采用强制通风堆肥法修复多环芳烃PAHs(16种)污染土壤,比较了春季和冬季时堆肥法对PAHs污染土壤的修复效果.结果表明,冬季时受污染土壤中PAHs降解率高于春季,1号堆料[m(土壤):m(猪粪):m(锯末)=1:1:1(干重)]和2号堆料[m(土壤):m(猪粪):m(锯末)=1:3:1(干重)]的总PAHs降解率〉70%,但1号堆料的总PAHs降解率(74.61%)高于2号堆料,低、中和高环三类PAHs的降解率分别为66.46%、79.12%和75.88%;堆肥过程结束后,受污染土壤(干重)中大部分PAHs残留量均≤1000μg/kg,但苯并[b]荧蒽在春季试验的残留量较高,它在1号和2号堆料的残留量分别为25000μg/kg和20000μg/kg,而它在冬季2个堆体的残留量均低于5000μg/kg;堆肥修复污染土壤过程中总PAHs降解的一级反应动力学拟合结果表明,冬季拟合程度高于春季,R2〉0.6,半衰期约为13d.
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 1 000 μg /kg(dry weight) except BbF,for example,BbF contents of these two piles in the Spring,25 000 μg /kg and 20 000 μg /kg,respectively,were much higher than those in the winter experiments,both less than 5 000 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.