Concomitant urea stabilization and phosphorus recovery from source-separated fresh urine in magnesium anode-based peroxide-producing electrochemical cells.

Autor: Arve PH; Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC, USA., Mason M; Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC, USA., Randall DG; Department of Civil Engineering, University of Cape Town, Cape Town, South Africa., Simha P; Department of Energy and Technology, Swedish University of Agricultural Sciences, Uppsala, Sweden., Popat SC; Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC, USA. Electronic address: spopat@clemson.edu.
Jazyk: angličtina
Zdroj: Water research [Water Res] 2024 Jun 01; Vol. 256, pp. 121638. Date of Electronic Publication: 2024 Apr 17.
DOI: 10.1016/j.watres.2024.121638
Abstrakt: In this study, we investigated the recovery of nitrogen (N) and phosphorus (P) from fresh source-separated urine with a novel electrochemical cell equipped with a magnesium (Mg) anode and carbon-based gas-diffusion cathode. Recovery of P, which exists primarily as phosphate (PO 4 3- ) in urine, was achieved through pH-driven precipitation. Maximizing N recovery requires simultaneous approaches to address urea and ammonia (NH 3 ). NH 3 recovery was possible through precipitation in struvite with soluble Mg supplied by the anode. Urea was stabilized with electrochemically synthesized hydrogen peroxide (H 2 O 2 ) from the cathode. H 2 O 2 concentrations and resulting urine pH were directly proportional to the applied current density. Concomitant NH 3 and PO 4 3- precipitation as struvite and urea stabilization via H 2 O 2 electrosynthesis was possible at lower current densities, resulting in urine pH under 9.2. Higher current densities resulted in urine pH over 9.2, yielding higher H 2 O 2 concentrations and more consistent stabilization of urea at the expense of NH 3 recovery as struvite; PO 4 3- precipitation still occurred but in the form of calcium phosphate and magnesium phosphate solids.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Sudeep Popat reports financial support was provided by NASA. Philip Arve reports financial support was provided by SC Space Grant Consortium. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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