Preparation Of Sodium Alginate Composite And Its Adsorption For Ionic Dyes

In recent years,with the rapid development of modern industry,the pollution of printing and dyeing wastewater has gradually attracted people’s attention.Untreated printing and dyeing wastewater is directly discharged into the natural environment,not only will cause harm to the animals and plants in the water,but also harmful substances will be passed into the human body through the biological chain,thus endangering human health.Sodium alginate（sodium alginate,SA）from brown algae and algae algae in the oceans,a kind of polysaccharide compounds extracted with stability,security,non-toxic,easy to take the characteristics of the molecular surface functional groups,sodium alginate can with metal ion or small molecular organic crosslinking gel formation,is a good carrier for load other materials,the composite material has often been as adsorbent used in the dyeing and printing wastewater treatment.In this study,three kinds of magnetic gel spheres,Fe₃O₄@SA/Ca,Fe₃O₄@SA/GO and Fe₃O₄@SA/CTS,were prepared by using sodium alginate as raw material,calcium chloride（CaCl₂）as cross-linking agent and magnetic Fe₃O₄,Chitosan（CTS）and Graphene Oxide（GO）,respectively.Using XRD,SEM,FT-IR,VSM and XPS test means of Fe₃O₄@SA/Ca,Fe₃O₄@SA/GO and Fe₃O₄@SA/CTS.the morphology structure of them,element content,specific surface area and magnetic characterization analysis,etc.With Methylene Blue（Methylene Blue MB）and fuchsine Basic Fuchsun（CB）cationic dye as adsorption object,and study influencing factors such as p H,adsorbent additive amount,reaction time,initial concentration of pollutant effect on the adsorption process,The adsorption behavior and mechanism were investigated by combining isotherm and kinetic model.The main research contents are as follows:（1）With SA,CaCl₂,Fe₃O₄as raw material was prepared by magnetic Fe₃O₄@SA/Ca gel material,and XRD,SEM,FT-IR,BET and other characterization,Fe₃O₄combined with the success of the SA,and its high purity almost do not contain other impurities,also has a variety of functional groups,has the high saturation magnetization and low remanence values,show that it has super paramagnetic properties,after completion of the adsorption experiment,the plus under the action of magnetic field can quickly reach the solid-liquid separation,in the p H=8,adsorbent additive amount of 1 g/L,MB concentration of 100 mg/L,The removal rate of MB reached 93.9%and the adsorption capacity reached 89.1mg/g.The adsorption kinetics data satisfied the pseudo-second-order kinetics model,and its adsorption isotherm satisfied the Langmuir adsorption isotherm model.The desorption and regeneration experiments for five times proved that Fe₃O₄@SA/Ca adsorbent was desorbed and regenerated under 0.1mol of HCl,and it had good reusability.（2）With SA,CaCl₂,Fe₃O₄,GO for the raw material preparation of magnetic Fe₃O₄@SA/GO gel material,and XRD,SEM,FT-IR,BET,XPS characterization,characterization results prove Fe₃O₄@SA/GO successful preparation,and its high purity,and adsorbent adsorption of MB before and after the functional group is very stable,with a variety of functional groups,have high saturation magnetization,after completion of adsorption experiment,the plus under the action of magnetic field can quickly reach the solid-liquid separation,in the p H=9,adsorbent additive amount of1.0 g/L,MB concentration of 100 mg/L,The removal rate of MB reached 92.4%and the adsorption capacity reached 94mg/g when the reaction time was 300min.The adsorption kinetics data satisfied the pseudo-second-order kinetics model,and the adsorption isotherm satisfied the Langmuir adsorption isotherm model.At different p H,Fe₃O₄@SA/GO adsorption of MB in the mixed solution was better than CB.When the p H was 9,the adsorption amount of MB was 86.18mg/g,and the adsorption amount of CB was 17.02mg/g.Five successive desorption and regeneration experiments have proved that the desorption and regeneration of Fe₃O₄@SA/GO adsorbent under 0.1mol HCl has a good reusability.（3）With SA,CaCl₂,Fe₃O₄,CTS as raw material was prepared by magnetic Fe₃O₄@SA/CTS gel material,and XRD,SEM,FT-IR,BET,XPS characterization,prove the successful synthesis of Fe₃O₄@SA/CTS adsorbent,Fe₃O₄@SA/CTS for spherical,uneven surface sag,with a variety of functional groups,have high saturation magnetization,adsorption experiment is completed,in additional magnetic field can quickly reach under the action of solid-liquid separation.When the initial concentration of MB or CB is 100 mg/L,the amount of adsorbent is 1.0g/L,the p H of MB is 11 or the p H of CB is 8,the reaction temperature is 25℃,the reaction time is240min,the rotation speed is 180 r/min,and the volume of water sample is 100 m L,the removal rate and adsorption capacity of MB and CB can reach 91.8%and 21.4%,and 88.6mg/g and 22.6mg/g,respectively.The adsorption kinetics data satisfy the pseudo-second-order kinetics model,and the adsorption isotherm satisfies the Langmuir adsorption isotherm model.The adsorption capacity of Fe₃O₄@SA/CTS for MB in the mixed solution was better than that of CB at different p H values.When the p H value was 9,the adsorption capacity of MB and CB was 82.57mg/g and36.57mg/g respectively.At the same time,Fe₃O₄@SA/CTS had good adsorption cycle performance.