连续与间歇臭氧化对多环芳烃污染土壤修复作用的比较研究

ontinuous ozonation can inactivate indigenous microbes due to the disinfection capability of ozone, which may affect subsequent bioremediation of soils. This study investigated the efficiency of removing polycyclic aromatic hydrocarbons from soils using intermittent ozonation technique, where ozone was sparged through the soil column every alternate day, resulting in shorter ozonation time for each ozonation circulation than continuous ozonation. The results showed that 85% Phe, 94% Ant, 76% Flu, 87% Pyr, and 91% BaP were removed on 32 d in continuous ozonation treatment, while 90% Phe, 84% Ant, 78% Flu, 81% Pyr, and 96% BaP were removed on 32 d in intermittent ozonation treatment, indicating both intermittent and continuous ozonation can effectively remove polycyclic aromatic hydrocarbons from soils. Fluorescien diacetate hydrolysis results indicated that the total microbial activity of intermittent ozonation was significantly (p < 0.05) higher than that of continuous ozonation treatment at 8, 16, 24 and 32 d. The toxicity bioassay of soil extracts showed that the relative luminescence increased from 5 to 30% at 8 d, without significant (p > 0.05) increase at 32 d in continuous ozonation treatment, while it increased to 61% at 32 d in intermittent ozonation treatment, indicating intermittent ozonation was more effective than continuous ozonation for the detoxification of soils contaminated with polycyclic aromatic hydrocarbons. It suggested that the both treatments were equally effective at removing polycyclic aromatic hydrocarbons from soil, but intermittent ozonation was better than continuous ozonaiton for further detoxification and maintaining the total microbial activity of soil.