Selecting the most effective coagulant is a critical decision for any water treatment facility. Two prominent inorganic polymer coagulants often considered are Aluminum Chlorohydrate (ACH) and Polyaluminum Chloride (PAC). While both serve the purpose of removing impurities, they possess distinct chemical characteristics that influence their performance and suitability for different applications. As a specialized chemical supplier, we aim to clarify these differences to help you make an informed choice.

Understanding Basicity and Al2O3 Content:

The key differentiators between ACH and PAC lie in their basicity and aluminum oxide (Al2O3) content, which directly impact their coagulating power.

  • Aluminum Chlorohydrate (ACH): ACH typically boasts a higher Al2O3 concentration, often around 23-24% in liquid form, and significantly higher basicity, typically ranging from 75% to 90%. Basicity refers to the ratio of hydroxide ions to aluminum, indicating the degree of polymerization and the net positive charge of the aluminum species. Higher basicity means a stronger positive charge, making ACH highly effective in neutralizing negatively charged particles in water.
  • Polyaluminum Chloride (PAC): PAC also offers enhanced polymerization compared to traditional alum but generally has a lower Al2O3 content (around 10-12% in liquid form) and lower basicity (often around 50%). While effective, its lower charge density may require higher dosages in certain challenging water conditions compared to ACH.

Performance Differences:

  • Floc Formation: ACH tends to form denser, faster-settling flocs, particularly beneficial in colder water temperatures where traditional coagulants may struggle.
  • pH Impact: Due to its higher basicity, ACH has a minimal impact on treated water pH, reducing the need for additional alkali compared to PAC, which can cause more significant pH depression.
  • Dosage Requirements: Generally, ACH can be used at lower dosages than PAC for achieving comparable water quality, leading to cost savings in chemical consumption and sludge handling.
  • Broad Applicability: ACH's strong performance across a wide pH range and varying water conditions makes it a versatile choice for diverse water sources.

Choosing the Right Coagulant:

For applications demanding superior performance, minimal pH impact, and reduced chemical usage, Aluminum Chlorohydrate is often the preferred choice. If cost is an extremely sensitive factor and water conditions are less demanding, PAC might be considered. However, for achieving the highest water quality and operational efficiency, particularly in challenging scenarios, investing in ACH as your primary coagulant is a strategic decision.

As a leading supplier, we offer both high-quality ACH and PAC. We encourage water treatment professionals to buy Aluminum Chlorohydrate from us for its proven advantages. Contact our technical sales team to discuss your specific water treatment challenges and determine the optimal coagulant for your facility.