Evaluación de la eficiencia de remoción de sulfametoxazol del agua residual empleando vermifiltración

Abstract

Emerging pollutants, due to their presence in aquatic ecosystems and the adverse effects they can have on human health and the environment, require priority attention in research and the development of mitigation strategies. This group includes pharmaceutical products, among them sulfamethoxazole, a widely used antibiotic whose presence in wastewater poses a significant environmental risk. This study used vermifiltration, a treatment technology based on gravity filtration through a biological substrate involving Californian red worms (Eisenia fetida). This technique is characterized by its low operating cost and rapid implementation. Two filtration systems were designed for the experiment: a vermicomposting filter with earthworms and a control filter without earthworms. Both were fed daily with 0.8 L of a synthetic wastewater solution supplemented with 1 ppm sulfamethoxazole over a period of 30 days. Samples were collected daily to obtain composite samples. These samples were concentrated by solid-phase extraction using Hypersep PEP cartridges with neutral pH and acetonitrile as the solvent, and then the sample was read on the HPLC. A maximum removal of 97.33% was obtained in the vermicompost filter and 84.17% in the blank with a saturation time of 20 days. The net removal by the worms was around 11.25%, a value that could be inferred as a viable method.