Effective water treatment is crucial for public health and industrial operations. Coagulants are essential chemicals used to destabilize and aggregate impurities in raw water, making them easier to remove. Historically, Aluminum Sulfate (Alum) has been a workhorse coagulant. However, Polyaluminium Chloride (PAC) has emerged as a superior alternative, offering significant technical advantages and improved performance in many water treatment scenarios.

The primary function of both PAC and Alum is coagulation and flocculation. They achieve this by neutralizing the negative surface charges of suspended particles, allowing them to aggregate into larger flocs. These flocs can then be more readily removed through sedimentation and filtration. However, the chemical structure and properties of PAC provide distinct benefits.

One of the most significant advantages of PAC is its wider optimal pH range for coagulation compared to Alum. While Alum typically performs best in a narrower pH window (6.5-7.5), PAC can be effective over a broader range, often from 5.0 to 9.0. This flexibility is invaluable, as raw water pH can fluctuate due to various factors. A wider operating range means less need for pH adjustment chemicals, reducing overall treatment costs and complexity.

Furthermore, PAC generally produces a lower volume of sludge compared to Alum. Studies and practical applications indicate that PAC can generate 30-50% less sludge. This reduction is highly beneficial as it lowers disposal costs and reduces the burden on sludge treatment facilities. The flocs formed by PAC are also typically denser and more compact, leading to faster sedimentation rates and more efficient removal in clarification processes.

The residual aluminum levels in treated water are another critical factor. PAC consistently results in lower residual aluminum (often 0.05-0.1 mg/L) compared to Alum (0.3-0.5 mg/L). Lower residual aluminum is important for meeting drinking water standards and for applications where high water purity is required. This makes drinking water grade polyaluminium chloride a preferred choice for municipal water treatment.

When businesses decide to buy polyaluminium chloride, they are investing in a more efficient and cost-effective treatment solution. NINGBO INNO PHARMCHEM CO.,LTD. offers various grades of PAC, including high purity grade poly aluminium chloride, to meet diverse water treatment needs. Their expertise ensures that clients receive products that optimize performance. Comparing PAC vs. Aluminum Sulfate clearly demonstrates that while Alum remains a viable option, PAC offers a more advanced and often more economical approach to water purification, making it the coagulant of choice for many modern applications.