Benzo[a]pyrene Decomposition by UV/ZnO Process: Treatment Condition Optimization by Design of Experiments

Abstract

Polycyclic aromatic hydrocarbons are nonpolar organic compounds that are made of two or more benzene rings. The most dangerous and the indicator of this group is benzo[a]pyrene consisted of five interlinked benzene rings the carcinogenic effect of which is confirmed by the World Health Organization. In this study, benzo[a]pyrene (BaP) decomposition with UV/ZnO process and treatment condition optimization is studied by design of experiments. The effects of initial concentration of BaP, radiation time, nanoparticle dose and pH were investigated. Thirty one samples were determined using a central composite design. The concentrations of BaP were measured by a high-performance liquid chromatography equipped with an 18 cm column. Data analysis were performed using the Design Expert software. In this study, the effects of BaP concentration, pH, contact time and ZnO concentration were studied. Optimum removal condition was obtained as 76% under 3.5 mg/L BaP, 1.5 g/L nanoparticles, pH equal to 4 and radiation time of 45 min. According to the obtained results UV/ZnO process is an effective procedure for the removal of BaPe from the aquatic solutions and this cleansing process can be done on a larger scale by optimizing the effective operational factors.