Effects of pre and post-ozonation on POFA hollow fibre ceramic adsorptive membrane for arsenic removal in water

Abstract

This study examined the use of modified palm oil fuel ash (POFA) prepared from agricultural waste as key material for fabricating the POFA hollow fibre ceramic membrane (PHFCM) to trap arsenite, As(III), and arsenate, As(V), from water. In this study, the ozonation technique was employed where the effects of pre- and post-ozonation on the adsorption capacity of PHFCM and fouling mitigation were investigated respectively. The highest sintering temperature of 1150 °C (PHFCM-11500) delivered maximum adsorption capacities that corresponded to 95.62 and 98.34 mg·g−1 of As(III) and As(V). PHFCM-1150 with sufficient mechanical strength (52.84 MPa) and excellent pure water flux (250.73 L/m2.h) were selected for further exploration with ozonation study. Pre-ozonation increased the adsorption performance while the fouling problem of PHFCM was successfully treated by post-ozonation. Additionally, the post-ozonation treatment offers a cost-effective application of PHFCM-1150 with only 3 min of optimum reaction time that enables the integrated reuse of the sorbent, with the practical and effective removal of As for industrial effluent/wastewater treatment. This study also demonstrated that PHFCM-1150 was effective and its respective As removal met the maximum discharge limit of 10 μg/L set by the World Health Organization and the national legislation in Malaysia.