Chapter 5

Question 1

Disinfection is the destruction of disease causing microorganisms called __________________

Answer 1

Pathogens

Question 2

All public water systems must have chlorination facilities ( true or false )

Answer 2

True

Question 3

In addition to disinfection, chlorine is used to remove taste,odor,and color in water,oxidize iron and manganese, control algae, and oxidize _______ gas in water.

Answer 3

Hydrogen sulfide

Question 4

Demand is the amount of chlorine used up by inorganics (minerals) or ___________

Answer 4

Organically

Question 5

__________ is the amount of chlorine left after the demand is met

Answer 5

Residual

Question 6

There are 3 types of chlorine residual : free residual, combined residual and ____________residual

Answer 6

Total

Question 7

The state requires within the distribution system a minimum chlorine residual of _______free or or _____combines, if ammonia is added

Answer 7

0.2mg/l. 0.5mg/l.

Question 8

DPD reacts with chlorine producing a pink to ______color

Answer 8

Red

Question 9

Utility operators use chlorine in 3 commercial forms: PURE CHLORINE in the Liquid or gas state; BLEACH SOLUTIONS, and Granular/Tablet compounds. ( true or false)

Answer 9

True

Question 10

At room temperature chlorine is a greenish - yellow gas that is _______times heavier than air

Answer 10

2 1/2 times

Question 11

Chlorine reacts with hydrocarbons producing heat or fire ( true or false)

Answer 11

True

Question 12

The maximum sustained gas withdrawal rate for pressure transmission 150 lb cylinders is _______lbs/day.

Answer 12

40

Question 13

Hypochlorous acid is the disinfectant and the _________residual

Answer 13

Free

Question 14

Liquid bleach used in public water systems must be _______approved

Answer 14

NSF

Question 15

The state requires _________to be kept in stock for disinfecting new water lines

Answer 15

Calcium Hypochlorite

Question 16

The rotometer indicates the feed rate in _______per day

Answer 16

Pounds

Question 17

Hypochlorinators consist of a mixing tank and a positive displacement feed pump ( true or false)

Answer 17

True

Question 18

Chlorinated rooms must be provided with facilities for determine the amount of disinfectant used _________

Answer 18

Daily

Question 19

If a major chlorine leak occurs , call the supplier and _______

Answer 19

TCEQ

Question 20

Most leaks occur at the container valve and can usually be stopped by closing the valve, tightening the packing nut or applying the outlet cap with gasket over the outlet ( true or false )

Answer 20

True

Question 21

If chlorine enters the eyes, flush with running cool water for at least ______minutes and seek medical attention

Answer 21

15