利用零价铁去除挥发性氯代脂肪烃的试验

选用四氯乙烯(PCE)、三氯乙烯(TCF)与四氯化碳(CT)为靶污染物,研究不同组合下,零价铁系统对各污染物降解的有效性及反应进行的影响因素.结果表明:实验选用的废料生铁可有效去除水中的有机氯代脂肪烃类,尤其对氯代烷烃具有较强的降解功能,且反应符合准一级反应动力学方程;当PCE和TCE共存时,PCE和TCE的反应速率常数K分别为0.0624mL·(m²·h)^-1和0.0357mL·(m²·h),说明氯代程度高的PCE脱氯快;当CT和PCE共存时,二者的K分别为0.1341mL·(m2·h)^-1和0.0129mL·(m²·h)^-1,CT的脱氯快且彻底,说明氯代程度相同时烷烃的脱氯优于烯烃;无论是哪种氯代烃,单独存在时其反应的半衰期均短于与其它组分共存时.

Degradation of Volatile Chlorinated Aliphatics by Zero-Valent Iron

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 0.0624mL·(m²·h)^-1 and 0.0357mL·(m²·h)^-1 respectively, showing the higher the chlorinated degree the quicker the reaction. When CT and PCE coexist, K was 0.1341mL·(m²·h)^-1 and 0.0129mL·(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.