A1 Journal article (refereed), original research

Enhanced ammonium removal and recovery from municipal wastewater by asymmetric CDI cell equipped with oxygen functionalized carbon electrode


Open Access publication

Publication Details
Authors: Pastushok Olga, Ramasamy Deepika, Sillanpää Mika, Repo Eveliina
Publisher: Elsevier
Publication year: 2021
Language: English
Related journal or series: Separation and Purification Technology
Volume number: 274
ISSN: 1383-5866
eISSN: 1873-3794
JUFO level of this publication: 2
Open Access: Open Access publication
Location of the parallel saved publication: http://urn.fi/URN:NBN:fi-fe2021061036476

Abstract

Following the concept of sustainable development and circular economy,
the Capacitive Deionization (CDI) was examined for the removal and
recovery of ammonium (NH4+) ions from municipal
wastewater towards prevention of eutrophication and obtaining a valuable
component for fertilizers production. The electrosorption study was
conducted in the symmetric CDI cell, composed of activated carbon (AC)
electrodes, and an asymmetric CDI cell, equipped with oxygen
functionalized AC (AC-ox) cathode. The asymmetric CDI cell was
demonstrated the enhanced performance in terms of the removal efficiency
towards ammonium ions (83%) and the related energy consumption (and
0.085 kWh/mmol NH4+), compared to the symmetric one with the following results: 30% removal of NH4+ ions and 0.215 kWh/mmol NH4+. The beneficial performance of the AC-ox electrode also has been observed in terms of NH4+ recovery: 20% recovered NH4+ ions, compared to 9% NH4+
recovered ions by AC pristine electrode. The presence of competitive
ions hindered the electrosorption efficiency. Nevertheless, the
time-dependent selectivity of the AC-ox electrode towards NH4+
ions was observed. The specific capacities of the symmetric and
asymmetric cells at 5 mV/s were calculated to be 10.4 F/g and 18.3 F/g,
respectively. Material characterization of AC before and after oxidation
explained the enhanced CDI performance of the AC-ox electrode due to
the increased hydrophilicity and additional oxygen functionalities on
the electrode surface.


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Last updated on 2021-16-06 at 07:31