Temperature dependence of sequential chlorinated ethenes dechlorination and the dynamics of dechlorinating microorganisms. (January 2022)

• Record Type: Journal Article
• Authors: Yamazaki, Yuji; Kitamura, Gaku; Tian, Xiaowei; Suzuki, Ichiro; Kobayashi, Takeshi; Shimizu, Takaaki; Inoue, Daisuke; Ike, Michihiko
• Is Part Of: Chemosphere. Volume 287:Part 1(2022)
• Publication Date: 2022-01
• Subjects: Thermally enhanced anaerobic dechlorination -- Chlorinated ethenes -- Dehalococcoides -- Microbial community structure -- qPCR -- Amplicon sequencing; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.131989
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Thermally enhanced bioremediation is a promising approach to shorten the bioremediation period of tetrachloroethene (PCE) and trichloroethene (TCE). To clarify the influence that temperature has on stepwise PCE dechlorination and associated microorganisms, this study conducted dechlorination experiments using contaminated soil and groundwater under five distinct temperature conditions (i.e., 15, 20, 25, 30, and 35 °C). PCE and TCE were dechlorinated most rapidly at 25–35 °C, whereas the preferable temperatures for the dechlorination of cis -1, 2- dichloroethene ( cis -1, 2-DCE) and vinyl chloride (VC) were 25–30 °C and 25 °C, respectively. Microbial community analysis revealed that Sulfurospirillum and Geobacter may have a dominant contribution to the dechlorination of PCE to cis -1, 2-DCE, whereas Dehalococcoides harboring VC reductase genes are likely major contributors to the dechlorination of cis -1, 2-DCE and VC. These results suggest that temperature influences various microbial groups, including major dechlorinating microorganisms, resulting in the different extent of PCE dechlorination. In addition, the microbial community structure greatly changed after the onset of the experiment, whereas the temperature influence of 15–30 °C on the microbial community structure was minor; however, the microbial community was significantly impacted at 35 °C. Collectively, these results suggest that thermally enhanced anaerobic dechlorination at 25 °C is useful for successful dechlorination of chlorinated ethenes in a short period. Highlights: Effects of elevated temperature on PCE stepwise dechlorination were examined. Overall dechlorination was achieved within the shortest period at 25 °C. Optimum dechlorination temperature varied depending on chlorinated ethene species. Behaviors of dechlorinating bacterial groups reflected the temperature preference. Thermal effects on microbial community structure below 30 °C were relatively small.