纳米零价铁在含水层中的腐蚀过程与产物演化对三氯乙烯去除的影响机理研究

纳米零价铁(nano-iron)的高去除效率和可被用于更深含水层的特性使其备受关注。然而，nano-iron在地下水中发生腐蚀产生大量腐蚀产物，腐蚀过程和产物演化对含水层渗透性和污染物去除机理有着重要影响。本研究以含水介质中nano-iron腐蚀过程和产物演化为研究对象，利用小角XRD、显微红外、激光拉曼光谱等原位表征手段刻画在不同地下水环境和水化学参数影响下nano-iron的腐蚀动力学过程和腐蚀产物从无定型到弱结晶再到结晶的过程，尤其关注腐蚀和产物演化过程中溶胀因子的变化，探讨nano-iron注入后含水层渗透系数变化的主要控制因素，同时以三氯乙烯（TCE）为代表性污染物探讨nano-iron去除氯代烃的动力学过程，揭示nano-iron去除氯代烃的机理，从微观矿物结构演化和纳米颗粒相互作用的角度去理解和把握地下水系统中nano-iron颗粒的腐蚀和产物演化对修复过程的影响。

People pay more and more attention on nano-iron because it has high removal efficiency and can be used in deeper aquifer. But nano-iron with high specific surface area is corroded easily and generates a lot of corrosion products compared to granular iron. It is unreasonable to ignore the effect on aquifer permeability and removal mechanism for pollutants from corrosion process and products evolution. The project will characterize nano-iron corrosion kinetic process and corrosion products evolution under different environment conditions from amorphors, weak crystallized to well crystallized by small angle XRD, laser Raman and micro-FTIR. We will focus on the relation between rust expansion coefficient and aquifer permeability. The factors will probed which control the change of permeability from nano-iron application. TCE, which is one of typical chlorinated hydrocarbons removed by granular iron, will be taken as model compound to reveal the removal mechanism by nano-iron and corrosion products. This research aims to well understand evolution process of nano-iron in groundwater from mineral structure and nano-particles interaction and it is helpful for nano-iron application.