Amidst the increasing global challenges of clean water and environmental sustainability, carbon-based nanocomposites (CNCs) have a promising future in practical applications. This chapter investigates the use of carbon nanomaterials, including activated carbon, carbon nanotubes (CNT), graphene (Gr), and graphene oxide (GO)-based nanomaterials to remove pollutants and heavy metals from the environment. Nanocomposites (NCs) exhibit good properties, for example, high performance, selectivity, world abundance, recyclability, and low manufacturing time. The review demonstrates various applications in wastewater treatment, drinking water treatment, and groundwater treatment, especially in industrial and pharmaceutical wastewater. Composite materials containing CNT and Gr bonds have emerged as solutions because of their unique electrical, thermal, and chemical properties. The latest developments, approaches, and issues related to carbon and graphene quantum dot-derived nanomaterials for environmental remediation have been discussed. It also explores new applications of nano-adsorbents in various fields such as aerospace, batteries, the chemical industry, sensors, and membrane science. This article demonstrates the development of carbon-based polymer NCs in solving environmental pollution problems and making the technology sustainable for future use.