Recycling refers to the process of treating used or waste materials to enable their reuse for new products.
Recycled Water refers to wastewater that is treated to enable its reuse.
Rapid population growth on earth (which has been uneven geographically) has resulted in strains on environmental resources such as water and food.
Fossil Fuel refers to combustible organic material such as coal, oil, or natural gas that is formed from the remains of living organisms.
Nuclear Energy refers to the energy generated by nuclear reaction.