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30 Cards in this Set

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  • Back
What does "potable" mean?
Potable (drinkable). (21 893)
What are some of the most noticeable physical qualities of water?
turbidity
color
taste and odor
temperature
foamability (21 894)
What causes water TURBIDITY and why is it important?
"Turbidity is easy to see and thus is a likely source of dissatisfaction for the would-be customer...caused by the presence of suspended material such as
clay
silt
inorganic material
plankton
organic material." (21 894)
What causes COLOR in water?
"Color... often caused by dissolved organic matter..." (21 894)
What can cause TASTE and ODOR in water?
"Taste and odor can be caused by
organic compounds
inorganic salts
dissolved gasses." (21 894)
What causes FOAMABILITY in water?
"Foamability is usually caused by concentrations of detergents." (21 894)
What are the chemical characteristics of water?
Alkalinity
Hardness
pH (21 894)
What toxic substances could be found in the water supply?
fluoride
lead
chlorides
copper
iron
manganese
nitrates
pesticides
sodium
sulfates
zinc (21.1 896)
What is the maximum allowable concentration coliform bacteria in potable water?
"The recommended maximum concentration of coliform bacteria is one organism per 100 mL (about 1/2 cup) water." (21.1 897)
What are the common water filtration methods?
sedimentation
coagulation
flocculation
slow sand filters
diatomaceous earth filters
direct filtration
membrane filtration
cartridge filtration
other: activated carbon, porous stone, ceramic, unglazed porcelain
What factors affect chlorine's ability to disinfect water?
Chlorine concentration
Contact time
Water temperature
pH (900)
What are 3 forms of chlorine used for disinfection?
Chlorine gas
Sodium hypochlorite solution
Solid calcium hypoclorite (900)
What are chloramines?
"adding ammonia to water containing chlorine...." (900)
Besides chlorine and chloramines, what are other means of disinfecting water?
ozonation
UV radiation
nanofiltration (901)
What does aeration (oxidation) do?
"...improve the taste and color of water and help remove iron and manganese." (902)
What are the factors involved in corrosion control?
acidity
conductivity
oxygen content
carbon dioxide content
water temperature
lower flow rates (903)
In brief, what is the sequence from corrosion to clogged pipes?
"Th products of corrosion often conribute to scale formation. Scale then lines surfaces, eventually clogging openings." (903)
What causes water hardness?
"Water hardness is dcaused primarily by calcium and magnesium deposits..." (903)
What are three water softening methods?
Ion exchange
reverse osmosis
electrodialysis (904)
What is the problem with micro-organisms in water?
"Some organisms may not be injurious to health but can multiply so rapidly that piping or filters become clogged or the water's appearance, odor, and taste are affected." (904)
What are the disadvantage and advantage of fluoride in water?
Children benefit from fluoride but it is not needed by adults and can be harmful to their teeth. (905)
What are the four types of wells?
Bored wells
Driven wells
Jetted wells
Drilled wells (906)
When would a BORED WELL be used and what is its measurement?
Bored wells "are...usually less than 100 ft deep... used when the earth to be bored through is boulder-free and will not cave in. The diameter range is 2 to 30 in." (906)
When are the dimensions of a DRIVEN WELL?
"The drive point is usually 1 1/4 to 2 in. in diameter...the well is driven to a point well below the water table." (906)
What are the Hydraulic Institute's recommendations for reducing electricity used by pumps?
"1. Design systems with lower capacity and total head requirements...
2. Avoid excessive capacity...
3. Select the most efficient pump type and size...
4. Use two (or more) smaller pumps instead of one large one...
5. Maintain pumps and system components in virtually new condition..." (906)
What are the common types of pumps used in well water supply?
Positive displacement pumps - reciprocating pump; rotary pump
Centrifugal pumps - turbine pump, submersible pump
Jet (or ejector) pumps (908)
What are the two critical factors when selecting a pump?
flow rate (volume per minute or hour)
total pressure (head)(908)
What is DOMESTIC hot water used for (and not used for)?
Domestic hot water is not used "for space heating, but for "bathing, clothes washing, dishwashing and other related functions." (916)
What are the advantages/disadvantages of higher hot water supply temperature ?
"Allow installation of smaller storage tanks...
Can be achieved at point of use...
Can cause scale to form on heating coils and within piping...
May be required by code for some applications but limited by code for others.
Limit the potential growth of Legionella pneumophila bacteria (above 140 degrees F)." (916)
What are the advantages/disadvantages of lower hot water supply temperatures?
"Are less likely to cause burns but may not achieve desired sanitation.
Mean less energy consumed, because storage and pipe heat losses are lower.
Allow installation of smaller heating units but require larger storage tanks.
Make possible the use of lower-grade heat sources for DHW such as solar energy or waste heat recovery." (917)