泥炭生物反应墙构建及修复地下水中石油烃

Construction of Peat Biobarrier to Remediate Petroleum Hydrocarbon Contaminated Groundwater

为有效修复地下水中溶解态石油烃污染物,在研究填充介质配比基础上,分别利用低温石油烃降解菌-泥炭-粗砂和泥炭-粗砂构建了泥炭生物反应墙和泥炭反应墙,考察了反应墙对地下水中BTEX、PAHs的修复效果。结果表明,泥炭与粗砂最适体积比为20：80,此时墙体渗透系数为1.17×10-4m/s,有效空隙率为7.5%;泥炭反应墙对BTEX去除率为32.63%~79.15%,吸附寿命为50~55 d,吸附能力大小为二甲苯〉乙苯≈甲苯〉苯,出水萘、α-甲基萘、β-甲基萘和菲浓度均低于2.85μg/L;泥炭生物反应墙对BTEX、PAHs修复效果良好,去除率分别为83.6%~97.83%、97.48%~99.85%,微生物降解作用明显,BTEX降解率为75.66%~90.16%。研究表明,泥炭生物反应墙内污染物去除过程为泥炭吸附和微生物降解,泥炭对石油烃特别是多环芳烃具有很强的吸附能力,生物降解能有效延长泥炭对污染物的吸附寿命。

In order to effectively remediate the dissolved petroleum hydrocarbon contaminants in aquifer,low temperature hydrocarbon degrading bacteria-peat-coarse sand and peat-coarse sand were adopted respectively to construct peat biobarrier and peat barrier.And the ratio of packing media,the removal efficiency of BTEX and PAHs were investigated through barriers in remediation of petroleum hydrocarbon contaminated groundwater.It is found that the hydraulic conductivity and available porosity of mixed media were 1.17×10-4 m/s,7.5% respectively when peat and coarse sand at the optimum volume ratio of 20：80.For peat barrier,the removal rates of BTEX were 32.63%-79.15%,sorption life was 50-55d,sorption capacity of peat barrier to BTEX was xylene ethylbenzene≈toluene benzene,effluent concentration of naphthalene,α-methylnaphthalene,β-methylnaphthalene and phenanthrene were all below 2.85μg/L.The removal efficiency for BTEX,PAHs were 83.6%-97.83%,97.48%-99.85% through remediation by peat biobarrier,and have an obviously effect on contaminants biodegradation,the degrading rates of BTEX were 75.66%-90.16%.The study indicated that removal mechanisms of hydrocarbon contaminants were peat sorption and biodegradation for peat biobarrier,peat had strong sorption capacity to petroleum hydrocarbon contaminants,especially for PAHs,contaminants biodegradation could efficiently prolong the sorption life of peat barrier.