Project 4 Paper Analyzing a Combined EAOP-Pyrite Water Remediation System Highlighted by NIEHS
A new paper by PROTECT Project 4 researchers investigates the effectiveness of a combined electrochemical advanced oxidation process (EAOP) and pyrite water remediation system to clean contaminated groundwater. The paper, which was published in the Journal of Hazardous Materials and led by postdoc Jong-Gook Kim, was highlighted in the NIEHS SRP August Research Brief.
The EAOP remediation technique applies an electrical current to water to remove contaminants, while the standard pyrite system deploys the mineral to absorb contaminants in water. In this study, researchers compared the effectiveness of these systems to the effectiveness of a system that combines the two techniques to clean water contaminated with arsenic, chromium, and sulfanilamide. Investigators found that the EAOP system on its own was able to remediate sulfanilamide but was less effective when it came to transforming arsenic and chromium into their less toxic forms. The individual pyrite system did not effectively treat or absorb high amounts of any of the contaminants. The combined EAOP-pyrite system, however, was able to effectively treat all three of the contaminants.
The combined EAOP-pyrite system utilizes a vertical acrylic flow-through reactor with a carbon fiber anode and graphite cathode. Researchers observed that the electrochemical reactions in the combined system produced hydroxyl radicals and dissolved oxygen, which activated the pyrite and generated dissolved iron. The electrodes in the system then transformed the iron into iron (oxy)hydroxide, which is able to remove both organic and heavy metal pollutants. The production of iron also led to the formation of green rust, which is a natural absorbent and reductant that plays a crucial role in the contaminant removal process. In this study, investigators saw that the green rust was especially effective in removing arsenic and sulfanilamide from water samples.
Visual abstract
The combined EAOP-pyrite system was able to overcome the limitations of the individual EAOP and pyrite systems while leveraging the benefits of each. These findings present a promising approach for in-situ groundwater remediation of organic and inorganic contaminants. Further research can be done to evaluate the economic viability and long-term sustainability of the combined system in real-world field conditions.
Read the full paper here. Read the NIEHS’s Research Brief of the paper here.