Disinfection

Question 1

Self contained breathing apparatus (SCBA) units are fitted with a ___ ___ ___ alarm that alerts the wearer to leave the contaminated site.

Answer 1

Low air pressure

Question 2

The purpose of the ___ ___ valve in the line going to chlorine injector is to shut off chlorine gas flow in case of a leak.

Answer 2

Vacuum relief valve

Question 3

The ___ creates the vacuum that is required to operate the chlorinator.

Answer 3

Injector

Question 4

The maximum chlorine withdrawal rate from a one ton container at 70 degrees F is ___ lb/day.

Answer 4

400 lb/day

Question 5

To permit maximum withdrawal rate when opening a chlorine cylinder valve, open ___

Answer 5

only one turn.

Question 6

___ ___ are the organisms used to indicate the likelihood that pathogenic bacteria may be present.

Answer 6

Coliform bacteria

Question 7

___ ___ should be fed as early as possible in the treatment process to allow for complete reaction before it enters the distribution system.

Answer 7

Potassium permanganate

Question 8

The two most important factors impacting the effectiveness of chlorination are ___ of the chlorine and ___ ___.

Answer 8

Concentration

Contact time

Question 9

The flexible copper tubing that connects a 150-lb chlorine cylinder to a manifold should be rated at ___ psi.

Answer 9

500 psi

Question 10

The most common water quality complaint for most utilities is ___ and ___.

Answer 10

Taste and odors

Question 11

___ ___ could cause pink water problems.

Answer 11

Potassium permanganate

Question 12

Infectious hepatitis is caused by a type of ___.

Answer 12

virus

Question 13

Chlorine supply lines should be replaced every ___.

Answer 13

Year

Question 14

Potassium permanganate should be fed ___ chlorine.

Answer 14

Before

Question 15

Ozone generally lasts a few ___ to a few ___ when it is dissolved in water for disinfection purposes.

Answer 15

Seconds to a few minutes

Question 16

One ton chlorine cylinders are equipped with two valves, one for ___ and one for ___.

Answer 16

Gas and Liquid

Question 17

Chlorine cylinders stored outside should be stored on ___ ___ to help prevent corrosion.

Answer 17

Elevated racks

Question 18

The pressure in a chlorine cylinder depends on the ___ of the liquid chlorine.

Answer 18

Temperature

Question 19

A ___ uniformly dispenses the chlorine solution into the water being disinfected.

Answer 19

Diffuser

Question 20

Pure liquid chlorine is ___ times more dense than water while chlorine gas is ___ times more dense than air.

Answer 20

1. 5

2. 5

Question 21

Monochloramine is a ___ chemical oxidant than potassium permanganate, ozone and chlorine dioxide.

Answer 21

Weaker

Question 22

Beyond the chlorination breakpoint, _ to _ % of the chlorine residual is free chlorine.

Answer 22

85 to 90 %

Question 23

___ is a toxic gas that has a bluish color and pungent odor.

Answer 23

Ozone

Question 24

___ is more effective in reducing the concentration of taste and odor compounds caused by actinomycetes species than chloramines, chlorine dioxide, and potassium permanganate.

Answer 24

Peroxone (a combination of ozone and hydrogen peroxide)

Question 25

One advantage of using ozone is that it has very little effect on the ___ of water.

Answer 25

pH

Question 26

Chlorine storage rooms should have a window in the door to allow for ___ ___ without entry.

Answer 26

Visual inspection

Question 27

Although chlorine gas will not explode in the presence of oxygen and an ignition source, it will ___ ___.

Answer 27

Support combustion

Question 28

The chlorine emergency kit _ is used to repair leaks on 150-lb chlorine cylinders.
The chlorine emergency kit _ is used to repair leaks on one ton chlorine cylinders.
The chlorine emergency kit _ is used to repair leaks on rail cars and tank trucks.

Answer 28

A
B
C

Question 29

Giardia lamblia species are classified as ___.

Answer 29

Protozoans

Question 30

___ is a weak oxidant that causes corrosion and scaling problems but is not an effective disinfectant.

Answer 30

Oxygen

Question 31

The ___ ___ ___ ___ should be called in the event of a large chlorine leak. They will dispatch an emergency response team.

Answer 31

Chemical Transportation Emergency Center

Question 32

Self contained breathing equipment used by operators during chlorine cylinder change out must be approved by the ___ ___ of ___ ___ and ___ (NIOSH).

Answer 32

National Institute of Occupational Safety and Health

Question 33

150-lb Chlorine gas cylinders are capable of delivering about ___ lb/day without “freezing up.” Additional cylinders should be placed on line to prevent exceeding ___ lb/day from any one cylinder.

Answer 33

42 lb/day

Question 34

Potassium Permanganate is most often used for oxidizing ___ and ___ for removal. It is also used for the reduction of taste and odor causing compounds, TTHM reduction and zebra mussel control. It is not registered with the USEPA as a disinfectant.

Answer 34

Iron and manganese

Question 35

The ___ ___ ___ ___ ___ is a mutual aid program that is in place to provide support for chlorine incidents occurring during transportation or at the user’s location.

Answer 35

North American Chlorine Emergency Plan

Question 36

Salmonella is classified as ___.

Answer 36

Bacteria

Question 37

Chlorine breakpoint occurs at point _ on the curve, after which all chlorine added will be in the free chlorine form.

Answer 37

4

Question 38

Choosing between chlorine, monochloramine, potassium permanganate, and ozone, ___ is the most effective for removing color, poor tastes, and odors.

Answer 38

Ozone

Question 39

Although ___ is an oxidant that causes corrosion problems, it is much weaker than ozone, potassium permanganate, and chlorine dioxide.

Answer 39

Oxygen

Question 40

Chlorine has an advantage over ___ because it is a much stronger oxidant.

Answer 40

Chloramines

Question 41

One disadvantage of ___ ___ is that it has the potential to produce COl2 by-products.

Answer 41

Chlorine dioxide

Question 42

An empty chlorine container can cause a ___ ___ condition in a chlorinator.

Answer 42

High vacuum

Question 43

A failed ___ is most likely the cause of a low vacuum condition in a chlorinator.

Answer 43

Injector

Question 44

The optimum wave length range for inactivating microorganisms is from ___ to ___ nanometers.

Answer 44

250 to 265 nm.