Across
- 3. make impure by polluting or poisoning
- 7. rubbish or waste
- 9. where slug decomposed by anaerobic bacteria
- 12. removes activation sludge with gravity
- 13. water changes from a liquid to a gas or vapor
- 15. the state or quality of being impure
Down
- 1. fuel by the breakdown organic matter
- 2. solid waste such as faeces
- 3. cause flocc to stick together
- 4. separating solid matter from a liquid
- 5. sand pebbles and dirt that settles
- 6. the process of rotting and decay
- 8. process water through chlorine and ozone
- 10. removing biological waste from water
- 11. matter that sinks to the bottom liquid
- 14. consisted of soaps and oils that floats