He Xiaojuan, Liu Fei, Huang Yuanying, Li Xudong, Tang Minggao, He Jiangtao
School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China.
Huan Jing Ke Xue. 2003 Jan;24(1):139-42.
Tetrachloroethene (PCE), trichloroethene (TCE) and carbon tetrachloride (CT) were selected as target contaminants in this paper. Experiments were conducted to determine the effectiveness of zero-valent iron on dechlorination reaction and reaction-affecting factors in different mixing conditions. The results show that selected iron scrapes were effective in the dechlorination of chlorinated aliphatics, especially for chlorinated alkanes, and dechlorination reaction was pseudo first order. When PCE and TCE coexist, the reaction rate constant (K) was 0.0624 mL.(m2.h)-1 and 0.0357 mL.(m2.h)-1 respectively, showing the higher the chlorinated degree the quicker the reaction. When CT and PCE coexist, K was 0.1341 mL.(m2.h)-1 and 0.0129 mL.(m2.h)-1 respectively; compared with PCE, CT was degraded much more quickly and thoroughly giving an account of alkane was prior to alkene in dechlorination when at the same chlorinated degree. Either chlorinated alkanes or alkenes, their degradation half-lives were lower in monocomponent condition than coexisting with other component.
本文选取四氯乙烯（PCE）、三氯乙烯（TCE）和四氯化碳（CT）作为目标污染物。开展实验以确定零价铁在不同混合条件下对脱氯反应的有效性及反应影响因素。结果表明，所选铁屑对氯代脂肪烃脱氯有效，尤其对氯代烷烃，脱氯反应为准一级反应。当PCE和TCE共存时，反应速率常数（K）分别为0.0624 mL·(m²·h)⁻¹和0.0357 mL·(m²·h)⁻¹，表明氯代程度越高反应越快。当CT和PCE共存时，K分别为0.1341 mL·(m²·h)⁻¹和0.0129 mL·(m²·h)⁻¹；与PCE相比，CT降解更快且更彻底，说明在相同氯代程度下，氯代烷烃在脱氯时优先于烯烃。无论是氯代烷烃还是烯烃，其在单一组分条件下的降解半衰期均低于与其他组分共存时的情况。
