This book summarizes the fundamental processes and mechanisms of the green synthesis of nanomaterials. It also reviews the potential applications of green synthesized products to environmental remediation in terms of antimicrobial activity, catalytic activity, removal of pollutants dyes, and heavy metal ion sensing. Further, the book examines nanotechnological advances in green chemical sensors for environmental proposes, focusing on the detection of contaminants in soil and water. The chapter also illustrates effect of development and research activities on environmental remediation using green nanotechnology. The possible hazards associated with nanomaterials and the harmful effects that may result from the exposure of aquatic animals to nanoparticles are also addressed in this book. Towards the end, the book explores the ethical and social implications of nanotechnology. This book offers material ideally suited for courses of nanoscience and technology students of any other field of science or engineering.