Removal of Phenanthrene from Contaminated Soil by Ozonation Process

In order to improve the ozonation efficiency for the remediation of PAHs contaminated soil, the performance experiments were carried out with quartz sand artificially contaminated with phenanthrene. The byproducts of phenanthrene were detected by GC-MS and the toxicity was evaluated by seed germination tests. The influence of the particle size and moisture content of quartz sand on the ozonation efficiency was investigated. In addition, two kinds of real soil was used to compare with the quartz sand. It was revealed that the phenanthrene removal rate reached 96% after 600 minutes by using the ozonation process. Three byproducts of phenanthrene, including 9,10-phenanthrenedione, (1,1’-biphenyl)-2,2’-dicarboxaldehyde, and (1,1’-biphenyl)-2,2’-dicarboxylic acid, were obtained. As proven by seed germination tests, the toxicity of the byproducts was lower than phenanthrene. The phenanthrene was removed more effectively by ozonation in the quartz sand with finer particle size. The ozonation efficiency was significantly improved by increasing the moisture content, which is assumed to be related to the alkalinity of quartz sand.