The Study On The Sorption Of Heavy Mental On The Preparation Of Magnesium Ferrite Composites

Adsorption method was an effective method to remove heavy metal ions,and the selection of efficient and convenient adsorbents was the core of this method.In this paper,magnesium ferrite was used as a template for magnetic media,and the ferrite composites were prepared by compounding magnesium ferrite with the extensively formed halloysite nanotubes in nature.The macro-static sorption method was used to study the sorption behavior of Co???,Ni???and Cd???on magnesium ferrite composites.The effects of different environmental conditions?time,pH,solid-liquid ratio,ionic strength,temperature,etc.?on the sorption of heavy metal ions in wastewater on composite materials were discussed.Experimental results showed:?1?The sorptions of Co???,Ni???and Cd???on MgFe₂O₄-HNT@starch were obviously affected by pH,and the sorption rates of Co???,Ni???and Cd???increased with increasing pH.?2?The results of kinetic experiments showed that the sorption rates of heavy metal ions on MgFe₂O₄-HNT@starch accorded with the pseudo-second-order sorption kinetic rate equation.?3?The effects of different anions on the sorption efficiency of Co???on MgFe₂O₄-HNT@starch were:ClO₄^-<NO₃^-<Cl^-;The effects of different cations on the sorption efficiency of Co???on MgFe₂O₄-HNT@starch was:Li⁺<Na⁺<K⁺.?4?The effect of solid-liquid ratio on the sorptions of heavy metal ions on magnesium ferrite composites was as follows:the sorption efficiencies increased with the increase of solid-liquid ratio within a certain solid-liquid ratio range,and then remained unchanged after reaching a certain level.This was related to the saturation of the sorption sites of the adsorbent.?5?The effect of temperature on the sorptions of heavy metal ions on magnesium ferrite composites was as follows:the affinity of the adsorbent towards heavy metal ions increased with the temperature increasing.The sorption isotherms indicated that the sorption isotherms were more consistent with Langmuir model.The adsorption process was spontaneous and endothermic.Finally,the XPS and FT-IR results of the magnesium ferrite composites before and after adsorption and the desorption experiments showed the sorption mechanism of heavy metal ions on the composites.