Estudo da persistência e da remoção de fármacos em águas de abastecimento do município de João Monlevade utilizando nanopartículas de sílica mesoporosa funcionalizadas

Abstract

The issue of emerging contaminants has been addressed by researchers worldwide since it represents a potential hazard to human health and the environment. Among these contaminants, the drugs widely used in human and veterinary health can be highlighted. Through ingestion followed by excretion, or irregular disposal, trace concentrations of these contaminants can reach the sewage networks and wellsprings, passing through the convenient water and sewage treatment steps without suffering relevant degradation or removal. Thus, considering the concerns regarding the exposition of drug traces through to the potable water ingestion, this study evaluated the persistence of drugs losartan, ciprofloxacin, dipyrone, paracetamol, and ketoprofen in water samples collected in different places located at João Monlevade city, state of Minas Gerais, Brazil. The methodologies used to quantify the drugs were based on the high-performance liquid chromatography technique (HPLC-DAD). The water samples were collected in eight different places and in two different periods. The obtained results revealed that losartan, amoxicillin, dipyrone, and paracetamol were detected in samples obtained from wellspring and treated water sources. The compounds with the highest concentration in descending order were losartan (2.18 to 2.59 μg/mL), amoxicillin (1.94 to 2.53 μg/mL), dipyrone (0.55 to 2.57 μg /mL) and paracetamol (0.0020 to 0.031 μg/mL) for samples collected in January 2020. For samples collected in May 2021, the compounds with the highest concentration in descending order were amoxicillin (1.80 to 2.37 μg/mL), losartan (1.59 to 2.28 μg/mL), dipyrone (0.09 to 0.67 μg/mL) and paracetamol (0.0016 to 0.0046 μg/mL). The drugs ketoprofen and ciprofloxacin were not detected in the studied samples, considering the limitations of the used technique. There is no available data in the literature regarding the potentially harmful effects on human health. However, it is crucial to consider that there are still few studies regarding the chronic effects of exposure to different drugs, confirming that specific levels are safe. This study also evaluated the removal performance of three drugs from the water through a synthetic material prepared in the laboratory, based on mesoporous silica nanoparticles (SBA-16) functionalized with 3-aminopropyl-trietoxysilane. After incubating the material with water containing the drugs, the nanostructured material could significantly reduce the presence of the drugs. After 27 hours, an adsorption efficiency of 92% of losartan was observed. At 24 hours, there were adsorption efficiencies of the order of 100% for amoxicillin and dipyrone drugs. From all the results obtained, the use of SBA-16 with APTES proved to be an alternative for removing drug residues from water supplies sources.