Grantee Research Project Results
Final Report: Development of Microwave-assisted Membrane Filtration for Pretreatmentof PFAS in Industrial Wastewater
EPA Contract Number: 68HERD19C0014Title: Development of Microwave-assisted Membrane Filtration for Pretreatmentof PFAS in Industrial Wastewater
Investigators: Moese, Mark
Small Business: BRISEA Group, Inc.
EPA Contact: Richards, April
Phase: I
Project Period: May 1, 2019 through October 31, 2019
Project Amount: $100,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2019) RFA Text | Recipients Lists
Research Category: SBIR - Water Quality , Small Business Innovation Research (SBIR) , Small Business Innovation Research (SBIR) Phase I (2018) , Small Business Innovation Research (SBIR): Phase 1 (2019)
Description:
Our designed microwave-assisted membrane (MWM) aims to provide a unique solution to the degradation of refractory PFASs for industrial wastewater treatment via advanced oxidation processes (AOPs). Our research objectives are (1) evaluation of the performance of MWM for the removal of PFOA (2) assessment system stability and anti-fouling performance of MWM in the treatment of PFOA water. (3) analysis of PFOA degradation mechanism by detecting the intermediate of PFOA degradation.
Our designed microwave-enhanced membrane (MWM) combines microwave catalysis (BiFeO3) and membrane filtration into a hybrid multifunctional filtration system that exhibits unparalleled antifouling characteristics and reactivity toward refractory water pollutants. Our hypothesis is that the microwave-absorbing catalyst (BiFeO3) coated on the ceramic membrane will produce hydroxyl radicals that enhance oxidative degradation of PFOA. Furthermore, reactive nanobubbles will be generated on membrane surface that prevents membrane fouling and assists degradation of PFOA via thermal or other chemical mechanisms. This MWM filtration systems will provide new insight to the current issues and limitations for industrial wastewater treatment of refractory PFASs.
Summary/Accomplishments (Outputs/Outcomes):
Some preparations have been made for the microwave-enhanced filtration experiment. The BFO-coated ceramic membrane was prepared, then characterized by XRD, EDX and SEM to confirm the presence of the BFO catalyst layer that is coated on the ceramic membrane. What's more, the nanobubbles formation under microwave irradiation have been proved by zeta potential measurement of DI water samples under different size distribution. We also established seven species of PFAS calibration curves used to detect the intermediate of PFOA degradation by LCQQQ.
The BFO-coated ceramic membrane (2.7 μg∙cm-2) was used in a dead-end filtration mode with the feed solution passing through the membrane. The PFOA (50 μg·L−1) and H2O2 solution (30 mM) were mixed in a volume ratio of 1:1 at a tee and pumped into the filtration unit at 1.25 mL·min-1, which rendered a hydraulic retention time of 2 min. The contributions of PFOA removal from physical separation and MW-Fenton-like degradation were differentiated and quantified by switching microwave irradiation (125W) "on" or "off". According to the result of the three consecutive rounds of filtration tests shown as fig, we found that the BFO-coated ceramic membrane has the capability of PFOA adsorption, which led to a PFOA concentration in the permeate that was lower than the initial concentration during the filtration stage without microwave irradiation. However, the adsorption and filtration did not remove PFOA, because surface adsorbed PFOA will be released at the beginning of microwave irradiation, shown by the sharply increased PFOA concentration and transmembrane pressure (TMP). After the microwave irradiation, the PFOA concentration was rapidly reduced as shown in the green area, indicating that the MW-assisted Fenton-like reaction on BFO-coated membrane was crucial for the PFOA degradation. The MW-assisted Fenton-like reaction contributed to a degradation rate as high as 84%.
Moreover, the optimized performance of the microwave-enhanced filtration system to PFOA degradation have been by explored under different experiment condition. For example, comparing the flow rate of 7 ml∙min-1 and 1.25 ml∙min-1, we found the latter own higher efficiency of PFOA under microwave irradiation (Figure 1d), while the PFOA fail to be degraded at 7 ml∙min-1(Figure 2b). And comparing the coated BFO concentration of 1.6 μg∙cm-2 (Figure 2c) and 2.7 μg∙cm-2(Figure 2a), we proved the lower catalyst concentration have deal with membrane fouling to provide a more stable system.
Finally, to confirm the degradation of PFOA, the fluoride ion in the solution was analyzed by an ion chromatography (IC). Fluoride ion concentrations of outlet (0.15 mg∙L-1) was higher than the concentration of inlet (0.08 mg∙L-1), proving the release of fluoride ion in the process of PFOA degradation. Meanwhile, PFPeA have been detected from outlet sample by LC-QQQ (Figure 2d), which shows that they may be the intermediates of PFOA degradation. Therefore, we speculate the possible mechanism of PFOA degradation
Figure 2. (a) three consecutive round of filtration tests under coated BFO concentration: 2.7 μg∙cm-2, flow rate: 1.25 ml-min1. (b) PFOA concentarion change under coated BFO concentration: 1.6 μg∙cm-2, flow rate: 7 ml-min-1. (c) PFOA concentration change under coated BFO concentration: 1.6 1.6 μg∙cm-2, flow rate: 1.25 ml-min1. (d) PFPeA concentration change with filtration time. The green area in the graph is the membrane filtration with microwave irradiation whereas the rest was under filtration only. under MW-catalytic membrane
filtration as follows:
C7F15COO-+·OH→C7F15COO·+HO- (1)
C7F15COO·→CO2+ C7F15· (2)
C7F15·+2H2O→C6F13COOH+2F- +2H++H (3)
Conclusions:
Throughout the six months of calls to companies and potential investors we determined many have interest in the technology, but most want some proof that it will work above the proof of concept stage. Many provided their thoughts on implementing an add-on to their current water treatment system in which their major concern was the overall cost of purchasing the equipment its requirements for implementation and how easy it will be to maintain the system and who would maintain the system.
Over the course of the project we also held initial discussions with three potential investor groups –IPAT as per our proposal, Everbright Greentech which is an investment holding company, that engages in the provision of environmental protection services to further evaluate investment interest in the technology; and Coway International Tech Trans Co. Ltd. who specializes in international technology transfer, and commercialization of technology through technology licensing, transfer, incubation, investment and financing. Discussions with these 3 firms have continued although at a slower pace than desired.
Based on our interviews and Foresight’s evaluation we feel that there is not only a need for the technology and interest in the water treatment industry for new technology but also interest in funding the development of our microwave membrane technology. We have also come to fully realize that future commercialization will require more significant efforts.
References:
- Fu, W.; Zhang, W., Microwave-enhanced membrane filtration for water treatment. Journal of Membrane Science 2018, 568, 97-104.
- Li, S.; Zhang, G.; Zhang, W.; Zheng, H.; Zhu, W.; Sun, N.; Zheng, Y.; Wang, P., Microwave enhanced Fenton-like process for degradation of perfluorooctanoic acid (PFOA) using Pb-BiFeO3/rGO as heterogeneous catalyst. Chemical Engineering Journal 2017, 326, 756-764.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 3 publications | 3 publications in selected types | All 3 journal articles |
---|
Type | Citation | ||
---|---|---|---|
|
Li S, Zhang G, Zhang W, Zheng H, Zhu W, Sun N, Zheng Y, Wang P. Microwave enhanced Fenton-like process for degradation of perfluorooctanoic acid (PFOA) using Pb-BiFeO3/rGO as heterogeneous catalyst. Chemical Engineering Journal2017;326:756-64 |
68HERD19C0014 (Final) |
Exit Exit |
|
Fu W, Zhang W. Microwave-enhanced membrane filtration for water treatment. Journal of Membrane Science 2018;568:97-104 |
68HERD19C0014 (Final) |
Exit Exit |
|
Liu F, Hua L, Zhang W. Influences of microwave irradiation on performances of membrane filtration and catalytic degradation of perfluorooctanoic acid (PFOA). Environment international. 2020;143:105969. |
68HERD19C0014 (Final) |
Exit |
The 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.