Sorption of As (III) and As (V) onto Dalbergia sissoo & Arundodonax Sawdust

Abstract

The application of low-cost, ecofriendly bioadsorbents as an alternate to the conventional methods of removing As (III)and As (V) ions from aqueous media has been investigated. Present study deals with the adsorption of As (III)and As (V) from aqueoussolution onto chemically modified form of saw dusts.The Chemically modified Dalbergiasissoo sawdust and Arundo donax sawdust were obtained by performing phosphorylation followed by treatment with iron (III) solution in aqueous media. Batch studies were performed at an initial concentration of 1mg/l to evaluate the influence of various parameters such as pH, equilibrium time, amount of adsorbent and concentration of adsorbate. Studies showed that pH of aqueous solution drasticall yaffected As (III)and As (V)adsorptionas a result the removal efficiency altered with the change in initial pH of the solution. The maximum efficiency for the iron (III)-loaded phosphorylated Dalbergia sissoo sawdust [FePDSD]andiron (III)-loaded phosphorylated Arundo donax sawdust [FePASD]were achieved at pH 9, &7 for As (III) and at pH 3, & 5 for As (V) respectively at an initial concentration of 1mg/l.Kinetics and isotherm modeling studies demonstrated that the experimental data best fit apseudo-first order and Langmuir isotherm model, respectively.The maximum adsorptioncapacities were found to be 1.334 mg/g & 1.667 mg/g for As (III), 3.646 mg/g &2.631mg/gfor As (V) with FePDSD and FePASD respectively. In summary, Dalbergia sissoo & Arundodonax sawdusts can be used as an efficient and economical material for the adsorptive removal of As (III) and As (V) from aqueous system.