Simultaneous degradation and adsorption of cyanide using modified fly Ash and TiO₂/UV

Abstract

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.