Issue 1, 2022

Disinfection of constructed wetland effluent by in situ electrochemical chlorine production for water reuse

Abstract

Constructed wetlands (CWs) are globally used for the treatment of wastewater. Due to various causes, often the water is not fully treated in terms of pathogen removal, requiring additional treatment. Here we evaluated the electrochemical disinfection (ED) of CW effluents to guarantee safe wastewater reclamation in decentralized settings. We used a two-chamber electrochemical cell to produce chlorine at a Ti/RuO2 anode with a synthetic electrolyte containing 18.3 mol Cl m−3 and subsequently tested it with CW effluents from two locations (Ecuador and Belgium). The effluents ran first to the anode for disinfection by chlorine and then to the cathode for recovering a circumneutral pH. Different flow rate, current density, and membrane type combinations were tested with the synthetic electrolyte to optimize chlorine production and later to disinfect CW effluents. The system produced about twice as much free chlorine when an anion exchange membrane was selected rather than a cation exchange membrane because of chloride electromigration to the anolyte. A 5-log removal of fecal indicators was observed without pathogen regrowth within 7 days after treatment when residual chlorine remained, allowing for non-potable water reuse. Lower residence times (15 s) and current densities (50 A m−2) induced the most energy-efficient operation with a charge density of 10.4 A h m−3 and an energy consumption of <0.1 kW h m−3. These results encourage CW + ED use, especially in low-income countries.

Graphical abstract: Disinfection of constructed wetland effluent by in situ electrochemical chlorine production for water reuse

Supplementary files

Article information

Article type
Paper
Submitted
29 ก.ย. 2564
Accepted
08 พ.ย. 2564
First published
09 พ.ย. 2564

Environ. Sci.: Water Res. Technol., 2022,8, 98-107

Disinfection of constructed wetland effluent by in situ electrochemical chlorine production for water reuse

S. Mosquera-Romero, A. Prévoteau, J. B. A. Arends, D. P. L. Rousseau, L. Dominguez-Granda and K. Rabaey, Environ. Sci.: Water Res. Technol., 2022, 8, 98 DOI: 10.1039/D1EW00708D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements