| In this study,lab-scale bioremediation experiments of soil contaminated by polycyclic aromatic hydrocarbon (PAHs) with aerated composting were compared in the Spring and Winter.Results showed that PAHs degradation rate in the winter was higher than that in the spring,and the total PAHs degradation rates were over 70% for both Pile 1 (the dry weight ratio of soil,swine manure and sawdust as 1∶1∶1) and Pile 2 (the dry weight ratio of soil,swine manure and sawdust as 1∶3∶1),but the PAHs degradation rate of Pile 1 as 74.61% was higher than that of Pile 2 the degradation rates of low,middle,high benzene-ring types PAHs were 66.46%,79.12%,75.88%,respectively.After composting most of kinds of PAHs contents in soil were less than 1000 μg/kg (dry weight) except BbF,for example,BbF contents of these two piles in the Spring, 25000 μg/kg and 20000 μg/kg,respectively,were much higher than those in the winter experiments,both less than 5000 μg/kg.The first reaction order model was used to simulate degradation of PAHs during composting,and results showed that the model was fitted better in winter (R2>0.6) than in spring,and the half-life of PAHs degradation in winter was about 13 d. |
