Acta Chimica Sinica ›› 2022, Vol. 80 ›› Issue (4): 476-484.DOI: 10.6023/A21120603 Previous Articles     Next Articles

Special Issue: 中国科学院青年创新促进会合辑



刘俊瑞a,b,c, 陈晶琳d, 杨杰b,c, 许肖锋b,c, 李若男b,c, 黄有桂b,c, 陈少华d, 叶欣d,*(), 王维b,c,*()   

  1. a 福建师范大学 化学与材料学院 福州 350007
    b 中国科学院福建物质结构研究所 中国科学院功能纳米结构设计与组装重点实验室 福州 350002
    c 中国科学院海西研究院厦门稀土材料研究中心 厦门 361021
    d 中国科学院城市环境研究所 中国科学院城市污染物转化重点实验室 厦门 361021
  • 投稿日期:2021-12-30 发布日期:2022-04-28
  • 通讯作者: 叶欣, 王维
  • 作者简介:
  • 基金资助:
    中国科学院青年创新促进会专项基金(2021302); 中国科学院青年创新促进会专项基金(2021305); 中国科学院福建物质结构研究所与中国科学院城市环境研究所融合发展基金培育项目(RHZX-2019-003)

K+-Site Ce-Doped Jarosite for Phosphate Adsorption: a Mechanism Study

Junrui Liua,b,c, Jinglin Chend, Jie Yangb,c, Xiaofeng Xub,c, Ruonan Lib,c, You-Gui Huangb,c, Shaohua Chend, Xin Yed(), Wei Wangb,c()   

  1. a College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China
    b CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
    c Xiamen Institute of Rare Earth Materials, Haixi Institute, Chinese Academy of Sciences, Xiamen 361021, China
    d CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
  • Received:2021-12-30 Published:2022-04-28
  • Contact: Xin Ye, Wei Wang
  • About author:
    Dedicated to the 10th anniversary of the Youth Innovation Promotion Association, CAS.
  • Supported by:
    Youth Innovation Promotion Association CAS(2021302); Youth Innovation Promotion Association CAS(2021305); FJIRSM&IUE Joint Research Fund(RHZX-2019-003)

Jarosite is a common iron-containing mineral. Researchers have studied its application for removing aqueous pollutants, such as Cr(VI) and As(V). Surprisingly, it shows adsorption for arsenates, but little for the structurally similar phosphate ions. In this study, we prepare cerium doped jarosite and prove the successful doping of cerium at the K+ site by X-ray diffraction (XRD), inductively coupled plasma-optical emission spectrometry (ICP-OES), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). Phosphorus adsorption experiments show that the small amount of cerium doping (Ce content: 8.75×10-5 mol/g) significantly improves the phosphate adsorption of jarosite, from 1.69 mg/g to 29.33 mg/g (pH=7, 24 h). The phosphate adsorption of Ce-doped jarosite exhibits good pH stability (from pH=3 to pH=11) and excellent selectivity, which is capable of maintaining more than 91% of its adsorption capacity in the presence of various competing anions, such as HCO3-, CO32-, humic acid anion, SO42-, NO3-, and SiO32-. Further analysis reveals that the adsorption process obeys the pseudo-second order kinetic model while the adsorption isotherms represent the Freundlich isotherm. The analysis indicates that the adsorption may be a chemical adsorption process that is easy to proceed. To explore the mechanism of adsorption enhancement, we first characterize the Zeta-potential of the pure jarosite and Ce-doped jarosite. The result indicates similarity of the surface potential between the two samples, which rules out the electrostatic adsorption mechanism. Next, based on the result of anion exchange chromatography, we confirm that the cerium doping greatly increases the exchange between the sulfate groups in jarosite and the phosphate groups in solution, from 2.85 mg/g to 24.90 mg/g. Finally, XPS high-resolution spectroscopy reveals that the chemical environment of Ce changes after the phosphate adsorption, likely indicating the formation of Ce—O—P chemical bonds to achieve specific chemisorption. These results may provide insights for the modification and application of jarosite, as a new adsorbent material for treating phosphorus rich wastewater.

Key words: jarosite, rare-earth doping, adsorption, phosphate pollutant, cerium