dewatering

Steps:

1. Coal Flotation: Fine coal (<0.5 mm) separated by froth; Waste (shale, clay) remains in water.

2. Waste Suspension: 5-15% solids, very fine clay particles.

3. Anionic Polyelectrolyte Preparation: High molecular weight (>12 million Da) product.

4. Dosage: 50-300 g/ton dry solids.

5. Thickener: Conical tank 10-30 meters diameter; Flocs settle to bottom; Clear water overflows (recovered); Underflow sludge (40-60% solids) goes to filter press or dam.

6. Final Dewatering: Filter press increases cake solids to 70-80%.

8.11 Phosphoric Acid Production (Gypsum Separation)

Application: Calcium Sulfate (Gypsum) Flocculation in Crude Acid

Process:

1. Phosphate Rock Acid Reaction: Phosphoric acid produced; By-product CaSO₄·2H₂O (gypsum) forms.

2. Reaction Mixture: Acid (25-30% P₂O₅) + gypsum crystals + impurities.

3. Anionic Polyelectrolyte Dosage: Special grade with high temperature (70-80°C) and low pH (1.5-2) tolerance; Dosage 10-50 ppm.

4. Thickener: Gypsum flocs settle; Clear acid overflows.

5. Gypsum Washing and Filtration: Gypsum cake filtered; Acid recovered.

SECTION 9: QUALITY SPECIFICATIONS

SECTION 10: TOXICOLOGICAL PROFILE

SECTION 11: GHS CLASSIFICATION AND LABELING

GHS Classification (in accordance with CLP and UN GHS):

SIGNAL WORD: NONE (not classified as hazardous)

Hazard Pictograms: NONE

Hazard Statements (H-Codes): Not classified as hazardous under GHS regulations.

NFPA 704 Hazard Classification:

SECTION 12: PRECAUTIONARY STATEMENTS (P-CODES)

SECTION 13: FIRST AID MEASURES

SECTION 14: FIREFIGHTING MEASURES

SECTION 15: STORAGE AND SHELF LIFE

SECTION 16: PACKAGING OPTIONS

SECTION 17: TRANSPORT INFORMATION

SECTION 18: REGULATORY STATUS

SECTION 19: OTHER NAMES AND SYNONYMS

SECTION 20: SUMMARY TABLE

SECTION 21: CRITICAL WARNINGS AND BEST PRACTICES

CRITICAL WARNINGS:

• Not classified as hazardous under GHS. Non-toxic, non-carcinogenic.

• Hygroscopic – absorbs moisture from air. Store in tightly closed, moisture-proof containers.

• Dust may cause mechanical irritation to eyes, skin, and respiratory system. Use appropriate dust control measures.

• Combustible (organic material). Keep away from open flames and high heat. Dust cloud may form explosive mixture.

• Shear-sensitive – high molecular weight chains break under high shear. Avoid high-speed mixing. Use gentle agitation (200-400 rpm).

• Temperature sensitive – performance decreases above 40°C. Degradation accelerates >60°C.

• Dissolution method critical – ALWAYS ADD POWDER TO WATER, NEVER ADD WATER TO POWDER. Add slowly with agitation to prevent lump formation.

• Solution stability – prepare fresh solutions daily. Maximum 24-48 hours with continuous agitation.

• Acrylamide monomer residue – neurotoxic in monomer form. Drinking water grade requires <0.01% residue.

BEST PRACTICE RECOMMENDATIONS:

Solution Preparation (Powder Form - CRITICAL):

• ALWAYS ADD POWDER TO WATER, NEVER ADD WATER TO POWDER.

• Use cold or warm water (10-30°C, max 40°C).

• Sprinkle powder slowly onto vigorously agitated water surface (vortex).

• Maintain low to medium agitation (200-400 rpm) – avoid high shear.

• Allow 30-60 minutes for complete dissolution.

• Solution concentration: 0.1-0.5% recommended.

• Use fresh solutions within 24-48 hours (with gentle agitation).

Solution Preparation (Emulsion Form):

• Directly dilute with cold or warm water.

• Mix for 5-10 minutes only.

• Use within 24-48 hours.

• Protect from freezing (emulsion breaks irreversibly).

Dosage Optimization:

• Perform jar tests to determine optimal dosage.

• Optimal dosage: largest flocs + clearest supernatant.

• Underdosing: small flocs, slow settling.

• Overdosing: floc dispersion, turbid water.

• Factors affecting dosage: solids concentration, particle size, pH, temperature, ionic strength.

Injection Point:

• Inject after coagulant addition (if used).

• Inject into slow mixing zone (not high shear area).

• Avoid injection before high-shear pumps (centrifugal pumps).

• Use static mixer or low-shear dynamic mixer.

Equipment Selection:

• Static mixer: low shear, good mixing.

• Slow rotating paddle mixer: protects flocs.

• Dosing pumps: peristaltic or progressive cavity pumps (avoid high-shear pumps).

Wastewater Treatment:

• Always use with cationic coagulant first (FeCl₃, Al₂(SO₄)₃, PAC).

• Coagulant dosage: optimize for charge neutralization.

• Flocculation: 10-20 minutes slow mixing.

• Sedimentation: allow sufficient retention time.

Sludge Dewatering:

• Dosage: 2-8 kg/ton dry solids (optimize by jar test).

• Inject directly into sludge stream before dewatering equipment.

• Belt press: optimize polymer dosage for cake solids.

• Centrifuge: adjust speed and differential for floc strength.

• Filter press: build cake progressively.

Textile Wastewater:

• Reactive dyes require cationic coagulant first.

• Anionic polymer bridges neutralized particles.

• pH adjustment to 6-8 essential.

Mining Applications:

• Use very high molecular weight grades (>15 million Da).

• Higher dosage for high clay content (up to 300 g/ton).

• Thickener feed pipe injection with static mixer.

Handling:

• Use in well-ventilated areas.

• Avoid dust formation.

• Use dust masks (N95/FFP2) when handling powder.

• Use gloves and safety goggles.

Personal Protective Equipment:

• Dust mask (N95/FFP2 or higher).

• Safety goggles.

• Protective gloves (nitrile, neoprene).

• Protective clothing.

Hygiene:

• Wash hands thoroughly after handling.

• Do not eat, drink, or smoke while using.

Storage:

• Store in tightly closed, moisture-proof containers (PE bags, fiber drums).

• Store in a cool, dry, well-ventilated area.

• Protect from direct sunlight, moisture, and high humidity.

• Opened packages should be resealed immediately.

• Emulsion: protect from freezing (5-30°C).

Spill Management:

• Sweep or vacuum (HEPA) and place in suitable sealed container.

• Avoid dust formation.

• Do NOT wash with water (creates slippery surface).

• Do not allow entry into drains or waterways.

Disposal:

• Dispose of in accordance with local, regional, and national regulations.

• Non-hazardous waste.

• Can be incinerated in compliance with regulations.

SPECIAL NOTE ON FLOCCULATION MECHANISM:

The flocculation process with anionic polyelectrolyte involves four stages:

Mechanism Details:

• Bridging: High molecular weight polymer chains adsorb onto multiple particles; Creates agglomerates.

• Charge Neutralization (Auxiliary): Anionic polymers are not for direct charge neutralization; Optimized for bridging after coagulation.

• Adsorption: Polymer chains attach to particle surfaces via hydrogen bonds and van der Waals forces.

SPECIAL NOTE ON DRINKING WATER GRADE:

For drinking water applications:

• Certification: NSF/ANSI 60 certified products required.

• Acrylamide Monomer Residue: ≤ 0.01% (strictly controlled).

• Heavy Metals: Strict limits (Pb ≤ 5 ppm, As ≤ 1 ppm).

• Polymer Residue: Must be <0.5 ppm in treated water.

• Injection: Low dosage (0.1-1 ppm) only.

• Filtration: Sand filter or membrane after flocculation.

• Disinfection: Chlorine or UV after polymer addition.

SPECIAL NOTE ON ENVIRONMENTAL AND SUSTAINABILITY:

LEGAL DISCLAIMER:
The information provided in this document is based on our current knowledge and experience and is presented in good faith. However, as all conditions of use are beyond our control, it does not constitute a binding specification or warranty. This Technical Data Sheet is for informational purposes only. Users are responsible for testing the suitability for their own applications. For complete safety, storage, use, handling, waste, and regulatory compliance information, please refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. Specific applications require laboratory jar tests and field trials. Please consult the manufacturer's technical support team for application-specific recommendations.