Document Type : Original Article
Department of Environmental Health Engineering, Hamadan University of Medical Sciences, Hamadan, Iran
Social Determinants of Health Research Center, Department of Environmental Health Engineering, Hamadan University of Medical Sciences, Hamadan, Iran
In this study, nanoscale zero-valent copper (nZVC) as catalyst activated persulfate (PS) was used for the degradation of p-chlorophenol (p-CP) under ultrasonic (US) irradiation in aqueous solution. The effect of different operational parameters such as solution pH (3.5-10.5), PS concentration (1-7.5 mm/L), nZVC dosage (5-35 mg/L) and initial p-CP concentration (10-100 mg/L) were evaluated at different contact time. Results indicated that US/PS/nZVC system achieve higher efficiency in p-CP degradation than US/PS, US/nZVC and PS/nZVC systems. The optimal p-CP removal efficiency (98%) was achieved within 40 min with 5 mm/L PS and 30mg/L nanocatalyst at 25 mg/L initial p-CP concentration. It was also observed that the p-CP degradation rate depends on initial p-CP concentrations. To clarify the mineralization of p-CP, TOC and COD were analyzed at optimum conditions. COD and TOC removal rate obtained from the US/PS/nZVC system with contact time of 60 min were 61and 75%, respectively. Through the use of methanol (MA) and tert-butyl alcohol (TBA) as radical scavengers, was identified as the main radical species that are generated during processes. The removal process of p-CP could be described by the pseudo-first-order kinetics. The apparent degradation rate constant (k) was 0.076 min-1 in US/PS/nZVC system at optimal conditions.