Removal of arsenic and fluoride from aqueous solution by biomass based activated biochar: Optimization through response surface methodology

In the present investigation, perennial grass (Saccharum ravannae L.) based activated biochar was synthesized for possible application in both arsenic (As) and fluoride (F^-) removal from aquous solution using optimization technique response surface methodology (RSM) based on central composite design (CCD). Influence of initial concentration, adsorbent dose and contact time on removal efficiency of As and F^- adsorption was investigated. Activated biochar was characterized by proximate and ultimate analysis, FTIR, XRD, Raman, SEM-EDX, BET, pH and electrical conductivity. Isotherm and kinetics models were also investigated. Results obtained from CCD showed that the best local maximum for As removal was at initial ion concentration 100 mg L^-1, adsorbent dosage 0.2 g 50 mL^-1 and contact time 60 min with removal percentage of 72.1 for As and for F^- the removal percentage was 24.3 at initial ion concentration of 25 mg L^-1, adsorbent dosage of 0.2 g 50 mL^-1 and contact time 60 min.