Which of the following is a coagulant?

Coagulants are substances that promote the aggregation of particles in water, helping to remove suspended solids and clarify water during treatment processes. Aluminum sulfate, commonly known as alum, acts as a coagulant by neutralizing the negative charges on suspended particles, allowing them to clump together and settle out of the water.

Ferric chloride also functions as a coagulant and is often used in water treatment facilities. Similar to aluminum sulfate, ferric chloride aids in the coagulation process by facilitating the aggregation of particulates. When introduced into water, it reacts with hydroxides to produce flocs that can then be easily removed from the water.

Both aluminum sulfate and ferric chloride effectively serve as coagulants in water treatment processes, making their identification as coagulants crucial for the understanding of water treatment operations. Recognizing that both options provided are indeed coagulants leads to the conclusion that both substances contribute to the fundamental processes of water purification.