One-step synthesis of chitosan-polyethyleneimine with calcium chloride as effective adsorbent for Acid Red 88 removal

Adsorption studies and effect of heat treatment on porous glass microspheres

“…The dye molecules could be adsorbed by the outer exposed pores via electrostatic interaction (see Figure 9) as no shift in adsorption bands was observed after dye adsorption. 56 The decrease in intensities of stretching vibration of P 3 O 9 2− and PO 3 2− in all the heat-treated microspheres could be attributed to hydrogen bonding and/or Lewis acid-base interaction between the Ca 2+ (from porogen and calcium based crystalline phases) and basic components (N=N, and OH groups) of AR88 dye which may have occurred on their surface (see proposed mechanism highlighted in Figure 11). 56 Based on these results, it is suggested that adsorption of AR88 onto microspheres depends on both their unique morphology and surface chemical properties of the microspheres.…”

“…56 The decrease in intensities of stretching vibration of P 3 O 9 2− and PO 3 2− in all the heat-treated microspheres could be attributed to hydrogen bonding and/or Lewis acid-base interaction between the Ca 2+ (from porogen and calcium based crystalline phases) and basic components (N=N, and OH groups) of AR88 dye which may have occurred on their surface (see proposed mechanism highlighted in Figure 11). 56 Based on these results, it is suggested that adsorption of AR88 onto microspheres depends on both their unique morphology and surface chemical properties of the microspheres. Although, higher surface area is one of the important parameters for an adsorbent, studies have reported that adsorption efficiency of an adsorbent is not only predominated by its surface area but also other factors such as surface chemistry and morphological features.…”

“…[52][53][54] Conversely, after the AR88 dye adsorption experiments the peaks associated with asymmetrically substituted -N=N-at 1475 cm −1 and bands assigned to S=O groups at 1146 cm −1 were observed, which were characteristic peaks for AR88. 55,56 Furthermore, the peaks at 793 cm −1 and 2900 cm −1 associated with aromatic C-H bending vibrations and C-H asymmetric stretching vibrations (from dye AR88), respectively, were also observed only after the adsorption experiment. [55][56][57] An intense band at 1630 cm −1 was also identified, which was associated with the aromatic skeletal stretching (C=C).…”

“…55,56 Furthermore, the peaks at 793 cm −1 and 2900 cm −1 associated with aromatic C-H bending vibrations and C-H asymmetric stretching vibrations (from dye AR88), respectively, were also observed only after the adsorption experiment. [55][56][57] An intense band at 1630 cm −1 was also identified, which was associated with the aromatic skeletal stretching (C=C). 58 niobyl(3+) cation (NbO 3+ ), which enters deform dra (octahedra, tetragonal pyramids) with a co covalent bond to oxygen.…”

Ternary Multicomponent Adsorption Modelling Using ANN, LS-SVR, and SVR Approach – Case Study

“…Due to increasing concentrations of various toxic and non-biodegradable contaminants like heavy metals in industrial wastewater, which have an adverse effect on human health and the environment, 1 various purification techniques have been proposed for wastewater treatment; adsorption is commonly being employed because of its high removal capacity of heavy metal ions using different adsorbents, low-cost of installation, operation and maintenance, and simple design. 2 Heretofore, numerous studies have reported the simultaneous interactions of multicomponent adsorption phenomenon of heavy metal ions on the adsorbent. [3][4][5] To design the adsorption equipment, it is mandatory to know the adsorption mechanisms.…”