1. Ozone was first initiated as a water treatment technology in 1974 with the discovery of chloroform, a disinfection byproduct, in drinking water. (True or False)

2. Ozone disinfectant in water produces a stable residual to ensure continued sanitation of the water as it flows through the pipes and to consumers’ taps. (True or False)

3. Ozone is used more as a chemical oxidant in water treatment than as a disinfectant. (True or False)

4. Ultraviolet (UV) light ozone generation is the only way to avoid creation of high concentrations of nitric acid, which can be very corrosive to downstream equipment. (True or False)

5. The amount of ozone transferred to the water is dependent on:

a. The concentration of ozone in gases exiting the ozone generator

b. The size of the bubbles in the water

c. The rate the bubbles rise through the water

6. The accepted concentration (C) and contact time (t) of ozone for 99.9 percent (3 log) inactivation of viruses is:

a. 0.1 milligrams per liter for 15 seconds

b. 0.5 milligrams per liter for five minutes

c. 0.4 milligrams per liter for four minutes

7. Clear water containing polyvalent ions and organic materials can produce turbid or cloudy water upon ozonation. (True or False)

8. Trihalomethanes (THMs) are readily oxidized by ozonation. (True or False)

9. A monitoring device that can be used to control a continuous level of ozone in a storage tank or circulating water system is a:

a. Venturi meter

b. Oxidation-Reduction Potential meter

c. DPD analyzer

10. Excess ozone can be destroyed by:

a. Heating to 600º F

b. Palladium, manganese or nickel oxides

c. Granular activated carbon