Microcosm Study on Response of Soil Microorganisms to Polycyclic Aromatic Hydrocarbons Contamination

Soil and groundwater contamination by petroleum and coal tar becomes one of the urgent environmental issues concerned by more and more scientists with regards to the public health. With the induction of organic contaminants to soil and groundwater it will change the environmental conditions within the plume and hence lead to the variation of indigenous microorganisms. The article aims to investigate the response of indigenous microorganisms to the petroleum contamination. Three polycyclic aromatic hydrocarbons (PAHs) phenanthrene, anthracene and pyrene were selected as the contaminants and tested using laboratory microcosm. The response of indigenous microorganisms to the PAHs induction was analyzed by measuring the change of soil microbial activity, soil catalase activity, contaminants concentration and geochemical parameters. The experimental results showed that: (1) the major parts of the PAHs were absorbed by the soil, its transport was retarded, (2) the soil microbial activity was inhibited at the initial stage of PAHs induction and then slowly increased, (3) the soil catalase activity was stimulated at first with PAHs induction and then inhibited within the range -0.05 mL (0.1 M KMnO₄)/g (soil).