接种降解菌对土壤中邻苯二甲酸二异辛酯降解的影响

邻苯二甲酸二异辛酯〔Di-(2-Ethylhexyl)phthalate,DEHP〕是农田土壤中常被检出的有毒有机污染物,在土壤中有较长的持留性,微生物降解是其从土壤中消失的主要途径.本文采用温室盆栽试验研究了接种两株从污水处理厂活性污泥中分离得到的高效DEHP降解菌及其混合菌悬液降解土壤中DEHP污染的效果,以及土壤中添加葡萄糖和种植作物对其降解效率的影响.结果表明,在土壤初始DEHP浓度为100mg kg-1的条件下,接种两种降解菌及其混合菌悬液都可显著提高土壤中DEHP消失的速率,其残留半衰期比不接种对照缩短了32~48d,但在相同条件下接种不同降解菌的处理之间没有显著差异.土壤中添加0.6%的葡萄糖虽然可以强烈地促进土壤微生物的整体活性,但并没有提高修复效率,反而在短期内延缓了降解菌对DEHP的降解,延长了DEHP在土壤中持留的半衰期;植物生长可显著提高降解菌的降解效率,降低土壤中DEHP的残留浓度.研究结果同时也表明,只添加葡萄糖或只种植植物对土壤中DEHP的降解并没有显著的影响.图3表4参14

Degradation of Di-(2-Ethylhexyl) phthalate in Soil by Inoculating Microorganisms

Di-(2-Ethylhexyl) phthalate (DEHP) is one of the poisonous organic pollutants and it remains in soil for long time. Microbial degradation is a major method to remove DEHP from soil. A pot experiment was carried out to study the effects of inoculation with two strains isolated from activated sludge, which could metabolize DEHP efficiently, on DEHP degradation in soil, and the effects of glucose and plant on DEHP degradation were also concerned. The results indicated that with the concentration of 100 mg kg -1 DEHP in soil, the inoculation of the two strains and their mixture could significantly accelerate the degradation of DEHP. The half life of residual DEHP was 32~48 days fewer than the control without inoculation, but there was no significant difference between the different inocula under the same condition. Application with 0.6% glucose in soil could intensively boost soil microbial activity, but had no advantage over DEHP degradation. On the contrary the glucose delayed the degradation at the beginning and prolonged the half life of DEHP in soil. The growth of plant could significantly promote the degradation of DEHP by inocula. The results also showed that there was hardly any influence of the DEHP degradation by plant or adding glucose into the soil only. Fig 3, Tab 4, Ref 14