Problem 1
Describe the function of (a) aeration and (b) addition of aluminum or iron sulfate in the purification of drinking water.
Problem 3
Describe how water can be disinfected by (a) membrane filtration and (b) ultraviolet irradiation.
Problem 4
What two other chemical methods, other than chlorination, are used to disinfect water? What are some advantages and disadvantages to these alternatives?
Problem 5
Explain the chemistry underlying the disinfection of water by chlorination. What is the acrive agent in the destruction of the pathogens? What are the practical sources of the active ingredient?
Problem 6
Explain why \(\mathrm{pH}\) control of water in swimming pools is important. What compounds are formed when the chlorinated water reacts with ammonia?
Problem 7
Discuss the advantages and disadvantages of using chlorination to disinfect water, including the nature of the THM compounds.
Problem 8
What is meant by the terms groundwater and aquifer? How does the saturated zone of soil differ from the unsaturated?
Problem 10
Name three important sources of nitrate ion to groundwater.
Problem 11
Construct a table that shows the common oxidation numbers for nitrogen. Deduce in which column the following environmentally important compounds belong: \(\mathrm{HNO}_{2}, \mathrm{NO}, \mathrm{NH}_{3}, \mathrm{~N}_{2} \mathrm{O}, \mathrm{N}_{2}\), \(\mathrm{HNO}_{3}, \mathrm{NO}_{3}{ }^{-}\). Which of the species become prevalent in aerobic conditions in a lake? Under anaerobic conditions? What is the oxidation number of nitrogen in \(\mathrm{NH}_{2} \mathrm{OH}\) ?
Problem 15
Define leachate.
