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

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

“…The SBSPy synthesized using the desirable reaction condition presented wg of 61.621 ± 0.002% and n T,COOH of 4.21 ± 0.07 mmol g -1 . These values were similar to those reported by Elias et al ( 2019) for the chemical modification of raw SB with SA and PA (phthalic anhydride), in a one-pot reaction to prepare SBSPh (wg = 60.52%, n T,COOH = 3.51 mmol g -1 ), and by Almeida et al (2019) for the chemical modification of raw SB with SA and TA (trimellitic anhydride), in a one-pot reaction to prepare SBST (wg = 73.2%, n T,COOH = 4.67 mmol g -1 ). It is important to note that the synthesis methods used to prepare SBSPh and SBST were different to the procedure used here to prepare Figure 3 Scheme for the chemical modification of raw sugarcane bagasse (SB) with pyromellitic anhydride (PyA) and succinic anhydride (SA), using the best reaction condition predicted using the desirability tool of Statistica ® SBSPy.…”

“…The 13 C Multi-CP SS NMR spectra of raw SB, SBSPy (SA added first), and SBPyS (PyA added first) are presented in Figure 2. The use of the Multi-CP excitation method (Bernardinelli et al 2015) enabled the acquisition of more quantitative 13 C NMR spectra (Almeida et al 2019. The introduction of PyA and SA into the SB structure was confirmed by the appearance of signals related to the aromatic carbons of the pyromellityl unit (region B, 120-140 ppm) and the methylene carbons of the succinyl unit (region A, 24-40 ppm) (Figure 2), respectively.…”

“…NMR spectra of raw SB, SBSPy, and SBPyS were acquired with a Bruker spectrometer (Model Avance 400) equipped with a 4-mm magic angle spinning (MAS) double-resonance probe, operating at frequencies of 100.5 MHz ( 13 C) and 400.0 MHz ( 1 H). Further information about other procedures used and the analysis conditions can be found in the studies of and Almeida et al (2019).…”

“…With this normalization and subtraction procedure, the spectral areas obtained from the regions A and B (subtracted from the area of the raw SB spectrum) became proportional to the number of carbon atoms of succinyl and pyromellityl units, respectively, introduced into SBSPy or SBPyS, relative to the number of C-1 carbon atoms per cellobiose unit (two β-D-anhydroglucose units (AGU) linked by a β(1→4) glycosidic bond). Further procedures used for calculation of the numbers of succinyl and pyromellityl units introduced into the SB structure were those reported by and Almeida et al (2019).…”

“…The continuous adsorption experiments were performed using three adsorption-desorption cycles, according to the methods described by Almeida et al (2019). The experimental conditions for continuous adsorption on a fixed-bed column were based on the results obtained in the batch adsorption studies of Cu(II) and Zn(II) on SBSPy ("Batch adsorption experiments" and "Batch desorption and readsorption experiments" sections), as well as on the results reported by Xavier et al (2018), who optimized the continuous adsorption of Co(II), Cu(II), and Ni(II) on sugarcane bagasse chemically modified with trimellitic anhydride (TA).…”