Nowadays, providing clean and accessible water to meet human needs is the major challenge of the 21st century. Nanoparticles have great potential for improving current technologies for water and wastewater treatment because of their novel properties. However, the risks associated with residual nanoparticles in treated waters and their difficult separation have limited their widespread applications in water and wastewater treatment. To overcome this limitation, it is required to efficiently immobilize nanoparticles on a suitable bed. This review provides details on the immobilization of nanomaterials on various beds of different materials and morphologies. The major points are 1) a comprehensive summary of the current status of different beds used to immobilize nanomaterials, and 2) the features, advantages, and disadvantages of different beds. Different beds, including beads, membranes, fibers, 3D porous structures, organic supports, and inorganic supports, have been investigated to immobilize nanomaterials. Considering the advantages and disadvantages of beads, spherical carbon beads have excellent mechanical properties, chemical, thermal, and mechanical resistance. Therefore, they can be the best choice for the treatment processes. Adsorptive membranes have several advantages, including high efficiency, mechanical strength, chemical resistance, and high flexibility. Therefore, they are the best choice of membranes as a substrate. Among different 3D porous structures, the aerogel type has better properties for the immobilization of nanoparticles. Organic supports, which are considered as vulnerable support for nanoparticles, have several disadvantages, including low mechanical, thermal, and chemical stability. Inorganic supports can be considered the best substrate due to their many merits and few drawbacks.