Removal of phenanthrene from contaminated soil by a combination of pre-ozonation and composting
臭氧预氧化-堆肥去除污染土壤中菲实验研究

Phenanthrene (phe)-contaminated soil samples were prepared by spraying phe -acetone solution into uncontaminated surface and subsurface red soils, and the feasibility to remove phe from the contaminated soil samples was investigated using a combination of pre-ozonation and composting. The organic content, temperature, phe concentration, and the germination index of the composting soil were monitored in this study. Results showed that the combined process with pre-ozonation and composting was effective for removing phe from the contaminated soil. Toxicity of the contaminated soil to plants was greatly decreased, and germination of the botanic seeds was increased due to the maturity of organic materials in composting. Ozonation quickened the startup of the following composting, and further decreased the residual concentration of phe. The organic content in soil greatly affected the efficiency of ozonation. After ozonation for 100 min, the removal efficiencies of phe from the contaminated surface and subsurface soil samples, whose contents of organic matter were 7.73% and 3.64%, were 52.1% and 76.4%, respectively. After pre-ozonation and composting for 31 d, the residual rates of phe were 1.1% and 0.9% for the surface and subsurface soil samples, respectively, while the corresponding residual rates were 15.0% and 14.5% without pre-ozonation. The germination indexes of all the soils were above 130%.