Opflow Cert. Set 3

Front 1

An ion-exchange softener is treating a flow rate of 245 gpm. Which is the operating time and hours if the softener unit reach 434,000 gallons before it requires regeneration?

Back 1

29.5 hr

Front 2

Which type of special photometer is used to analyze for heavy metals in water?

Back 2

Atomic absorption spectrophotometer

Front 3

Coagulate alum reacts with natural alkalinity in water, forming

Back 3

Aluminum hydroxide

Front 4

Which level of threshold order number (TON) will result in customer complaints?

Back 4

7 TON

Front 5

Molarity is the number of

Back 5

moles of solute per liter of solution

Front 6

Current meters are primarily used for measuring flow in lines that are

Back 6

3 in. or greater

Front 7

Which of the following methods is only a short-term remedy for preventing external corrosion?

Back 7

Extra thickness for pipe walls

Front 8

Which one of the following types of substances is corrosive and may interfere with biological treatment?

Back 8

Acids and alkalies

Front 9

Which element is used as a standard for atomic wieghts?

Back 9

Carbon

Front 10

Determine the specific gravity (sg) of an unknown liquid, if the density of the liquid is 70.9 Ib/ft3

Back 10

1.14 SG

Front 11

In general, the current drawn by a motor the instant its connected to the power source, called the locked-rotor current, is usually______

times the normal full load current of the motor

Back 11

5 to 10

Front 12

Pressure-relief valves are most similar to

Back 12

globe valves

Front 13

The 4 membrane technologies Filtration. What is the correct pore size from largest to smallest?

Back 13

Microfiltration, ultrafiltration, nanofiltration, reverse osmosis

Front 14

Liquid chlorine is which color?

Back 14

Amber

Front 15

When reduction occurs

Back 15

Electrons are gained by the species being reduced

Front 16

It's recommended filter system alarms should be tested every

Back 16

60 days

Front 17

A heterogeneous mixture is

Back 17

A suspension is composed of two or more substances

Front 18

Which filter type uses pressure for filtration?

Back 18

Diatomaceous earth filter

Front 19

Which is the most effective wavelength when using ultraviolet light for disinfection?

Back 19

2,650 anglstroms

Front 20

Slash produced by water draw from sources with relatively low turbidity

Back 20

Can be gelatinous and difficult to handle.