Urine-powered synergy of nutrient recovery and urine purification in a microbial electrochemical system. Issue 10 (29th August 2018)

• Record Type: Journal Article
• Authors: Gao, Yifan; Sun, Dongya; Wang, Han; Lu, Lu; Ma, He; Wang, Lisheng; Ren, Zhiyong Jason; Liang, Peng; Zhang, Xiaoyuan; Chen, Xi; Huang, Xia
• Is Part Of: Environmental science. Volume 4:Issue 10(2018)
• Page Start: 1427
• Page End: 1438
• Publication Date: 2018-08-29
• Subjects: Water-supply -- Periodicals; Water security -- Periodicals; Water resources development -- Periodicals; Water chemistry -- Periodicals; 553.705
• DOI: 10.1039/c8ew00306h
• Languages: English
• ISSNs: 2053-1400

Abstract

Abstract : Energy in urine was extracted to synergize the in situ urine purification and nutrient recovery with net electricity production via a microbial electrochemical system named U-Power. Abstract : This study demonstrates that the chemical energy contained in human urine can synergize the in situ nutrient recovery and purification of urine itself. This process was achieved using a urine-powered microbial electrochemical system named U-Power, which can provide a maximum power density of 21.3 W m −3 via the degradation of fresh human urine. Urea hydrolysis was induced by anodic microorganisms and further accelerated by the electrical potential inside U-Power to provide ammonium and balance the pH in the anode. Driven by the electrical potential generated by U-Power, the NH4 + and PO4 3− contained in urine migrated into the high nutrient concentration recovery solution. On average, 93.8% of organics, 73.1% of nitrogen and 86.2% of phosphorus were removed, along with recovery concentrations of 1234 mg L −1 nitrogen and 101 mg L −1 phosphorus. Both the above purification and recovery processes require no energy input but output a satisfactory power density among all present urine treatment studies, together with an average current efficiency of 178% and a coulombic efficiency of 26%. By achieving the triple benefits of energy-positive recovery of nutrients from urine, avoiding the complicated and energy-intensive process of nutrient removal in downstream wastewater treatment facilities, and avoiding the energy and hygiene issues combined with the storage and reuse of urine, U-Power represents a promising tool to pave the way for a sustainable water–energy–nutrient nexus.