Lanthanum(III)-Coated Ceramics as a Promising Material in Point-of-Use Water Treatment for Arsenite and Arsenate Removal

Low-cost and efficient As(V) (arsenate) and As(III) (arsenite) sorbents for point-of-use (POU) water filtration are needed for areas suffering from high arsenic contamination in their drinking water sources. In this study, lanthanum (La)-coated ceramic materials were used to produce both granules and disk filters for the removal of As(V) and As(III). Results from filtration experiments showed that the La coated granules and disk filters could effectively treat similar to 11200 solutions, as well as similar to 6400 and similar to 3200 PVs of As(III) and similar to 14500 pore volumes (PVs) of As(V) contaminated contaminated solutions to meet the drinking water standard (<0.010 mg/L), respectively. Batch experiments were further conducted to elucidate the sorption behaviors of As(V) and As(III), and the sorption capacities reached 24.8 and 10.9 mg/g for As(V) and As(III), respectively. Characterization of La coated ceramic material before and after As sorption suggested that the removal of As(V) may be primarily attributed to the formation of surface LaAsO4 precipitates, while formation of inner-sphere complexes with La on the ceramic surface contributed to As(III) removal. La-coated ceramic material could be used as a promising low-cost and efficient arsenic removal medium for POU household water treatment.