Study On The Preparation And Influencing Factors Of The Alumina Porous Membrane Support For Water Treatment

With the continuous improvement of the material preparation technology andthe human demands on the water quality, membrane technology is used in watertreatment industry more and more. Compared to the traditional organic polymermembrane, porous inorganic membrane shows a distinct advantage on the corrosion-resistant, life and mechanical strength. For this reason, in recent years, the inorganicmembrane has begun to involve in water treatment industry. It is sure to have a goodprospect. Just because the poor quality of the support membrane--the basis of theporous inorganic membrane, the domestic inorganic membrane is always staying at alow level. The report about preparation of the support membrane is few at home andabroad, so basic research in this area is required to guide practice.The sheet inorganic porous ceramic membrane support was prepared by themethod of solid sintering and dry pressing, taking alumina as raw material. The orderof influence on the aperture size distribution, porosity, water flux and corrosionresistance at the point of aggregate particle diameter, the adding amount of adhesives,the adding amount of sintering aid and sintering temperature was studied. We alsoused index d70 for the first time to measure the size of the aperture size distribution inthe data analysis process. The experiment identified four parameters of preparing theporous ceramic membrane support through comprehensive analysis. The properproject that the aggregate particle diameter is mesh of 230-260, the adding amount ofadhesives is 15%, the adding amount of sintering aid is 2% and the sinteringtemperature is 1300℃was received. The experiment also made many optimizedselections on the kind of adhesive, the kind of sintering aid, the adding amount ofwater, molding pressure and heating rate to determine the optimal conditions ofpreparing the porous ceramic membrane support.The influencing factors of the support structure and properties which were theadding amount of pore-forming, the adding amount of adhesives and theircombination methods, aggregate particle diameter, the adding amount of sintering aidand sintering method were researched. The results showed that ,to combine the liquidadhesive with the solid adhesive, it would make an obvious effect on reducingaperture size distribution. The ratio of solid and liquid would be more appropriate tocontrol between 2:3 to 3:2. In order to get a high porosity of the support membrane,the experiment added a certain amount of pore-forming. The total amount of the adhesives and the pore-forming should not exceed 20%, or it would have a negativeimpact on the strength and aperture size distribution of the support membrane. Wealso found that, it would have an obvious effect on reducing the sintering temperature,but have little effect on the change of pore structure to add a certain amount ofsintering aid. However, dosage of the sintering aid should be controlled below 5%,otherwise it would have a negative impact on enhancing the corrosion resistance ofthe support membrane.In order to study the effect of water treatment of support membrane, theexperiment chose two kinds of simulated water samples: filtered water andcontaminated surface water. The results showed that the support membrane couldhave a good removal effect on the turbidity, reaching up to 86.73% and 88.36%respectively. But the ability of removing CODMn was bad, only 3-4 percent. Theremoval effect on UV254 and DOC was worse.