Electrochemical and bioelectrochemical ammonium recovery from N-loaded streams using a hydrophobic membrane

Bioelectrochemical systems enable the recovery of ammonium from wastewater with low energy requirements and as a concentrated nitrogen-rich stream. This work aims to thoroughly investigate different cathodic electrode configurations and to optimize the operational conditions for active ammonium reco...

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Bibliographic Details
Authors: Ul Kausar, Zainab|||0000-0002-2007-2277, Galeano, Mariella Belen, Sulonen, Mira Lotta Kristiina|||0000-0003-4812-3360, Baeza, Mireia|||0000-0002-2240-6410, Baeza, Juan Antonio|||0000-0003-1290-1669, Guisasola, Albert|||0000-0002-3012-7964
Format: article
Publication Date:2025
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:315708
Online Access:https://ddd.uab.cat/record/315708
https://dx.doi.org/urn:doi:10.1016/j.bioelechem.2025.109013
Access Level:Open access
Keyword:Ammonium recovery
Cation exchange membrane
Hydrophobic membrane
Microbial electrolysis cell
Ni foam
Stainless steel
Description
Summary:Bioelectrochemical systems enable the recovery of ammonium from wastewater with low energy requirements and as a concentrated nitrogen-rich stream. This work aims to thoroughly investigate different cathodic electrode configurations and to optimize the operational conditions for active ammonium recovery from synthetic wastewater as concentrated ammonium sulphate. Different applied current intensities (50 mA, corresponding to 5 A m, and 75 mA, corresponding to 7.5 A m) and initial ammonium concentrations (between 0.3 and 3 g L N-NH ) were tested in an abiotic electrochemical system to understand the upper threshold of the used three-chamber configuration with hydrophobic membrane in terms of ammonium recovery rate (R). With an external current of 75 mA, the highest value was 55 gN-NH m d when removing 97 % from an initial ammonium concentration of 3 g L. Bioelectrochemical ammonium removal/recovery was evaluated under different applied potentials (0.8, 1.0, 1.2, and 1.4 V) using two configurations: a Nickel-based gas diffusion electrode (GDE) and a configuration with the cathode (stainless steel or nickel foam) physically separated from the hydrophobic membrane. The highest removal rate (R) (21 gN-NH m d) was exhibited for stainless steel cathode at 1.4 V mainly due to its higher current density, which increased the cations migration. This higher R also led to a higher R (17 gN-NH m d).