1. Look at daring
2.List three major processes that occur in natural water purification and, for each, identify the contaminates
1. Thermal energy from the sun causes water to evaporate from oceans and other water sources, like distillation.
2.Bacterial action converts dissolved organic contaminates into a few simple compounds.
3.Filtration through sand and gravel removes nearly all suspended matter
3. How are the properties of aluminum hydroxide related to the process of flocculation?
It traps and removes the suspended particles
4.Why is calcium oxide (CaO) sometimes added in the final steps of municipal water treatment?
It is used to neutralize such acidic water, raising its pH to a proper level
5.Fluoride, and ingredient in many types of toothpaste, is sometimes added to municipal water supplies in the last stage of water treatment. How much fluoride is added and what is its purpose?
1ppm of flurried is added to the water, and it treats water in a process known as fluoridation, which can reduce tooth decay
6.What are advantages of chlorinated drinking water compared to untreated water?
Removing the organic material
7. Is there a disadvantage to using colorization in water treatment? Explain
the chlorine added in post-chlorination can still promote formation of THMs , even if to a lesser extent than with pre-chlorination
8. Water from a clear mountain stream may require chlorination to make it sae for drinking. Explain
The reason that clear mountain water might require chlorination is because of all the chemicals in the air that we have from pollution may have traveled into the water, causing some impurities to the water.
9.List two alternative to use of chlorination in municipal water treatment.
Charcoal filter and ultraviolet light
18. Explain what would happen to Earth's hydrologic cycle if water evaporation suddenly stopped?
There would be no evaporation cycle meaning that the cycle would just stop, and all the water would just stay on land and never be reused.
19. One unique characteristic of water is that it is present in all three physical states in the range of temperatures found on Earth. How would the hydraulic cycle be different if this were no true?
It would be different because then you couldn't be able to evaporate it, when the water turns into gas, then there would be no evaporation.
20. WHy does the EPA limit the concentration of THMs to 80 ppb instead of requiring their total elimination for municipal water supplies?
They didn't eliminate it because they need a little bit of chlorine in the water
21.Compare how the various processes used in the foul-water investigation are similar to steps in the natural purification of water?
One step that is like the foul water investigation is the filtering through the gravel and sand. Both the natural filtration process and the foul-water investigation both used the sand gravel system to purify the water.
22. Some physicians recommend consuming about 2 L of water daily. Municipal water supplies may contain up to 1 ppm fluoride. Assume that you drink 2 L of water per day. At 1ppm fluoride, how many grams of fluoride ion would you consume in
A. One Day?
1ppm
B. One week?
7ppm
C. One Year?
365ppm
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