添加淀粉和通气对固定化Fusarium.sp修复煤矿区老化污染土壤HMW-PAHs的影响

Effect of starch and aeration addition on degradation of HMW-PAHs by immobilized Fusarium. sp in a polluted and aged soil of a coal mining area

为了提高Fusarium.sp对PAHs的修复效果,在典型煤矿区老化污染土壤中添加淀粉和通气,经为期60 d的土壤培养试验,研究玉米秸秆固定化Fusarium.sp对土壤10种HMW-PAHs的修复效果及不同处理下土壤中酶活性变化规律。结果表明：HMWPAHs（High molecular weight-PAHs）总量去除率表现为固定化菌剂＋淀粉＋通气处理（J＋D＋O,29.19%）≈固定化菌剂＋淀粉处理（J＋D,25.89%）〉固定化菌剂处理（J,16.54%）;4环、5环和6环PAHs去除率在J＋D＋O和J＋D两组处理间的差异均不显著,且与J处理相比均有显著提高（P〈0.05）;三组处理对单个HMW-PAH的去除率分别为9.12%~21.73%、17.93%~43.12%、24.34%~35.79%,J＋D＋O和J＋D处理对单个HMW-PAH的修复效果均有显著促进作用,其中,对Bk F的去除增幅最大,分别增加了68.09%、63.78%。从酶活性规律看,土壤过氧化氢酶活性呈CK〉J〉J＋D〉J＋D＋O（P〈0.05）的规律,且与10种PAHs单体的去除率呈显著或极显著负相关;土壤木质素过氧化物酶活性却与Chry、Bk F、In P、Db A、Bghi P去除率呈显著正相关。综上认为,不同处理对单个PAHs的去除具有其选择性,且添加淀粉的两处理均显著提高了土壤中HMW-PAHs的修复效果。

The soil incubation experiment was performed to study the effect of starch and aeration addition on HMW-PAHs degradation by Fusarium.sp in polluted and aged soil of a coal mining area. After 60 days incubation, the degradation rate of 10 HMW-PAHs as well as the change rule of soil enzyme activities were analyzed. The results showed that the treatments were in the following order in terms of ∑ 10HMW-PAHs degradation rate：immobilized Fusarium.sp ＋ starch ＋ aeration（J＋D＋O, 29.19%）≈immobilized Fusarium.sp ＋ starch（J＋D,25.89%）immobilized Fusarium.sp（J, 16.54%）. There was no significant difference between J＋D＋O and J＋D for the degradation of ∑4-rings, ∑5-ring and ∑6-ring PAHs, but their degradation rates were higher than J significantly（P0.05）. The degradation range of 10 individual HMW-PAHs were 9.12%~21.73%, 17.93%~43.12%, 24.34%~35.79% in J, J＋D and J＋D＋O treatments respectively. The results demonstrated that far higher degradation rates of the 10 individual HMW PAHs were achieved in J＋D＋O and J＋D treatments than those in J treatment, but there was no significant difference between J＋D＋O and J＋D. The removal rates of Bk F presented the highest increase extent in the two treatments and increased 68.09%, 63.78% respectively. In addition, the treatments were in the following order in terms of catalase enzyme activities：CKJJ＋DJ＋D＋O（P0.05）. We found that there were significant（P0.05）linear negative correlation between the removal rates of the 10 individual HMW-PAHs and catalase activity in soil. However, the degradation rate of Chry, Bk F, In P, Db A, Bghi P had significant（P0.05）linear positive correlation with lignin peroxidase activity. In conclusion, the individual PAH was removed by different treatments selectively, and the degradation rate were significantly improved by adding starch.