2022 Volume 2 Pages 88-93
Poly- and perfluoroalkyl substances (PFAS) are environmentally persistent organic compounds of industrial origin and harmful to human health and ecosystems. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) remain the most common PFAS in aquatic environments despite recent regulations on their use. In the water purification process, selection of materials such as activated carbon (AC) to efficiently adsorb and remove PFOS and PFOA remains a major challenge from the viewpoints of cost, efficiency of organic pollutant removal and disposal of used adsorbents. For efficient water purification, here we aimed to identify effective and low-cost carbon-based adsorbents (granular AC [GAC] and powdered AC [PAC]) with good physiochemical properties for removing PFOS and PFOA. The conventional GAC removed 12% of PFOA but could not remove PFOS. Alternatively, PAC #1, #2 and #3 removed >90% of PFOS and PFOA in 72 h at 25°C. Moreover, only a marginal difference in adsorption performance was observed among coconut husk, coal and wood. The removal rate of PFOS and PFOA by PAC #3 (at 1 mg/L) was 100% and 98%, respectively, rendering it the most effective water purification adsorbent. PAC #1, #2 and #3 had a significant adsorption effect compared with PAC #4 and GAC and are more cost-effective than conventional GAC, thereby making them ideal for water purification. This study presents a feasible water purification method involving PFOS and PFOA removal.