Green nanotechnology is the development of nanotechnology in an environmentally friendly way. It aims to minimize health and environmental risks associated with nanotechnology and encourage replacing existing products with more sustainable nano-enabled alternatives. Green nanotechnology uses principles of green chemistry and engineering to produce nanomaterials and products without toxic ingredients and seeks lifecycle solutions to environmental problems. Examples include using nanoscale membranes to separate waste, nanocatalysts to make reactions more efficient, and nano-sensors for process control. Overall, green nanotechnology has potential to benefit the environment through applications like cleaning waste sites, desalination, pollution treatment, and development of more sustainable energy and transportation technologies.