多环芳烃污染土壤的植物-微生物联合修复初探

在温室盆栽条件下,通过种植紫花苜蓿单独或联合接种菌根真菌(Glomus caledonium L.)(AM)和多环芳烃专性降解菌(DB),研究了利用植物-微生物强化修复多环芳烃(PAHs)长期污染土壤的效果。试验结果表明,接种菌根真菌和PAHs专性降解菌能促进紫花苜蓿的生长和土壤中PAHs的降解。经过90天修复试验,种植紫花苜蓿接种AM、DB和DB+AM处理的PAHs的降解率分别为47.9%、49.6%、60.1%,均高于只种植紫花苜蓿的对照处理(CK)(21.7%)。另外,随着PAHs苯环数的增加,其平均降解率逐渐降低,但是接种PAHs专性降解菌能够提高4环和5环PAHs的降解率。同时也发现土壤中脱氢酶活性和PAHs降解菌数量越高的处理,土壤PAHs的降解率也越高,这也是种植紫花苜蓿接种微生物能够有效促进土壤PAHs降解的原因。

Interaction of phytoremediation-microorganism to remediation of aged polycyclic aromatic hydrocarbons (PAHs) polluted soils

A pot experiment in greenhouse was carried out to investigate the interactive effects of arbuscular mycorrhizal fungi (AM) inoculation and PAHs-specific degrading bacteria (DB) inoculation on the phytoremediation of long-term PAHs contaminated soils. The results indicated that AM and DB inoculation promoted PAHs degradation in the soil with alfalfa (Medicago sativa L.). After 90 days, total PAHs content in soil reduced by 47.9% and 49.6% for the treatment of AM and DB respectively, but only by 21.7% for control. For the treatment of DB+AM, total PAHs content in soil reduced 60.1%, showing synergy effect of AM and DB inoculation. In addition, the average PAHs degradation gradually reduced with the increase of PAHs rings, but DB inoculation promoted the degradation of four-ring PAHs and five-ring PAHs. The removal ratio of PAHs from soil increased with the increases of the amount of culturable PAHs degrading microorganisms and the activity of dehydrogenase. Therefore arbuscular mycorrhizal fungi inoculation and PAHs-specific degrading bacteria inoculation were effective to the phytoremediation of long-term PAHs contaminated soils.