Photocatalytic efficacy of pyrite in the degradation of antiretroviral drugs: Biomphalaria glabrata as a bioindicator of toxic and genotoxic effects

Population growth and the increase in the consumption of different pharmaceuticals combined with the insufficiency in the removal of these compounds by conventional treatments have contributed to the increase in the detection of these contaminants in aquatic matrices. Aiming to contribute in solving this problem, this promoted the degradation of a mixture of the drugs lamivudine and zidovudine in different matrices (aqueous solution and synthetic effluent) using the heterogeneous photo-Fenton process applying pyrite as a catalyst and artificial solar radiation. At the end of the treatment, degradations greater than 99 % were found for zidovudine in both matrices studied, while for lamivudine, 97 % and 94 % degradations were obtained for aqueous solution and synthetic effluent, in that order. In the investigation of toxic effects using Biomphalaria glabrata molluscs, embryotoxicity tests showed embryonic lethality in 100 % of individuals for all samples. Acute toxicity tests on adult molluscs resulted in mortality rates of 100 % (aqueous solution after treatment) and 50 % (synthetic effluent after treatment). Thus, to investigate cellular changes, genotoxicity analyses were carried out, and different degrees of DNA damage were observed, however, the highest level of damage to this organism was not observed. Therefore, B. glabrata demonstrated to be sensitive to toxic effects at the concentrations present in the matrices studied, providing evidence to predict the ecotoxicological potential of samples when released into aquatic ecosystems.