Tolerância e potencial fitorremediador da Lemna minor em água contaminada por amoxicilina

Abstract

Water quality is of paramount importance for the well-being of all beings. However for many drinking water is not available. One of the factors is contamination by pollutants such as drugs. Despite its importance in treating pathologies and acting to improve the quality of human life, it has caused contamination in the environment in several ways. Among these drugs is amoxicillin, a beta-lactam antibiotic, effective in the treatment of infections caused by bacteria. The incorrect disposal of this drug, such as in sewage treatment networks, where its compounds are not completely eliminated, is a cause for concern, resulting in studies of some methods for this removal, such as phytoremediation. This process uses plants that remove, stabilize or degrade pollutants from water or soil. In this study, the antibiotic amoxicillin was used as a contaminant in the aqueous medium and the plant Lemna minor, as a potential phytoremediator, in order to evaluate its behavior and efficacy. The experiments were carried out in culture wells, repeated in periods of 05, 10 and 15 days, with independent variables being amoxicillin concentration, amount of initial plant mass and solution pH and as dependent variables the amoxicillin remaining in the solution, mortality or growth of fronds, amount of dry mass and chlorophyll a and b. Tolerance analysis was performed visually, evaluating mortality by fronds (yellow and white color and frond count) and for stress, chlorophylls a and b were evaluated. Kinetic evaluation was also carried out, for that the best result was used to determine the effluent resistance time during the experiment. During the 10 days of kinetic analysis, there was no variation in pH or chlorophylls a and b, showing a removal of approximately 80% of amoxicillin. Thus, it can be considered that there are conditions for Lemna to be used to remove the drug used from the aqueous medium.