Study On The Treatment Effect Of Modified McM-41 Molecular Sieve On Alkaline Dye Wastewater

In our contemporary society,the increasing discharge of industrial pollution poses a great threat to society and human civilization.According to statistics,printing and dyeing wastewater account for a large proportion of the large amount of industrial pollution wastewater discharge,and is considered to be one of the most difficult industrial discharge wastewater.Among a series of methods developed by the country to treat polluted wastewater,the adsorption method is widely used due to factors such as low cost and easy operation.In recent years,mesoporous materials have been recognized as research hotspots and frontiers in materials science.Extensive research has been carried out in many fields including water treatment.Among them,MCM-41 mesoporous silica material has excellent characteristics such as large specific surface area,high thermal stability,and ordered pore structure.So,it has received considerable attention in the field.The purpose of this experiment is to obtain MCM-41 mesoporous molecular sieve and its modified materials by artificial synthesis,and to explore the adsorption properties of different metal modified MCM-41 mesoporous molecular sieve to the basic dye methylene blue.The experiment was conducted under the conditions of adsorption temperature 298.15 K,p H = 7,adsorption dosage 30 mg,and initial MB concentration 50 mg / L.Attapulgite was selected as the silicon source,CTAB was the surface active stencil agent,and the silicon-based MCM-41 mesoporous molecular sieve was prepared by hydrothermal synthesis.Nine different samples of MCM-41 mesoporous molecular sieve were successfully synthesized by changing the water-silicon ratio,the amount of stencil agent,and other experimental conditions.Afterwards,through the comparative study of the adsorption performance of the sample on the wastewater of basic dye methylene blue,it is concluded that MCM-41（M-6）is the best adsorbent in the sample.Taking MCM-41（M-6）as a template,with cobalt nitrate hexahydrate,aluminum sulfate,titanium dioxide gel,and cerium nitrate as cobalt source,aluminum source,titanium source and cerium source.Modified molecular sieves Co-MCM-41,Al-MCM-41,Ti-MCM-41,and Ce-MCM-41 were successfully synthesized by the impregnation method,and the adsorption kinetics and isothermal curve model were studied.Among the four metal-modified molecular sieves,the adsorption effect of Co-MCM-41 and Ti-MCM-41 on methylene blue is better than that of MCM-41 mesoporous molecular sieve.Co-MCM-41 shows the best adsorption performance due to intermolecular electrostatic interaction;Al-MCM-41 has a certain degree of decrease in the order uniformity of the doping channel structure of aluminum element.So,the adsorption effect of the basic dye methylene in the molecular sieve prepared in this experiment is the worst.The removal rate of methylene blue by Ce-MCM-41 molecular sieve is slightly lower than that of MCM-41 molecular sieve but much higher than that of aluminum-doped molecular sieve materials.In short,the molecular sieve materials synthesized in this experiment can be arranged in order from excellent to poor adsorption performance: Co-MCM-41,Ti-MCM-41,MCM-41,Ce-MCM-41 and Al-MCM-41.