At what pH range is coagulation most effective?

Coagulation is a critical process in water treatment where particles are removed from the water to improve its clarity and quality. The effectiveness of coagulation is significantly influenced by pH levels, as pH affects the charge of particles in the water and the solubility of coagulants.

In the range of 5.5 to 8.0, coagulation is most effective because this is where many commonly used coagulants, such as aluminum sulfate (alum) and ferric chloride, operate optimally. At this pH range, the coagulants can effectively neutralize charges on suspended particles, allowing them to aggregate and form larger flocs that can settle or be filtered out of the water.

Lower pH levels, such as 3.0 to 4.5 or 4.5 to 5.5, can inhibit the coagulation process. At these lower pH levels, there is a higher concentration of hydrogen ions that can lead to the coagulant being more soluble and less effective at binding particles. Additionally, at the upper range of 8.0 to 10.0, the conditions may lead to the precipitation of coagulants, reducing their availability for effective coagulation.

Therefore,