ELETROCOAGULATION-FLOTATION APPLIED TO THE TREATMENT OF WASTEWATER GERATED IN PLASTIC RECYCLING INDUSTRY

Abstract

An alternative for final disposal of the growing amount of plastic residues produced by the population has been their mechanical recycling witch demands washing plastic foils prior to industrial process. The produced wastewater is reused in the same industrial process. The present study presents Eletro-coagulation-Flotação (ECF) as a form of treatment of effluents of recycling of plastics, the treatment is based on the electrolysis, coagulation and flotation with coagulant production in situ. This study used a pilot scale system in which chemical coagulation take place, starting from the passage of electric current for aluminum electrodes followed by sludge flakes formation. These solids were separated from the liquid phase by flotation due to the formation of micro bubbles of hydrogen, generated in the electrolysis of the water. The efficiency of the treatment was verified in terms of removal of DQO, ammonia nitrogen and turbidity, values obtained were of 80%, 80% and 90% respectively. There was also disinfection, being this an additional favorable characteristic of the process. The responsible factors for the efficiency were related to under current effluent hydraulic detention time, distance between the electrodes, pH and intensity of the electric current.