Preparation And Performance Of Conductive Microfiltration Carbon Membranes

Conductive microfiltration carbon membrane is a novel inorganic membrane, which is prepared by inexpensive precursors-coal. It can be applied in many fields due to their thermal and chemical stability, good conductivity and mechanical strength. Cooperating with Tianjin Polytechnic University, our group has developed a new type of membrane materials named of electro-catalytic carbon membrane, which possesses self-cleaning function according to the conductive properties of the carbon membranes. The membrane has better anti-fouling property and good effect on treating industrial waste water, especially for the non-biodegradable water. The pore structure properties and electrical conductivity has good effect on efficiency of the conductive microfiltration carbon membrane in waste water treatment. Thus it is important to study the pore structure and electrical conductivity of carbon membrane as well as their relationship.In this paper, the pore structure, electrical conductivity and mechanical strength of the carbon membrane were optimized by adding the additives and employing the blending methods. The relationship between electrical conductivity and pore structure was studied. We also studied the effects of electrochemical oxidation on waste water treatment and water flux in Low voltage electric field condition. The TG, SEM and Bubble-pressure methods were employed to characterize structure properties of carbon membranes. The results showed that the pore structure of carbon membranes was further developed by adding pore formers and additives. When the addition ratio of coking and lean coal is2:8, the mechanical strength of carbon membrane is the highest, while comparatively high flux maintained. The electrical conductivity of the carbon membrane was enhanced along with the decrease of porosity as well as the addition of carbon black or graphite. The flux of carbon membrane was significantly improved owing to the effect of electro osmosis and electrochemical reaction. Simultaneously, with the increase of electric-field strength and electrical conductivity, the flux increased more dramatically. The carbon membrane was tested in water/methylene blue waste system. Because of the synergistic effects of electro osmosis, electrochemical reaction and the change of hydrophilic, the carbon membrane had both high flux and ability to oxidized-degrade methylene blue. Under the flux of236L·h-1·m-2·Bar-1, the degradation efficiency is98.3%, which shows that conductive carbon membrane has both excellent anti-pollution ability and degradation efficiency.