Across
- 2. _________ water reuse is more common along longer rivers but is also dangerous, since treated wastewater is immediately reused.
- 5. The _______ the LD50 value is, the more toxic it is.
- 8. If a body of water has a high biochemical oxygen demand (BOD) value, then this value will most likely be low (two words).
- 9. A ______ tank system is common in rural areas in order to reduce the BOD value of wastewater.
- 11. ________ ________ 50 indicates the mass of the poison per kilogram of body weight necessary to kill 50% of a population (two words).
- 14. If a person's mass is 100kg, and the LD50 for aflatoxin (moldy foods) is 5mg/kg, then a lethal dose for this person would be ________ _______ mg (number, two words).
- 15. Thermoelectric and this category are the largest users of water in the United States.
- 16. ________ water reuse is safe and planned, where treated wastewater is pumped to recharge zones to replenish groundwater.
- 17. Most of earth's water can be found in our ________.
- 18. Screens, grit removal, and sedimentation are part of the _________ treatment process in a wastewater treatment plant.
Down
- 1. A _______ source pollutant is easy to identify, such as pipes from an industrial site.
- 3. This type of stream flows year-round, as it is fed by the water table, not by rain.
- 4. This source of freshwater takes a very long time to regenerate.
- 6. As opposed to chronic toxicity, ________ toxicity refers to immediate adverse events of ingesting a toxic substance.
- 7. These particles make the great Pacific garbage patch look cloudy, like a soup.
- 10. The addition of this chemical helps to eliminate cholera bacteria from drinking water.
- 12. __________ treatment in a wastewater treatment plant is driven by activated sludge, where bacteria lower the BOD value.
- 13. This process is caused by an excess of nutrients in a body of water, and may eventually cause dead zones.