Enhanced removal capability of kaolin toward methylene blue by mussel-inspired functionalization

Abstract

Adsorption is an effective and commonly adopted method for removal of organic pollutants from environment. In this work, we described the synthesis and the adsorption behavior of poly(sodium p-styrenesulfonate hydrate) (PSPSH)-modified kaolin, which was obtained by combination of mussel-inspired chemistry and Michael addition reaction. The amino-terminated PSPSH was synthesized by free radical polymerization using cysteamine hydrochloride as the chain transfer agent and sodium p-styrenesulfonate hydrate as the monomer. Raw kaolin and PSPSH-modified kaolin were characterized using several techniques including transmission electron microscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis, and X-ray photoelectron spectroscopy in detail. The adsorption of methylene blue onto modified kaolin from aqueous solution was investigated, in which the effects of contact time, temperature, solution pH, and initial methylene blue concentration were studied. The experiment data were analyzed using two common adsorption models: Langmuir and Freundlich isotherm models. The kinetic adsorption data were analyzed using pseudo-first-order, pseudo-second-order, and intraparticle diffusion model. The values of thermodynamics constants such as entropy change (DS 0 ), enthalpy change (DH 0 ) and Gibbs free energy (DG 0 ) were also determined. The modified kaolin showed favorable dispersibility and convenient separation, high efficiency, and good regeneration capability in the removal of methylene blue from solution.Qiang Huang and Meiying Liu have contributed equally to this work.

Preparation of polymeric silica composites through polydopamine-mediated surface initiated ATRP for highly efficient removal of environmental pollutants

“…The pseudo-first-order kinetic model is based on the assumption that the adsorption process is controlled by diffusion. The adsorption rate is proportional to the value of difference between equilibrium adsorption capacity and adsorption amount at time t [59]. The pseudo-second-order model assumes that the adsorption process is controlled by chemical adsorption involving the valence forces via the exchange or sharing electrons between adsorption active sites on the surface of adsorbent and adsorbate [60].…”

“…Therefore, it is necessary to develop efficient treatment methods for the removal of CR from waste effluents. Some physical and chemical methods, such as coagulation/flocculation [11], filtration [12], oxidation [13][14][15][16][17][18][19][20], micellar enhanced ultrafiltration [21], adsorption [22][23][24][25][26], microbial degradation [27] have been used to remove dye pollutants. Adsorption is one of the most widely used methods due to its easy operation, cost effectiveness and high efficiency.…”

Homogeneous Zr and Ti co-doped SBA-15 with high specific surface area: preparation, characterization and application

“…The positive value of ΔH°demonstrates that the adsorption reaction is endothermic. Likewise, the value of ΔS°is positive, reflecting some structural change in MB and Zr-Ti-SBA-15 and the affinity for MB [44].…”

Removal of Diazo Dye Direct Red 28 and Tetra Azo Dye Direct Black 22 Using Synthesized Magnetic Kaolin Supported Zinc Ferrite

“…2,19 The peak at 910 cm -1 can be attributed to Al-OH-Al stretching vibration. 22 The peaks at 796, 752 and 691 cm -1 may be due to the tensile vibrations of Si-O-Si, Si-O-Al and Si-O-Mg and the bending vibrations of SiO in the structure of kaolin. 2 The peaks detected at 910, 940, 1001, 1030, and 1117 cm -1 in the spectrum of kaolin disappeared in the FTIR spectra of KZF and KZF-200.…”