Disinfection
Safety
Laboratory
Equipment
Math
100

This chlorine compund will lower the pH of water.

What is chlorine gas?

100

This gas is odorless and colorless. It occurs naturally in certain types of bedrock and is the 2nd leding cause of lung cancer.

What is radon?

100

The chemical added to microbiological sample bottles to neutralize chlorine.

What is sodium thiosulfate?

100
This part of a pump may be closed, open, or semi-open.
What is an impellar?
100
Find the density of ferric chloride in lbs/gal. (Specific Gravity of ferric chloride is 1.140)
What is 9.5 lbs/gal?
200

A substance present in water that will reduce the effectiveness of disinfection by sheilding pathogens from the disinfectant.

What is turbidity?

200
The only type of self contained breathing appaatus than should be used at water plants.
What is positive pressure?
200

A device that sterilizes laboratory equipment using pressurized steam.

What is an autoclave?

200
This type of pump is most commonly used to feed chemicals.
What is a positive displacement pump?
200
A clarifier has a diameter of 82 ft and a depth of 12 ft. Find the surface area of the clarifier in square ft.
What is 5278 ft²?
300

A chlorine residual that is formed by the reaction of chlorine with other substances in the water such as ammonia. It is not as effective as free residual.

What is a combined residual?

300

One volume of liquid chlorine gas will expand at room temperature and pressure this many volumes of gas.

What is 460?

300

A sample that contains essentially the same constituents as the body of water from which it was taken.

What is a representative sample?

300
The instrument that measures the amount of light scattered by particles in a water sample.
What is a nephelometric turbidimeter?
300
450 ml of 5 N NaOH is diluted to one liter. Find the new normality of the solution.
What is 2.25 N
400

The two tests used to determine the effectiveness of chlorine disinfection.

What are total coliform and chlorine residual?

400
The fusible plug in a chlorine cylinder is designed to melt at this temperature.
What is 158 F?
400
The maximum amount of time between the collection of a bacteriological sample and its analysis. The holding time.
What is 30 hours?
400

The leakage of seal water around the packing on a centrifugal pump is important because it acts as _________. (a corrosion inhibitor, a scale inhibiter, or a coolant).

What is a coolant?

400
A laboratory solution is made by taking 52 milligrams of Sodium Chloride and dissolving it in a liter of water. Find the concentration in mg/L.
What is 52 mg/L?
500
This disinfectant must be manufactured on site. It is a bluish, toxic gas with a pungent odor. It leaves no residual and requires large amounts of energy to generate.
What is ozone?
500
The number of people required to respond to a chlorine leak.
What is 4? To entrants and two attendants
500
This test for fluoride is subject to more interferences.
What is SPADNS?
500
During a routine inspection of a centrifugal pump, the operator notices the bearings are excessively hot. This is most likely the result of _____.(overlubrication, a worn impeller, or a worn packing)
What is overlubrication?
500

Calculate the Langeleir Index for the following information. pH = 8.6 Temperature =15◦C TDS = 200 mg/L Calcium = 50 mg/L Alkalinity = 100 mg/L

What is 0.38 ,non-agressive?

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