👉 The process of removing or reducing contaminants from a substance, typically by using chemicals and equipment to remove them. In the context of environmental science, it is often used in the field of water treatment and waste management, where the goal is to reduce the concentration of harmful substances in water and other substances in order to improve its quality and safety for human consumption or industrial use. For example, a general term that can be applied to this process is "dechlorination," which involves using chemicals to remove chlorine