Preparation Of Porous Magnesium Silicate Adsorption Material By Ball Milling Method And Its Adsorption Properties

With the deepening of urbanization and the continuous improvement of people's living standards,more and more industrial wastewater and domestic sewage containing organic dyes are discharged into the environment.This will not only seriously damage the ecological environment,but also cause security risks to people's health,and will further affect the sustainable and healthy development of our economy and society.In comparison,the adsorption method has the advantages of simple operation,low cost and short treatment cycle,which is one of the effective ways to treat organic dye wastewater.The effect and efficiency of the adsorption method mainly depend on the chemical composition,pore structure and surface properties of the adsorption material.Two-dimensional layered porous magnesium silicate adsorption materials have attracted wide attention in scientific research and industry due to their rich raw materials and simple preparation.At present,hydrothermal method or solvent-thermal method is mainly used to control the preparation,accompanied by a large number of reactions and washing wastewater,which is not conducive to large-scale preparation and application.In view of the above problems,this paper aims to prepare high-efficiency and low-cost porous magnesium silicate adsorption materials,develops a green and clean ball milling solid-phase synthesis method,and systematically studies the key parameters of ball milling speed,time,ball material ratio,etc.In the process of ball milling on the chemical composition,crystal structure,pore structure,surface properties of porous magnesium silicate adsorption materials and their adsorption properties for methylene blue organic wastewater.The relationship between the structure and the adsorption properties of magnesium silicate was revealed.The main research results of this paper are as follows:(1)A series of porous magnesium silicate adsorption materials with different pore structures were successfully prepared by ball milling solid-phase synthesis.The effects of key operating factors such as ball milling speed,ball milling time,ball material ratio and material ratio on its chemical composition,crystal structure,pore structure and adsorption performance of methylene blue were systematically discussed,and controllable preparation parameters were optimized.The results show that when the rotation speed of the ball mill is 250 rpm,the ball milling time is 6 hours,the ball material ratio is 2:1,the volume ratio of the utensil is 10:1,the molar ratio of the material Si:Mg=1.25,and the number of times of centrifugal washing is 4,the porous magnesium silicate has the best adsorption performance for methylene blue solution,the maximum adsorption capacity is 280 mg/g,and its adsorption thermodynamics follows the single-layer chemical adsorption.(2)Based on the interface effect of organic-inorganic solvents,a new method of wet milling was developed,in which a certain amount of anhydrous ethanol and glycol dispersant were introduced into the ball milling process respectively.The effects of the type and amount of dispersant on the chemical composition,pore structure and adsorption performance of the prepared magnesium silicate adsorbent were investigated in detail.The results show that the introduction of the two dispersants does not change the adsorption thermodynamic behavior of magnesium silicate on methylene blue,but significantly improves the pore structure and surface properties of magnesium silicate adsorption materials,greatly improving its adsorption performance on methylene blue.For example,the optimal amount of anhydrous ethanol is 7.5%of the material quality,and the modified amount of methylene blue adsorption is 312 mg/g,the best amount of glycol is 15%of the mass of the material,and the adsorption amount of methylene blue after modification is 333 mg/g.