DEDUCING THE DISTRIBUTION OF TERMINAL ELECTRON-ACCEPTING PROCESSES IN HYDROLOGICALLY DIVERSE GROUNDWATER SYSTEMS
DEDUCING THE DISTRIBUTION OF TERMINAL ELECTRON-ACCEPTING PROCESSES IN HYDROLOGICALLY DIVERSE GROUNDWATER SYSTEMS
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DOI：
10.1029/94wr02525
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发表时间：
1995-02-01
影响因子：
5.4
通讯作者：
VROBLESKY, DA
中科院分区：
文献类型：
--
作者：
CHAPELLE, FH;MCMAHON, PB;VROBLESKY, DA
通过考虑电子受体（硝酸盐、硫酸盐）消耗、中间产物（氢（H-2））浓度和最终产物（亚铁、硫化物和甲烷）产生的模式，研究了四种水文不同的地下水系统中微生物介导的终端电子接受过程（TEAPs）的分布。在每个水文系统中，可以得出一个主要teap的确定值，但每个确定值的置信水平不同。例如，在圣华金河谷的部分湖相含水层中，所有三个指标（硫酸盐浓度下降，H-2浓度在1-2 nmol范围内，硫化物浓度沿流动路径增加）都表明硫酸盐还原是主要的TEAP，从而使测定结果具有高度的可信度。在佛罗里达部分含水层和含油烃污染的含水层中，硫化物和甲烷的产生以及氢的浓度分别在1 ~ 4 nmol和5 ~ 14 nmol范围内，表明硫酸盐还原和甲烷生成。然而，由于在这些系统中不能记录电子受体的消耗，因此TEAP测定的可信度较低。在Black Creek含水层中，没有观察到硫酸盐消耗和硫化物产生的模式，但H，浓度表明硫酸盐还原是主要的TEAP。在这种情况下，只有一条证据可用，对TEAP诊断的信心最低是合理的。由于该方法基于可测量的水化学参数和微生物电子转移过程的生理学，因此与传统的基于eh的方法相比，它能更好地描述地下水系统中的主要氧化还原过程。
The distribution of microbially mediated terminal electron-accepting processes (TEAPs) was investigated in four hydrologically diverse groundwater systems by considering patterns of electron acceptor (nitrate, sulfate) consumption, intermediate product (hydrogen (H-2)) concentrations, and final product (ferrous iron, sulfide, and methane) production. In each hydrologic system a determination of predominant TEAPs could be arrived at, but the level of confidence appropriate for each determination differed. In a portion of the lacustrine aquifer of the San Joaquin Valley, for example, all three indicators (sulfate concentrations decreasing, H-2 concentrations in the 1-2 nmol range, and sulfide concentrations increasing along flow paths identified sulfate reduction as the predominant TEAP, leading to a high degree of confidence in the determination. In portions of the Floridan aquifer and a petroleum hydrocarbon-contaminated aquifer, sulfate reduction and methanogenesis are indicated by production of sulfide and methane, and hydrogen concentrations in the 1-4 nmol and 5-14 nmol range, respectively. However, because electron acceptor consumption could not be documented in these systems, less confidence is warranted in the TEAP determination. In the Black Creek aquifer, no pattern of sulfate consumption and sulfide production were observed, but H, concentrations indicated sulfate reduction as the predominant TEAP. In this case, where just a single line of evidence is available, the least confidence in the TEAP diagnosis is justified. Because this methodology is based on measurable water chemistry parameters and upon the physiology of microbial electron transfer processes, it provides a better description of predominant redox processes in groundwater systems than more traditional Eh-based methods.