Synthesis of chitosan‐nTiO₂ nanocomposite, application in adsorptive removal of Cu(II)—Adsorption and desorption study, mechanism, scale‐up design, statistical, and genetic algorithm modeling

Abstract

The present study comprises the preparation of chitosan-nTiO 2 nanocomposites and their characterization with the help of scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Various adsorbent samples are prepared with different weight ratios of chitosan to nTiO 2 . The adsorption capacity of the prepared adsorbents towards Cu(II) in an aqueous solution is also tested. The adsorption experiment is performed in batch mode under varying experimental conditions. Several isotherm and kinetic models are analyzed with the experimental data, and thermodynamic conditions required for adsorption are also determined. The highest elimination of Cu(II) was 39.19% with the adsorbent chitosan without nTiO 2 (CWT) with 20 mg L À1 initial Cu (II) concentration at adsorbent dosage 3 gL À1 and 98.5% with the adsorbent CTNC1-1 (chitosan/nTiO 2 nanocomposite with the mass proportions of chitosan:nTiO 2 = 1:1) and 93% with CTNC2-1 (chitosan/nTiO 2 nanocomposite with the mass proportions of chitosan:nTiO 2 = 2:1) with 10 mg L À1 initial Cu(II) concentration at adsorbent dosage 5 g L À1 . The isotherm model confirmed the monolayer adsorption.Maximum Langmuir adsorption capacities (q L ) of the adsorbents for Cu(II) were given as CTNC1-1 > CTNC2-1 > CWT. The pseudo-second-order model excellently depicted the kinetic process with good correlation for all adsorbents. The statistical (R-square is more than 0.99) and genetic algorithm (GA) model (R-square is more than 0.99) effectively predicted the percentage removal of Cu(II).

Chitosan‐nTiO2 Nanocomposite Synthesis and its Adsorptive Removal Capacity for Methylene Blue from its Aqueous Solution: Batch Adsorption Study and Modeling

“…The tetragonal anatase structure of TiO 2 remained unaltered in the composite with CS. [23] The crystallinity (%) was analyzed to be 29.94 (CTNC1-1) and 31.57 (CTNC2-1).…”

“…The breakdown process ended at ~540 °C for CWT with 0 % residue, indicating the complete oxidative decomposition of carbonaceous mass, [22] whereas, for CTNC1-1 and CTNC2-1, the residuary masses were ~27 % and ~18 % attributable to nTiO 2 residue. [23] pH PZC s were determined as 7.4 (CWT),7.5 (CTNC1-1) and 7.65 (CTNC2-1) (Figure S6).…”

“…Each investigation was repeated in triplicates, with a reproducibility range of � 0.5 % and relative deviation � 2.5 %. Bending of C-N 685 694 630 671 625 675 [23] TiÀ OÀ Ti stretching vibration --Peaks between 400-700 cm À 1 Peaks between 400-700 cm À 1…”

“…[16][17][18][19][20][21] However, the limited solubility in acidic solution and the nonporous feature of CS are its significant shortcomings, so it needs chemical modification. [22][23][24] With the innovation of nanotechnology, different CS-metal oxide nanobio composites are designed by a range of nano-metal-oxides (nMOs), and their adsorptive suitability for organics is checked. [5,[25][26][27][28][29] TiO 2 nanoparticles are widely used in wastewater treatment due to their mechanical, physicochemical, and photocatalytic properties, thermal stability, and biocompatibility.…”

Adsorptive elimination of methylene blue dye from aqueous solution by chitosan‐nSiO2 nanocomposite: Adsorption and desorption study, scale‐up design, statistical, and genetic algorithm modeling

“…mutation, chromosome, and so on, was used to formulate GA. The hybrid of GA and ANN has been utilized as an optimization method over the past few years 24,25 …”