Department of Applied Geology, Aquatic Geochemistry and Hydrogeology, Institute of Geoscience, Kiel University, Ludewig-Meyn-Straße 10, 24118 Kiel, Germany.
Department of Applied Geology, Aquatic Geochemistry and Hydrogeology, Institute of Geoscience, Kiel University, Ludewig-Meyn-Straße 10, 24118 Kiel, Germany.
J Contam Hydrol. 2023 Sep;258:104236. doi: 10.1016/j.jconhyd.2023.104236. Epub 2023 Aug 26.
We report on the potential of elevated groundwater temperatures and zero-valent iron permeable reactive barriers (ZVI PRBs), for example, through a combination with underground thermal energy storage (UTES), to achieve enhanced remediation of chlorinated hydrocarbon (CHC) contaminated groundwater. Building on earlier findings concerning deionized solutions, we created a database for mineralized groundwater based on temperature dependence of tetrachloroethylene (PCE) degradation using two popular ZVIs (i.e., Gotthart-Maier cast iron [GM] and ISPAT sponge iron [IS]) in column experiments at 25 °C-70 °C to establish a temperature-dependent ZVI PRB dimensioning approach. Scenario analysis revealed that a heated ZVI PRB system in a moderate temperature range up to 40 °C showed the greatest efficiency, with potential material savings of ~55% to 75%, compared to 10 °C, considering manageability and longevity. With a 25 °C-70 °C temperature increase, rate coefficients of PCE degradation increased from 0.4 ± 0.0 h to 2.9 ± 2.2 h (GM) and 0.1 ± 0.1 h to 1.8 ± 0.0 h (IS), while TCE rate coefficients increased from 0.6 ± 0.1 h to 5.1 ± 3.9 h at GM. Activation energies for PCE degradation yielded 32 kJ mol (GM) and 56 kJ mol (IS). Temperature-dependent anaerobic iron corrosion was key in regulating mineral precipitation and passivation of the iron surface as well as porosity reduction due to gas production.
我们报告了地下水温度升高和零价铁渗透反应屏障（ZVI PRB）的潜力，例如，通过与地下热能储存（UTES）相结合，实现氯化碳氢化合物（CHC）污染地下水的强化修复。基于早期有关去离子溶液的发现，我们创建了一个基于温度的数据库，用于研究在 25°C-70°C 下使用两种流行的 ZVI（即 Gotthart-Maier 铸铁[GM]和 ISPAT 海绵铁[IS]）进行的地下水矿化的四氯乙烯（PCE）降解，以建立一个依赖温度的 ZVI PRB 尺寸设计方法。情景分析表明，在 40°C 以下的中等温度范围内，加热的 ZVI PRB 系统显示出最大的效率，与 10°C 相比，考虑到可管理性和耐久性，潜在的材料节省约为 55%至 75%。随着 25°C-70°C 温度的升高，PCE 降解的速率系数从 0.4±0.0 h 增加到 2.9±2.2 h（GM）和 0.1±0.1 h 增加到 1.8±0.0 h（IS），而 TCE 的速率系数从 0.6±0.1 h 增加到 5.1±3.9 h GM。PCE 降解的活化能为 32 kJ mol（GM）和 56 kJ mol（IS）。依赖温度的厌氧铁腐蚀是调节矿物沉淀和铁表面钝化以及由于气体产生导致孔隙率降低的关键。
