Preparaton And Properties Of The Nano Fe₃O₄ Coated With Polysilicate Sulfate-Chitosan Composites

In this paper,the magnetic flocculant " polysilicate sulfate-chitosan coated nano iron tetrachloride"?PFSS-CTS @ Fe₃O₄?was prepared by sol-gel method.The surface morphology and structure of the experimental materials and products were analyzed and characterized by scanning electron microscopy,Fourier transform infrared spectroscopy and X-ray diffractometer,and the product was used to treat the water samples of a sewage treatment plant from Weifang.The experiment is divided into two parts:Part ?: Preparation and characterization of products?1?Preparation of polysilicate ferric sulfate-chitosan?PFSS-CTS?composites,and in the preparation process to the product of the experimental water sample turbidity removal rate as a measure,studied the impacts on the flocculation effect with the factors of n?Si?/n?Fe??m?PFSS?/m?CTS??pH?aging time etc.The results show that : when the n?Si?: n?Fe?= 1: 1,m?PFSS?: m?CTS?= 5: 1,the reaction pH was around 1.6,the aging time was 1d,PFSS-CTS flocculant showed the best treatment effects on water samples,the products produced under these conditions are used for subsequent experiments.?2?Using hydrothermal method to prepare the Fe₃O₄,and dipping nanometer Fe₃O₄ in PFSS-CTS prepared under optimum preparation conditions ultrasound to get the final product PFSS-CTS@Fe₃O₄ by sol-gel method.?3?The surface morphology and structure of the experimental materials and products were analyzed and characterized by scanning electron microscopy,Fourier transform infrared spectroscopy and X-ray diffractometer.The results of three representations show that: PFSS-CTS was coated on the surface of Fe₃O₄,and the magnetic flocculant PFSS-CTS @ Fe₃O₄ was successfully prepared.Part ?: Product performance testingThe flocculant PFSS-CTS and the magnetic flocculant PFSS-CTS @ Fe₃O₄ prepared under the optimum preparation conditions were used to flocculate the wastewater,and the flocculation effects of the two flocculants were compared respectively;the effects of water pH,flocculant dosage and wastewater settling time on the flocculation efficiency were investigated by COD,turbidity and chromaticity.Experiment result shows that the removal efficiency of PFSS-CTS@Fe₃O₄ was better than PFSS-CTS in the treatment of wastewater at COD,turbidity and chromaticity.The pH range of PFSS-CTS and PFSS-CTS@Fe₃O₄ is 6-9,the optimum dosage is 180mg/L,the best settling time is 30 min and 20 min respectively.