Homework 7/1

Page 102 #1-9 18-22

11.    

The Hydrologic Cycle

22.    Evaporation and condensation, which removes almost all dissolved substances, bacterial action, which converts, dissolved organic contaminants into a few simple compounds, and filtration through sand and gravel removes almost all suspended matter.

33.    Flocculation is a process in which the alum and slaked lime react to form aluminum hydroxide, which is a sticky material that traps and removes the suspended particles. 

44.    Calcium oxide is added to neutralize the waters acidity level to an appropriate amount.

55.    Approximately 1 ppm of fluoride is added to decrease tooth decay. 

66.    The advantage of chlorinated drinking water against untreated water is killing disease-producing microorganisms in water.

77.    There is a disadvantage in using chlorination in water treatment. This disadvantage is that water can react with organic compounds produced by decomposing animal and plant matter to form substances that can be harmful to humans.

88.    Yes it might need chlorination to make it safe because the bacteria in the water needs to be destroyed in order to make it safe and pure.

99.    Two alternatives of using chlorination in municipal water treatments are: charcoal filtration and the use of ozone or ultraviolet light.

118. The whole cycle would end because evaporation is the first part and if that step fails then so do the others, and it would be the end of mankind.

119. If this were not true the hydrologic cycle would be different in the aspect of including steps like evaporation, which would make water a gas or any of the other steps becoming solids, liquids, or vapors.

220. The EPA has a limit because there are alternatives, which can eliminate THM health risks and chlorine is needed to kill bacteria.

221. These steps are similar because they both work on purifying water. Some steps including when water passes gravel, sand, and rock, suspended mater are filtered out which is similar to sand filtration are more similar to others.

222. A) 1 ppm fluoride

B) 7 ppm of fluoride

C) 365 ppm of fluoride