Study on the Photocatalytic Degradation of Diesel Pollutants in Seawater by a Sonochemically Prepared Nano Zinc Oxide

Abstract

Semiconductor ZnO nanocrystal has been synthesized by a sonochemical method and characterized by XRD and SEM techniques. The results indicate that the as-prepared ZnO is of hexagonal wurtzite structure. The photocatalytic degradation of diesel pollutants in seawater is investigated by utilization of ZnO in simulated diesel-polluted seawater exposed to UV irradiation. In the experiment, the influences of ZnO dosage, initial concentration of diesel, pH value, photocatalytic degradation reaction time and the presence of assistance oxidant peroxide, respectively, on the diesel pollutants removal from seawater are investigated. A systematic optimization study is carried out through a orthogonal test on the basis of the results of the single-factor experiments. It reveals that when the experiment is undertaken under the very condition: the ZnO dosage is 1g/L, the initial concentration of diesel 1g/L, the pH value 7, the reaction time 3h and the concentration of peroxide 0.16%, the removal rate of diesel pollutants in seawater is expected to reach 84 %.