Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Fundamentals of Engineering > Water and Wastewater > Flashcards

Water and Wastewater Flashcards

1
Q

Acidity

A

ability of a solution to neutralize hydroxide, arises from CO2 release during biological activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Alkalnity

A

ability of a solution to neutralize hydrogen ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

MCL

A

maximum contaminant level: enforceable standards set by EPA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Primary drinking water standards

A

derived from MCLs, continuously revised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Secondary contaminant standards

A

nonenforceable, based on aesthetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

pH

A

describes the alkalinity/acidity of a solution- the higher the hydrogen ion concentration, the higher the acidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Bicarbonate (HCO3-) is the primary source of…

A

… alkalinity in natural waters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

To express the alkalinity of a solution….

A

… all species are converted to equivalents of CaCO3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hardness

A

sum of all multivalent cations (primarily Ca2+ and Mg2+), results from water contact with minerals in subsurface environments (leads to scaling)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Total solids

A

(TS) residue on evaporation = weight of residue/ volume of dried sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Total suspended solids

A

(TSS) = weight of residue on filter/volume of filtered sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Toal dissolved solids

A

(TDS) = weight of residue from filtrate/volume of dried sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Total fixed solids

A

(TFS) = weight of residue after ignition/ original volume of TS sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

TS =

A

TFS + TVS = TSS + TDS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Turbidity

A

waters that have suspended solids (generally colloidal) which scatter light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Oxygen solubility in water is highly dependent on…

A

… temperature (the higher the temperature, the lower the DO cnc) *oxygen solubility also decreases with increasing solute cncs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Biochemical oxygen demand (BOD)

A

dissolved oxygen consumed in the biological utilization of the substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Chemical oxygen demand (COD)

A

rapid test, useful for industrial waste waters where toxic compounds inhibit biological activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Additional WQIs

A

nutrients, chlorine residual, heavy metals, trace organics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Residence time

A

time a molecule of water is present in the reactor vessel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Tracer

A

non-reactive chemical used to determine the hydraulic characteristics of a reactor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Oxidation is used in water treatment to…

A

… transform soluble Fe2+ and Mn2+ to their insoluble counterparts (can also be achieved using chlorine and potassium permanganate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Coagulation

A

Adding chemicals to cause aggregates to form (reduces electrostatic repulsions present in colloidal and particle suspensions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Aluminum sulfate

A

(alum) most common coagulant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Softening

A

removing excess metallic cations (hardness) from water through the addition of hydrated lime and soda ash, causing soluble forms to precipitate as insoluble forms

26
Q

Sedimentation

A

particles fall out of suspension in quiescent water

27
Q

Terminal settling velocity (Vs)

A

rate at which particles move in the vertical direction

28
Q

Stoke’s law can be applied…

A

… in low Re scenarios

29
Q

Overflow rate

A

surface settling rate, fluid velocity in the vertical direction

30
Q

Backwashing

A

reversing flow of water or air to clean filter

31
Q

Disinfection

A

chlorine gas used to inactivate biological contaminants, creates free available residual chlorine (hypochlorous acid and hypochlorite ions)

32
Q

Log removal

A

desired amount of treatment, specific to microbial species

33
Q

Adsorption

A

contaminant attaches to solid with extremely high surface area (often achieved through air stripping)

34
Q

Henry’s law

A

environmental contaminants have a linear partitioning relationship between the liquid and gas phase at low concentrations when the two phases are in equilibrium

35
Q

Reverse osmosis

A

semi-permeable membrane restricts flow of dissolved ions in aqueous solutions, causing pure water to flow into saline solution to equilibrate, creating pressure difference (osmotic pressure). pressure can then be applied to saline side of membrane, forcing water particles back to pure water side

36
Q

Electrodialysis

A

membrane selectively allows cations and anions to pass through pores- electric current is applied to a collection of alternating layers

37
Q

Ion exchange resin

A

charged surface attracts undesirable ions (often metallic cations which cause hardness)- named after what type of ion they attract

38
Q

Sludge

A

mixture of solids and water from presedimentation, coagulation/flocculation, filter backwashing, lime softening

39
Q

Concentrates

A

wastewater generated by membrane filtration

40
Q

Thickening

A

meant to increase solids content of sludge

41
Q

Conditioning

A

increasing the dewaterability of sludge through the addition of chemicals

42
Q

Dewatering

A

increasing solids content of sludge to greater than 8% through centrifugation, vacuum filtration, plate and frame, and bed filter press

43
Q

Domestic wastewater

A

residential, commercial, institutional sources

44
Q

Municipal wastewater

A

domestic + some permitted industrial wastewater

45
Q

Industrial wastewater

A

high concentrations of biologically inhibiting contaminants, pretreated prior to discharge

46
Q

Conventional WWTP

A

preliminary, primary settling, biological aeration, secondary clarification, tertiary treatment, disinfection, sludge processing

47
Q

Preliminary treatment

A

removes large particles via screening and grit removal

48
Q

Flow equalization

A

some influent is diverted to holding tank during peak flow periods and released later

49
Q

Primary treatment

A

solid particles fall out of suspension in quiescent tanks via sedimentation

50
Q

Secondary (biological) treatment

A

bacteria reduce BOD

51
Q

Activated sludge

A

biosolids rich in bacteria from the final clarifier are returned to aeration tank

52
Q

Mixed liquor suspended solids (MLSS)

A

concentration of bacteria in aeration tank

53
Q

Solids retention time (SRT)

A

average length of time a single cell (solids) spends in the treatment system

54
Q

Stabilization ponds

A

symbiosis between algae and aerobic bacteria cohabit with anaerobic sedimentary activity, naturally treating domestic wastewater from small populations

55
Q

Nitrification

A

conversion of ammonia to nitrate

56
Q

Denitrification

A

reduces nitrates to nitrogen gas, nitric oxide, and nitrous oxide

57
Q

Phosphorus removal

A

removed from wastewater by precipitation with lime, alum, or ferric salt

58
Q

Activated carbon

A

removes heavy metals and organic material not consumed in secondary treatment via adsorption

59
Q

Disinfection

A

removal of pathogens via chlorination or UV light

60
Q

Anaerobic digestion

A

hydrolysis of organic compounds to acids, followed by formation of carbon dioxide and methane

Fundamentals of Engineering (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions