Coagulants are substances that help particles in a liquid clump together, making them easier to remove. They are commonly used in water treatment processes to improve water quality by removing impurities and suspended solids. Common coagulants include alum and iron salts, which work by neutralizing the charges on particles, allowing them to aggregate. In addition to water treatment, coagulants are also used in various industries, such as food production and pharmaceuticals. For example, in cheese-making, coagulants like rennet help milk proteins coagulate, forming curds. This process is essential for producing many dairy products.