Water treatment chemicals are substances used to enhance the of water by removing reducing impurities, contaminants, and undesirable substances. These chemicals are employed in various stages of the water treatment process, including purification, disinfection, coagulation, flocculation, sedimentation, filtration, and pH adjustment.

Here are some commonly used water treatment chemicals:

1. Coagulants: These chemicals, such as aluminum sulfate (alum) or iron salts, are added to water to destabilize suspended particles and form larger, solid flocs that can be easily removed.

2. Flocculants: Flocculating agents, such as polyacrylamide or polydiallyldimethylammonium chloride (polyDADMAC), are used to enhance the agglomeration of particles into larger clumps or flocs for easier separation.

3. Disinfectants: Chlorine compounds, such as chlorine gas, sodium hypochlorite, or chlorine dioxide, are commonly used as disinfectants to kill or inactivate harmful microorganisms in water.

4. pH Adjusters: Acidic or alkaline chemicals, like sulfuric acid or sodium hydroxide, are employed to adjust and maintain the pH of water within the desired range for optimum treatment processes and to prevent corrosion.

5. Oxidizing Agents: Chemicals like potassium permanganate or hydrogen peroxide are used to oxidize and remove organic and inorganic impurities in water, including iron, manganese, and hydrogen sulfide.

6. Scale and Corrosion Inhibitors: These chemicals, such as polyphosphates or zinc orthophosphate, are added to water to prevent the formation of scale deposits and control corrosion in pipes and equipment.

7. Activated Carbon: Activated carbon is a porous material that is effective in adsorbing organic compounds, taste, and odor-causing substances from water.

8. Antifoaming Agents: Antifoam chemicals are used to control foam formation and minimize the interference caused by foam during water treatment processes.

It's important to note that the selection and use of specific water treatment chemicals depend on the characteristics of the water source and the desired water quality standards. Water treatment professionals and experts carefully assess the water composition and conduct tests to determine the appropriate chemicals and dosages for effective treatment.