Synthesis and application of sugarcane bagasse cellulose mixed esters. Part II: Removal of Co2+ and Ni2+ from single spiked aqueous solutions in batch and continuous mode

Abstract Sugarcane bagasse cellulose succinate trimellitate (SBST) was prepared by a one-pot synthesis method. The synthesis of this novel mixed ester was investigated by a 2 3 -factorial design. The parameters investigated were time, temperature, and succinic anhydride mole fraction ( χ SA ). The responses evaluated were the adsorption capacity ( q Co2+ and q Ni2+ ), weight gain ( wg ), and number of carboxylic acid groups ( n T,COOH ). 13 C Multiple Cross-Polarization solid-state NMR spectroscopy, 1 H NMR relaxometry, and Fourier-transform infrared spectroscopy were used to elucidate the SBST structure. The best SBST reaction conditions were 100 °C, 660 min, and χ SA of 0.2, which yielded SBST with a wg of 57.1%, n T,COOH of 4.48 mmol g −1 , and q Co2+ and q Ni2+ of 0.900 and 0.963 mmol g −1 , respectively. The maximum adsorption capacities ( Q max ) (pH 5.75, 25 °C) estimated by the Redlich-Peterson model for Co 2+ and Ni 2+ were 1.16 and 1.29 mmol g −1 . The Δ ads H ° values for Co 2+ and Ni 2+ adsorption obtained by isothermal titration calorimetry were 8.03 and 6.94 kJ mol −1 . Regeneration and reuse of SBST were investigated and the best conditions applied for fixed-bed column adsorption in five consecutive cycles. SBST was fully desorbed and Q max values for Co 2+ (0.95 mmol g −1 ) and Ni 2+ (1.02 mmol g −1 ) were estimated using the Bohart-Adams model.