蚯蚓活动对高羊茅修复土壤芘污染的强化作用

为了探讨土壤动物在植物修复多环芳烃类有机污染物过程中的作用,采用盆栽试验法,对比研究了蚯蚓(Pheretimasp.)活动对高羊茅(Festuca arundinacea)修复土壤芘污染的影响效应.在72d的试验期间,蚯蚓活动促进了芘污染土壤(20.24～321.42mg.kg-1)中高羊茅的生长,其根冠比明显增大.试验结束时,种植高羊茅的土壤中芘的去除率高达55.89%～82.01%,其平均去除率(69.91%)比无蚯蚓活动的土壤-植物(高羊茅)系统(60.06%)提高9.85%,比无植物对照组(18.24%)提高50.67%.各种生物、非生物修复因子中,植物-微生物交互作用(plant-icrobial interaction)对芘去除的贡献率(44.08%)最为突出,比无蚯蚓活动时(37.54%)提高6.53%.说明蚯蚓活动可强化土壤-植物系统对土壤芘污染的修复作用.

A study on the contribution of earthworm inoculation to the remediationof the pyrene-polluted soil by Festuca arundinacea

To investigate the contribution of the soil macrofauna on the dissipation of polycyclic aromatic hydrocarbons (PAHs) in rhizosphere soil,pot experiments were carried out to study the effect of earthworms (Pheretima sp.) working on pyrene-polluted soil being remedied by Festuca arundinacea.The results showed that earthworms' activities promoted the roots growth of Festuca arundinacea in soils (with Pyr concentrations ranging from 20.24 to 321.42mg·kg^-1),and the root/shoot ratio was apparently increased.Seventy-two days after earthworms were introduced,the Pyr in the soils with the plants was 69.91% removed,which was 9.85% greater than that was without earthworms,and 50.67% greater than in non-vegetated soils without earthworms.Among all possible pathways,the plant-microbial interaction was proved to be most efficient in Pyr degradation,and it accounted for 44.08% of the total removal with earthworms' activities,which was 6.53% higher than the soils without earthworms.Besides the accumulation of Pyr in grass was found to be reduced by incubation of earthworm in soils,thus the ecological risks of Pyr could be relieved.It was suggested that introducing earthworms into the soil-plant system could be a feasible way for establishing high efficient phytoremediation of soil polluted by PAHs.