Study on photocatalitycal detoxification of wastewater contaminated with cyanides

Abstract

The presence of free and complex cyanide in industrial wastewater is a problem of major concern owing to the well-known toxicity of these species for the living organism even at low concentration values. Large volumes of wastewater contaminated with pollutants are generated by different industries including gold milling processes. The conventional processes used up today to treat these type of wastewater are mainly chemical or/and biological. A promising method for treating wastewater contaminated with cyanide consists in turnover of pollutant into less dangerous species by photooxidation in the presence of polycrystalline semiconductor oxides under UV/solar radiations. It was studied the degradation of cyanide from wastewater by heterogeneous photocatalyses with TiO2 (anatase) suspended in solution. The experimental results show that the efficiency of cyanide degradation is affected by pH, TiO2 dose and contact time.