Enhanced arsenic removal using lateritic bauxite modified by heating and blending

Abstract

The use of bauxite to remove arsenic from wastewater has been confirmed to be effective, but its removal efficiency in literature is not up to 90%, hence the need to devise a more effective method to remove arsenic from wastewater. In this study, a novel material was prepared by thermally modifying and blending yellow and red lateritic bauxite to form thermally modified and blended yellow and red lateritic bauxite (TYB + TRB). The adsorption isotherm, morphology and chemical composition of the novel material were determined by the Langmuir and Freundlich models, Scanning Electron Microscopy (SEM) and X-ray Fluorescence (XRF), respectively. Application of the novel material in arsenic removal resulted in >97% removal efficiency within 60 min. The arsenic adsorption by TYB + TRB conformed to the Freundlich model. The SEM image depicted a compacted earth material after use of the TYB + TRB to remove arsenic from the wastewater. The XRF results also showed a drastic reduction in the chemical composition of the novel bauxite except Ti, thus suggesting the occurrence of multiple mechanisms during the arsenic removal. This study demonstrated the potential of TYB + TRB to be developed and used as the most suitable material for wastewater treatment. HIGHLIGHTS TYB + TRB was prepared to superimpose the arsenic removal performance of bauxite.; The removal efficiency of arsenic by TYB + TRB was >97%.; The mode of adsorption is explained by the Freundlich model.; The chemical composition of the TYB + TRB reduced drastically after arsenic removal except Ti.; The novel material is a promising material for highly effective arsenic removal.;

Keywords

• arsenic
• bauxite
• removal efficiency
• thermally modified and blended yellow and red lateritic bauxite
• wastewater