Waste-derived low-cost ceramic membranes for water treatment: Opportunities, challenges and future directions
As a waste-to-resource strategy, solid waste-derived ceramic membranes have attracted growing research interests for various water treatment applications due to their low costs, renewable and sustainable features, and potentially high removal efficiencies for pollutants. However, waste-derived ceramic membranes still face some challenges, such as less controllable membrane structures and properties due to the varying compositions and impurities in the solid wastes. In addition, waste-derived ceramic membranes have often restricted applications for pharmaceutical, biotechnological, food and beverage products. In this critical review, the advantages of waste-derived ceramic membranes are highlighted in terms of their properties and material sources by comparing with conventional materials. We also analyze the key roles of different solid wastes and the parameters in fabricating ceramic membranes. Various water treatment applications of waste-derived ceramic membranes are summarized based on the separation mechanisms. Since the waste-derived ceramic membrane for water purification is an emerging technology, there are numerous opportunities in this exciting area. The directions for future research and development are recommended accordingly. This review provides an important guidance for turning solid wastes into valuable ceramic membrane products for water treatment.