Chemical Feed

Question 1

Explain the following terms and their relationship to each other: free chlorine, total chlorine, demand, residual, pre-chlorination, post-chlorination, and breakpoint chlorination

Question 2

What is the process of chlorination called as a treatment process and how does it differ from sterilization

Question 3

What are the physical properties of chlorine, what hazards does it present, what advantages does it have over most other disinfections, and how does it react with bacteria

Question 4

What is the purpose of a fusible plug, at what temperature does it melt, and where is it located on a 150-lb. and 1-ton cylinders

Question 5

What is the correct procedure to follow in changing a chlorine cylinder and what item should always be replaced with a new one in doing so

Question 6

How, when, and where should residuals be taken and what information do they provide

Question 7

What is DBP used for in relation to chlorine and how does it work

Question 8

What is SCBA, where should it be stored in relation to the chlorine room, what special training should be used with it, and at what frequency

Question 9

What are the three available forms of chlorine and what are the most common percentage strengths of each of the three forms

Question 10

What is HTH and what different forms and strengths is it commonly available in

Question 11

What effect does the addition of chlorine gas to water have on the water’s pH

Question 12

What chemical is used to detect chlorine leaks and how is it best used

Question 13

What type of piping should be used for chlorine

Question 14

How much expansion will take place if one gallon of liquid chlorine is vaporized, and what is the specific gravity of chlorine gas

Question 15

What type of respiratory protection should be used when working with chlorine

Question 16

What are the two different types of chlorine residual and what are the advantages and disadvantages of each

Question 17

What are other types of disinfectants other than chlorine and what are some of the advantages and disadvantages of each

Question 18

How are hypochlorite solutions generally added to drinking water

Question 19

How many turns should the valve on a chlorine cylinder be opened and where should the valve wrench be kept

Question 20

What is a rotameter and what does it do

Question 21

What is the minimum dosage for disinfecting new water mains using the tablet method as described in AWWA C-651

Question 22

What effect do the following water quality parameters have on the disinfection process: temperature, pH, turbidity, organic matter, and hardness

Question 23

Where do most chlorine leaks occur, what type is the most serious and what action is usually taken first to stop a leak

Question 24

What are chloramines, how are they formed, what problems can result from their presence in a water system, and what advantages does monochloramine have over a free residual

Question 25

What is a yolk used for in a gas chlorination system

Question 26

What is a chlorinator that works off of the pressure of a chlorine cylinder called

Question 27

When chlorinating water, what does an injection check valve do

Question 28

What is the maximum chlorine feed rate in a 24-hour period for a 150-lb cylinder

Question 29

How pure is chlorine gas when calculating dosages

Question 30

What are the precautions for handling Calcium Hypochlorite

Question 31

What is slug method disinfection

Question 32

DBPs are formed when disinfectants react with what