The continued increase in the global population has resulted in increased water demand for domestic, agricultural, and industrial purposes. These activities have led to the generation of high volumes of wastewater, which has an impact on water quality. Consequently, more practical solutions are needed to improve the current wastewater treatment systems. The use of improved ceramic membranes for wastewater treatment holds significant prospects for advancement in water treatment and sanitation. Hence, different studies have employed ceramic membranes in wastewater treatment and the search for low-cost and environmentally friendly starting materials has continued to engender research interests. This review focuses on the application of coal fly ash in membrane technology for wastewater treatment. The processes of membrane fabrication and the various limitations of the material. Several factors that influence the properties and performance of coal fly ash ceramic membranes in wastewater treatment are also presented. Some possible solutions to the limitations are also proposed, while cost analysis of coal fly ash-based membranes is explored to evaluate its potential for large-scale applications.

The growing demand for organic dyes across industries increases their environmental impact since wastewater containing organic dyes poses serious risks to aquatic life, human beings, and the environment. The removal of organic dye residues is a challenge for traditional wastewater treatment facilities, highlighting the need for advanced treatment techniques that balance cost-effectiveness and sustainability in the face of today’s strict environmental regulations. The use of low-cost starting materials in ceramic membrane technology has recently become more popular as a feasible option because of its affordability and effectiveness, leveraging the synergy of adsorption and filtration to improve dye removal. Recent developments in ceramic membranes derived from waste and natural materials are examined in this review paper, along with their types, mechanisms, and applications in eliminating organic dyes from wastewater. The various forms of ceramic membranes derived from waste and natural materials are classified as follows: those composed solely of inexpensive starting materials, composites of inexpensive materials, hybrids of inexpensive and commercial materials, and inexpensive materials functionalized with cutting-edge materials such as carbon nanotubes and nanoparticles. These membranes have shown promising results in lab-scale research, but their large-scale use is still limited. The factors that negate the commercialization of these membranes are also critically discussed. Finally, key challenges and future research opportunities in the development of sustainable ceramic membranes for highly efficient dye removal are highlighted.