Surfactants in waste water: Development, current status and associated challenges

Abstract

Using soaps, disinfectants, sanitizers, surface cleaners, and detergents on a large scale has increased during COVID-19, making it apparent again to review their scale of usage. Increasing consumption of disinfectants, soaps, and detergents for hygiene enhancement in medical, domestic, and corporate sectors triggers a significant increase in the contaminants in wastewater. Surfactants facilitate cleansing by lowering the surface tension. Surfactants, the main ingredients of soaps, detergents, and cleansing agents, impart different properties to the cleansing systems. Surfactants are used as substrates in the synthesis of various products, including dyes, pigments, pesticides, exchange resins, plasticizers, and pharmaceuticals, along with their primary use in household and laundry detergents and cleaners, cosmetics, textile and tanning industry, paints, preservative coatings, pulp and paper, and petroleum products. A significant portion of surfactants is let into the water bodies through laundry detergents. The detergent formulations constitute almost 40% of surfactants. The quest for effective detergents and disinfecting properties has led to the pursuit of newer alternatives for surfactant incorporation.The current manuscript represents the journey of surfactants in terms of their development over time, the modifications carried out to impart desired traits, and their hazardous implications. A study on species of Anabas testudineus showed that the fishes are fatally affected by detergent concentrations above 200 mg/L. It further encompasses the proposed alterations to combat the harmful environmental effects. Cationic surfactants were observed to have a more hazardous impacts than anionic and non-ionic surfactants. The manuscript emphasizes the utilization of more environment-friendly substitutes for surfactant molecules. It presents an overview of different molecules which are a part of surfactants, hazardous traits, and prospects associated with different surfactant entities.