Competitive Adsorption of Arsenic and Fluoride onto Economically Prepared Aluminum Oxide/Hydroxide Nanoparticles: Multicomponent Isotherms and Spent Adsorbent Management

Abstract

The present study deals with adsorptive removal of arsenic and fluoride in single as well as bicomponent system using aluminum oxide/hydroxide nanoparticles (AHNP). For single component system, the Langmuir maximum adsorption capacity of the adsorbent is found as 833.33 ?g/g for arsenic and 2000 ?g/g for fluoride at optimum conditions. The adsorption process is well explained by Langmuir isotherm and pseudo-second-order kinetic models for both arsenic and fluoride. A real groundwater sample, having arsenic 512 ?g/L and fluoride 6300 ?g/L along with other ions, has also been treated successfully. Among different isotherms, the modified competitive Langmuir isotherm is found to be most suitable to represent the bicomponent system. Solidification of the spent adsorbent through brick formation is investigated, and this process is found to be an effective option for its management. Through economic evaluation, the adsorbent and treatment costs are found as ?86.89 INR/kg and 0.36 INR/L, respectively. © 2017 American Chemical Society.