Ultrasonic Method to Synthesize Glucan-g-poly(acrylic acid)/Sodium Lignosulfonate Hydrogels and Studies of Their Adsorption of Cu²⁺ from Aqueous Solution

Abstract

In the paper, a green ultrasonic method was applied to prepare glucan-g-poly­(acrylic acid) (GL-g-PAA), sodium lignosulfonate-g-poly­(acrylic acid) (SLS-g-PAA), and glucan-g-poly­(acrylic acid) /sodium lignosulfonate (GL-g-PAA/SLS) hydrogels with the participation of initiator ammonium persulfate (APS) and cross-linker N′,N-methylenebis­(acrylamide) (NMBA), and these hydrogels were taken as absorbents to remove the Cu2+ ion from aqueous solutions. The structure, morphology, and stability of hydrogels were confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The various experimental conditions that influence the adsorption capacity were investigated such as temperature (25–50 °C), pH (1.0–6.0), adsorbent dosage (10–60 mg), foreign ions (300 mg·L–1), and contact time (0–180 min) as well as the initial concentration of the Cu2+ ion solution (100–600 mg·L–1). In addition, the experimental results indicated that the adsorption isotherms of the hydrogels for Cu2+ ions was in line with the Freundlich model, and the adsorption kinetics of the lyogels for Cu2+ ions were in good agreement with the pseudo-second-order model. The maximum adsorption capacities were 195.6, 188.5, and 221.4 mg·g–1 for GL-g-PAA, SLS-g-PAA, and GL-g-PAA/SLS, respectively. The thermodynamic parameters of Cu2+ ion adsorption onto preceding hydrogels were calculated. The positive ΔS° value reflected that adsorption is a process of entropy increase. The ΔG° was negative, revealing that the adsorption was a spontaneous process, and the ΔH° was positive value, suggesting that the adsorption was endothermic in nature.

Applicability of Iron (III) Trimesic (Fe-BTC) to Enhance Lignin Separation from Pulp and Paper Wastewater

“…Lignin effluence has been through cooking and bleaching processes using chlorine, which may cause transformation into toxic substances (Ali & Sreekrishnan 2001;Kaur et al 2018;Norgren & Edlund 2014;Nyman et al 1986). Lignin can be recycled and some lignin-derived materials have good mechanical and physicochemical properties that can be used in the manufacture of plastics, resins, and fuel production (Naseem et al 2016;Norgren & Edlund 2014), biosorbent materials (Klapiszewski et al 2017a), adsorbents , super adsorbent polymer composites Wang et al 2014), polymeric hydrogel (Wang et al 2017), surfactants , and materialassisted synthesis of catalysts . Few studies have attempted to separate and recycle lignin from treated effluent.…”

Fabrication of Ananas comosus leaf extract modified titanium dioxide nano bio adsorbent for the sequestration of basic dye from aqueous phase: equilibrium and kinetic studies

“…Langmuir isotherm thrusts homogenous sorption of sorbate on the sorbent. This is characterized by monolayer adsorption [31]. The linearized equation of the model is presented by equation (4) [32].…”

“…This isotherm is empirical model employed for adsorbent nature that is heterogenous. This is characterized multilayer adsorption [31]. The linear form of this isotherm was tested against dye adsorption was given by equation (6) [33].…”

“…To investigate the adsorption efficiency and mechanism of the system, two kinetic models (Pseudo-first order and pseudo-second order were incorporated to examine the experimental data achieved by altering the contact time [31]. The establishment of kinetic model of Pseudo-first order is on the theory of membrane diffusion and Pseudo-second order based on rate limiting step of adsorption along with mechanism of adsorption [42].…”

A synthesis and performance evaluation of a highly efficient ecological dust depressor based on the sodium lignosulfonate–acrylic acid graft copolymer

“…As a byproduct from the papermaking industry, sodium lignosulfonate (LSL) benets from its low cost, with an annual production of approximately 150 000 tons in China. 15,16 Lignin is a renewable resource with good water solubility and cohesion, nontoxicity, and biodegradability. The active groups in SLS molecules such as hydroxyl and the sulfonic group can bond with coal particles and form a solidied layer on the coal's surface.…”