Batch and continuous adsorption of Cu(II) and Zn(II) ions from aqueous solution on bi‐functionalized sugarcane‐based biosorbent.

Abstract

A new one-pot synthesis method optimized by a 23

experimental design was developed to prepare a biosorbent, sugarcane bagasse cellulose succinate pyromellitate (SBSPy), for the removal of Cu(II) and Zn(II) from single-component aqueous solutions, in batch and continuous modes. The bi-functionalization of the biosorbent with ligands of diferent chemical

structures increased its selectivity, improving its performance for removing pollutants from contaminated water. The suc- cinate moiety favored Cu(II) adsorption, while the pyromellitate moiety favored Zn(II) adsorption. Sugarcane bagasse (SB)

and SBSPy were characterized using several techniques. Analysis by 13C Multi-CP SS NMR and FTIR revealed the best order of addition of each anhydride that maximized the chemical modifcation of SB. The maximum adsorption capacities of SBSPy for Cu(II) and Zn(II), in batch mode, were 1.19 and 0.95 mmol g-1, respectively. Homogeneous surface difusion, intraparticle difusion, and Boyd models were used to determine the steps involved in the adsorption process. Isothermal

titration calorimetry was used to assess changes in enthalpy of adsorption as a function of SBSPy surface coverage. Fixed- bed column adsorption of Cu(II) and Zn(II) was performed in three cycles, showing that SBSPy has potential to be used in

water treatment. Breakthrough curves were well ftted by the Thomas and Bohart-Adams models.