通过微宇宙实验,研究了蚯蚓对不同土壤中芘的微生物降解率的影响及蚯蚓对芘的富集率.结果表明,有机质较高土壤中芘的微生物降解率和蚯蚓富集率都低于有机质低的土壤,而老化作用降低了芘的生物有效性.无论在新鲜染毒还是老化的土壤中,蚯蚓均可提高土壤中芘的去除率和微生物降解率.在新鲜染毒的红壤和潮土中,蚯蚓可使芘的去除率由41.78%和27.02%分别提高到89.24%和57.53%,其中分别有51.48%和41.63%是蚯蚓促进的微生物降解作用引起的,37.76%和15.90%归因于蚯蚓富集作用.而在老化的红壤和潮土中,蚯蚓可使芘的去除率由36.53%和20.50%分别提高到91.93%和45.46%,其中分别有54.43%和32.83%是蚯蚓促进的微生物降解作用引起的,37.50%和12.63%归因于蚯蚓富集作用.
Earthworm-enhanced biodegradation and earthworm accumulation of pyrene in different soils were studied in laboratory-controlled soil microcosms.The results showed that biodegradation and earthworm accumulation were generally lower in soils containing more organic matter(OM)than those in soils containing less OM,and aging reduced the bioavailability of pyrene.Earthworms improved the biodegradation and removal of pyrene both in freshly spiked and aged soils.When freshly spiked,the removal of pyrene from spiked red earths and fluvo-aquic soils increased from 41.78% to 89.24%,and 27.02% to 57.53%,respectively,after the introduction of earthworms.Earthworm-enhanced biodegradation contributed 51.48% and 41.63% to the pyrene removal in the two soils,respectively,while earthworm uptake contributed 37.76% and 15.90%.After aging,the removal of pyrene in red earths and fluvo-aquic soils increased from 36.53% to 91.93%,and 20.50% to 45.46%,respectively,after the introduction of earthworms,among which 54.43% and 32.83% was ascribed to earthworm-enhanced biodegradation,while 37.50% and 12.63% was ascribed to earthworm uptake.