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

摘要

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 (chi(SA)). The responses evaluated were the adsorption capacity (q(co2+) and q(Ni2+)), weight gain (wg), and number of carboxylic acid groups (n(T center dot COOH)). C-1(3) Multiple Cross-Polarization solid-state NMR spectroscopy, H-1 NMR relaxometry, and Fourier-transform infrared spectroscopy were used to elucidate the SBST structure. The best SBST reaction conditions were 100 degrees C, 660 min, and chi(SA) of 0.2, which yielded SBST with a wg of 57.1%, n(T center dot 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 degrees C) estimated by the Redlich-Peterson model for Co2+ and Ni2+ were 1.16 and 1.29 mmol g(-1). The Delta H-ads degrees values for Co2+ and Ni2+ 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 fixedbed column adsorption in five consecutive cycles. SBST was fully desorbed and Q(max) values for Co2+ (0.95 mmol g(-1)) and Ni2+ (1.02 mmol g(-1)) were estimated using the Bohart-Adams model. (C) 2019 Elsevier Inc. All rights reserved.