Methyl tert-butyl ether (MTBE) is a common gasoline additive; it has become a groundwater pollutant in many countries. Granular activated carbon (GAC) adsorption treatment is not cost effective for removing MTBE because it is not well adsorbed on activated carbon. Employing highly acclimated bacteria to degrade adsorbed MTBE to extend the service period of the GAC adsorber will make it more cost effective. Using the conventional inoculation method of circulating the seeding solution of MTBE degraders came with the spent GAC sample from a biological GAC treatment system of a MTBE remediation site to treat a high MTBE influent (30. 0 mg/L,simulating a newly contaminated groundwater) ,the effluent samples of inoculated coal and coconut GAC columns were nearly the same as those of the non-innoculated columns because the slow growing MTBE degraders were not easily retained and the low MTBE degradation rate. After a start-up period of less than two months,the small GAC columns filled with new coconut GAC on top of the same spent GAC became effective biological activated carbon (BAC) systems capable of removing ＞40％ MTBE from the influent; a small dose of hydrogen peroxide provided the essential dissolved oxygen to sustain aerobic degradation of MTBE in the adsorbers; adding peroxide to the nfluents of two serial adsorbers is desirable in treating newly contaminated groundwater. When MTBE concentration of the influent declined steadily, the BAC capability prevented the sudden rise of MTBE concentration in the effluent and helped to restore the long term treatment effectiveness. Treating the low MTBE influent (1.0 mg/L),the five BAC columns of different spent GAC amount and operating conditions all demonstrated outstanding treatment performance in the 165 days of operation with stable MTBE removals of ＞97％ and cumulative removal of ＞282％ of the theoretical adsorptive capacity of the columns. The research has established an effective inoculation method to enable long term removal of MTBE in a GAC adsorber as well as a source of highly acclimated MTBE degrading bacteria.%甲基叔丁基醚(MTBE)是一种常见的汽油添加剂,但汽油油箱和地下储油罐的泄漏.造成了汽油及添加剂对地下水的污染.实验分析了生物活性炭吸附工艺去除地下水中MTBE的可行性,结果表明:(1)处理高MTBE进水(模拟新污染的地下水)实验时,对椰壳活性炭(简称椰壳炭)柱,煤质活性炭(简称煤质炭)柱采用菌液循环接种法接种来自美国南加州La Mirada MTBE污染点生物活性炭柱更换下来的废弃炭(简称废弃炭)中的菌液,90 d的运行中,接种炭柱出水MTBE与未接种炭柱总体一致.(2)与典型活性炭穿透曲线形成鲜明对比,在下层填充带有MTBE降解菌的废弃炭、上层覆盖不同椰壳炭比例的3个炭柱内,MTBE去除率总体先降后升的现象说明了炭拄内微生物降解作用逐渐增强,显示生物活性炭功能建立.(3)总体上,在165 d处理低MTBE进水的实验过程中,5个不同尺寸、废弃炭比例、操作方式建立的生物活性炭柱对MTBE的去除率高于97%.5个炭柱中累积的MT-BE去除量至少为理论吸附量的2.82倍.废弃炭较多有利于快速建立生物活性炭功能;较多的椰壳炭在长期应用过程中可以去除更多MTBE,并能抵制进水浓度变化对处理效果的不良影响.炭拄长期去除MTBE主要是依靠新建立的生物活性炭功能,而非废弃炭中少量MTBE降解菌的作用.(4)不同浓度的H202溶液在进入炭柱后,均迅速地被分解为溶解氧,剩余低浓度的H2O2在炭柱内不会对细菌产生不利影响,印证了H2O2的供氧能力与适用性.在实际应用活性炭吸附工艺时,一般均采用双柱串联处理方式,用以提高吸附容量利用率并保证出水水质稳定.
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