Quick-Pick by System
| Sludge Type | Primary Conditioner | Polymer | Dewatering Method | Target Cake Solids |
|---|---|---|---|---|
| Municipal secondary (WAS) | — | CPAM 50–60% charge, Mw 6–8M | Belt press / centrifuge | 18–22% |
| Municipal primary + secondary mixed | — | CPAM 40–50% charge, Mw 8–10M | Belt press | 20–25% |
| Municipal anaerobic digested sludge | — | CPAM 30–40% charge, Mw 10–12M | Centrifuge | 22–28% |
| Industrial (paper mill fiber sludge) | Alum / PAC pre-treatment | CPAM 20–30% charge, Mw 10M | Belt press / filter press | 25–35% |
| Industrial (metal hydroxide sludge) | FeCl₃ + lime, pH 9–10 | CPAM 30% low dose | Filter press | 35–45% |
| Food/beverage processing sludge | PAC or chitosan | CPAM or chitosan polymer | Belt press | 18–25% |
| Mining tailings (fine) | Lime / pH adjustment | APAM high Mw 18–22M | Thickener + filter | 60–75% (filter cake) |
| Chemical / pharmaceutical sludge | FeCl₃ pre-conditioning | CPAM high charge 60% | Filter press / centrifuge | 30–40% |
All Grades (by chemistry class)
Cationic Polyacrylamide (CPAM) — Belt Press, Centrifuge, Filter Press Grades(3)
The primary polymer conditioner for biological sludge. Municipal WAS sludge is highly anionic (zeta potential −20 to −40 mV) due to EPS and cell wall components — CPAM neutralizes this charge and bridges particles into large, rigid flocs that release water under mechanical pressure. Belt press requires medium-MW (6–8M), high-charge (50–60%) CPAM that forms quick-releasing flocs; centrifuge needs lower-MW (5–7M) for faster dissolution; filter press tolerates higher-MW for stronger cake structure.
sludge conditioners
Cationic PAM for Sludge Dewatering (High Charge 60–80%)
CAS: 69418-26-4
High charge density cationic PAM specifically optimized for mechanical sludge dewatering. Produces drier cake and clearer filtrate on centrifuges, belt presses and filter presses.
View Details →flocculants
Cationic Polyacrylamide (CPAM) — High Charge Density
CAS: 69418-26-4
High charge density cationic PAM (60–80% cationicity) for challenging sludge with high organic content. Superior charge neutralization for oily, colloidal and bio-sludge systems.
View Details →flocculants
Cationic Polyacrylamide (CPAM) — Medium Charge Density
CAS: 69418-26-4
Medium charge density cationic PAM (30–50% cationicity), the workhorse grade for centrifuge and belt press sludge dewatering across municipal and industrial applications.
View Details →Inorganic Conditioners — FeCl₃ Solution & PAC(2)
Ferric chloride (FeCl₃, 38–40% solution) and PAC are used as primary or pre-conditioning agents for industrial sludges with low organic content or high metal loading. FeCl₃ lowers pH to 3–5 (breaking gel structure), forms Fe(OH)₃ colloids that co-precipitate with sludge particles, and significantly reduces filterability resistance. PAC is milder (less pH drop) and preferred when downstream reuse requires lower iron content in centrate.
sludge conditioners
Ferric Chloride for Sludge Conditioning
CAS: 7705-08-0
Ferric chloride solution used as inorganic sludge conditioner before filter press dewatering. Improves filtration rate and cake dryness, especially for biological sludge.
View Details →sludge conditioners
PAC for Sludge Conditioning
CAS: 1327-41-9
Polyaluminum chloride used as sludge conditioner for alum sludge and drinking water sludge. Improves dewatering without adding iron coloration to the cake.
View Details →Lime / Quicklime — Alkaline Deep Conditioning(1)
Quicklime (CaO) or hydrated lime Ca(OH)₂ raises sludge pH to 12+ for pathogen kill (Class A biosolids), destroys EPS matrix, and dramatically improves dewaterability via calcium bridging between sludge particles. Lime conditioning is the standard pre-treatment for sludge landfill or agricultural land application. Lime + FeCl₃ combination (dual conditioning) is widely used in European and US municipal STPs for filter-press dewatering to 35–45% cake solids.
Natural / Bio-based — Chitosan Bioflocculant(1)
Chitosan (deacetylated chitin, 85–95% deacetylation degree) is a natural cationic polymer that conditions sludge from food processing, brewery, and aquaculture without introducing synthetic polyacrylamide residuals. Approved for food-contact wastewater and biosolids intended for agricultural reuse in jurisdictions with PAM restrictions. Dose is 3–10× higher than CPAM for equivalent dewaterability; best combined with PAC as primary coagulant.
High-MW Anionic PAM — Mining Tailings & Industrial Thickening(1)
Ultra-high molecular weight anionic PAM (Mw 18–22M, hydrolysis 20–30%) is the conditioner of choice for mineral tailings where solids are negatively-charged fine particles (coal, iron ore, copper flotation tailings). Works by long-chain bridging across large inter-particle gaps. Dosed into thickener feed at 20–100 g/ton ore to achieve overflow clarity <100 mg/L TSS and underflow density 60–75% solids.
Imported Brand → China Equivalent
Equivalents are indicative; verify against TDS for project-critical applications.
| International Brand Grade | China Equivalent | Major Chinese Producers |
|---|---|---|
| SNF Flopam EM 640 (CPAM emulsion, 50% charge) | CPAM emulsion 50% charge Mw 7M | 山东诺尔生物、安徽巨成、河北邯郸顺天 |
| BASF Zetag 4145 (CPAM, sludge dewatering) | CPAM powder 50–60% charge Mw 6M | 山东诺尔生物、巩义恒泰、安徽巨成 |
| Kemira Superfloc C-494 (CPAM centrifuge) | CPAM 40% charge Mw 8M for centrifuge | 巩义恒泰、河北邯郸顺天 |
| Veolia Hydrex 8170 (CPAM belt press) | CPAM 60% high-charge belt press grade | 安徽巨成、山东诺尔生物 |
| Kemira PIX-313 (FeCl₃ 40% solution) | FeCl₃ 38–40% solution | 山东天力净水、江苏聚仕、河南天旭 |
| Kemira Kemfloc A5 (PAC sludge grade) | PAC 28–30% Al₂O₃ sludge conditioning grade | 巩义市净水材料、河南瑞洁 |
| SNF Flopam AN934 SH (APAM tailings) | APAM high Mw 20M, hydrolysis 25% | 东营信亨、山东诺尔生物、巩义恒泰 |
| Chitosan Solutions ClearFloc C-200 (chitosan) | Chitosan 90% deacetylation, Mw 200K | 青岛明月海洋生物、南通罗斯海洋 |
Frequently Asked Questions
▶How do I select the right CPAM charge density for my sludge?
Run a jar test with 5 charge densities (20%, 30%, 40%, 50%, 60%) at fixed dose. The optimum charge is the one giving lowest CST (Capillary Suction Time) — typically 40–60% for municipal WAS and 20–30% for digested or mixed primary-secondary sludge.
How do I select the right CPAM charge density for my sludge?
Run a jar test with 5 charge densities (20%, 30%, 40%, 50%, 60%) at fixed dose. The optimum charge is the one giving lowest CST (Capillary Suction Time) — typically 40–60% for municipal WAS and 20–30% for digested or mixed primary-secondary sludge.
▶When should I use FeCl₃ or lime instead of polymer?
Use FeCl₃ + lime for filter-press dewatering of industrial inorganic sludge to >35% cake solids, or when high-strength Class A biosolids (pH 12+ for 30 min) are required. Polymer alone rarely achieves >30% cake solids without inorganic pre-conditioning for difficult industrial sludges.
When should I use FeCl₃ or lime instead of polymer?
Use FeCl₃ + lime for filter-press dewatering of industrial inorganic sludge to >35% cake solids, or when high-strength Class A biosolids (pH 12+ for 30 min) are required. Polymer alone rarely achieves >30% cake solids without inorganic pre-conditioning for difficult industrial sludges.
▶What is CST and how do I use it to optimize conditioner dose?
CST (Capillary Suction Time, seconds) measures how fast water drains from conditioned sludge into blotting paper under capillary force. Lower CST = better dewaterability. A CST below 80 s indicates acceptable conditioning; below 40 s is excellent. Run a dose ladder (1, 3, 5, 8, 12 kg/ton DS) and plot CST vs dose — the optimum is the dose at the CST minimum.
What is CST and how do I use it to optimize conditioner dose?
CST (Capillary Suction Time, seconds) measures how fast water drains from conditioned sludge into blotting paper under capillary force. Lower CST = better dewaterability. A CST below 80 s indicates acceptable conditioning; below 40 s is excellent. Run a dose ladder (1, 3, 5, 8, 12 kg/ton DS) and plot CST vs dose — the optimum is the dose at the CST minimum.
▶Why does my CPAM make good flocs in the jar test but poor cake in the belt press?
Belt press flocs must survive shear in the polymer dosing pump, mixing zone, and belt nip points. Over-mixed or too-high-MW polymer forms fragile flocs that break under press shear. Reduce polymer dilution pipe length, lower mixing G-value, or switch to a lower-MW higher-charge CPAM more resistant to shear breakage.
Why does my CPAM make good flocs in the jar test but poor cake in the belt press?
Belt press flocs must survive shear in the polymer dosing pump, mixing zone, and belt nip points. Over-mixed or too-high-MW polymer forms fragile flocs that break under press shear. Reduce polymer dilution pipe length, lower mixing G-value, or switch to a lower-MW higher-charge CPAM more resistant to shear breakage.
▶What documents are available — COA, MSDS, TDS?
Standard: COA, MSDS/SDS, TDS for every grade. For food/agricultural-reuse biosolids, CPAM PAM monomer content certificate (acrylamide <0.05%), NSF/ANSI 60, EU EN 1407, or GB/T 17514 compliance letters available on request.
What documents are available — COA, MSDS, TDS?
Standard: COA, MSDS/SDS, TDS for every grade. For food/agricultural-reuse biosolids, CPAM PAM monomer content certificate (acrylamide <0.05%), NSF/ANSI 60, EU EN 1407, or GB/T 17514 compliance letters available on request.