Studies on Production of Low-Cost Ceramic Membranes and Their Uses in Wastewater Treatment Processes

Abstract
The need for water is increasing owing to the rapidly increasing world population, urbanization, industrialization, global climate changes, and intensive agricultural activities. While the importance of water is increasing day by day, the purification and reuse of water have become more and more essential. Reducing the pollutants at the source as much as possible and if it will be given to the receiving environment, giving the wastewater treatment in accordance with the current discharge regulations, are priority processes. Of the advanced separation methods, membrane separation technology is used to reduce water resource use and control environmental pollution and has advantages such as high separation efficiency, convenient operation, compact equipment, and energy-saving. Membranes are divided into two categories according to their structures: organic and inorganic membranes (or ceramic membranes). Compared to organic membranes, inorganic membranes have many advantages such as high thermal and chemical stability, good resistance to microbial erosion, easy regeneration and cleaning, high mechanical strength, and long-term stability in harsh conditions. The high cost of ceramic membranes is an important disadvantage. In recent years, it is seen that membrane production costs are reduced by using natural minerals such as kaolin, quartz, bauxite, diatomite, clay, limestone, dolomite, zeolite, and industrial wastes instead of the commonly used ceramic membrane raw materials. By using these raw materials, besides reducing the cost of ceramic membranes, it also contributes to lowering the temperatures required for their production. In this study, studies on ceramic membranes produced from industrial wastes (waste ash, sawdust, sewage sludge, construction and demolition wastes, waste diatomite, rice husk ash, sugarcane pulp ash, corn cob ash waste etc.) were examined.