Tratamento de lixiviado de aterro sanitário por eletrocoagulação: efeitos da variação temporal nos parâmetros físico-químicos

Abstract

The increase in municipal solid waste generation, associated with the greater volume of waste disposed of in landfills, can intensify leachate production—an effluent with high pollutant load and low biodegradability—whose quantity also depends on factors such as rainfall patterns, waste compaction, and the effectiveness of cover layers. Its improper disposal poses serious environmental and public health risks. In this context, the present study investigated the efficiency of the electrocoagulation process using aluminum electrodes in the treatment of leachate from a Municipal Sanitary Landfill in the state of Paraná, assessing physicochemical parameters at different treatment times. The methodology involved collecting and characterizing the leachate in terms of pH, turbidity, color, conductivity, COD, phosphorus, and nitrite before and after the application of the process in a batch-operated bench-scale reactor. The Central Composite Rotational Design (CCRD) incorporated variations in leachate concentration and treatment time, with evaluation of the removal efficiency for each parameter. The results demonstrated that electrocoagulation promoted reductions of up to 99.79% in turbidity and 98.25% in color, and achieved up to 87.75% COD removal, with better performance at intermediate treatment times and higher concentrations. Conductivity exhibited a decreasing trend, while pH increased slightly after treatment, remaining within a neutral range and reflecting the electrochemical effects of the process. It is concluded that electrocoagulation proved to be a viable and efficient alternative for sanitary landfill leachate treatment, particularly for the removal of organic matter and suspended particles, and may be integrated with other processes to ensure compliance with legal effluent discharge standards.