Progress on electrochemical and photoelectrochemical urea and ammonia conversion from urine for sustainable wastewater treatment

• Published in: Applied catalysis. B, Environmental Vol. 362; p. 124718
• Main Authors: Akkari, Sophia, Sánchez-Sánchez, Carlos M., Hopsort, Guillaume, Serrano, Karine Groenen, Loubière, Karine, Tzedakis, Théodore, Benyahia, Raihana, Rebiai, Lamia, Bastide, Stéphane, Cachet-Vivier, Christine, Vivier, Vincent, Lopez-Viveros, Melissa, Azimi, Sam
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2025; Elsevier
• Subjects: Ammonia electro-oxidation; By-products; Catalysis; Chemical engineering; Chemical Sciences; Electrocatalysis; Environmental Engineering; Environmental Sciences; Other; Photoelectrochemical reactors; Urea electro-oxidation; Urine valorization; Wastewater treatment; PECR; STH; ATR-IR; TRL; SHE; DFT; EDS; IC; Urea electro-oxidation; Eapp; Eocell; By-products; MS; SIAAP; TOC; Urine valorization; LCA; Wastewater treatment; EEO; EIS; SEC; Re, Rp, Rpe; SEG; SERS; MIS; TKN; η; NF; SEM; OER; ν; FE; FTO; TCO; NP; BDD; MAV; ΔRG; SEV; υ; F; PANI; SAV; Eo; NHE; N; RHE; RPM; P; Electrocatalysis; RDE; SF; ClER; FTIR; COD; Photoelectrochemical reactors; XPS; GC; EAOP; Ammonia electro-oxidation; AOR; DAFC; j; CP; PEC; PB; CV; PC; HER; SCE; WWTP; ΔfGj; DNA; Eanode; CPC; DEMS; UOR; TN; Urine Valorization; Ammonia Electro-oxidation; Urea Electro-oxidation; Wastewater Treatment
• ISSN: 0926-3373
• DOI: 10.1016/j.apcatb.2024.124718

The valorization of urine through the electro-oxidation of urea offers a promising alternative for industrial wastewater treatment plants. This operation, implemented at room temperature, allows, in addition to the depolluting action, the generation of hydrogen at the cathode. Using inexpensive electrodes and photo-assisting the process, this method has potential for industrial application. This review delves into the recent advancements in the electrochemical treatment of urea and ammonia from urine, understanding and optimizing the electrolysis process under various conditions. Notably, the electrolysis of urea and ammonia in alkaline medium over nickel oxyhydroxide (NiOOH) catalyst, has emerged as a promising avenue, offering enhanced selectivity and efficiency. The exploration extends to urine management, urea degradation, catalyst deactivation, reaction selectivity, and the detection of reaction products, as well as photoelectrochemical processes in a future reactor perspective, where the synergistic combination of photocatalysis and electrochemical oxidation opens new pathways for urine valorization. [Display omitted] •Urea contained in urine represents a relevant nitrogen source in circular economy.•Electrocatalysts for both urea and ammonia electro-oxidation reactions are required.•Electroactive molecules in the urine matrix are responsible for deactivation.•H2 production coupled with either UOR or AOR on NiOOH anodes requires Eºcell of −1.32 V.•Photo-assisted UOR and AOR processes present a lot of potential for future development.