Adsorption of tannic acid from aqueous solution onto surfactant-modified zeolite

• Published in: Journal of hazardous materials Vol. 193; pp. 102 - 111
• Main Authors: Lin, Jianwei, Zhan, Yanhui, Zhu, Zhiliang, Xing, Yunqing
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15-10-2011; Elsevier
• Subjects: Adsorbents; Adsorption; Applied sciences; aqueous solutions; Atmospheric pollution; Cetylpyridinium bromide; cetylpyridinium chloride; Chemical engineering; copper; electrostatic interactions; Exact sciences and technology; Fourier transform infrared spectroscopy; heat production; hydrogen bonding; ionic strength; Kinetics; Mathematical models; Pollution; scanning electron microscopes; Scanning electron microscopy; Solutions; Spectroscopy, Fourier Transform Infrared; Surface-Active Agents - chemistry; Surfactant-modified zeolite; Tannic acid; tannins; Tannins - chemistry; Tantalum; temperature; Thermogravimetry; Water; X-Ray Diffraction; Zeolites; Zeolites - chemistry; Tannic acid; Surfactant-modified zeolite; Cetylpyridinium bromide; Adsorption; Scanning electron microscopy; Second order; Pollutant behavior; Electrostatic interaction; Thermogravimetry; Adsorption capacity; Zeolite; Surfactant; X ray diffraction; Pollutant emission; Modeling; Loading; Ionic strength; Thermodynamic parameter; pH; Air pollution; Phase partition; Kinetics; Aqueous solution
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.07.035

Surfactant-modified zeolites (SMZs) with various loadings of cetylpyridinium bromide (CPB) were used as adsorbents to remove tannic acid (TA) from aqueous solution.
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► Surfactant modified zeolites (SMZs) have a good tannic acid (TA) adsorption capacity. ► Adsorption capacity for SMZ with bilayer was relatively high at solution pH 3.5–7.0. ► Adsorption was well described by pseudo-second-order kinetic model. ► Adsorption fitted well with Langmuir, Redlich-Peterson and Sips isotherm models. ► Coexisting Cu(II) in aqueous solution resulted in markedly enhanced TA adsorption.
Surfactant-modified zeolites (SMZs) with various loadings of cetylpyridinium bromide (CPB) were used as adsorbents to remove tannic acid (TA) from aqueous solution. The TA adsorption efficiencies for natural zeolite and various SMZs were compared. SMZ presented higher TA adsorption efficiency than natural zeolite, and SMZ with higher loading amount of CPB exhibited higher TA adsorption efficiency. The adsorption of TA onto SMZ as a function of contact time, initial adsorbate concentration, temperature, ionic strength, coexisting Cu(II) and solution pH was investigated. The adsorbents before and after adsorption were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), thermogravimetric analysis (TGA), and Fourier transform infrared (FT-IR) spectroscopy. The adsorption kinetics of TA onto SMZ with CPB bilayer coverage (SMZ-CBC) followed a pseudo-second-order model. The equilibrium adsorption data of TA onto SMZ-CBC were well represented by Langmuir, Redlich-Peterson and Sips isotherm models. The calculated thermodynamic parameters indicated that TA adsorption onto SMZ-CBC was spontaneous and exothermic. The TA adsorption capacity for SMZ-CBC slightly decreased with increasing ionic strength but significantly increased with increasing Cu(II) concentration. The TA adsorption capacity for SMZ-CBC was relatively high at solution pH 4.0–7.0, and decreased with an increase in solution pH from 7.0 to 8.5. The mechanisms controlling TA adsorption onto SMZ-CBC at solution pH 5.5 include electrostatic attraction, hydrogen bonding and organic partitioning.