Lectures 19-21 + TBL 6 Flashcards
1
Q
Reactions in which elements may be converted from one into another, involving particles within the nucleus, and a release or absorption of large amounts of energy. The rate of the reaction is not influenced by external factors
A
Nuclear reactions
2
Q
nuclear particles (protons and neutrons)
A
Nucleons
3
Q
Different forms of the same element
A
isotopes
4
Q
When unstable nuclei emit one or more particles and / or electromagnetic radiation
A
radioactive decay
5
Q
High energy particles and ____ size particles can penetrate _____
A
smaller, more
6
Q
When high energy photons with very short wavelength are emitted, which changes neither the atomic mass or mass number. Accompany most nuclear reactions and convertes something from an excited to a relaxed state
A
gamma radiation
7
Q
Emission of a particle equivalent to a He nucleus (mass # = 4, atomic mass = 2)
A
alpha radiation
8
Q
Emission of either an electron or a positron from the nucleus
A
beta radiation
9
Q
When an electron is emitted in beta radiation, the atomic number ____ by 1. When a positron is emitted in beta radiation, the atomic number ____ by 1
A
increases, decreases
10
Q
Radionuclides have different rates of decay/ Each nuclide has a characteristic ____ ____ and _____ ____. Rates of decay are independent of ___, ____, _____, etc., and obey first order _______
A
decay constant, half life, T, P, S, kinetics
11
Q
The time interval over which the initial number of atoms is exactly halved
A
half life
12
Q
As t–> inifinity, the number of parent atoms approaches ______, and the number of daughter atoms approaches ______. The range of the decay constant can be from ______ (fast), to _____ (slow)
A
0, N0, 3x10^6s, 2x10^-18s
13
Q
From the earth or cosmic sources
A
natural environmental radioactivity
14
Q
Radioactivity from the time earth was formed (~4.6x10^9 years)
A
primary / primordial radioactivity
15
Q
The primary radioactive elements
A
40K, 232Th, 235U, 238U
16
Q
_____ is naturally abundant, and primordial, meaning it has a long ______. About _____ the 238U originally present on earth has decayed.
A
238U, half life, half
17
Q
As U decays, the daughters formed are:
A
Th, Pa, Ra, Rn, Po, Pb, Bi
18
Q
The daughters formed from U decay are also ________ and decay by either ____ or ____ decay with varying ______ until the final stable ____ is formed. With each decay, there is a change in _______. ___ and ____ are very soluble while ___ ______ _____ ____ and ____ are not. ____ is a gas
A
radioactive, alpha, beta, decay constants, Pb, chemistry, U, Ra, Pa, Th, Po, Bi, Pb, Rn
19
Q
The soluble U species in aqueous solution are
A
(UO2)(OH)5+, (UO2)(CO3)34-
20
Q
radiation from outside earth, mainly a stream of nuclei and protons. React with the atmosphere to produce secondary particles
A
secondary / cosmogenic
21
Q
Examples of secondary radiation
A
3H, 14C, 7Be, 26Al, 32Si, 39Ar
22
Q
examples of man-made / anthropogenic environmental radioactivity
A
- nuclear weapons, 2. nuclear fuel cycle (reactors, reprocessing plants), 3. others (low level waste, naval reactors, accidents)
23
Q
All radioactive species can end up in
A
soils and surface waters
24
Q
In general, exposure from radiation from _____ ____ is greater than from _____ ____
A
natural sources, artificial sources
25
Most exposure to radiation is from ____ sources (76.1%), the next is ____ (22.9%) Typically the greatest exposure is from _____ because it is a gas. In water, the greatest concern is______. Natural exposure is greater at higher ______ from cosmic rays, thus pilots, flight attendants and people who live in mountains have higher exposure
natural, medical (x-rays), Rn, Ra2+, elevation
26
Radon is naturally produced in the environment, from decay of U in ____, ____ or _____. It is ____, ______, tasteless, and emits ______ radiation. It is a gas, moves through soil, and escapes to the ______ or seeps into buildings. When radon is confined to enclosed or poorly -______ spaces, it _______ to high levels. Radon levels are generally highest in ______ and crawl spaces, because these areas are nearest to the source and poorly ventilated. In ____ ____ radon gas is very low level and does not pose a health risk
rock, soil, water, colourless, odorless, ionizing, atmosphere, ventilated, accumulates, basements, open air
27
the production of ions which is the primary effect of alpha and beta particles and gamma rays on materials.
ionizing radiation
28
alpha particles are ____ do not ____ deeply, but are very harmful if _____ because they produce a lot of ______. Beta particles are _____ penetrating than alpha, but less ______ per unit (less ionization), ______ penetrate the most.
large, penetrate, swallowed, ions, more, energy, gamma rays
29
Radiation initiates harmful reactions in _____, resulting in acute radiation poisoning. _____ ____ is destroyed, there is _____ damage, and _____
tissue, bone marrow, genetic, cancer
30
The factors in ranking danger of radiation
1. type of radiation, 2. energy of radiation, 3. half-life of source
31
_____ life times are not very harmful in the environment because they ____ quickly. Long life times are _____ harmful because they are _____ _____. ____ _____ are the most hazardous
short, decay, not, low activity, intermediate life-times
32
In drinking water, the common radionuclides are _____, ____, and ____, which are leached from _____. _____ is of the most concern, as it often occurs beyond the _____ _____ _____. However, is is well removed by ________ processes (like Ca). Nuclear ____, _____ and _____ have increased concern about contamination of water by other sources.
U, Ra, K, minerals, Ra, maximum contaminant level, softening, weapons, power, accidents
33
Human sources of ______ to the atmosphere over the last 60 years was much _____ than the natural levels in the ______. _____ released more than ______, but less than ______
Cesium-137. less. ocean. Fukushima, three-mile island, chernobyl
34
____ ___ _____ _____ released much more radioactivity in the ocean than _____ ______. However, there is still much more _____ _____ radiation
global nuclear weapons testing, reactor accidents, natural occurring
35
The main sources of pollutant acidity are (3)
1. acid rock drainage, 2. industrial wastes, 3. acid rain
36
The problem with pollutant acidity is that ___ ___ are sensitive to ____ extremes, and have a maximal __ ___
aquatic biota, pH, growth rate
37
Acid rain is a ______ problem and a danger to ____, ____, _____, _____, etc. It is associated with heavy _______. Normal pH of rain is ______ due to CO2. Acidic rain has a pH of ______, but can be as low as ______. Areas are least sensitive to the effects of acid rain if they are primarily comprised of _______ ____ (CaCO3) The ____ ion can offset the added _____ from the acid rain
regional, crops, lakes, buildings, forests, industry, 5.6, 4-5, 2, carbonate bedrock, carbonate, H+
38
The main sources of acid rain are from ______ and _____ in the atmosphere. ____ of these oxides produces ___, _____, and ______. It can also be from ______.
sulphur oxides, nitrogen oxides, oxidation, HSO4, HNO4, H2SO3,CO2
39
The sources of sulphur oxides include _____ burning, roasting of ___ ____ _____. The _____ _____ in Sudbury Ontario is the world's largest single point emission source of _____.
coal, metal sulphide ores, Ni smelter, SO4
40
Sources of nitrogen oxides include ______ sources, and oxidizing agents in the atmosphere are ______, _______, and _______
combustion, ozone, hydrogen peroxide, peroxides (CH3O2)
41
Even in highly polluted atmospheres, NO2 and SO2 are _______. But even at low concentrations, SO2, ______, and ______ have a bigger effect on ___ in fresh waters that are _____ ____, than CO2, as they are more ____ in water (bigger _____) and they are stronger _____ (bigger ____)
<1ppm, SO3, HNO3, pH, poorly buffered, soluble, Kh, acids, ka
42
Acid rain can impact plants in that pH < _____ damages leaves and alters ____ ____. In water, it is a problem where underlying rocks provide poor ____ ____ (ie. limestone vs granite (no carbonates)). Some of the worst hit areas are ______, ______, Scandinavia, and Germany. Lowering pH increases the _______ of many metals (ex. Al)
3.5, soil chemistry, buffering capacity, E. Canada, N.E. USA, solubility
43
Some natural sources of salts include ______ _____ and ____ ______ Anthropogenic sources include _____ ____, road ______, dissolution from ______ ____, ground water ________, and ______
sea spray, evaporative basins, water softening, de-icing, ore piles, intrusions, irrigation
44
While light rainfall is taken up by ____ ___ and evaporates back to the air fairly quickly, heavier rain and ______ can cause water to penetrate deeper into the soil before _______. Heavy ____ for crops and landscaping can penetrate to layers of the soil that contain higher levels of ______ ____, _____ and _____ them and bring them back to the surface as the water evaporates.
plant roots, irrigation, evaporation, irrigation, mineral salts, dissolve, mobilize
45
One of the biological problems with salinity is that biota are suited to a particular salinity, since ____ limits the acceptable salinity range (_______). The more salty ______ and less salty _____, will result in water being ______ ____ of cells. Depending on the environment, it can cause cells to either ____ ___ or _____.
osmosis, osmoregulation, environment, cell, pulled out, blow up, shrivel
46
The tendency for solvent molecules (ie. H2O) to move from low to high solute concentration (ie. salt) to equalize concentration
osmosis
47
The chemical problems with salinity increase is that it increases _________. Salt increases the water's ability to carry ________, and which take part in _______ (redox reaction). Also, the salt is ________ which means it attracts water, and water is needed along with _______ for the reaction. The salt helps _____ water and increases the rate of ______
corrosion, electrons, corrosion, hydroscopic, oxygen, gather, oxidation
48
H2S is a product of anaerobic decay of ____ ___ containing S, and anaerobic reduction of SO4 by ________. It is a ______ acid, and ______ and _____ are dominant in water. H2S has a very high affinity for ____, and forms _____ complexes and ______. It oxidizes to ____ when exposed to O2. Wastes from ____ plants and _____ may also contain H2S. H2S is very ______.
organic matter, microorganisms, weak, H2S, HS, metals, MS, precipitates, SO4, chemical, mills, volatile
49
The problem with H2S is that at lower levels there is a ____ ____ smell. You can fix this by added _____ _____ to an open pitcher which ______ and _____ H2S. At higher levels, it is very _____ and you lose the ability to smell it.
rotten egg, lemon juice, protonates, degasses, toxic
50
The main sources of sewage are _____ (sinks, dishwashers, rubs, toilets), which consists of ____ ___, ____, ____ ___, etc. It can also come from _______ sources such as _____ ____, chemical industries, ____, etc., which may contain elevated levels of ____, toxic organic pollutants, and general ___ ______
domestic, human feces, detergents, toilet paper, industrial, food processing, printing, metals, organic matter
51
Most municipalities treat ____ ___ then dispose of the ___ __ in near water bodies (river, lake, oceans). The remaining sewage _____ is disposed of in _____ or the ocean (_____ ____). Sometimes it is incinerated or further tested and treated to use as ______ (biosolids)
raw sewage, liquid residue, sludge, landfills, offshore dumping, fertilizer
52
The "used water" in sewage should be low in _____, acceptably free of ____ ____, and ______. Contamination of drinking water by sewage is the leading cause of disease such as _____ and typhoid fever. Easily oxidizable components such as ____, ______, are removed by standard water treatment (______). Other components, such as _____ , _____,, and _____ ____ ______, are not as easily removed
BOD, persistent pollutants, pathogen, cholera, solids, oil, aeration, metals, salts, degradation resistant organics
53
BOD is due to all the things in water which could consume ____, most of which is ____ ____. unless ______(ie. by turbulent mixing), water becomes ______ if BOD > O2. Addition of oxidizable _______ such as sewage, affects BOD and therefore can effect O2 levels
oxygen, organic matter, re-aerated, anoxic, pollutants
54
High O2, no oxidizable pollutant / recovered to pre-pollutant conditions
clean zone
55
pollutant levels are high and dropping, O2 is dropping, and pollutant is being decomposed by O2
decomposition zone
56
Pollutant levels are still dropping but being decomposed by alternate oxidants
septic zone
57
Pollutant is gone and O2 is increasing again - mixing into system due to turbulence
recovery zone
58
Different ____ decompose matter in _____ and _____ zones
bacteria, decomposition, septic
59
A class of organic compounds produced by incomplete combustion or high-pressure processes.
Polynuclear aromatic hydrocarbons (PAHs)
60
PAHs form when complex organic substances are exposed to ______ _____, or ______. PAHs are _____ soluble and ______ to fish and possibly humans. Their structure consists of several ________ _____ stuck directly to each other
high temperatures, pressures, fat, carcinogens, benzene rings
61
Pesticides/insecticides that are applied to plants and soils.
DDT / organochlorine insecticides
62
DDT and organochlorine insecticides are _______, meaning while they provide longer pesticide resistance, they are also transported by ____ and ____ ___ ____ into water systems. They are also resistant to breakdown by _______, especially if the Cl is attached to a _____ ___ (ie. DDT). Even if they breakdown, they breakdown into another organochlorine which is still toxic.The structure is benzene separate by a _____ bridge and __
stable, thunder, ground water run-off, hydrolysis, aromatic ring, alkene, Cl
63
Used a coolant-insulation fluids (e.g. transformers) and found around the world in water, sediments and in birds and fish
Polychlorinated biphenyls (PCBs)
64
PCBs are a special class of waste which have very high _____ and biological _______. It is _______ and accumulate in ______, therefore can ______. It is also somewhat _____ and transported in the atmosphere up to the arctic. The structure consists on one bond between the benzene rings with ____ attached around them, and there are 209 possible congeners. PCBs can also _____, and the highest levels are reached in the ____ of fish-eating birds and herring gulls. Congeners with Cls in the ____, _____ and _____ are the most toxic, but the toxicity is mostly due to the breakdown products such as ______ and ______, which form through oxidation when _____.
chemical, stability, lipophilic, fats, bioaccumulate, volatile, Cl, biomagify, eggs, 3, 3', 4, 4', 5, 5', polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzodioxins (PCDDs), heated
65
Different arrangement of Cls around benzene rings
Congeners
66
The problematic byproducts of PCBs and organochlorine pesticides
dioxins / polychlorinated dibenzodioxins
67
Pesticides such as ______ are widely used to control ______. It is cheap and prevents it from competing with crops from the beginning of the growing season. It is estimated that it can increase crop yields by up to ____% However, the byproducts such as _______ are _____ resistant and often found in water.
atrazine, weeds, 6, hexachlorobenzene, degradation
68
The most notorious byproduct of pesticides is _____, which are never purposefully synthesized. A common dioxin is ______, which is one of the most toxic synthetic compounds known to animals. They are also the by-product of the ____ and ____ industry. They are ____, and _____ and a hazardous waste where ____ is required, which may still not be destroyed if the temperature is not high enough. Up to ____ possible congeners. The structure consists of an ____ bridge between the benzene rings, and Cl around them, which makes them more toxic.
dioxins, TCDD, pulp, paper, stable, persistent, incineration, 75, oxygen
69
PBCs must be well ___ and disposed of, because their breakdown products may not disappear even when _____, so you need to pay attention to what the compound is _____ into, otherwise it may be more toxic
contained, heated, transforming
70
When a substance builds up in an organism over its lifetime because it is more soluble in fat than water and stored in fatty tissues
bioaccumulation
71
When a substance is not metabolized but adsorbed, causing concentrations to increase up the food chain
Biomagnification
72
Less treated water for lawns and toilets
grey water
73
More treated water for drinking
blue water
74
______ water sources are usually quite clean and require little treatment (e.g. groundwater and ______). But there are some toxins in groundwater, such as the ____ in Bangladesh. Shallow water sources require _______ treatments (e.g. rivers, lakes). Some communities are beginning to consider ______ water now
deep,, aquifers, As, more, recycled
75
When sewage is treated all the way to drinking water quality
recycled water
76
When large particles are allowed to settle out (using settling ponds and lakes) - does not remove fine particles
Primary settling
77
When air is bubbled through water and readily oxidizable materials are oxidized. It prevents reducing agents from consuming chemical disinfectants to be added later and removes Fe2+
Aeration
78
Aeration prevents the formation of ___ ____ compounds, and also prevents the formation of ________ precipitation from its colloidal form, which can stain sinks
organic Cl, Fe(OH)3
79
Used to remove fine particles (colloids, bacteria, etc.) and some ions (via a co-precipitation reaction)
coagulation
80
______ _____ is a common coagulant and and dissolves in water to yield _____ _____. It can also react with _____ to form ______ which precipitates at pH _____ (gelatinous). While it is initially _______, and settles slowly, it carries other fine particles down with it (______ _____), and clears them. ______ can also be used for coagulation.
filter alum, hydrated Al3+, HCO3, Al(OH)3, 6-8, colloidal, secondary settling, FeCl3
81
The last step of water treatment which kills bacteria and viruses that are too small to aggregate
disinfection
82
chemical disinfectants stay in the water long enough to prevent re-contamination while water is in the _____ ______.
distribution system
83
____ is the most common disinfectant, used to some extent, usually as a _____ _____ because it has ______ ____ ability. There is one power of disinfectant per _____. All forms of chlorine are oxidizing agents except for _____.
Cl, secondary disinfectant, residual disinfecting, Cl2, Cl-
84
The components of active chlorine (Cl+)
Cl2, HOCl, OCl-
85
Cl2(aq) is only present in pH < ______, which means it is not present in drinking water. Most of the chlorine is _____ ______. _____ is 100x as effective as _____, and the ______ is critical in determining the dose of the Cl2 to use. Higher pH requires _____ Cl2. HOCl is _____ effective because it is a ____ molecule, which penetrates ____ ____ and readily destroys ______
1.5, HOCl, OCl-, HOCl, OCl-, pH, more, more, neutral, cell membranes, microorganisms
86
If Fe2+ is still present before chlorination, it consumes _____, making it ____, which is not an effective disinfectant.
Cl2, Cl-
87
Factors influencing chlorine demand
1. anything that can be oxidized and consume Cl+ (BOD), 2. pH
88
Drawbacks to using chlorine are that the ________. it can also be toxic because industrial _____ may contain ______ which can get chlorinated, and _____ _____ can lead to the formation of ______ (CHCl3). These are both toxic. Cl2 is no longer commonly used as a primary disinfectant in developed countries
odor/taste, discharge, phenols, humic acids, trichloromethanes
89
Prepared by passing high voltage discharge (15000V) through dry air, in which O3 is produced and absorbed in the water.
ozone
90
Ozone is _____ effective than Cl2. It is also more _____ must be made ______ and cannot be _____, due to its short half life. There is also no ______, meaning Cl2 is required as a secondary disinfectant. However, it is a ______ ____ only and is a _______ reaction which means it requires less time in contact with water, smaller _____ and faster ____ time. It is ______ on a large scale
more, expensive, on-site, stored, residual, oxidizing agent, faster, facilities, through, economic
91
A wavelength of <3000nm which is very damaging to life, is penetrated through water using low pressure Hg arc lamps (254nm)
ultraviolet radiation
92
The benefits of UV is that it has a short ____ ___ (1-10s), it can run on a ___ ___ basis, is not influenced by _____ or ______, and leaves no toxic _____. However, the light must _____ the water through ____ tubes, and it may be absorbed by _____ and ___ by particles, so they must be absent or minimal for effectiveness They also leave no _____.
contact time, flow through, pH, temperature, residue, penetrate, narrow, organics, scattered, residual
93
The primary water treatment processes at Seymour-Capilano filtration plant is ____, then _____ and _____. The primary treatment process at the coquitlam water treatment plant is ____ then ____ and ______
filtration, UV, chlorine, UV, ozone, chorine
94
_____ and ____ adjustments may be used to control _____ before or after the disinfection step. For soft water, to _______ pH, _____ corrosion, and decrease potential ____ from pipes. ______ and _____, ____, or _____ can be added. The added _____ coats pipes and forms scale. Additionally, ______ can be used to form insoluble _____ ____ complexes on pipe surfaces
pH, alkalinity, corrosion, increase, decrease, Pb, lime CO2, soda ash (Na2CO3), limestone, Ca2+, orthophosphates, lead phosphate
95
raw water from seymour and capilano reservoirs arrives at the plant
inlet blending
96
Coagulants are added in the flash mixer to combine small particles together to form floc
pre-treatment
97
12 tanks provide hydraulic retention time and agitation using mixers to increase the size of the floc
flocculation
98
filters capture the floc to remove the particles, organic matter and microorganisms from the water
filtration
99
UV light is the primary disinfectant used in seymour to inactivate microorganims
UV disinfection
100
clearwells provide the contact time needed for chlorine to effectively kill microorganisms. They also have lime and CO2 added for corrosion control
clearwells and post-treatment
101
water is distributed via a combination of gravity flow and pumps and is then stored in reservoirs located throughout metro vancouver
water distribution
102
Tooth enamel is made of _____, which contains basic anions such as ____ and ____, which can dissolve in acid. _____ can replace the OH- ion making _____, making teeth stronger and less soluble in acid. Fluoride is sometimes added to drinking water with low ____ content. ___ppm is recommended but too high levels of even____ppm can lead to ____ (dental fluorosis). natural [F-] in vancouver is _______ but it is not added.
hydroxyapatite (Ca5(PO4)3OH), PO4, OH-, F-, fluorapatite, natural, 1, 3-5, mottling, <0.05
103
reverse osmosis in which pressure is applied to one side of a semi-permeable membrane so the purified water flows to the low pressure side, and the high pressure side increases in salt concentration which is flushed out.
desalination
104
desalination is used on ___ and ____ where seawater is abundant. It also removes ____ and other contaminants, but is not the method of choice on a _____ scale unless fresh water is scarce
ships, islands. bacteria, large
105
When Flint started using their own water supply, it was more ______ largely due to _____ _____ de-icing. Adding extra ____ to combat e. coli lead to unsafe levels of __________. The dissolved ____ from corroded iron pipes reacted with Cl2 to form _____. Adding ____ to reduced those, made the water more _____.
corrosive, road salt, Cl2, trihalomethanes, Fe2+, Cl-. FeCl3, corrosive
106
Produced by a reaction of chlorine with organic matter; is toxic
trihalomethanes (CH3Cl)
107
Alternatives for de-icing the road include ______ ___ and ____, but there are currently no alternatives that are as good as salt. Salt is not as bad if it flows into the _______.
vegetable matter, sand, ocean
108
After the Pb contamination was acknowledged in Flint, Free water bottles were provided, and Flint switched back to ____ water supply which had added ________. New _____ were constructed, which replaced the old lead piping
Detroit, orthophosphates, pipelines
109
While the Pb contamination in Flint was _____ the As contamination in Bangladesh was not. In Flint, ____ was converted to ____, while in Bangladesh, ____ was adsorbed on _____, and was released eventually as ____.
visible, Pb(s), Pb2+, As, FeOOH, As3+
110
Chloride ions in water can break the protective ____ layer that forms on the surface of some metals, making the metal more susceptible to _____
oxide, corrosion
