Ammonia Recovery from Manure Wastewater and Simultaneous Electrosynthesis and Wastewater Treatment Using Ion Selective Redox Material

Abstract

The environmental pressure due to greenhouse gas emissions and water contamination generated by livestock manure motivates the development of new approaches to reduce their environmental impacts and improve sustainability. Effective approaches to recover nutrients, especially ammonia, from manure wastewater to produce fertilizer are needed. Here we develop a new electrochemical strategy to achieve simultaneous ammonium (NH4 +) ion recovery and electrochemical synthesis using potassium nickel hexacyanoferrate as the ammonium ion-selective redox material to mediate the process. Our approach is built on our recent advances in designing modular electrochemical synthesis mediated using redox active materials (which we call redox reservoirs). Specifically, NH4 + (and K+) can be spontaneously uptaken from manure wastewater with a nutrient (NH4 + and K+) selectivity of ~100% driven by the oxidation of organic matter. Subsequently, NH4 +-rich fertilizers are released electrochemically together with the electrosynthesis of value-added chemicals, such as H2O2 as a disinfectant, without expensive ion-exchange membranes. We will also discuss our preliminary results on simultaneous advanced oxidation processes to improve the treatment of PFAS chemicals in wastewater. These results provide a new conceptual strategy for distributed electrochemical resource recovery and on-demand electrochemical manufacturing that can improve the sustainability of agricultural and wastewater treatment processes