石油污染土壤的生物修复研究

Bioremediation of Petroleum-contaminated Soil

通过田间试验研究了玉米和向日葵两种植物对石油污染土壤的修复作用,考察了外源菌(DX-9)对植物修复的强化和协同效应,对"外源菌-植物"修复效果进行了初步评价。结果表明,在10000mg.kg-1污染浓度下,150d玉米、向日葵试验区土壤中石油降解率分别为42.5%和46.4%,较对照区提高了100.5%和118.9%。外源节细菌的施加可使生物修复速度显著加快,150d"DX-9-玉米"和"DX-9-向日葵"试验区石油烃降解率分别达到72.8%和76.4%,较同期单独植物修复的降解率提高了71.3%和64.7%。500d各试验区土壤中石油烃降解率分别为95.5%、96.1%、97.6%和98.9%,土壤中石油烃含量均低于国家标准规定限量(<500mg.kg-1);土壤主要理化性质、生物群落分布、呼吸强度及植物不同部位中石油烃的残留量与对照无显著差异。结果表明:玉米、向日葵与节细菌对石油污染土壤的联合生物修复效果显著;经过两年修复,污染土壤恢复健康状态。

The bioremediation of corn, sunflower, Arthrobacter（ DX-9 ）-corn,（ DX-9 ）- sunflower to the petroleum-contaminated soil were studied by field trial, which was obtained by selective enrichment culture from the sludge in sewage of a oil refinery,the tests in shaking flasks showed that it could degrade petroleum hydrocarbon well and the removal rates could reach 90.8% with initial concentration of 10 000 mg· kg-1 at 20 d. The effect of bioremediation of DX-9-eorn and DX-9- sunflower was evaluated after the field experiment had been finished. The resuits showed that ,when the initial coneentrtation of petroleum in soil were 10 000 mg· kg-1, removal rate of petroleum in the soil of experiment- ed field of corn and that of sunflower could reach 42.5% and 46.4%, increasing by 100.5%, 118.9% compared with controlled fields by 150 days operation. Adding DX-9 could increased the biodegradation rate of phytoremediation obviously, the dgradation rates of eom-DX-9, sunflower-DX-9 section were higher than those of corn and sunflower With removal being 72.8% and 76.4%, increasing by 71.3%, 64.7% at 150 d. After 500 days of bioremediation,the degradation rates of petroleum hydrocarbon in corn, sunflower, corn-DX-9 and sunflower-DX-9 sec- tion were up to 95.5%,96. 1%,97.6% and 98.9% respecitvely. Petrolie content in the soil of experimented fields was lower than the govern- ment-required standard （ 〈500 mg· kg-1 ）. The properties, biome distribution and respiration intensity of the soils in experimented fields, the residue of petroleum in various parts of plants were not significant different compared with controlled fields. It indicated that DX-9 combined with plant could increase evidently the effect of bioremediation, contanminated soil could restore its health after two years of bioremediation.