Research progress on aquatic environmental behavior and aquatic toxicity of sulfonamide drugs

Sulfonamides (SAs) are commonly found in aquatic environment, and most of them are released into the environment in the form of parent molecules or metabolites. Low concentrations of SAs can be detected in surface water, groundwater, seawater, and even drinking water, and they pose potential risks to the aquatic eco-environment and human health due to their high emissions and strong pseudo persistence in the environment. Focusing on the fate of SAs in the aquatic environment, the typical behavioral patterns of SAs in adsorption, migration, transformation, degradation and bioconcentration in the aquatic environment were summarized. Moreover, an analysis was conducted on the toxic effects of SAs on aquatic plants, aquatic animals and aquatic microorganisms. The results showed that studies on the behavior of SAs in the aqueous environment had mostly focused on its adsorption characteristics and patterns on the surface of environmental media. However, there were fewer studies on the transport transformation and bioconcentration patterns of SAs under hydrodynamic conditions. Previous studies revealed that the adsorption of SAs on the surface of environmental media mainly occurred in the form of cation exchange and molecular binding, and the charge density of the adsorbent surface was an important factor determining the adsorption amount. SAs existed widely in the aquatic environment. Although the concentration level of SAs was low, the negative impact on aquatic organisms would produce potential ecological risks, mainly manifested as interfering with the growth and development process of aquatic plants, causing the characteristic deformities of aquatic animals, interfering with the community structure and function of aquatic microorganisms, and ultimately causing macro impacts on the entire water environment and its circulation. In the future, the study on the concentration and contribution rate of SAs attenuation process in water environment and the standardized toxicity test of aquatic organisms should be strengthened, so as to further study SAs ecotoxicology and solve SAs pollution problem.