wastewater manuel

What converts mechanical energy to water horsepower?

The impeller

Two types of pumps used in the water industry:

Positive displacement and centrifugal

Type of pump used to move heavy liquid

Positive Displacement

Name an unexpected cause of motor bearing failure

over-lubrication

What provides lubrication for the pump seal?

Water

What is the result of operating a piston pump with both check valves open?

It will not pump.

Item that discharges water from a centrifugal pump

Vanes of impeller

The item that adjusts the rate of flow of the lubrication of water?

Packing gland

It converts energy from velocity head to pressure:

Valute (?spelling?)

Electrical service for our industrial equipment is

440 V

The ____ prevents the leakage from the stuffing box from getting into the motor bearing

slinger ring

The correct way to install new packing is

90 degree interval

_______ are used to eliminate leakage associated with packing

Mechanical Seal

_____ is used to prevent water from leaking from the pump, must be lubricated by allowing a steady drip to leak from it

packing

The ___ is a replacement component that prevents wear from the packing

shaft sleeve

Who may remove a lock out/tag out?

The installer

The ___ distributes lubrication water to the shaft sleeve

lantern ring

What is cavitation?

bubbles imploding against the impeller

Cavitation in a pump is often caused by

partially closed gate valve

What will happen if you add new packing to old packing?

scarring

If a reduced fitting is needed on the pumps suction, what is the proper type?

incentric

What type of pumps are piston/diaphragm pumps?

Positive displacement

The motor driving a pump is sometimes referred to as

the prime mover

Common solution pumps are usually..

Positive displacement pumps

What is the correct drip rate for centrifugal pump stuffing box?

1 drop/sec or per manufacturer instructions

What will happen if a positive displacement pump is operated with the discharge gate valve closed?

Damage

To pump to a higher elevation you must install your pumps in what configuration?

Straight/in a row/in series

What is the proper drip rate for a mechanical seal?

zerooooo

What effect will a clogged inlet line have on the mercury pressure gauge of a suction lift pump?

It will read higher

How do you control the CFM of air delivered by a positive displacement blower?

Adjust the RPMs of the blower

1 gallon =

8.34 lbs, 3.785 liters, 3,7875 ml

1 cf =

62.4 lbs, 7.48 gal

1 acre =

43,560 square feet

1 mile =

5,280 feet

1 day =

1440 mins

1 ml =

10 mg/L

1% =

10,000 mg/L

1 cf/s =

448 gpm

Equation for watts

Volts x Amps

ppm means

parts per million

MCL means

Maximum contaminant level

MRDL means

Maximum residual disinfectant level

1 ppm in one million gallons is..

8.34 lbs

Area of circle =

pi x radius squared

Flow MGD =

chemical feed lbs of 100% pure divided by the (dose mg/L multiplies by 8.34 lbs/gal)

1 lb =

454 grams

1 gpg =

17.1 ppm

1 ppm dry weight =

1 mg/L

1 ppb =

1 microgram/L

1 ft head =

0.433 psi

1 psi =

2.31 feet head

1 ppm =

1000 ppb

ppb =

parts per billion

ml means

milliliter

MGD means

Million Gallon Day

gpd means

gallons per day

gpm means

gallons per minute

gps means

gallons per second

fps means

feet per second

1 milliliter is __ of a liter

1/1000

0.746 Kw equals how many watts

746

how many gpm in a MGD

694 (700)

What gas is most like to cause corrosion on metal and concrete surfaces in an aerobic wwtf?

CO2

The most important factor that influences the amount of DO present in a sample is:

The temperature of the sample

The solids in raw (primary) sludge from domestic sewage will usually contain about:

60-85% volatile solids

The pounds of suspended solids per person per day contributed to normal domestic wastewater is:

0.2

What is not removed by preliminary treatment?

dissolved solids

The overall BOD removal in a well operated waste stabilization pond facility should be:

70-80%

What is least likely to affect the performance settling in a primary clarifier?

Total dissolved solids in the water

When biodegradable organic wastes are discharged into a sluggish stream and an appreciable oxygen depletion develops you would expect the point of minimum dissolved oxygen level in the stream to be:

3-5 days flow time below the point of discharge of the waste

T/F ponding or pooling of filters is usually caused by freezing weather

F

T/F The aging process caused by excess nutrients being discharged into a body of water from wastewater treatment plant is known as eutrophication

T

T/F sludge pumping is most commonly done with a positive displacement pump

T

T/F Electrical current is measured as voltage

F

T/F Primary Clarifiers are used to remove nonsettleable solids

T

The flow through the grit chamber is reduced to ___ which allows the grit to settle out

1 ft/s

Gravity sewer lines should be installed at a slope that maintains a minimum flow of ___ to prevent grit from settling in the lines

2 ft/s

What is meant by detention time?

The theoretical time it would take the flow to completely displace the effective volume of the tank

The primary purpose of draft force ventilation in the lift station is to

Remove dangerous gases

Sludge pumping is most commonly done with a ____

Positive displacement pump

Raw sewage pumping is most commonly done with a

centrifugal

Organic wastes are wastes which come from __

A plant source

What type of sample is the pH always performed on?

grab

Organic loading in a lagoon is defined as

BOD/acre/day

Two processes most commonly used for secondary or biological treatment in a wastewater treatment plant are:

trickling filter and activated sludge

What is the recommended application rate for treating a lagoon with sodium nitrate on the first day of application?

100 lbs/acre

Which is an indication that the sludge collection mechanism in a clarifier is not working?

The sludge being pumped from the clarifier is very thin

In accordance with good practice, public sanitary sewer lines should be laid at:

a fixed grade of 0.25 in per foot of pipe

For waste stabilization ponds, the minimum water depth should not be less than

2 ft

Wastewater sludge that has been dried on a vacuum filter will have about what solids content?

70%

Good primary sludge withdrawn from a primary settling tank is about:

4.0 to 6.0% solids

Carbon dioxide, one of the gases given off by the decomposition of sludge, is not considered toxic, but it may cause

corrosion

The volatile solids content of undigested primary sludge collected from plants serving separate sewer systems will normally be

60-80%

In an activated sludge plant it is essential that the DO in all parts of the aeration tanks be at least

1.0 mg/L

A low-rate or standard-rate trickling filter is one having a hydraulic loading rate of about:

25-90 gal/day/sqft

Grit chambers that are designed to remove grit, without allowing the organic matter to settle, have a flow velocity of

0.5-1.0 fps

The BOD of secondary effluent from an activated sludge plant normally will be in the range of

less than 30 mg/L

Hydrogen sulfide gas is not only a poisonous gas, but it also will cause __

corrosion in the system

Inorganic solids may also be called

nonvolatile solids

The pH scale ranges from

0-14