PHYSICAL-CHEMICAL AND BIOLOGICAL PROCESS TO TREAT CONTAMINATED EFFLUENT BY CYANIDE

Abstract

Cyanide has been used in thermal processes as an important enabler in the treatment of the steel. However, their presence can cause human poisoning when inhaled and contamination of water bodies when disposed without proper treatment. Accordingly, due to the importance of the issue to human health and environmental quality, this study aims to evaluate the effectiveness of the combined treatment biological and physico-chemical industrial wastewater contaminated contaminated by cyanide. The methodology used for the removal of cyanide was coagulation-flocculation (ferrous sulfate), followed by activated sludge biological reactor and filtration. The results achieved an average efficiency of 90.3% removal of cyanide in the final effluent, thus indicating the efficiency of the system. Furthermore, the quality of the final effluent was supplying the demand of the Brazilian legislation in relation to the parameter total cyanide, and secured the reduction of the concentration of barium and parameters of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) which made possible the release of effluent into waterways by service quality limit established by Brazilian legislation.

Key words: Cyanide, industrial effluent, physical-chemical treatment, biological treatment.