An Overview of Water Treatment Chemicals: Classification and Core Functions

Water is the source of life, but the increasing water pollution and growing demand for clean water have made water treatment an indispensable part of modern society. Water treatment chemicals, as the core driving force of water purification processes, play a crucial role in removing pollutants, preventing equipment damage, and ensuring water quality meets relevant standards. This article provides a comprehensive overview of the classification and core functions of water treatment chemicals, laying a foundation for understanding their application and development.

Water treatment chemicals can be divided into several major categories based on their functions: coagulants and flocculants, corrosion and scale inhibitors, biocides and disinfectants, pH adjusters, and auxiliary agents. Coagulants and flocculants are the first line of defense in water treatment, which can aggregate fine suspended particles and colloidal substances in water into large flocs, facilitating sedimentation and filtration. Common products include aluminum sulfate, polyaluminum chloride (PAC), and polyacrylamide (PAM). Corrosion and scale inhibitors are mainly used in industrial circulating water systems, boilers, and pipelines to prevent metal corrosion and scale formation, thereby extending equipment service life and improving energy efficiency. Biocides and disinfectants are responsible for inactivating harmful microorganisms such as bacteria, viruses, and algae in water, ensuring the safety of drinking water and industrial water. pH adjusters are used to regulate the acidity and alkalinity of water, creating a suitable environment for other treatment chemicals to function. Auxiliary agents, including defoamers, sludge conditioners, and chelating agents, assist in optimizing the treatment process and improving treatment efficiency.

Each type of water treatment chemical has its unique working mechanism and application scenarios. For example, coagulants work by neutralizing the charge of colloidal particles, while flocculants promote the aggregation of flocs through bridging or netting effects. Corrosion inhibitors form a protective film on the metal surface to isolate the metal from corrosive media, and scale inhibitors inhibit the crystallization and growth of scale-forming ions by chelation, dispersion, or lattice distortion. Disinfectants kill microorganisms through oxidation, alkylation, or other reactions. Understanding the classification and functions of these chemicals is essential for selecting appropriate products in practical water treatment projects and achieving efficient and economical water purification.