Zero-valent iron (ZVI) based permeable reactive barrier (PRB) is a commonly used engineering method for interceptive and passive treatment of trichlorethene (TCE) in the groundwater through reductive pathways; however, passivation of iron challenges the long-term performance of ZVI. E-Redox™ (I) technology was applied to reverse passivation and enhance TCE reduction. The E-Redox™ (I) laboratory study was conducted in a packed with ZVI (passivated) and sand mixture to simulate a ZVI-PRB. Results indicate that the presence of elevated concentration of nitrate can quickly passivate virgin ZVI, as shown in the diminished efficiency in TCE reduction. The application of EIR™ on passivated ZVI reverted the trend and achieved up to approximately 70% of the TCE degrading efficiency of the virgin ZVI.