Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Environ Sci Technol. 2011 Jan 15;45(2):719-25. doi: 10.1021/es102420r. Epub 2010 Dec 16.
A continuous-flow column study was conducted to investigate the long-term effects of persulfate oxidation on the abundance and activity of the indigenous microbial community and phenanthrene-degrading bacteria in contaminated soil from a former manufactured gas plant (MGP) site. Approximately six pore volumes of a 20 g/L persulfate solution were introduced into the column, followed by simulated groundwater for 500 days. Soil samples were collected from the surface of the soil bed and along the column length immediately before and after persulfate injection and up to 500 days following injection. Exposure to persulfate led to a 2- to 3-log reduction in total bacterial 16S rRNA genes, severe inhibition of (14)C-acetate mineralization (as a measure of general microbial activity), and a decrease in community diversity. However, relatively rapid recovery of both bacterial gene abundance and activity was observed within 30 days after persulfate exposure. Mineralization of (14)C-phenanthrene was also inhibited but did not recover until 100 days postoxidation. Known phenanthrene-degrading bacterial groups decreased to below detection limits throughout the column, with recovery times from 100 to 500 days after persulfate injection. These findings suggest that coupling biological processes with persulfate oxidation is possible, although recovery of specific contaminant degraders may occur much later than the general microbial community recovers. Furthermore, the use of total bacterial quantity or nonspecific measures of activity as a surrogate for the recovery of contaminant degraders may be inappropriate for evaluating the compatibility of chemical treatment with subsequent bioremediation.
采用连续流柱实验研究了过硫酸盐氧化对受污染土壤中土著微生物群落和菲降解菌丰度和活性的长期影响，该污染土壤来自于一个前煤气厂（MGP）场地。大约向柱中注入了 6 个孔隙体积的 20 g/L 过硫酸盐溶液，随后用模拟地下水进行了 500 天实验。在过硫酸盐注入前后和注入后 500 天内，立即从土壤床表面和沿柱长采集土壤样品。过硫酸盐暴露导致总细菌 16S rRNA 基因减少了 2-3 个对数，（14）C-乙酸盐矿化作用（作为一般微生物活性的衡量标准）严重受到抑制，群落多样性下降。然而，在过硫酸盐暴露后 30 天内，细菌基因丰度和活性均迅速恢复。（14）C-菲的矿化作用也受到抑制，但直到氧化后 100 天才恢复。整个柱中已知的菲降解细菌群下降到检测限以下，过硫酸盐注入后 100-500 天恢复。这些发现表明，尽管特定污染物降解菌的恢复可能比一般微生物群落的恢复晚得多，但可以将生物过程与过硫酸盐氧化结合使用。此外，将总细菌数量或非特异性活性测量作为污染物降解菌恢复的替代指标，可能不适合评估化学处理与后续生物修复的兼容性。
