The Microbial Electrochemical Current Accelerates Urea Hydrolysis for Recovery of Nutrients from Source-Separated Urine

Abstract

This study demonstrates that a wastewaterdriven microbial electrochemical process greatly facilitates traditional rate-limiting urea hydrolysis and efficiently recovers ammonium and phosphate nutrients from source-separated urine. Using both synthetic and diluted actual urine and wastewater, 76−87% of nitrogen and 72−93% of phosphorus were continuously removed from source-separated urine and collected in recovery solutions. The acceleration of hydrolysis and nutrient recovery were driven by the electrical potential generated during wastewater treatment. The efficient nutrient recovery is attributed to the increase in the rate of hydrolysis induced by continuous ammonium migration and removal, which alleviates storage, health, and operational issues associated with the utilization of urine. Further investigations of removal behaviors of micropollutants under electrochemical conditions will be performed.

Recovery of Nutrients from Residual Streams Using Ion-Exchange Membranes: Current State, Bottlenecks, Fundamentals and Innovations

“…MMFC are widely investigated to recover N III from wastewater [ 113 ], landfill leachate [ 82 ] and urine [ 114 , 115 , 116 ], where the conversion of urine to ammonium via ureolysis is accelerated by a generated electric field. The presence of CEM and AEM in such cells makes it possible to separate P V (which is in the form of phosphoric acid anions) and NH 4 + cations.…”

“…The second one is a periodic cleaning of membranes using acids, alkalis, perchlorates, and other oxidizing agents [ 90 ] or enzymes [ 9 , 114 , 247 , 248 , 249 ]. Xue et al [ 90 ] clearly demonstrated the effectiveness of such treatment ( Figure 25 ).…”

Revealing the mechanism of formation and transformation of chlorinated by‐products during electrolyzing synthetic urine using Ti/RuOx‐IrOx and BDD electrodes

“…Urine as the liquid metabolites of mammal makes up only about one percent of the total domestic wastewater (DWW) volume, but it contributes to nearly 80% of nitrogen and 50% of phosphorous in DWW [1]. Direct discharge of untreated urine not only causes water pollution but also causes potential infections by pathogens in urine [2].…”

Membrane Selection for Electrochemical Treatment of Septage

“…The CEM divided cell electrolytic reactors have been reported to separate and concentrate NH + 4 from synthetic wastewater (Gildemyn et al, 2015;Ren et al, 2017), urine (Luther et al, 2015), and anaerobic digestate (Desloover et al, 2015). The AEM divided cell reactors have been reported for phosphate (PO 3− 4 ) recovery (Zhang et al, 2013;Chen et al, 2017;Ledezma et al, 2017;Ren et al, 2017). NH + 4 and PO 3− 4 recoveries up to 90% have been demonstrated.…”