Study of hybrid membrane filtration and photocatalysis for removal of perfluorooctanoic acid (PFOA) in groundwater.

Groundwater contamination in Thailand from leaking of leachate due to improper solid waste disposal can cause contamination by PFOA (one of the perfluorinated compounds). This study proposed a new idea for the removal of PFOA from groundwater using a combination of membrane filtration and photocatalysis. Spiked groundwater samples were treated by nanofiltration and the rejected part was sent to a UV contact tank for photocatalysis. All samples were analyzed by high-performance liquid chromatography-tandem mass spectrometer (HPLC-MS/MS). The results showed that the removal efficiency of nanofiltration was 99.62%, and the rejected part was degraded by photocatalysis at an efficiency of 59.64%. Thus, the contaminants released to the environment were only 34.23%, which is around three times lower than nanofiltration alone. The results of this technical feasibility study proved that hybrid membrane filtration and photocatalysis are able to remove and degrade the contaminants in the rejected part significantly before being released to the environment, which has been the biggest gap in the processing of membrane filtration, and should be studied further in other aspects, such as fouling effects, energy consumption, and operating costs in a long-term pilot run.