Developmental study on trichloroethylene degradation by a bioreactor

生物反应器降解三氯乙烯的进展研究

基本信息

批准号：
02556014
负责人：
UCHIYAMA Hiroo
金额：
$ 3.14万
依托单位：
National Institute for Environmental Sciences
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

1. Characterization of liquid-solid phase trichloroethylene (TCE) degradation by Methylocystis sp. M (strain M) immobilized in Ca alginate was studied to maximize the degradation rate. The results obtained were as follows. (1) In order to get the cells of strain M possessing high specific activity for TCE degradation, elimination of Cu (almost to zero) in the medium and harvesting the cells at the end of the log phase were very important. (2 ) Kinetics constants (V max and Ks) and optimum conditions for TCE degradation (pH, temperature, DO) by immobilized cells were cleared. (3) The half life of the degradability of strain M was relatively short, and which was caused by the toxicity of intermediates formed by TCE degradation in the cells. (4) Inactivated cells by the intracellular toxicity were reactivated by incubation with methane or methanol, suggesting that the immobilized cells was possible to be repeatedly used in the TCE degradation. (5) Under the optimum conditions obtained, semicontinuous TCE degradation in a 5L bioreactor showed that the total amount of approximately 13mg TCE could be degraded in 120h.2. We also studied on the gas-solid phase TCE degradation system by the immobilized cells. The gaseous TCE of 0.3ppm, which was fed continuous into the glass-column bioreactor, was almost completely degraded in about 50h. The maximum TCE concentration to be degraded by this reactor was 100ppm, suggesting that, as the gaseous TCE concentration exhausted from ducts of TCE treatment facilities was too high (300-500ppm), the gaseous TCE was necessary to be diluted and be applied to the bioreactor.

1. 甲基囊藻降解液固相三氯乙烯 (TCE) 的表征。研究了固定在海藻酸钙中的 M（菌株 M），以最大限度地提高降解率。得到的结果如下。 (1)为了获得对TCE降解具有高比活性的菌株M细胞，消除培养基中的Cu(几乎为零)并在对数期结束时收获细胞是非常重要的。 (2)明确了固定化细胞TCE降解的动力学常数(V max 和Ks)和最佳条件(pH、温度、DO)。 (3)菌株M的降解性半衰期较短，这是由于TCE在细胞内降解形成的中间体的毒性所致。 (4)通过与甲烷或甲醇一起孵育，由细胞内毒性灭活的细胞被重新激活，这表明固定化细胞可以在TCE降解中重复使用。 (5)在所得到的最佳条件下，在5L生物反应器中进行半连续TCE降解，结果表明120h内可降解总量约13mg TCE。2。我们还研究了固定化细胞气固相TCE降解系统。将0.3ppm的气态TCE连续送入玻璃柱生物反应器中，在约50h内几乎完全降解。该反应器降解的最大TCE浓度为100ppm，表明由于TCE处理设施管道排出的气态TCE浓度过高（300-500ppm），需要将气态TCE稀释后应用于生物反应器。