Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, D-04318 Leipzig, Germany.
Water Res. 2010 Mar;44(6):1785-96. doi: 10.1016/j.watres.2009.12.002. Epub 2010 Jan 13.
A novel aerated treatment pond for enhanced biodegradation of groundwater contaminants was tested under field conditions. Coconut fibre and polypropylene textiles were used to encourage the development of contaminant-degrading biofilms. Groundwater contaminants targeted for removal were benzene, methyl tert-butyl ether (MTBE) and ammonium. Here, we present data from the first 14 months of operation and compare contaminant removal rates, volatilization losses, and biofilm development in one pond equipped with coconut fibre to another pond with polypropylene textiles. Oxygen concentrations were constantly monitored and adjusted by automated aeration modules. A natural transition from anoxic to oxic zones was simulated to minimize the volatilization rate of volatile organic contaminants. Both ponds showed constant reductions in benzene concentrations from 20 mg/L at the inflow to about 1 microg/L at the outflow of the system. A dynamic air chamber (DAC) measurement revealed that only 1% of benzene loss was due to volatilization, and suggests that benzene loss was predominantly due to aerobic mineralization. MTBE concentration was reduced from around 4 mg/L at the inflow to 3.4-2.4 mg/L in the system effluent during the first 8 months of operation, and was further reduced to 1.2 mg/L during the subsequent 6 months of operation. Ammonium concentrations decreased only slightly from around 59 mg/L at the inflow to 56 mg/L in the outflow, indicating no significant nitrification during the first 14 months of continuous operation. Confocal laser scanning microscopy (CLSM) demonstrated that microorganisms rapidly colonized both the coconut fibre and polypropylene textiles. Microbial community structure analysis performed using denaturing gradient gel electrophoresis (DGGE) revealed little similarity between patterns from water and textile samples. Coconut textiles were shown to be more effective than polypropylene fibre textiles for promoting the recruitment and development of MTBE-degrading biofilms. Biofilms of both textiles contained high numbers of benzene metabolizing bacteria suggesting that these materials provide favourable growth conditions for benzene degrading microorganisms.
一种新型曝气处理池用于强化地下水污染物的生物降解，在野外条件下进行了测试。椰纤维和聚丙烯纺织品被用于促进污染物降解生物膜的发展。目标去除的地下水污染物为苯、甲基叔丁基醚（MTBE）和氨。在这里，我们呈现了前 14 个月运行的数据，并比较了一个配备椰纤维的池塘和另一个配备聚丙烯纺织品的池塘的污染物去除率、挥发损失和生物膜发展情况。通过自动化曝气模块不断监测和调整氧气浓度。模拟从缺氧区到好氧区的自然过渡，以最大限度地减少挥发性有机污染物的挥发率。两个池塘都显示出苯浓度从系统入口的 20mg/L 持续降低到出口的约 1μg/L。动态空气室（DAC）测量表明，只有 1%的苯损失是由于挥发，这表明苯损失主要是由于好氧矿化。MTBE 浓度从入口处的约 4mg/L 在运行的前 8 个月内降低到系统出水中的 3.4-2.4mg/L，在随后的 6 个月运行中进一步降低到 1.2mg/L。氨浓度仅从入口处的约 59mg/L 略微降低到出口处的 56mg/L，表明在连续运行的前 14 个月内几乎没有硝化作用。共焦激光扫描显微镜（CLSM）表明，微生物迅速定植在椰纤维和聚丙烯纺织品上。使用变性梯度凝胶电泳（DGGE）进行的微生物群落结构分析表明，水和纺织品样本的模式之间几乎没有相似性。椰纤维纺织品比聚丙烯纤维纺织品更有效地促进 MTBE 降解生物膜的招募和发展。两种纺织品的生物膜都含有大量的苯代谢细菌，这表明这些材料为苯降解微生物提供了有利的生长条件。
