More than 300 million people worldwide are affected by toxic levels of arsenic in the groundwater used for drinking. Iron based electrochemical technologies, such as iron electrocoagulation, have been demonstrated as effective methods to remove arsenic to below the WHO-MCL of 10 µg/L in resource poor regions. Recently, Air Cathode Assisted Iron Electrocoagulation (ACAIE) has been demonstrated as a promising technology to rapidly remove arsenic in the groundwater at extremely short retention times (~30 seconds). However, the long term performance of the ACAIE system is poorly understood, especially the degradation (fouling) of the air cathodes. Current work aims to address the knowledge gap regarding the durability and longevity of the air cathodes used in the ACAIE reactors, specifically, the influence of current density (at 5 mA/cm2 and 50 mA/cm2) and exposure time to a given electrolyte (representative of California groundwater). System performance is evaluated using a combination of electrochemical (linear sweep voltammetry) and physical characterization techniques (contact angle, x-ray photoelectron spectroscopy, scanning electron microscopy, and BET surface area) to quantitatively assess air cathode degradation over time and better understand the causes behind observed fouling. These analyses will be combined with wet-chemical measurements (e.g., total iron and H2O2 faradaic efficiency) to understand the impact of fouling on bulk solution parameters.

Influence of current density on the long term performance of air cathodes used in a novel water treatment technology for arsenic remediation

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.