Modeling adsorption of copper(II), cobalt(II) and nickel(II) metal ions from aqueous solution onto a new carboxylated sugarcane bagasse. Part II: Optimization of monocomponent fixed-bed column adsorption

• Published in: Journal of colloid and interface science Vol. 516; pp. 431 - 445
• Main Authors: Xavier, Amália Luísa Pedrosa, Adarme, Oscar Fernando Herrera, Furtado, Laís Milagres, Ferreira, Gabriel Max Dias, da Silva, Luis Henrique Mendes, Gil, Laurent Frédéric, Gurgel, Leandro Vinícius Alves
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-04-2018
• Subjects: Design of experiments; Desorption; Fixed-bed adsorption; Isothermal titration calorimetry; Metal ion; Modeling; Metal ion; Desorption; Isothermal titration calorimetry; Fixed-bed adsorption; Design of experiments; Modeling
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2018.01.068

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In the second part of this series of studies, the monocomponent adsorption of Cu2+, Co2+ and Ni2+ onto STA adsorbent in a fixed-bed column was investigated and optimized using a 22 central composite design. The process variables studied were: initial metal ion concentration and spatial time, and the optimized responses were: adsorption capacity of the bed (Qmax), efficiency of the adsorption process (EAP), and effective use of the bed (H). The higher Qmax for Cu2+, Co2+ and Ni2+ were 1.060, 0.800 and 1.029 mmol/g, respectively. The breakthrough curves were modeled by the original Thomas and Bohart-Adams models. The changes in enthalpy (ΔadsH°) of adsorption of the metal ions onto STA were determined by isothermal titration calorimetry (ITC). The values of ΔadsH° were in the range of 3.0–6.8 kJ/mol, suggesting that the adsorption process involved physisorption. Desorption (Edes) and re-adsorption (Ere-ads) of metal ions from the STA adsorbent were also investigated in batch mode, and the optimum conditions were applied for three cycles of adsorption/desorption in a fixed bed column. For these cycles, the lowest values of Edes and Ere-ads were 95 and 92.3%, respectively, showing that STA is a promising candidate for real applications on a large scale.