Classification of Chemicals for Water System Treatment

Disinfectants: Chlorine-based compounds such as chlorine gas, sodium hypochlorite (bleach), or chlorine dioxide are commonly dosed into water systems to disinfect and kill pathogens, bacteria, and other harmful microorganisms.

pH Adjusting Chemicals: Acids (e.g., sulfuric acid, hydrochloric acid) or bases (e.g., sodium hydroxide, lime) are added to adjust the pH of water to desired levels for optimal treatment processes or to meet regulatory requirements.

Coagulants: Coagulants such as aluminum sulfate (alum) or ferric chloride are added to facilitate the aggregation of suspended particles in water, aiding in their removal during the coagulation and sedimentation process.

Flocculants: Polymers or organic compounds known as flocculants are often dosed into water to encourage the formation of larger flocs, which helps in the removal of fine particles and colloidal substances during the clarification or filtration stage.

Corrosion Inhibitors: Chemicals such as orthophosphate compounds or zinc orthophosphate are added to water systems to prevent corrosion and protect metal surfaces, particularly in distribution pipelines and plumbing systems.

Scale Inhibitors: Scale inhibitors, such as polyphosphates or chelating agents, are added to water to prevent the formation of scale deposits caused by calcium, magnesium, and other minerals that can impair the efficiency of equipment and piping systems.

Sequestering Agents: Sequestering agents, such as sodium hexametaphosphate or EDTA (ethylene diamine tetraacetic acid), are used to bind and neutralize metal ions in water, preventing their precipitation and reducing the formation of scale or undesirable reactions.

Antifoaming Agents: Surfactants or silicone-based compounds are sometimes added to water systems to control foam formation, which can interfere with treatment processes or affect the efficiency of equipment.

Dispersants: Dispersants are chemicals added to water to break down or disperse oil, grease, or organic compounds, facilitating their removal during treatment processes such as flotation or sedimentation.

Oxidizing Agents: Certain oxidizing agents, such as potassium permanganate or hydrogen peroxide, may be dosed into water systems to oxidize and remove organic contaminants, odors, or color compounds.