Comparative study of Hg() biosorption performance of xanthated and charred sugarcane bagasse from aqueous solutions

• Published in: RSC advances 2022-10, Vol.12 (46), p.29865-29877
• Main Authors: Homagai, Puspa Lal, Bhattarai, Mahesh, Radhika, K. M, Ghimire, Kedar Nath, Paudyal, Hari, Bhattarai, Ajaya
• Format: Article
• Language: English
• Subjects: Adsorption; Aqueous solutions; Bagasse; Chemistry; Comparative studies; Endothermic reactions; Isotherms; Mercury compounds; Sugarcane
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d2ra05266k

The main target of this study was to evaluate the efficiency of charred xanthated sugarcane bagasse (CXSB) and charred sugarcane bagasse (CSB) in the removal of Hg( ii ) ions from aqueous media. Batch experiments were performed to study the experimental parameters such as effects of pH, concentration, contact time and temperature. The adsorption velocity of Hg( ii ) onto CSB and CXSB was fast and reached equilibrium within 60 minutes. Isotherm and kinetic studies showed that Hg( ii ) uptake using both the biosorbents followed Langmuir isotherm and pseudo second order kinetics. The maximum adsorption capacity of Hg( ii ) at optimum pH 4.5 onto CSB and CXSB was found to be 125 mg g −1 and 333.34 mg g −1 , respectively. A negative value of Δ G ° and positive Δ S ° value (0.24 kJ mol −1 for CSB and 0.18 kJ mol −1 for CXSB) for both the biosorbents confirm the spontaneous nature of Hg( ii ) adsorption. A positive value of Δ H ° (52.06 kJ mol −1 for CSB and 30.82 kJ mol −1 for CXSB) suggests the endothermic nature of biosorption. The investigated results shows that CXSB compared to CSB can be used as a low cost and environmentally benign bio-adsorbent for the removal of Hg( ii ) ions from aqueous solutions. Ion exchange adsorption mechanism of Hg( ii ) onto the monomeric unit of charred xanthated sugarcane bagasse (CXSB).