22.1 Introduction22.2 Carbon Nanomaterials for Environmental Devices and Techniques22.3 Functionalized Nanomaterials for Environmental Techniques22.4 Nanoseparation Device for Environment22.5 Magnetic Nanomaterials for Environment22.6 Bionanomaterial-Based Devices for Environment22.7 Nano-Lab on a Chip for Environment22.8 Toxicity, Economy, and Legalization of Nanotechnology22.9 Nanotechnology: A Green and Sustainable Vision22.10 ConclusionsReferences