Experiments with Fe(III)-rich, chloroethene-contaminated sediment demonstrated that trichloroethylene (TCE) and vinyl chloride (VC) were completely reduced to ethene regardless of whether electron donor(s) were added at 1 × stoichiometry or 10 × stoichiometry relative to all-electron acceptors. Unamended controls uniformly reduced TCE to ethene with a mean time to complete dechlorination (operationally defined as the presence of stoichiometric ethene production) of 79 days. Adding 1 × and 10 × acetate hindered the rate and extent of TCE and VC reduction relative to unamended controls, with several only partially reduced when the experiments were terminated. Adding high molecular mass (soybean oil derivative) substrates did not increase microbial reductive dechlorination relative to unamended incubations, and in many cases, hindered microbial dechlorination in favor of methanogenesis. The mean time to complete dechlorination was comparable between low (× 1) and high (× 10) electron donor concentration for all lipid-based electron donors tested. Those tested included Newman Zone® Standard without sodium lactate (96 vs. 75 days, respectively), CAP 18 ME (85 vs. 94 days, respectively), EOS 598B42 (68 vs. 72 days, respectively), and acetate (134 vs. 125 days, respectively). These data suggest that the addition of an electron donor does not always increase the rate and extent of reductive dechlorination but will increase costs. In particular, increasing the concentration of electron donors higher than the stoichiometric demand only decreased complete microbial reductive dechlorination, which is the opposite of most standard “more time and more electrons” approaches. These data argue that site-specific electron donor demands must be evaluated, and in some cases, a monitored natural attenuation (MNA) approach is most favorable.

对富含 Fe(III)、氯乙烯污染的沉积物进行的实验表明，无论电子供体是以 1 × 化学计量比还是 10 × 化学计量比添加，三氯乙烯 (TCE) 和氯乙烯 (VC) 都完全还原为乙烯。全电子受体。未经修改的对照品将 TCE 均匀地减少为乙烯，同时完成脱氯的平均时间（操作上定义为存在化学计量的乙烯生产）79 天。添加 1 × 和 10 × 醋酸盐阻碍了 TCE 和 VC 降低的速度和程度，相对于未修改的对照，当实验终止时，其中一些仅部分降低。相对于未经修正的孵育，添加高分子量（大豆油衍生物）底物不会增加微生物还原脱氯，并且在许多情况下，会阻碍微生物脱氯，有利于产甲烷。完成脱氯的平均时间对于所有测试的基于脂质的电子供体，低 (× 1) 和高 (× 10) 电子供体浓度之间具有可比性。测试的产品包括不含乳酸钠的 Newman Zone® Standard（分别为 96 天和 75 天）、CAP 18 ME（分别为 85 天和 94 天）、EOS 598B42（分别为 68 天和 72 天）和醋酸盐（分别为 134 天和 72 天） . 125 天，分别）。这些数据表明，添加电子供体并不总能提高还原脱氯的速度和程度，但会增加成本。特别是，将电子供体的浓度增加到高于化学计量要求只会降低微生物的完全还原脱氯，这与大多数标准的“更多时间和更多电子”方法相反。这些数据表明，必须评估特定地点的电子供体需求，并且在某些情况下，