Polyferric Sulfate Effective Coagulant Wastewater Treatment

Polyferric Sulfate (PFS) , also referred to as polymeric ferric sulfate , is categorized as an iron-based inorganic polymer coagulant. It presents in solid form as either light yellow powder or granules, while its aqueous solution appears as a reddish-brown transparent solution. This chemical compound is characterized by high water solubility and is represented by the chemical formula [Fe ₂ (OH) _n (SO ₄ )(6-n)/2] _m , where n is less than 2 and m is greater than 10.

Features:

High Flocculation Efficiency: Polymeric Ferric Sulfate (PFS) demonstrates a remarkable ability to efficiently flocculate due to its strong adsorption properties. It forms large, dense flocs rapidly, resulting in quick settling for fast water clarification. In applications such as wastewater treatment, it can notably reduce water turbidity in a short timeframe.

Wide pH Adaptability: PFS shows effectiveness in pH levels ranging from 4 to 11. Its adaptability to low-temperature, low-turbidity water, and water within the pH range of 5 to 9 surpasses that of low-molecular iron and aluminum salts, making it less susceptible to fluctuations in water temperature and pH.

Strong Charge Neutralization Ability: With high-positive-charge iron(III) ions and polymeric species like Fe2(OH)3 3+, Fe2(OH)2 4+, and Fe3(OH)6 3+, PFS enhances charge neutralization capabilities. Its high cationic charge boosts surface activity, facilitating effective neutralization of suspended particles and forming larger aggregates for quicker sedimentation.

High Cost-Effectiveness: Compared to traditional inorganic coagulants, PFS delivers superior treatment outcomes with lower dosage requirements. Its cost per ton of water treatment is 30%-60% lower than that of conventional aluminum salts, leading to reduced treatment expenses.

Good Settling Performance: The flocs produced by the reaction of PFS with water are sizeable, dense, and settle rapidly. The resulting sludge exhibits good dewaterability, reducing sludge volume and simplifying subsequent sludge management processes.

Strong Adaptability: PFS is highly effective in treating various water types, including highly turbid water, low-turbidity water, water with high algal content, drinking water, and sewage.

Extended Shelf Life After Dissolution: Unlike some coagulants that lose efficacy shortly after dissolving, PFS maintains stability in solution for extended durations, allowing for better storage and utilization.

Self-Indicating Properties: Excessive dosage of PFS can be identified through its red coloration, aiding in preventing wastage and cost savings.

Applications:

Wastewater Treatment:
Polyferric sulfate (PFS) finds extensive application in wastewater treatment across industries such as papermaking, dyeing, electroplating, food processing, pharmaceuticals, fertilizers, and pesticides. It effectively eliminates pollutants like organic matter, suspended solids, heavy metal ions, phosphorus, and arsenic from wastewater, thereby lowering chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Additionally, it helps mitigate membrane fouling during reverse osmosis pretreatment of dyeing wastewater.

Drinking Water Purification:
PFS plays a crucial role in purifying drinking water by removing algae, iron ions, color, odor, and organic matter from raw water. This process enhances water quality and ensures the safety of drinking water. PFS's non-toxic and harmless properties prevent secondary water pollution and have no adverse effects on human health.

Sludge Dewatering:
When used in conjunction with small amounts of Polyacrylamide, PFS delivers outstanding results in sludge dewatering. It enhances dewatering efficiency and decreases sludge moisture content effectively.

Phosphorus Removal:
PFS can be a replacement for aluminum salts in wastewater treatment plants to eliminate residual aluminum pollution in drinking water and facilitate phosphorus removal from domestic sewage.

Other Applications:
Apart from the mentioned uses, PFS also serves in antimony removal from textile wastewater, arsenic removal, algae removal, iron reduction without phosphate compounds, and total aluminum removal. Its high efficiency demonstrates effectiveness in treating pollutants in municipal wastewater, slaughterhouse effluent, and meat processing effluent.