Biocides and Disinfectants: Ensuring Water Microbial Safety

Microorganisms such as bacteria, viruses, and algae are widely present in natural water and industrial wastewater. If they are not effectively controlled, they will not only cause water quality deterioration but also pose a serious threat to human health and industrial production. Biocides and disinfectants are important chemicals for inhibiting or killing microorganisms in water, which play a key role in ensuring the safety of drinking water and the stable operation of industrial water systems. This article discusses the types, disinfection mechanisms, and application prospects of biocides and disinfectants.

Disinfectants for drinking water mainly include chlorine-based disinfectants, ozone, chlorine dioxide, and ultraviolet (UV) radiation. Chlorine-based disinfectants, such as liquid chlorine, sodium hypochlorite, and calcium hypochlorite, are the most widely used disinfectants due to their low cost and good disinfection effect. They kill microorganisms by releasing hypochlorous acid, which destroys the cell wall and enzyme system of microorganisms. However, chlorine-based disinfectants may produce disinfection by-products (DBPs) such as trihalomethanes, which are harmful to human health. Ozone and chlorine dioxide are efficient disinfectants with h3 oxidation capacity, which can kill microorganisms quickly and do not produce harmful DBPs. They are widely used in advanced drinking water treatment, but their cost is relatively high.

Industrial biocides are mainly used to control microbial growth in circulating water systems, cooling towers, and wastewater treatment plants. They can be divided into oxidizing biocides and non-oxidizing biocides. Oxidizing biocides, such as chlorine, ozone, and hydrogen peroxide, kill microorganisms through oxidation. Non-oxidizing biocides, such as isothiazolinones, quaternary ammonium salts, and glutaraldehyde, inhibit the growth and reproduction of microorganisms by interfering with their metabolic processes. Albemarle's Stabrom® 909, a stabilized bromine-based biocide, is widely used in industrial cooling systems for its high efficacy across a wide pH range and no need for additional activators. With the increasing demand for environmental protection, green biocides, such as plant extracts and microbial metabolites, are gradually developed and applied, which have the advantages of low toxicity, biodegradability, and no pollution to the environment.