Tratamento de lixiviados de aterro sanitário combinando coagulação (sulfato de alumínio) e técnicas eletroquímicas (diamante dopado com boro)
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Data
2019-03-08
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Universidade Federal de Goiás
Resumo
Landfill leachate contains a wide variety of organic and inorganic compounds that give the effluent high toxicity, high organic load and low biodegradability. Due to its complex composition, this effluent has acquired high research interest in the use and combination of new treatment technologies which can provide the balance of the environment. This study presents and discusses the results obtained in the treatment of raw landfill leachate with a combination of coagulation-flocculation and electrochemical techniques using a filter-press reactor with a boron-doped diamond electrode. The treatment success was demonstrated by the quality of treated water, which was evaluated based on parameters such as color, odor, turbidity, chemical oxygen demand, biochemical oxygen demand, free and total chlorine, total nitrite and nitrate, ammonia and microbiological tests (mesophiles and thermotolerant coliforms). The best conditions for coagulation-flocculation involved a dosage of 20 mL/L of Al2(SO4)3 at pH 6.0 followed by electrochemical treatment by 3 h. To reduce the energy consumption, the best condition for electrochemical treatment was performed by the application of different limiting current density step sequences, in the order to keep the applied current always closer to that in which the process is mostly controlled by diffusion (limiting current, Ilim). This strategy reduced the energy consumed in removing the organic load by up to 40% while maintaining a similar effective mineralization rate (> 90% removal) between stages. Microbiological tests revealed that the number of mesophiles was reduced by more than twelve orders of magnitude after electrolysis, indicating the important sanitizing effect caused by the HClO/chloramine species generated in the process. The parameters color, turbidity and ammoniacal nitrogen were completely eliminated from the treated landfill leachate at the end of the electrolysis process.
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Diamante dopado com boro, Lixiviado de aterro, Tratamento eletroquímico, Águas residuais, Coagulação-floculação, Boron doped diamond, Landfill Leachate, Electrochemical treatment, Wastewater, Coagulation-flocculation
Citação
OLIVEIRA, M. S. Tratamento de lixiviados de aterro sanitário combinando coagulação (sulfato de alumínio) e técnicas eletroquímicas (diamante dopado com boro). 2019. 72 f. Dissertação (Mestrado em Química) - Universidade Federal de Goiás, Catalão, 2019.