Efficient removal of Congo red from pH-unregulated aqueous solutions by lignosulfonate-based polycatecholamine |
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Authors: | Song Gao Gang Wei Qiang Liu Qinze Liu Tingting Gao Jinshui Yao |
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Affiliation: | 1. School of Materials Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 People's Republic of China;2. School of Materials Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 People's Republic of China
Shandong Dongyue Silicone Materials Co Ltd., Zibo, 256401 People's Republic of China;3. Department of Chemistry, Tianjin University, and the National Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072 People's Republic of China;4. Key Laboratory of Fine Chemicals in Universities of Shandong, School of Chemistry and Pharmaceutical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 People's Republic of China |
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Abstract: | Lignosulfonate-based polycatecholamine (PCEA-LS) was synthesized by a two-stage approach involving Mannich and catechol–amine reactions, and it was directly used to adsorb Congo red (CR) from the pH-unadjusted aqueous solution. PCEA-LS was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Various factors affecting on removal of CR by PCEA-LS were investigated in depth, including contact time, adsorbent dosage, and initial concentration of CR and adsorption temperature. The adsorption kinetics, isotherm, and thermodynamics of PCEA-LS for CR were explored in detail, and then its adsorption mechanism was systematically elucidated. Results indicated that the removal process of CR followed the pseudo-second-order kinetic model, and the isotherm data fitted the Langmuir model well. The maximum adsorption capacity reached 972.6 mg g−1 at 30°C in the pH-unadjusted (pH = 6.25) solution possibly due to the hydrogen bond, π–π stacking, and electrostatic interaction between PCEA-LS and CR. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48640. |
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Keywords: | adsorptiont congo red lignosulfonate polycatecholamine |
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