Environmental pollution is now a global threat, and the severity is increasing day by day due to the up-scaled industrialization, extensive agricultural practices, and anthropogenic activities brought on by the massive growth of world population. The practices being quite uncontrolled and unabated, the quality of environment is deteriorating from the accumulation of organic and inorganic pollutants. In view of this, when the need for a better and cleaner environment becomes difficult to meet, nanotechnology came with a bigger hope and immense opportunities. The desired combination of physical and chemical properties has been achievable from the traditional materials when they are manipulated at nanoscale. Metal and metal oxides, graphene and carbon nanomaterials, clay and zeolites, silica, polymer composites are a few of these materials. Their unique physical and chemical features are combined in designing technologies that are greener, innovative, and sustainable. In the form of nanoparticles, tubes, fibers, and wires, they are integrated as adsorbents, catalysts, and membranes. Meanwhile, their enhanced reactivity, tunable characteristics improved the efficacy of the methods that are once expensive and less effective. The chapter makes a comprehensive overview on a broad class of nanomaterials, focusing on their general working mechanism in remediation and sensing technology and pollution management in recent years.