Simultaneous Removal of Fluoride and Arsenic from Aqueous Solution using Activated Red Mud

Abstract

Red mud, a waste tailing from alumina production, was activated with calcination and acid treatment for simultaneous removal of F − and As from water solution. After activation, the specific area and Si-O-M and Al-O-H functional groups of the activated red mud (ARM) greatly increased. Results showed that the adsorption equilibrium time for F − , As(V), and As(III) was 18, 12, and 48 h, respectively. Kinetic data revealed that adsorption kinetics well followed the pseudo-second order model for F − , As(V), and As(III). The presence of As(V)/As(III) improved the adsorption rate of F − . With the co-existence of F − and As, F − adsorption was independent of initial solution pH between 4.0 and 10.0, and As adsorption between 2.0 and 10.0. Adsorption of F − , As(V), and As(III) was better described by the Langmuir model than the Freundlich model, indicating that adsorption was in the form of a monolayer. Fluoride had a significant effect on As(V) adsorption, while the less affected As(III) adsorption. The presence of 1.0 mg/L As(III)/As(V) had no significant influence on F − adsorption. ARM had high adsorption capacity for F − , As(V), and As(III), which resulted from the increases in the specific area and Si-O-M and Al-O-H functional groups. Results demonstrated that ARM is a potential adsorbent for simultaneous removal of F − and As from contaminated groundwater.

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

“…(D)). A similar observation was also reported in a previous study of F − adsorption on red mud . On Ti‐based MBOs (i.e.…”

“…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.…”

“…Fe‐based materials such as goethite, goethite‐ and hematite‐coated sand, and granular ferric oxides (GFO) have also been employed as adsorbents for aqueous As(V) and F − . Besides, bond char, activated red mud and industrial solid wastes were observed to adsorb As(V) and F − from wastewater. 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 − .…”

Comparative study on synchronous adsorption of arsenate and fluoride in aqueous solution onto MgAlFe-LDHs with different intercalating anions

“…18,19 It is known that one of the most promising methods for simultaneous removal of arsenic and uoride is adsorption because of its low-cost and convenience. Recently, many adsorbents have been used to remove arsenic and uoride simultaneously, such as granular TiO 2 -La material, 15 aluminum oxide/hydroxide nanoparticles, 20 iron oxide nano particles, 14 chemically treated laterite, 21 brick pieces and marble powder, 22 activated red mud, 23 and layered double hydroxide. 24,25 Layered double hydroxides (LDHs) may be suitable adsorbents for the treatment of arsenic and uoride complexes pollution in water.…”