Mechanistic study of simultaneous arsenic and fluoride removal using granular TiO2-La adsorbent

Abstract

h i g h l i g h t s Simultaneous As(III) and F removal is achieved by using granular TiO 2-La composite. LaCO 3 OH showing orientated growth on TiO 2 {1 0 0} facet with matched lattice fringes. Molecular-level coadsorption mechanism is investigated by EXAFS and DFT calculation. The importance of crystal facet in material synthesis and adsorption is highlighted.

Evaporation‐induced self‐assembly (EISA) synthesized mesoporous bimetallic oxides (MBOs) enabling enhanced co‐uptake of arsenate and fluoride from water

“…A wide range of point‐of‐use treatment techniques has been developed in past decades to remove both anions (i.e. As and F − ) from waters, including reverse osmosis (RO), nanofiltration (NF), ion exchange, electrocoagulation, and adsorption . Of these techniques, adsorption is the most cost‐effective technique with high performance …”

“…Adsorption of As(V) or F − from aqueous solution has been extensively studied over the last two decades with a focus on development of high‐efficiency, low‐cost and environmentally‐benign adsorbents . A wide variety of adsorbents were developed to remove As(V) and F − from drinking water, e.g.…”

“…However, these adsorbents, especially Al‐ and Fe‐based adsorbents, have a higher affinity for As(V) than F, leading to an undesired performance for simultaneous removal of both As(V) and F − . In general, arsenic has a high affinity to metal (oxyhydr)oxides especially Al‐, Fe‐based (oxyhydr)oxides and titania, whereas fluoride is likely to bind to solids containing rare earth elements . Jing et al .…”

“…In general, arsenic has a high affinity to metal (oxyhydr)oxides especially Al‐, Fe‐based (oxyhydr)oxides and titania, whereas fluoride is likely to bind to solids containing rare earth elements . Jing et al . developed a novel TiO 2 ‐La granular composite adsorbent that exhibited high adsorption capacities for As(III) (114 mg g −1 ) and F − (78.4 mg g −1 ).…”

“…However, there have been only a few attempts to investigate the co‐uptake of both As(V) and F − by adsorbents containing two components (e.g. Fe and Al, Ti and lanthanum, Fe and zirconium, and Ti and cerium), and no systematic studies to evaluate the effectiveness of other bimetallic composites for the co‐uptake of As(V) and F − have been reported yet.…”