Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna, Via Terracini 28, 40131, Bologna, Italy,
Biodegradation. 2014 Jun;25(3):337-50. doi: 10.1007/s10532-013-9664-z. Epub 2013 Oct 6.
A procedure for the design of an aerobic cometabolic process for the on-site degradation of chlorinated solvents in a packed bed reactor was developed using groundwater from an aquifer contaminated by trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA). The work led to the selection of butane among five tested growth substrates, and to the development and characterization from the site's indigenous biomass of a suspended-cell consortium capable to degrade TCE (first order constant: 96 L gprotein(-1) day(-1) at 30 °C and 4.3 L gprotein(-1) day(-1) at 15 °C) with a 90 % mineralization of the organic chlorine. The consortium immobilization had strong effects on the butane and TCE degradation rates. The microbial community structure was slightly changed by a temperature shift from 30 to 15 °C, but remarkably affected by biomass adhesion. Given the higher TCE normalized degradation rate (0.59 day(-1) at 15 °C) and attached biomass concentration (0.13 gprotein Lbioreactor(-1) at 15 °C) attained, the porous ceramic carrier Biomax was selected as the best option for the packed bed reactor process. The low TeCA degradation rate exhibited by the developed consortium suggested the inclusion of a chemical pre-treatment based on the TeCA to TCE conversion via β-elimination, a very fast reaction at alkaline pH. To the best of the authors' knowledge, this represents the first attempt to develop a procedure for the development of a packed bed reactor process for the aerobic cometabolism of chlorinated solvents.
采用地下水作为填充床反应器中现场降解氯代溶剂的需氧共代谢过程的设计方法，该地下水取自被三氯乙烯（TCE）和 1,1,2,2-四氯乙烷（TeCA）污染的含水层。这项工作导致从五种测试的生长基质中选择了丁烷，并从现场的土著生物量中开发和表征了一种能够降解 TCE 的悬浮细胞联合体（在 30°C 和 4.3 L gprotein(-1) day(-1)时的第一级常数为 96 L gprotein(-1) day(-1)），有机氯的 90%矿化。联合体固定化对丁烷和 TCE 的降解速率有很强的影响。微生物群落结构因从 30°C 到 15°C 的温度变化而略有改变，但显著受生物质粘附的影响。鉴于更高的 TCE 归一化降解速率（15°C 时为 0.59 day(-1)）和附着的生物质浓度（15°C 时为 0.13 gprotein Lbioreactor(-1)），多孔陶瓷载体 Biomax 被选为填充床反应器工艺的最佳选择。所开发的联合体表现出的 TeCA 降解率较低，这表明需要包括基于 TeCA 到 TCE 转化的化学预处理，该转化通过β消除进行，这是一种在碱性 pH 值下非常快速的反应。据作者所知，这是首次尝试开发用于需氧共代谢氯代溶剂的填充床反应器工艺的方法。
