The presence of xenobiotics in wastewater, particularly emerging contaminants such as pharmaceuticals, poses an ecotoxicological risk to the environment and human health. One of the main pharmaceutical products detected in water is diclofenac, which can be sold without a prescription. The lack of health regulations indicates the necessity of finding environmentally friendly treatment alternatives to remove this type of contaminant. Among these alternatives, biotechnology, specifically biological processes, offers a sustainable option compared to conventional treatments. Current treatment methods used in wastewater treatment plants are ineffective at removing diclofenac, a chlorinated aromatic compound highly resistant to degradation processes. In recent years, new treatment methods have gained prominence due to the favorable results they have yielded, including physicochemical, biological, and advanced processes. Biological treatments are notable for their low cost and the high level of effectiveness and efficiency with which they can remove toxic compounds. For this reason, the aim of this research project was to evaluate the degradation efficiency of a biological treatment in a bioreactor using a microbial community consisting of five bacterial strains, which was isolated from a pharmaceutical effluent and cultivated in a continuous culture system. Removal efficiencies ranging from 99.38 to 99.98% were achieved at various volumetric loading rates (from 0.087 to 1.043 g L−1d−1). Influents and effluents from the biological reactor were analyzed using bioassays to determine any potential toxic effects. The results showed that the effluents did not elicit a negative response in the bioindicators, indicating high toxicity in the influents.
Brener-Mizrahi et al. (Sun,) studied this question.