Project 5: Green Remediation by Solar Energy Conversion Into Electrolysis

美国环保署支持采用绿色补救措施，该措施考虑了所有环境影响和 纳入战略，以最大限度地提高净环境效益。我们的长远目标是发展绿色 基于太阳能转化为地下水中铁的电解法的修复。电解法 牺牲铁阳极将导致污染物的化学减少，包括氯化溶剂 地下水。双电极电解体系中铁的氧化还原动力学及亚铁离子的释放 通过控制电流密度和极性可以优化氢气的充放电性能。 污染物的转化。该工艺适用于岩溶地下水含水层，因为动态 沟槽和裂缝中的流动条件需要控制铁的反应速度。这一过程将使用太阳能 不会对地下水环境产生不利影响。该项目将对效果进行评估 铁电解对地下水地球化学的影响，论证了三氯乙烯的转化 间歇和流动条件下铁电解法模拟地下水非极性有机污染物 条件，评估极性反转和电压/电流强度的影响，开发预测工具 改造的“模型”，评估对含水层物理性质的影响，评估 经处理的水的细胞毒性，并评估对其他污染物(如半极性污染物)命运的任何不利影响 有机化合物，如邻苯二甲酸盐)。该项目将在利用岩溶含水层的细胞中进行实验。 特征，包括用石灰岩砌块建造的实验装置。该计划包括2D 使用GeoBed(在项目4中开发)进行的实验室小规模测试和小规模现场测试。初级阶段 将被控制的实验变量是水流量、电流/电压和电解液 打字。将被监测的主要因变量是pH、ORP、溶解氧、碱度、 阳离子和阴离子浓度，污染物浓度，亚铁和铁离子浓度， 沉淀物、电导率和电压/电流。一个符合法拉第铁定律的模型 将开发和验证电解和反应流程。该项目将评估电力需求和 制定一项利用太阳能电池板进行实地实施的战略。

The US EPA supports the adoption of green remediation, which considers all environmental effects and incorporates strategies to maximize the net environmental benefit. Our long-term goal is to develop a green remediation based on conversion of solar energy into iron electrolysis in groundwater. Electrolysis of sacrificial iron anodes will cause chemical reduction of contaminants, including chlorinated solvents in groundwater. The kinetics of iron redox in a two-electrode electrolysis system and release of ferrous ions and hydrogen gas can be optimized by controlling the electric current density and polarity for effective transformation of contaminants. The process is suited for karstic groundwater aquifers because the dynamic flow conditions in channels and fractures require controlled rates of iron reactivity. The process will use solar energy and will not produce adverse effects on groundwater environment. The project will evaluate the effect of iron electrolysis on groundwater geochemistry, demonstrate the transformation of trichloroethylene (TCE) as a model nonpolar organic contaminant in groundwater by iron electrolysis under batch and flow conditions, evaluate the effects of polarity reversal and voltage/current intensity, develop a predictive tool "model" for transformation, evaluate the effects on the physical properties of the aquifer, assess the cytotoxicity of treated water, and evaluate any adverse effects on the fate of other contaminants (e.g., semipolar organics such as phthalates). The project will conduct experiments in cells using karst aquifer characteristics, including experimental setups that are constructed of limestone blocks. The plan includes 2D lab pilot-scale testing using the GeoBed (developed in Project 4) and a small-scale field test. The primary experimental variables that will be controlled are the water flow rate, electric current/voltage and electrolyte type. The primary dependent variables that will be monitored are pH, ORP, Dissolved Oxygen, alkalinity, cation and anion concentrations, contaminant concentration, ferrous and ferric ion concentrations, precipitates, electrical conductivity, and voltage/current. A model that couples Faraday's law for iron electrolysis and reactive flow will be developed and verified. The project will assess power requirement and engineer a strategy that utilizes solar panels for field implementation.