The Preparation And Applied In Wastewater Treatment Of Magnetic Rectorite Composite Materials

This paper summarized the research status of magnetic microporous mineral composite at home and abroad, and described research significance of magnetic rectorite.The optimum conditions of preparation of nano-Fe₃O₄ with coprecipitation method were studied. The solution was deloyed as molar ratio of Fe³⁺/Fe²⁺ 4 to 3 by using ferric chloride, ferrous sulfate as raw material, and used NaOH to adjust pH value to 11, stirred at 60℃for 1.5 h, crystallized at 80℃. The analysis of XRD, SEM, TEM, and VSM indicated that the products were mainly Fe₃O₄, average granularity of Fe₃O₄ was 14.1 nm, had well characteristic of superparamagnetism, and saturated magnetic intensity, remanence and magnetic coercive force of Fe₃O₄ was 56.337 emu·g^-1, 1.19480 emu·g^-1, 0.167A·m^-1, respectively.Magnetic rectorite with Fe₃O₄ loaded was prepared by fractional steps method. The analysis of XRD, TEM, and VSM indicated that the surface of rectorite was covered evenly by Fe₃O₄, and saturated magnetic intensity of magnetic rectorite increased with the content of Fe₃O₄ increasing. Using intercalation principle, magnetic rectorite with Fe₃O₄ pillared was prepared by using ferric chloride, ferrous sulfate and organic-rectorite as raw material. The analysis of XRD, SEM, magnetism and specific surface area indicated that Fe₃O₄ was in the layer of rectorite.The expriment that magnetic rectorite with Fe₃O₄ loaded used to dispose analogue metal ions and organic dye wastewater indicated that the adsorption of contaminant in wastewater on magnetic rectorite was mainly rectorite. When the concentration of contaminant in wastewater was fixed, the adsorption rate of metal ions and decoloration rate of organic dye on magnetic rectorite increased with time prolonging, and adsorption tended to saturation after certain time. The relationship of the adsorption rate of metal ions was Cu²⁺>Zn²⁺>Cd²⁺, and the decoloration rate of methylene blue was better than metbyl orange. With pH value increasing, the adsorption rate of metal ions and decoloration rate of methylene blue on magnetic rectorite increased, but the decoloration rate of metbyl orange on magnetic rectorite reduced. The removal rate of metal ions and decoloration rate of organic dye on magnetic rectorite increased with addition amount of magnetic rectorite increasing. With the initial concentration of wastewater increasing, the removal rate of metal ions and decoloration rate of organic dye on magnetic rectorite reduced, and the adsorption rate of metal ions increased. The magnetic separation and recovery experiments that magnetic rectorite was used to dispose analogue methylene blue wastewater indicated that magnetic separation and recovery rate of all samples reached to over 96%, which indicated the adsorbent was easily recovered by using magnetic separation process after wastewater treatment.