Inorganic Chemicals Industry ›› 2023, Vol. 55 ›› Issue (8): 124-131.doi: 10.19964/j.issn.1006-4990.2022-0643

• Environment·Health·Safety • Previous Articles     Next Articles

Study on adsorption of cadmium-humic acid by hydroxyiron oxide

TANG Yifu1(), CAO Changchun1,2(), LÜ Peng1   

  1. 1.College of Environmental Science and Engineering,Guilin University of Technology,Guilin 541004,China
    2.Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas,Guilin 541004,China
  • Received:2022-11-01 Online:2023-08-10 Published:2023-08-25
  • Contact: CAO Changchun E-mail:yvantang77@163.com;caochch@glite.edu.cn

Abstract:

Iron nitrate and potassium hydroxide were used as raw materials to prepare hydroxyiron oxide samples to investigate the adsorption effect on Cd2+ as well as the adsorption isotherms and kinetic properties.XRD,SEM,BET,FT-IR and XPS were used to characterise the morphology and structure of the samples and to analyse the adsorption mechanism.The results showed that the experimentally produced hydroxyiron oxide product was α-FeOOH,which had good adsorption effect on Cd2+ at pH of 5~7.The adsorption capacity of α-FeOOH on Cd2+ was up to 20.34 mg/g at a temperature of 25 ℃,adsorbent dosage of 0.03 g,pH of 6,background humic acid mass concentration of 20 mg/L,and initial mass concentration of Cd2+ of 20 mg/L.The adsorption process followed the Langmuir and Freundlich isothermal adsorption model and quasi secondary kinetic model.The complexation of Cd2+ by hydroxyl groups on the surface of α-FeOOH and carboxyl groups on the surface of HA layer was its important adsorption mechanism.

Key words: hydroxy iron oxide, cadmium contamination, humic acid, complexation, adsorption

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