Grantee Research Project Results
PFASs Removal by Photocatalysis for Water Reuse
EPA Grant Number: SV840022Title: PFASs Removal by Photocatalysis for Water Reuse
Investigators: Liu, Jia
Institution: Southern Illinois University - Carbondale
EPA Project Officer: Aja, Hayley
Phase: II
Project Period: July 1, 2020 through June 30, 2022
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2020) Recipients Lists
Research Category: P3 Awards
Objective:
Based on the success of PFAS removal by Fe0 nanoparticles (NPs) under ultraviolet (UV) C light during the bench-scale Phase I project, the overall objective of the Phase II project is to conduct PFAS removal and degradation (e.g., PFOA and PFOS) from wastewater effluents (WEs) in an enhanced pilot-scale for WE reuse in agriculture. The specific objectives are as follows.
- To study the influence of pH of WEs on PFAS removal/degradation in bench-scale, for the purpose of achieving optimal PFAS removal with minimal pH adjustment of the WEs.
- To design and fabricate a point-of-use (POU) system, including an innovative sequencing batch photoreactor (SBPR), and a magnetic separation reactor
- To investigate WEs treatment in lab-scale (spike PFAS if needed) in a sequencing-batch mode using the POU system in terms of PFAS removal and bacterial inactivation; to determine optimal concentration of dissolved oxygen in the WEs for PFAS removal, and the proper dosage and utilization duration for Fe0 NPs in the SBPR.
- To treat WEs containing PFAS in the field, where WEs have been used for irrigation purposes; to analyze the finished water quality for water reuse.
- To verify no PFAS residue in the used iron particles after their separation from the POU system, for possible application in acid mine drainage affected sites.
Approach:
The overall experimental approach of the Phase II project is to achieve PFAS removal in WEs in pilot-scale (from lab to field) based on the successful Phase I bench-scale study, with the support of local stakeholders comprising two wastewater treatment plants (WWTPs) in the City of Carbondale, IL, and the Illinois Department of Natural Resources (IDNR). The specific approaches are as follows.
1) Our two partners from the City of Carbondale are Northwest WWTP and Southeast WWTP. Northwest WWTP has utilized a portion of their WEs to irrigate a nearby golf course. Both of the WEs from the two WWTPs will be studied for the impact of pH on PFAS removal from WEs in bench-scale in lab.
2) The POU system will be designed based on the most cost-effective technology achieved in Phase I - by Fe0 NPs under UVC with presence of O2, with consideration of: area of each piece of agricultural lands available near the two WWTPs, the amount of irrigation water needed for each agricultural land, the whole cycle duration for the POU system, and the hydraulic retention time of the SBPR.
3) The energy consumption in the Phase II pilot-scale project was calculated to be very low − the annual UVC energy consumption is ~20 KWh for a 90 US-gallon SBPR (UVC light intensity ~2.3 W/m2, 30 min hydraulic retention time).
4) Water quality of the POU treated WEs will be evaluated on concentrations of PFAS, and on concentrations of bacteria (i.e., total coliform and Escherichia coli – microorganisms monitored for potable water, and Enterococci – indicators of environmental fecal contamination), as bacteria can be inactivated under UVC, which makes the POU system as a PFAS removal system as well as a disinfection unit that is critical for wastewater reuse.
5) The WEs from both WWTPs will be studied in pilot-scale in the lab by the designed POU system.
6) The POU system will then be installed in Northwest WWTP for treatment efficiency test, after current wastewater treatment units, and before current installed discharge pipeline of the WEs for irrigation purposes.
7) Used iron particles will be deposited on an abandoned coal mine site in Southern Illinois, managed by IDNR, Office of Mines and Minerals. The used iron particles (zero-valent iron core and iron oxide shell) could potentially increase the pH of the abandoned mine site affected by acid mine drainage (pH ~2.5).
Expected Results:
Successful completion of Phases II of this project will inform best practices to enable the cost-effective reuse of PFAS-contaminated WEs in agriculture, which will provide direct benefits to U.S. communities and regions (and beyond) where insecurity of freshwater resources is present and/or water use follows unsustainable trajectories. Moreover, the proposed efforts will impact the global effort to improve the broader environmental impact of water treatment and water recycling, e.g., by reducing contamination of groundwater and surface water resulting from runoff of reclaimed irrigation water, by restoring groundwater and surface water resources for access by future generations or for other uses through closed-loop usage of treated WEs, and by protecting soil and aqueous ecosystems from exposure to PFAS through direct discharge, irrigation, agricultural runoff, and infiltration. Besides, the products of the proposed research should better enable the safe reuse of WEs, thereby lowering costs for agriculture, without sacrificing the health of neighboring populations. Project results will be disseminated in water treatment, water reuse, and agricultural communities through oral/poster presentations at conferences and workshops, publications in peer-reviewed journals, and through media broadcast. Middle and High School students will be educated about the work in Saluki High School Water Workshops and Regional/State Science Fairs of the Illinois Junior Academy of Science.
Publications and Presentations:
Publications have been submitted on this project: View all 3 publications for this projectJournal Articles:
Journal Articles have been submitted on this project: View all 3 journal articles for this projectSupplemental Keywords:
nZVI, nanomaterial, clean water, pathogenProgress and Final Reports:
P3 Phase I:
PFASs Removal by Photocatalysis for Water Reuse | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.