A Novel Permeable Reactive Barrier Approach for Phenolic and Nitrogen Pollutants Removal via Direct Fuel Cells with Its Electricity Retrieval

Permeable reactive barrier (PRB) is an in situ remediation of contaminated sites mostly suitable for halogenated pollutants like halo-hydrocarbons reduced by zero-valent irons (ZVI) developed during early 1990’s. However, remediation of some nitrogen-pollutants like ammonia and urea is unsuccessful due to lack of reactants. Most recent advanced direct ammonia/urea fuel cells utilize indirect hydrogen within ammonia/urea molecules to generate electricity. Herein, a comprehensive study based on the chosen design, working principles, advantages and disadvantages of direct ammonia fuel cells for new approach of PRBs for denitrifying nitrogen-contaminant is summarized. Most surveys are carrying out in our laboratories and this work aims to review the most recent advances in ammonia fuel cells integrated with PRBs and demonstrates the proximity of this technology to future applications. Meanwhile, several challenges such as how to accumulate ammonia and urea in order to achieve satisfying energy recovery, oxidants formation, power densities and long term stability are also summarized in this review.