Sequential synergetic sorption analysis of Gracilaria Rhodophyta biochar toward aluminum and fluoride: A statistical optimization approach

Abstract

The present work proposes the synthesis of robust biochar from Gracilaria Rhodophyta red weeds for sequential removal of Al(III) and fluoride from wastewater. The sorption experiments have been modelled by preliminary optimization of operational parameters using 2⁴ factorial statistical modelling. The model has estimated an optimum sequential‐synergetic removal of 44.5 mg/g of Al(III) and 2.1 mg/g of fluoride onto the biochar. FESEM, BET, XRD, EDX and FTIR established the potentiality of biochar towards synergetic‐sorption of Al(III) and fluoride. The thermodynamic analysis projected that the adsorption is physisorption in nature. The adsorption of Al(III) and fluoride follows the Langmuir and Freundlich isotherm models respectively and the kinetic analysis established the pseudo‐second‐order deposition of Al(III) and fluoride ions. The synthesised adsorbent is regenerative enough and could achieve synergetic removal of Al(III) and fluoride ions from industrial and ground water contaminated water bodies.