Development of a novel polyvinylidene fluoride membrane integrated with palm oil fuel ash for stabilized landfill leachate treatment

Abstract

Stabilized landfill leachate is a complex wastewater containing high concentration of non-biodegradable organic compounds and Ammoniacal nitrogen. Thus, an advanced treatment such as membrane technology is required to treat leachate effectively. In this study, membrane filtration process was employed to treat stabilized leachate. A new type of membrane was fabricated by incorporating palm oil fuel ash (POFA) into hydrophobic polyvinylidene fluoride (PVDF) polymer to produce flat sheet membrane via phase inversion technique. Response Surface Methodology (RSM) was applied to optimize the membrane fabrication. The filtration process was carried out using cross-flow ring (CFR) test. The best removal efficiencies of COD, colour and NH3–N was found using a membrane with the following composition: 13.9 wt% PVDF and 1.2 wt% POFA. To improve the permeability and anti-fouling ability, the best performing membrane was further modified using polyvinyl alcohol (PVA). The performance and characterization of unmodified and modified membranes were systematically analyzed. The results showed that filtration properties of modified membrane were efficiently developed by 0.5 wt% of PVA. Pure water flux value was enhanced from 40.16 to 81.08L/m2.h and transmembrane pressure was reduced from 0.60 to 0.55 bar as a result of the surface and pore size improvements. Moreover, the modified membranes significantly enhanced the removal of COD (57.06%), colour (58.27%) and NH3–N (55.44%) due to the newly developed microstructure. This study offers the best way to develop PVDF- POFA membrane improved by PVA for stabilized landfill leachate treatment. The produced PVDF membrane was also economical compared to the commercially available PVDF membrane.