CIESC Journal ›› 2022, Vol. 73 ›› Issue (9): 3929-3939.DOI: 10.11949/0438-1157.20220501

• Separation engineering • Previous Articles     Next Articles

Microfludically-generated lanthanum hydroxide cross-linked chitosan microspheres for phosphate removal

Chengwei LI1(), Huayong LUO1(), Mingxuan ZHANG1, Peng LIAO2, Qian FANG1, Hongwei RONG1, Jingyin WANG1   

  1. 1.School of Civil Engineering, Guangzhou University, Guangzhou 510006, Guangdong, China
    2.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, Guizhou, China
  • Received:2022-05-04 Revised:2022-06-09 Online:2022-10-09 Published:2022-09-05
  • Contact: Huayong LUO

氢氧化镧交联壳聚糖微球的微流控制备及其除磷性能

李承威1(), 骆华勇1(), 张铭轩1, 廖鹏2, 方茜1, 荣宏伟1, 王竞茵1   

  1. 1.广州大学土木工程学院,广东 广州 510006
    2.中国科学院地球化学研究所环境地球化学国家重点实验室,贵州 贵阳 550081
  • 通讯作者: 骆华勇
  • 作者简介:李承威(1996—),男,硕士研究生,1287377003@qq.com
  • 基金资助:
    广州市科技计划项目(202102020694);广东省自然科学基金项目(2020A1515010856);国家自然科学基金项目(52170071);广东省教育厅创新强校青年创新人才类项目(2019KQNCX109);广州大学研究生创新能力培养资助计划项目(2020GDJC-M49)

Abstract:

Lanthanum hydroxide [La(OH)3] cross-linked chitosan (CS) microspheres (La-CS-M) were prepared based on microfluidic technology. The compositions and structures of La-CS-M were characterized by various means. The performance and mechanism of its adsorption and removal of phosphate in water were explored. The results showed that La(OH)3 was successfully loaded within La-CS-M. Compared with the cross-linked chitosan spheres (La-CS) prepared by traditional dropping method, the surface and interior of La-CS-M were porous with an volumetric mean particle size of 415.8 μm, porosity of 89.22%, average pore size of 960.0 nm, and pHpzc of about 6.5. La-CS-M maintained a high adsorption capacity in a wide pH range from 3.0 to 10.0, and the presence of CO32- had a more negative effect on phosphate adsorption compared to Cl-, NO3-, SO42- and humic acid (HA). The adsorption kinetic data and isotherm results were well fitted with pseudo-second-order model and Langmuir model, achieving a maximum adsorption capacity of 56.48 mg/g at pH 6.0. Combined with XPS characterization and adsorption data, it could be deducted that the adsorption mechanism of La-CS-M involved electrostatic adsorption and formation of inner sphere complex (through coordination exchange or Lewis acid-base interaction). After phosphate adsorption, La-CS-M could be desorbed by 2.5 mol/L NaOH solution, exhibiting good reproducibility and adsorption stability.

Key words: lanthanum hydroxide, chitosan microspheres, microfluidic, preparation, adsorption, wastewater

摘要:

基于微流控技术制备了氢氧化镧[La(OH)3]交联壳聚糖(CS)微球(La-CS-M),并对其组成和结构进行表征,探究了微球吸附去除水中磷酸盐的性能和机理。结果表明,La-CS-M成功负载了La(OH)3,与传统滴落法制备的氢氧化镧交联壳聚糖球(La-CS)相比,其表面和内部具有疏松多孔结构,其体积平均粒径为415.8 μm,孔隙率为89.22%,平均孔径为960.0 nm,pHpzc约为6.5。La-CS-M在宽pH范围内(3.0~10.0)均保持较高吸附量,CO32-对La-CS-M吸附性能影响较Cl-NO3-SO42-以及腐殖酸(HA)明显。吸附动力学数据符合准二级动力学模型,等温吸附数据符合Langmuir模型且在pH=6.0时最大吸附量为56.48 mg/g。结合XPS表征和吸附数据推测La-CS-M的吸附机理涉及静电吸附和形成内层配合物(通过配位交换或Lewis酸碱作用)。吸附磷酸盐后La-CS-M可通过2.5 mol/L NaOH溶液实现脱附,具有良好的再生性和吸附稳定性。

关键词: 氢氧化镧, 壳聚糖微球, 微流控, 制备, 吸附, 废水

CLC Number: