Preparation And Application Of Magnetic Fe₃O₄ Composites In Dyeing Wastewater Treatment

Large amounts of inorganic salts and surfactants exist simultaneous with dyes in water.Textile effulents with low penetrations,high toxicity,and high COD,so dyestuff wastewater has a serious effect on environment.The magnetic Fe₃O₄ composites catalytic hydrogen peroxide discoloration of the dyeing wastewater.The advantages of this catalyst is not only easy to be separated and feasible to be used repeatedly,but also has no secondary pollution to the environment.This study prepared magnetic Fe₃O₄ composites and used to remove several types of pollutants including rhodamine B,methylene blue,aniline,catechol,KMnO4 and K2Cr2O7 which cause water environment pollution.By examining the impact of various factors on the removal,the optimum experimental conditions were choosed to achieve the purpose of efficiently removing harmful pollutants.The main results are as follows:1.Surface gelatin functioned magnetic composites have been successfully prepared through a facile one-pot solvothermal method,containing iron oxide grains,shell for gelatin.The effects of reaction system,reaction time and reaction temperature on the structural,morphological and magnetic properties of magnetite particles are studied.The size and form of particles was observed by scanning electron microscope?SEM?.The crystal structure was identified using x-ray diffraction?XRD?method.Nanospheres were of a regular spherical inner multiphase structure,uniform particle size distribution,with good dispersion stability and magnetic response.Fe₃O₄/gelatin composite particles can be stable for a long time.2.Preparation of Fe₃O₄ had a good catalytic degeadation in the treatment of rhodamine B simulated wastewater.The experimental results showed that when the initial concentration were 50 mg/L,the target compound could be removed efficiently from solution over a wide pH range from 1 to 13 in the presence of Fe₃O₄ as peroxidase-like catalyst and H2O2 as oxidant.Under optimal conditions,RhB could be removed completely after 30 min of reaction at 50 ?,Furthermore,Fe₃O₄ catalysts showed the high magnetization,temperature tolerance,long-term storage and operational stability,and could be readily solid-liquid separation by applying an external magnetic field.3.We used natural sand replaced the traditional chemicals,and Fe₃O₄-Sand magnetic composites have been successfully prepared through vacuum drying method.The optimal praration conditions of Fe₃O₄-Sand are that H2O2/Sand/Fe₃O₄ is 20:10:0.1,temperature is 70 ?,vacuum drying.The size and surface morphology of particles was observed by scanning electron microscope?SEM?;and the chemical composition of particles was analysised by FT-IR.Preparation of Fe₃O₄-Sand had a good catalytic performance in the treatment of methylene blue,aniline and catechol simulated wastewater.The experimental results showed that when 15g Fe₃O₄-Sand filled diameter 1cm,length 20cm filter column,H2O2 as oxidant the material,the removal capacity of methylene blue,aniline,catechol,KMnO4 and K2Cr2O7 is 150 mL,200 mL,140 mL,70 mL and 80 mL.