What is the main purpose of using coagulants in water treatment?

• A. Improve solubility of contaminants
• B. Reduce pathogen levels
• C. Form larger aggregates of particles
• D. Enhance oxygen levels

Answer: (C)

The primary purpose of using coagulants in water treatment is to form larger aggregates of particles, a process known as coagulation. Coagulants help to destabilize fine particles suspended in water, allowing them to clump together into larger masses or flocs. Once these flocs are formed, they can be more easily removed from the water during the subsequent filtration or sedimentation processes. This is crucial for improving water clarity and quality, as it effectively reduces the concentration of suspended solids, which can include various pollutants and particulates.

While other methods of water treatment also contribute to different aspects of water quality, such as reducing pathogen levels or improving the solubility of contaminants, they do not specifically target the clumping of particles like coagulants do. Similarly, while enhancing oxygen levels is important for aerobic treatment processes, it is not the primary function of coagulants in water treatment.