Knowledge Network Node
Environmental Science. 2020, (01) Core

Adsorption of Phosphate on Mg/Fe Layered Double Hydroxides（ Mg/Fe-LDH）and Use of Mg/Fe-LDH as an Amendment for Controlling Phosphorus Release from SedimentsChinese Full TextEnglish Full Text (MT)

WU Jun-lin;LIN Jian-wei;ZHAN Yan-hui;CHENG Yong-qian;BAI Xiao-yun;XIN Hui-min;CHANG Ming-yue;College of Marine Ecology and Environment,Shanghai Ocean University;Chinese Research Academy of Environmental Sciences;

Abstract: We determine the efficiency and mechanism of Mg/Fe layered double hydroxides（Mg/Fe-LDH） addition for the control of phosphorus（P） release from sediments by studying the adsorption behavior and mechanism of phosphate from an aqueous solution on Mg/Fe-LDH.The impact of Mg/Fe-LDH addition on the mobilization of P in sediments as well as the adsorptive removal of phosphate by sediments is investigated,and the stabilization of P bound by Mg/Fe-LDH is also evaluated.Results showed that the kinetics data of phosphate adsorption onto Mg/Fe-LDH fitted better with the Elovich kinetics model than with the pseudo-first-order and pseudo-secondorder kinetics models,and that the Freundlich and Dubinin-Radushkevich models were more suitable for describing the adsorption isotherm behavior of phosphate on Mg/Fe-LDH than the Langmuir model.Phosphate adsorption possessed a wide effective pH range of4-10.Coexisting Ca2+ and Mg2+ enhanced phosphate adsorption onto Mg/Fe-LDH,while coexisting Na+,K+,and Cl-had negligible impacts on the phosphate adsorption.The presence of SO42- and HCO3-in aqueous solution inhibited the adsorption of phosphate on Mg/Fe-LDH.The phosphate adsorption mechanisms were deduced to be anion exchange,electrostatic attraction,ligand exchange and inner-sphere complex formation.The addition of Mg/Fe-LDH into sediments not only greatly reduced the concentration of reactive soluble P（SRP） in the overlying water,but also significantly decreased the level of SRP in the pore water.In addition,Mg/Fe-LDH addition also increased the adsorption capacity for the sediments,and the phosphate adsorption ability for the Mg/Fe-LDH-amended sediments increased with increased amendment dosage.Almost half of the phosphate bound by Mg/Fe-LDH existed in the form of relatively stable P,i.e.,metal oxide-bound P（NaOH-rP）,which was difficult to release back into the water column under normal pH and anoxic conditions.Nearly half of the phosphate bound by Mg/Fe-LDH existed in the form of easily released P,i.e.,NH4Cl extractable P（NH4Cl-P） and redox-sensitive P（BD-P）,which had a high risk of re-releasing into the water column.We conclude that it is very necessary for Mg/Fe-LDH to be recycled from the sediments after the application of Mg/Fe-LDH as an amendment to control sedimentary P liberation.
Keywords：

sediment; internal phosphorus loading; Mg/Fe layered double hydroxides; addition; release control;

  • DOI：

    10.13227/j.hjkx.201907174

  • Series：

    (B) Chemistry/ Metallurgy/ Environment/ Mine Industry

  • Subject：

    Environment Science and Resources Utilization

  • Classification Code：

    X52

Download the mobile appuse the app to scan this coderead the article.

Tips: Please download CAJViewer to view CAJ format full text.

Download: 1108 Page: 273-283 Pagecount: 11 Size: 1551K

Related Literature
  • Similar Article
  • Reader Recommendation
  • Associated Author