The results of environmental pollution has been catastrophic to the ecosystem, this has forced climate change, threatened food security, and ultimately, human survival. The quest to restore the environment to its pristine state is underway. Environmental science, and nanotechnological development and advancement, have championed much of these efforts, because it hinges on a sustainable approach, agreed by the league of nations. Environmental science and nanotechnology have effectively been employed to sense, monitor and cure conventional environmental pollutions, and through engineering innovations and advancements, the application have been extended to the emerging contaminants. While much have been achieved on this front, the current result and strategy is insufficient to tackle the current environmental challenges. The current issue hopes to advance and support innovative concept, science, engineering and technology, that promotes a sustainable methodology to the sensing, monitoring and curing of conventional, and emerging contaminants, with special focus on the recovery, regeneration and reuse of environmental waste. The issue shall cover the following themes: Environmental science and nanotechnology in clean water; Environmental science and nanotechnology in wastewater purification; Role of Environmental science and nanotechnology in resource recovery, regeneration and reuse; pollution signals in freshwater, reclaim and wastewater.