Research Center for Environmental Health AND School of Public Health, Kurdistan University of Medical Sciences, Sanandaj, Iran
Due to the present water shortage and environmental problems associated with industrial effluent, investigation of novel treatment technologies is an essential approach. Being a highly toxic chemical of asphyxiating characteristics, cyanide is seen as a major environmental pollutant in a wide range of industrial effluents. The present study aimed to address the adsorption and photocatalytic degradation of cyanide using activated fly ash and TiO2/UV. To investigate the removal efficiency of cyanide, two sets of experiments were designed. First, cyanide was absorbed by activated fly ash and degraded via a photocatalytic process, individually. Second, simultaneous adsorption and degradation was examined. The removal efficiency of cyanide by modified fly ash (MFA), TiO2/UV, and their combination (MFA-TiO2/UV) was 76.1%, 81%, and 86.6%, respectively. Optimal conditions for the combination of activated fly ash AFA-TiO2/UV were contact time of 6 hours, temperature of 100 °C, and AFA: TiO2 ratio (w/w) of 1:1. Under these conditions, a maximum removal rate of 92.4% was obtained when 1.2 g of MFA/TiO2 was used with a pH value of 3 in the presence of UV light. Based on the results of cyanide removal, it can be concluded that the combination of adsorption and photocatalytic degradation with MFA-TiO2/UV can be utilized to improve the removal of cyanide from wastewater.