Across
- 2. The type of digestion that treats effluent in waste water treatment.
- 6. What planet has an atmosphere that resembles the Earth's first atmosphere?
- 7. A human product that can contaminate water sources.
- 13. A process that can carry on indefinitely without affecting future generations.
- 15. The amount of greenhouse gases emitted over the full lifecycle of a product.
- 16. and Algae What two types of organisms were the first to produce oxygen?
- 18. Removal of solids from water
- 19. The process of killing microorganisms in water.
- 21. What greenhouse gas is released by cattle farms?
- 22. The correct term for destruction of forests.
- 23. Which gas burns with a squeaky pop?
Down
- 1. What is bleached by chlorine gas?
- 3. A resource that can be replaced at the same rate it is used.
- 4. What released the gases that made up the Earth's first atmosphere?
- 5. A material that contains only one element or compound.
- 7. The formation of which rock type removed CO₂ from the air?
- 8. Making salt water drinkable.
- 9. The main pollutant from agriculture that can affect rivers.
- 10. What gas made up the majority of the Earth's early atmosphere?
- 11. What process created the oxygen in the atmosphere?
- 12. A product made from an artificial process.
- 14. Water that is drinkable
- 17. What chemical is used to test for Carbon Dioxide?
- 20. The type of digestion that treats solid matter in waste water treatment.