Clean water supply is an essential element for the entire sustainable human society, and the economic and technology development. Membrane filtration for water and wastewater treatments is the premier choice due to its high energy efficiency and effectiveness, where the separation is performed by passing water molecules through purposely tuned pores of membranes selectively without phase change and additional chemicals. Ceramics and polymers are two main candidate materials for membranes, where the majority has been made of polymeric materials, due to the low cost, easy processing, and tunability in pore configurations. In contrast, ceramic membranes have much better performance, extra-long service life, mechanical robustness, and high thermal and chemical stabilities, and they have also been applied in gas, petrochemical, food-beverage, and pharmaceutical industries, where most of polymeric membranes cannot perform properly. However, one of the main drawbacks of ceramic membranes is the high manufacturing cost, which is about three to five times higher than that of common polymeric types. To fill the large gap between the competing ceramic and polymeric membranes, one apparent solution is to develop a ceramic-polymer composite type. Indeed, the properly engineered ceramic-polymer composite membranes are able to integrate the advantages of both ceramic and polymeric materials together, providing improvement in membrane performance for efficient separation, raised life span and additional functionalities. In this overview, we first thoroughly examine three types of ceramic-polymer composite membranes, (i) ceramics in polymer membranes (nanocomposite membranes), (ii) thin film nanocomposite (TFN) membranes, and (iii) ceramic-supported polymer membranes. In the past decade, great progress has been made in improving the compatibility between ceramics and polymers, while the synergy between them has been among the main pursuits, especially in the development of the high performing nanocomposite membranes for water and wastewater treatment at lowered manufacturing cost. By looking into strategies to improve the compatibility among ceramic and polymeric components, we will conclude with briefing on the perspectives and challenges for the future development of the composite membranes.

Metal–Organic Frameworks (MOFs), which are well-known for their highly controllable level of porosity, large specific surface area, and structural diversity, have been regarded as a class of promising materials for gas storage/separation, liquid separation, energy storage, and conversion. Recently, the applications of MOFs in water technology and sustainability have drawn increasing attention in the research community, although they are much under-investigated. For applications in water technologies, a rational integration of MOFs and bulk substrates is a necessary engineering strategy to improve their stability and recyclability and avoid the potential secondary contamination. In this mini overview, MOF-boosted filtration membrane technology is critically looked into and the current state-of-the-art is discussed. We focus on the membrane filtration technology promoted by MOFs for water treatment, with particular emphasis on the permeability-selectivity trade-off and membrane fouling. In this connection, the configuration and fabrication of MOF-boosted membranes are visited, followed by those MOF-mediated membranes, such as high-permeable membranes, adsorptive membranes, antifouling membranes, and catalytic membranes, where the multi-functionalities are among the key characteristics. A summary is made on the controlling features of these MOF-boosted membranes for water and wastewater treatment, together with the particular challenges and future perspectives.