生物曝气去除MTBE的实验

Experiments on MTBE Removal Using Biosparging

在一维土柱模拟装置上采用生物曝气技术去除饱和土壤和地下水中的甲基叔丁基醚(MTBE).通过实验和非线性最小二乘法拟合得到MTBE在生物降解过程中的Monod参数:最大利用速率、半饱和常数和生物得率.考察了在不同污染物初始浓度和不同微生物接种量情况下生物曝气对MTBE的去除效果及生物贡献率.实验结果表明:MTBE初始质量浓度为50 mg/L和100 mg/L时,降解率分别为23.23%和12.08%,降解量分别为25.74 mg和26.75 mg.对于高污染物浓度,挥发是主要的去除机理.在初始污染物浓度相同的情况下,微生物数量的增加直接导致了污染物总去除量的增加,微生物的数量决定了所能降解的污染物的质量.

A soil column set-up was designed to study the removal effect of methyl tea-butyl ether（MTBE） and volatilization-to-biodegradation ratio during the biosparging process at different initial concentrations of MTBE in saturated soil and grotmdwater. Monod coefficients including the maximum specific substrate utilization rate, half-saturation coefficient and the yield coefficient were obtained from batch experiments and least-square method. Experimental results show that when the initial concentrations of MTBE are 50 mg/L and 100 mg/L, the biodegradation ratios are 23.23% and 12.08%, and the degradation mass is 25.74 mg and 26.75 rag, respectively. It is the volatilization that controls the dominant removal mechanism at high contaminant concentration. The increase of microorganism numbers induced to the more removal mass of contaminates at the same initial concentration of MTBE. So numbers of microorganism determine the mass of contaminates which could be removed by biodegradation.