Preparation of low-cost microfiltration membranes from fly ash

Abstract

Commercial ceramic membranes have undergone a rapid growth during the last two decades. The interest in ceramic membrane has increased concurrently with new processes and new applications. Membrane processes are being used more and more in many fields such as water treatment. The use of membrane technology to replace a separation or purification step in an industrial process may reduce the overall consumption of energy. The development of membrane processes to treat wastewater is generally limited because the price of the membranes is too high, which is particularly true for the inorganic membranes. One of the challenges for future development of the inorganic membranes will be to produce low-cost membranes from natural materials such as clay, fly ash and apatite which are in abundance and which need lower firing temperature than metal oxide materials and have high flux performance to treat large volumes of liquid effluent. Porous ceramic membranes have great potential for opening new types of applications to which polymeric membranes cannot be applied. Inorganic microfiltration and ultra-filtration membranes have been used in a wide variety of processing. The preparation of porous ceramic membranes, which need to have uniform pore sizes, to be as thin as possible without defects, seems to represent a different strategy from conventional preparation of ceramic bulk bodies. This new research field of ceramic processing will contribute much to the development of membrane science and technology. The aim and purpose of this work is fabrication and characterization of low cost ceramic membranes using low cost materials. Membranes were prepared using fly ash as major constituent after trying various compositions. Membranes were casted in circular disk of thickness 5mm and diameter 55mm. The membranes were sintered at four different temperature to study the effect of temperature on membrane performance .The membranes characterization was done using techniques like XRD ,SEM and TGA. Membranes porosity was determined using pycnometric method and to check chemical stability of membranes they were subjected to acid and base treatment for 7 days.