Efficient removal of Cr(VI) by polydopamine-modified lignin from aqueous solution: Batch and XAFS studies  

作　　者：Xiao-jie Guo Wei-kang Fu Jing-yuan Ma Bo-jun Xi Chen Wang Meng-yao Guan 

机构地区：[1]College of Materials and Environmental Engineering,Hangzhou Dianzi University,Hangzhou 310018,China [2]College of Textile and Garment,Shaoxing University,Shaoxing 312000,China [3]Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201204,China

出　　处：《Water Science and Engineering》2024年第1期51-61,共11页水科学与水工程（英文版）

基　　金：supported by the Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ19E030017);the Research Start-up Fund(Grant No.KYS205619042);the Technological Research Project for Public Welfare of Zhejiang Province(Grant No.LGG19E030005).

摘　　要：Lignocellulose has the potential to become a bio-based adsorbent due to its biodegradability and renewability.In this study,a novel polydopamine functionalized-lignin(lignin@PDA),prepared via self-polymerization of dopamine(PDA)on lignin,was used as a bio-based adsorbent for rapid scavenging of hexavalent chromium(Cr(VI)).The morphology,functional groups,crystalline structure,and chemical composition of lignin@PDA were characterized with a scanning electron microscope-energy dispersive spectrometer,Fourier transform infrared spectroscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The Cr(VI)adsorption process of lignin@PDA was studied using batch experiments as a function of pH,ionic strength,adsorbent dose,and contact time at room temperature.The adsorption rate of lignin@PDA was five times greater than that of the unmodified lignin,with a maximum adsorption capacity of 102.6 mg/g in an acidic medium.The adsorption of Cr(VI)on lignin@PDA fit the pseudo-secondorder equation and the Freundlich model,indicating that the adsorption process was mainly dominated by chemisorption and surface complexation.The thermodynamic parameters showed that adsorption of Cr(VI)on lignin@PDA was an endothermic and spontaneous process.The X-ray absorption fine structure results showed that sorption and reduction of Cr(VI)into Cr(II)occurred simultaneously on lignin.Moreover,PDA coating not only improved the reactivity of lignin but also promoted the complete reduction of Cr(VI)by lignin.According to these results,polydopamine functionalized-lignin is a promising bio-based adsorbent for immobilization of Cr(VI)from wastewater.

关 键 词：LIGNIN POLYDOPAMINE Hexavalent chromium EXAFS Adsorption mechanism 

分 类 号：X703[环境科学与工程—环境工程]