工业水处理 ›› 2025, Vol. 45 ›› Issue (5): 71-78. doi: 10.19965/j.cnki.iwt.2024-0375

• 试验研究 • 上一篇    下一篇

磁性镧改性镁铁水滑石/生物炭去除污水中的磷

杨振宇(), 李大鹏(), 单苏洁   

  1. 苏州科技大学环境科学与工程学院,江苏 苏州 215009
  • 收稿日期:2024-08-27 出版日期:2025-05-20 发布日期:2025-05-22
  • 通讯作者: 李大鹏
  • 作者简介:

    杨振宇(1999— ),硕士,E-mail:

  • 基金资助:
    国家自然科学基金青年项目(52300059)

Removal of phosphorus from wastewater by magnetic lanthanum- modified magnesium iron hydroxide/biochar

Zhenyu YANG(), Dapeng LI(), Sujie SHAN   

  1. School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
  • Received:2024-08-27 Online:2025-05-20 Published:2025-05-22
  • Contact: Dapeng LI

摘要:

生物炭(BC)由于具备丰富的孔隙结构和表面官能团,在污水除磷方面受到广泛研究,但其吸附容量偏低、缺乏选择性等缺点仍有待改进。通过两次共沉淀将四氧化三铁(Fe3O4)和镧改性镁铁水滑石(La-MgFe-LDH)依次负载到玉米秸秆生物炭(BCm)上,制备出磁性镧改性镁铁水滑石/生物炭复合吸附剂(La-MgFe-LDH/BCm@Fe3O4),并通过静态磷酸盐吸附实验和实际污水除磷实验探究其除磷性能。结果表明,La-MgFe-LDH/BCm@Fe3O4对磷酸盐具有较高的吸附容量(48.75 mg/g,以P计),极快的除磷速度(60 min达到吸附平衡)以及优异的pH(3~11)适应性和抗干扰能力。La-MgFe-LDH/BCm@Fe3O4对生活污水和二沉池出水中的总磷也有很好的去除效果。复合吸附剂层间的碳酸根与磷酸盐之间的阴离子交换作用以及复合吸附剂中金属离子和磷酸盐之间的表面络合作用是主要除磷机制。La-MgFe-LDH/BCm@Fe3O4具备实际污水除磷的应用前景。

关键词: 生物炭, 水滑石, 磁改性, 磷, 吸附, 生活污水

Abstract:

Biochar(BC) has been widely studied for phosphorus removal from wastewater due to its rich pore structure and surface functional groups, but its poor adsorption capacity and lack of selectivity still need to be improved. Magnetic lanthanum-modified magnesium iron hydroxide/biochar composite adsorbent(La-MgFe-LDH/BCm@Fe3O4) was prepared by co-precipitation of ferroferric oxide(Fe3O4) and lanthanum-modified magnesium iron hydroxide(La-MgFe-LDH) on corn stalk biochar(BCm) in turn. The phosphorus removal performance was investigated by static phosphate adsorption experiment and actual wastewater phosphorus removal experiment. The results showed that La-MgFe-LDH/BCm@Fe3O4 had a high adsorption capacity for phosphate(48.75 mg/g, calculated as P), extremely fast phosphorus removal rate(reaching adsorption equilibrium in 60 minutes), excellent pH(3-11) adaptability and resistance to disturbance. Furthermore, La-MgFe-LDH/BCm@Fe3O4 also had good removal effect on total phosphorus in domestic sewage and secondary sedimentation tank effluent. The main mechanism of phosphorus removal was the anion exchange between carbonate and phosphate and the surface complexation between metal ions in composite adsorbent and phosphate. La-MgFe-LDH/BCm@Fe3O4 had the prospect of phosphorus removal from actual wastewater.

Key words: biochar, hydrotalcite, magnetic modification, phosphorus, adsorption, domestic sewage

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