【摘要】 利用含水砂柱在厌氧条件下开展汽油模拟石油类污染地下水的特征研究.结果表明,苯、甲苯、乙苯和二甲苯(简称为BTEX)各溶解组分均能够自然衰减.BTEX总浓度衰减的速率系数为0.0158d-1,其中苯浓度衰减的速率系数为0.0243d-1,甲苯为0.0268d-1,乙苯为0.0118d-1,二甲苯为0.0085d-1.苯与甲苯相对容易衰减,而二甲苯与乙苯的衰减则需要较长的时间.BTEX溶解组分浓度及电子受体浓度的降低、二氧化碳气体的明显产生以及黑色硫化亚铁沉淀的产生,表明砂柱在严格厌氧条件下存在三价铁和硫酸盐被优先用作电子受体的内在生物降解作用,参与作用的微生物主要是杆状铁还原菌和硫酸盐还原菌.更多还原

【Abstract】 An anaerobic aquifer sandy column is used to study the natural removal of benzene, toluene, ethylbenzene and xylene (BTEX) in the aquifer by injecting gasoline. The results show that BTEX can be removed by natural attenuation including intrinsic biodegradation. Natural attenuation rates of soluble BTEX compounds are various. Rate coefficient of total BTEX is about 0.015 8 d -1 . Among them, rate coefficient of benzene is about 0.024 3 d -1 , rate coefficient of toluene about 0.026 8 d -1 , rate coefficient of ethylbenzene about 0.011 8 d -1 , and rate coefficient of xylene about 0.008 5 d -1 . Benzene and toluene compounds are removed easily. However, xylene and ethylbenzene are relatively recalcitrant. With the decrease of BTEX and electron acceptors concentrations and the increase of CO_ 2 concentration and black depositions of FeS, it is suggested that intrinsic biodegradation in which ferric iron and sulfate are first used as electron acceptors take place in the aquifer under anaerobic condition. Microorganisms involved in these reduction processes are mainly the rod-shaped Fe(Ⅲ)-reduing bacteria and sulfate-reduing bacteria.更多还原