Natural attenuation of chlorinated ethenes in hyporheic zones: A review of key biogeochemical processes and in-situ transformation potential

WATER RESEARCH

卷:128

Review

Weatherill, John J.¹  Atashgahi, Siavash²  Schneidewind, Uwe³  Krause, Stefan⁴  Ullah, Sami⁴  Cassidy, Nigel⁵  Rivett, Michael O.^6,7 

[1] Keele Univ, Sch Phys & Geog Sci, Keele, Staffs, England

[2] Wageningen Univ & Res, Lab Microbiol, Stippeneng 4, NL-6708 WE Wageningen, Netherlands

[3] Rhein Westfal TH Aachen, Dept Engn Geol & Hydrogeol, Aachen, Germany

[4] Univ Birmingham, Sch Geog Earth & Environm Sci, Birmingham, W Midlands, England

[5] Univ Birmingham, Sch Engn, Birmingham, W Midlands, England

[6] Univ Strathclyde, Dept Civil & Environm Engn, Glasgow, Lanark, Scotland

[7] GroundH2O Plus Ltd, Birmingham, W Midlands, England

关键词: Chlorinated ethenes;    Hyporheic zone;    Natural attenuation;    Biogeochemistry;    Biotransformation;    Heterogeneity;   

DOI  :  10.1016/j.watres.2017.10.059

来源: Elsevier

【 摘 要 】

Chlorinated ethenes (CEs) are legacy contaminants whose chemical footprint is expected to persist in aquifers around the world for many decades to come. These organohalides have been reported in river systems with concerning prevalence and are thought to be significant chemical stressors in urban water ecosystems. The aquifer-river interface (known as the hyporheic zone) is a critical pathway for CE discharge to surface water bodies in groundwater basefiow. This pore water system may represent a natural bioreactor where anoxic and oxic biotransformation process act in synergy to reduce or even eliminate contaminant fluxes to surface water. Here, we critically review current process understanding of anaerobic CE respiration in the competitive framework of hyporheic zone biogeochemical cycling fuelled by in-situ fermentation of natural organic matter. We conceptualise anoxic-oxic interface development for metabolic and co-metabolic mineralisation by a range of aerobic bacteria with a focus on vinyl chloride degradation pathways. The superimposition of microbial metabolic processes occurring in sediment biofilms and bulk solute transport delivering reactants produces a scale dependence in contaminant transformation rates. Process interpretation is often confounded by the natural geological heterogeneity typical of most riverbed environments. We discuss insights from recent field experience of CE plumes discharging to surface water and present a range of practical monitoring technologies which address this inherent complexity at different spatial scales. Future research must address key dynamics which link supply of limiting reactants, residence times and microbial ecophysiology to better understand the natural attenuation capacity of hyporheic systems. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

Free