“Bioensaios aplicados ao monitoramento da toxicidade de efluentes e lixiviados provenientes de um aterro sanitário classe II

Abstract

With the disposal of waste in landfills, leachate is formed, which can cause various environmental impacts, from contaminating the groundwater to mutations in the macro and microbiota. To monitor and assessthis effluent, various techniques are used, but the most common ones are ecotoxicological tests, as they provide an overview of how this effluent can impact the surrounding environment. Thus, the objective was to demonstrate the environmental impacts of chorume and its potential effects on the macro and microbiota, using Allium cepa L. as chronic toxicity tests and Aliivibrio fischeri for acute toxicity tests. In this study conducted at the regional landfill in southern Minas Gerais, samples were collected and diluted at different concentrations to evaluate their effects on the germination of Allium cepa L. and the viability of Aliivibrio fischeri. Seeds exposed to chorume had their germination inhibited, and other parameters reduced, while samples of surface and groundwater showed consistent results. Chorume was found to be toxic at high concentrations for both Allium cepa L. and Aliivibrio fischeri, whereas water samples did not indicate toxicity related to the landfill. In a second study, biotests with Allium cepa L. and Aliivibrio fischeri were used to assess the toxicity of effluents and surface waters. It was observed that the germination and growth of Allium cepa L. were influenced by precipitation levels and sample concentrations. Diluting contaminated samples improved germination, indicating the possibility of reducing the negative effects of effluents through this treatment method. The Aliivibrio fischeri test showed toxicity in chorume, while water samples yielded non-toxic or inconclusive results. Diluting samples under high precipitation levels and low operating capacity resulted in less impact on phytotechnical parameters, indicating greater treatment effectiveness.