Environmental Toxicity of Sodium Dodecylbenzenesulphonate in Aquatic Systems by Biotesting Results

The discharge of synthetic surfactants into the environment poses a serious threat to natural water bodies, as even at relatively low concentrations, they harm the biological processes of aquatic organisms. The molecules of dissolved detergents, by wedging themselves between water molecules, weaken the surface film. The hydrophilic part promotes the dissolution of the substance in water, while the hydrophobic part repels it. As a result, the entire water surface is covered with a peculiar film, which leads to the accumulation of toxic substances and a decrease in the oxygen concentration in the aquatic environment. To study the impact of surfactants on living organisms, we assess the ecological impact of synthetic surfactants on the biota of natural water bodies. We performed toxicological bioassays of aqueous solutions with low concentrations of sodium dodecylbenzenesulfonate on the crustacean Daphnia magna, which serves as a standard test organism both in Ukraine and abroad. The concentration of sodium dodecylbenzenesulfonate that caused the mortality of 50% of test organisms (LC₅₀) was determined, and the degree of toxicity of sodium dodecylbenzenesulfonate to aquatic ecosystems was found according to the EU Directive 93/67/EEC.