Design And Characterization Of Ceramic Membrane Materials On Treatment Of Cool Rolling Wastewater

To resolve serious membrane fouling and low permeation flux during the treatment of cold rolling wastewater with ceramic membranes, appropriate ceramic membrane materials were chosen for investigation of their respective surface properties. A critical flux model was established to provide a foundation for the concerned industrial design of ceramic membrane equipments. The surface electrochemical theories were introduced to describe the influences of the surfactant upon the membrane surface properties,which was further discussed with the adsorption data. The above influences on microfiltration process were also investigated. The results showed that the permeation flux apparently varied with the property of the membrane surface. The flux increased from 100L/(m2·h) to 300L/(m2·h) due to the addition of 100mg/L sodium laurgl sulphate(SDS). The influence of water treatment reagent and the adsorbent on the microfiltration was also given. The effect was different from that of those used in traditional flocculation and aiding filtration. The membrane fouling due to the adsorption of the reagents should be considered. Based on experiments, it was proposed that surface properties of the ceramic membrane had apparent influence on the microfiltration of cool rolling wastewater, so the Zeta potentials of different ceramic membranes were analysed in this paper. The surface property of zirconia membrane was improved by adding 20％ silicon dioxide and 10％ alumina. The wetting property and Zeta potential of the composite plate membrane were measured, the wetting property showed no changes, whereas Zeta potential changed, which would help to control the membrane fouling in treatment of the cool rolling wastewater. This work also provided a new way to develop a special membrane used for oily waste water treatment.A critical flux model containing feed viscosity was established based on the resistance model. The relationship among the membrane permeation flux and working pressure, cross-flow velocity , feed viscosity was given. The calculated results were in good agreement with the experimental data. The optimum operating pressure at different conditions were also given. As the viscosity was introduced ,the model would give certain guidence to the process design for similar treatment systems.As stated above, this paper enriched the theoretical aspects of ceramic membrane process by investigating the effects of the pretreatment upon the separation, the surface properties of the membrane as well as establishment of a critical flux model . These work offered a new approach for the development of new ceramic membranes and settlement of the problem emerged in the treatment of oily waste water.