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

Abstract

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 ∼11200 and ∼14500 pore volumes (PVs) of As­(V) contaminated solutions, as well as ∼6400 and ∼3200 PVs of As­(III) 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.

Ceramic water filter for point-of-use water treatment in developing countries: Principles, challenges and opportunities

“…Improved CWF designs that can simultaneously achieve both high flow rate and effective bacterial removal are desirable but remain a great challenge. In addition, CWFs often have limited capability of removing contaminants such as viruses and chemical pollutants (Yang et al, 2019a).…”

“…For instance, ceramic disk filter modified with ferric iron was developed to improve arsenic removal, and the filter performance was strongly affected by the ferric iron loading (Robbins et al, 2014). Recently, lanthanum (La), an abundant rare earth element with relatively low cost, was applied in our study as a novel and effective coating for ceramic materials to target the removal of negatively-charged arsenate (As(V)) and non-charged arsenite (As(III)) (Yang et al, 2019a). The La-coated ceramic material showed substantially enhanced capture of both As(V) and As(III) with the sorption capacities of 24.8 and 10.9 mg/g, respectively.…”

Sequential uptake of cadmium and methylene blue from binary solution using zeolite‐TiO2 modified porous CaCu3Ti4O12 photocatalyst

“…Numerous water treatment technologies at the point-of-use level are carried out in household practices. 1 The drinking water treatment household systems contribute to facilitating the community; however, it requires a certain level of expertise by the users. Since antiquity, ceramic water filter (CWF) has been used in manufacturing the household filters.…”

“…Therefore, the modification of ceramics is essential to sustain the efficiency of these filters. Recently, to improve the adsorptive capacity of ceramic materials in the removal of contaminants upon modification with metal oxides have been successfully studied 1,2,13,14 …”

“…Recently, to improve the adsorptive capacity of ceramic materials in the removal of contaminants upon modification with metal oxides have been successfully studied. 1,2,13,14 Previously, various catalysts and adsorbents, such as carbon nanotubes, 15 activated bentonite, 16 date palm leaves, 17 centaurea stem, 18 modified-carbonized date pits/ZnO, 19,20 and Co 3 O 4 nanocube doped polyaniline nanocomposite, 21 have been employed for the efficient removal of toxicants from aqueous solutions. In general, TiO 2 NPs are well known for their photocatalytic potentials.…”