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Waste Management > Air Quality Test > Flashcards

Air Quality Test Flashcards

1
Q

What determines the effects of airborne chemicals?

A

concentrations affect whether or not the chemical is considered air pollution or not

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2
Q

Where does all the weather occur?

A

Troposphere

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3
Q

Methanogenesis or biomethanation

A

The formation of CH4 (methane) by microbes known as methanogens.

  • These organisms have been identified only from the domain Archaea, a group distinct from both eucaryotes and bacteria, although many live in close association with anaerobic bacteria.
  • Anaerobic respiration (do not use oxygen to respire; oxygen inhibits the growth of methanogens)
  • In the rumen, anaerobic organisms, including methanogens, digest cellulose into forms usable by the animal. The useful products of methanogenesis are absorbed by the gut, but methane is released from the animal mainly by belching (eructation). Lots of emissions!
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4
Q

Early history of air pollution

A
  • pre industrial, air pollution was not a concern, though there were some small management issues concerning waste/sewage etc
  • first ‘clean air act’ was in 1273 when king edward prohibited the use of sea coal
  • 1911, London fog killed 1150 ppl, and term SMOG was coined - when coal burning became prevelant.
  • Though nothing changed much until 1952 when anti-coal movement sparked (4,000-12,000 deaths) when correlation between smog and deaths was found. -British Clean Air Act!
  • 1960’s ‘solution to pollution is dilution’ - lots of tall stacks were built in order to diffuse the problem
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5
Q

Different types of smog

A

chronic poor air quality: modern terminology, ex LA smog vs. London smog

  • LA - photochemical
  • London smoke/fog
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6
Q

So2

A

Sulphur dioxide

  • primary pollutant
  • forms CAC in atmosphere - acid in atmosphere

-from:
human activity - : combustion of fuels containing sulphur coal (50%); oils, diesel fuel, gasoline (25-30%); smelting, pulp & paper

nature - volcanoes, forest fire, oceans (DMS (dimethyl sulphide) from phytoplankton (most abundant biological sulphur compound)

-effects:
human health - respiratory and cardiovascular problems
environmental health - acid rain, vegetation, water and soil damage

-Can react with other chemicals to form secondary pollutants

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7
Q

What effects concentrations?

A

Meterology - air density.. Cold air sinks (radiation inversion) etc - unstable air moves around = good. Stable = not good.

-causes smog, that sits over the area of production, rather than being spread around

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8
Q

Smog

A
  • “Smog” was a combination of adverse weather conditions and higher than normal emissions from domestic coal combustion.
  • smoke and fog combination
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9
Q

Why worry about air quality management?

A
  • Human Health (& animal)
  • Environmental Health - acid rain, soil & vegetation & aquatic
  • Climate Change - ocean current imbalances, GHG’s
  • Economics (health, agriculture, infrastructure, tourism/recreation)
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10
Q

Sources of air pollution

A

-Natural (volcanoes, forest fires, vegetation, surface dust)
-Anthropogenic (fossil fuel combustion: transportation, industrial processes, power generation, agriculture, solvents evaporation)
-

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11
Q

Major groups of air pollutants

A

Primary - emitted directly into the atmosphere

Secondary - formed through chemical reactions in the atmosphere

CAC’s

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12
Q

CAC’s

A
  • criteria air contaminants
  • A group of pollutants that cause air issues like smog and acid rain - ** Most monitored air pollutants for environmental health
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13
Q

Primary pollutants

A
  • SO2 - sulphur dioxide
  • NO2 - nitrogen dioxide
  • C02 - Carbon dioxide
  • PM - particulate matter: TSP (total suspended matter), some PM10, some PM2.5
  • VOC’s - volatile organic compounds
  • TRS (total reduced sulpher) - headaches and nausea (most common) - primary cause of odours
  • Other toxic compounds - metals, POP’s (persistent organic pollutants)
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14
Q

Secondary pollutants

A

-gases or pollutants created in atmosphere through chemical reactants
ex.
-PM2.5
-tropospheric ozone - O3
-PANs - powerful respiratory and eye irritants

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15
Q

CACs

A

Air issues such as smog and acid rain and other health effects, result from the presence of, and interactions between, a group of pollutants known as Criteria Air Contaminants (CAC) and some related pollutants.
- Most commonly monitored air pollutant
species

-SO2,  NO2,  CO,  PM10,  PM2.5,  VOC’s 
and NH3 (ammonia).. Also ground level O3  and 2o PM2.5 (secondary)
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16
Q

Ground level ozone

A
  • Ground-level ozone is a colorless and highly irritating gas that forms just above the earth’s surface.
  • It is called a “secondary” pollutant because it is produced when two primary pollutants (a nitrogen oxide (NOx) and a VOC) react in sunlight and stagnant air.
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17
Q

NO2

A

CAC focus

-From:
human activity - fossil fuel combustion, waste burning, agricultural
natural - volcanoes, forest fires, soil bacteria

-effects:
human health - respiratory
visibility impact (absorbs blue wavelengths transmits longer wavelengths in the visible spectrum hence reddish, brown haze)
environmental health - vegetation damage, reacts in atmosphere to make acid rain, reacts with VOCs to create tropospheric O3
can form secondary pollutants

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18
Q

CO

A

CAC focus

-from:
human - combustion of fuel
natural - forest fires, volcanoes

-effects:
colourless, odourless, highly toxic

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19
Q

PM

A
  • mixture of solid particles and liquid droplets that remain suspended in the air.
  • measured in micrometers -> µm= 10^-6m
  • TSP - 100µm-20µm
  • ex desert dust, sea salt, pollens
  • effects - respiratory problems
  • found as primary or secondary pollutants
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20
Q

primary PM

A
  • PM10µm mostly
  • directly emitted to the atmosphere where it typically resides for a few hours to few days, depending on particle size distribution and meteorology

-sources:
paved and unpaved roads, construction, agriculture, forest fires, vehicle emissions, etc
disintegration of larger particles - ex soil
wind-blown dust, products of grinding or polishing (mills ex)
sea spray, pollens and molds

-usually expelled by cillia in body

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21
Q

primary VOCs

A
  • carbon containing compounds (gas)
  • reactive - can undergo photochemical reactions with nitrogen oxides to form tropospheric O3, PM2.5, acid rain

-from:
human - solvent evaporation (paints, solvents), oil and gas
natural - vegetation

-effect:
human health - some increased risk of cancer

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22
Q

secondary PM

A
  • PM2.5 (µm) or smaller
  • secondary consists of organic compounds, nitrates, sulphates and metals
  • residency time: few days to few weeks
    - may be transported long distances

-smaller size causes more respiratory problems (Chronic Obstructive Pulmonary Disease COPD), may also be absorbed into bloodstream

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23
Q

secondary tropospheric O3

A
  • very reactive & short lived
  • Formed from the reaction of VOCs and NOx in the presence of sunlight (photochemical SMOG) (main component of photochemical smog!)
  • NOx, CO, and VOC’s are called ozone precursors

-effects:
human - respiratory problems
environmental - damage to vegetation, rubber and some plastics

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24
Q

POPs

A
  • persistent organic pollutants
  • PCBs, DDT (pesticides)
  • bioaccumulate (long term effects to life), & travel long distances quickly (multiple cycles of evaporation)
  • from: humans - many synthesized chemicals
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25
Q

Ambient air quality (surrounding)

A
  • quality is concerned with concentrations in ambient air - units ppb or ppm (vol/vol) or μg/m^3 (mass/vol) at spfc temp
  • compare results with accepted standards for quality
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26
Q

Standards/Objectives/Guildelines

A
  • benchmarks in order to protect environment
  • based on scientific study/historical health data/clinical trials
  • need to balance with industrial development
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27
Q

Canada vs States

A

States has laws against it that if challenged, law is enforced.. Canada doesn’t have these laws (no legal implication), have ‘shame’ -compensation rather than stoppage

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28
Q

National vs provincial vs regional

A

CEPA (national) - Canadian environmental protection act (minimum requirement from all industry)

EMA (provincial) - environmental management act - may be different, but can’t be less stringent than national laws, may specify levels not mentioned in national law

Regional - ex CRD
-may be set more stringent than provincial

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29
Q

National vs Provincial

A
  • NAAQO (national ambient air quality objectives)
    • 3 tiers - max desirable (upper limit for long term goal for air quality)
      - max acceptable (aimed to provide adequate protection against effects on soil, vegetation etc)
      - max tolerable (where action is required due to a diminishing margin of public health safety)
  • CWS - Canada wide standards (not legally binding) - PM2.5 (30 μg/m3, 24 hr average ) and O3 (65 ppb, 8 hour average)
  • BC - Levels A, B, C - that correlate to the national tiers
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30
Q

averaging times and metrics

A
  • due to acute (relating to short term exposure), or chronic (long term)
  • shorter averaging times reveal more variability (concentration fluctuations)
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31
Q

Air Quality Health Index

A
  • Public communication of state of air in a given region - made understandable to public
  • based on O3, PM10, PM2.5 and NO2, to name a few
  • scale 1-10+ (1-3 desirable, 4-6 acceptable, 7-10 max tolerable)
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32
Q

Future air quality standards..

A

-multi-stakeholder collaborative process - AQMS (air quality management system)
-Includes:
new CAAQS (Canadian air ambient quality standards)
BLIERS - base level industrial emissions requirements
regional air shed coordination, to identify transboundary flows
enhanced collaboration among governments

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33
Q

Why monitor air quality?

A
  • determine current air quality conditions
  • regulatory compliance
  • assess effectiveness of mgmt methods
  • Make short term predictions (notice trends)
  • examine correlation between emissions and health of human & ecosystem
  • research (transport and transformation) ex transboundary air pollution
  • source identification
34
Q

Monitoring constraints

A
  • budget (personnel, equipment, maintenance, analysis etc)
  • site availability (leasing, power, theft, public acceptance), AQ noise (meteorological barriers, microclimates, blackbody heating (pavement), nearby construction, proximity to large emitter
  • timing (seasonal constraints)
35
Q

Design considerations

A
  • species (NO3? O3? etc)
  • time resolution (per second/min/hour?)
  • duration of program
  • Concentration ranges (low and high, ppb, ppm)
  • location and spatial resolution (how many stations needed? Will station meet objectives?)
36
Q

3 categories of monitoring stations

A
  • continuous stations
  • non-continuous stations
  • mobile monitors
37
Q

continuous stations

A

-constantly monitor air quality via an ambient air intake tube and archive or automatically transmit the data to a MOE database. Eg. Topaz

38
Q

non-continuous stations

A

-collect air pollutants on filters/absorbants (or in canisters in the case of VOC’s). The filters or canisters are collected after a discrete period of time (e.g. 24 hours) and sent to a certified laboratory for chemical and/or gravimetric (weight) analysis.

39
Q

mobile monitors

A

-instruments installed in a large vehicle or an airplane, used to assess ambient AQ over short periods of time in areas not covered by the permanent monitoring network, or for special studies. Ex. The MOE Mobile Air Monitoring Laboratory (MAML) eg. James Bay Cruise Ship Study

40
Q

types of AQ measurements

A
  • real time
  • grab samples
  • integrating
41
Q

real-time

A
  • continuous
  • Provide instantaneous readings and indicate rates of change
  • High sensitivity, more detailed information but requires the most resources to acquire and operate instrumentation

-typically sample 1-hr avg. conc. of:
PM10, PM2.5, NO2, SO2, H2S, O3, CO (typically CACs) & Wind speed, direction, Turbulence (U,V,W)‏, Temperature

42
Q

grab sample

A
  • A ‘snapshot’ in situ sample which is collected and taken away for lab. analysis
  • Only indicative of conditions at the precise time the sample is taken
43
Q

integrated

A
  • non-continuous
  • Continuous sampling (over an hour, day, week etc.) for later lab analysis…analysis is averaged over time period
  • Contains no detail regarding concentration fluctuations during sample period
  • Generally straightforward and inexpensive.
  • Includes passive monitoring (exposure filter pads, ….and even lichens)‏
44
Q

Importance of meteorological monitoring

A
  • Establishing correlation between resulting AQ data and the corresponding meteorological conditions. (without meteorological records, data is ambiguous)
  • Input to air quality dispersion models - need to measure conditions at the location where model is applied.
  • constraints are similar to aq monitoring constraints
45
Q

typical instrument types

A
  • HOURLY
    • PM10 , PM2.5
      - (TEOM (microbalance), BAM-C14 (beta particles/attenuation), GRIMM-laser/particulate scattering)
    - Gases - various spectroscopic methods:
      - SO2 , H2S (pulsed fluorescence; differences in UV wavelengths during excitation and decay of SO2
      - NOx (chemiluminescence; NO -> O3 rxn = emits photon
  • 24 HOURS
    - PM10 and PM2.5: filter based (Partisol ®: filter canisters)‏
    - Volume of air drawn through filter over a 24 hour period
  • Grab Samples (snapshot)‏
    - VOC’s, Toxics (canisters/plastic bags sealed for lab analysis)‏
46
Q

Mobile monitoring

A
  • sampling while moving/usually w gps
  • real time and grab sampling
  • determine areas with high concentrations
  • ex MAML - mobile air monitoring laboratory - takes meteorological and continuous/non-continuous measurements
47
Q

meteorological data

A
  • air quality measurement
    • Temp, RH, precipitation, wind velocity & turbulence - UVW anemometer)

-instruments on tower (10m or higher, unobstructed/uninfluenced)

48
Q

emissions inventory

A

-A database that lists, by source (anthro/bio), estimates of air contaminants discharged into the atmosphere of a defined area, during a given time period.

49
Q

emissions inventory limitations

A
  • budget
  • doesn’t provide an indication of the impact of these pollutants on the environment.
  • It is an estimate and as such the method includes inherent uncertainties and assumptions.
  • Provides estimates of primary emissions only, not secondary pollutants such as O3, or fractions of PM2.5 that are secondary.
50
Q

purpose of emissions inventory

A
  • helps determine pollutants and relative amounts that are being emitted
  • provides baseline of data for comparison with future estimates - (proactive mgmt, calc emission trends, AQ feedback)
  • provides input to dispersion models which estimate impact on ambient air quality
51
Q

Emission source types

A
  • point source
  • area source
  • mobile sources
52
Q

point source

A

-A stationary emissions source that can be identified by name and location (typically large industrial sources: refineries, power plants, pulp mills..typically permitted)

53
Q

area source

A
  • Usually comprised of a number of small point sources (e.g. residential emissions (furnaces-fireplaces-lawnmowers), restaurants, …) combined over an area
  • Alternatively a diffuse stationary source e.g. emissions from ponds, swamps, forests, farms, sewage lagoons etc.
54
Q

mobile source

A
  • Moving sources that are either on-road (cars, trucks) or non-road sources (heavy equipment, aircraft, locomotives, marine vessels)
  • Individual mobile sources may be referred to as line sources (Line sources follow linear routes; roads, highways, aircraft corridors, maritime lanes etc.)
55
Q

top down vs bottom up approach

A
  • Top down approach
    • Total emissions from a particular source from national or provincial statistics are pro-rated to the provinces and sub-regions based on population, fuel consumption, etc.)
  • Bottom up
    • A better with less uncertainty as locally procured source data are used to estimate emissions
56
Q

How emissions determined?

A
  • Surveys
    • Residential heating, woodstove use, industrial activities (frequency of car use, fuel/equipment type)
  • Permit Information
    • Regulated sources - permitted emissions limits (max emission rates for that source; typically point sources)
  • Surrogate Measures
    • Emission Factors developed for specific sources (very common method)
    • Material balances based on amount of material entering a process and consumed by the process. Net difference is representative of emissions to the air. eg. Liters of gasoline/heating fuel sold, Refinery crude stock processed
  • Direct Measurement
    • Source Sampling: measured emissions (vehicle Inspection Maintenance programs, smoke stack sampling as part of permit requirements)
57
Q

Two approaches to reducing emissions

A
  • technical

- non-technical

58
Q

technical approach to reducing emissions

A

-Based on technological fixes such as end of tailpipe treatment, scrubbers, improved combustion technology, cleaner fuels.

59
Q

non-technical approach to reducing emissions

A
  • Based on influencing individual and societal behaviors to encourage reduced energy consumption, alternate forms of transportation ..walking, cycling, etc.
  • ..encouraging adoption of technical solutions (e.g. wood stove change out program..scrap it car incentives, electric bikes….more sails on tankers..)‏
60
Q

international efforts..

A

-Asias pollution is affecting world’s weather via grasshoper effect

61
Q

Reducing domestic emissions

A
  • woodstove change-out programs
    • High PM2.5 levels from wood smoke are a common problem in Western Canada/US
    • Old stoves replaced with new US EPA certified stoves (70% cleaner)‏
    • Incentives include discount on new stoves, public education regarding smoke/health, energy efficiency needs
  • Vehicle ‘scrap it’ programs
    • Provides incentives to remove 2000 or older, high polluting vehicles off the road ($ or transportation passes)
  • vehicle inspection programs
    • ‘Aircare’
62
Q

Technical large PM control

A
  • settling chambers
    • industrial (point source)
    • remove PM > 40µm
    • low cost and maintenance but only takes large pm and requires lots of space
  • cyclones
    • remove 95% of PM >20µm
    • Circular motion imparted to gas stream in cylinder, increased gravitational forces
    • low cost and low maintenance but PM still ≥ 10µm and limited lifespan
63
Q

technical small PM control

A
  • wet scrubbers
  • Electrostatic Precipitator (ESPs)‏
  • Fabric filters
64
Q

wet scrubbers

A
  • Traps PM in gas stream by direct contact with an aerosol spray of water (or some liquid ie. for SO2 gases)‏
    • 90% efficiencies PM> 8 µm
    • Venturi: 98% efficiencies PM > 0.5 µm scrubber
    • low cost and efficient but needs high power and wet disposal
65
Q

electrostatic precipitator (ESPs)

A
  • PM in gas stream is charged (-) and/or ionized in an electrostatic field and can thus be removed by collecting on (+) charged collecting electrode surfaces and trapped, neutralized then removed (rapping, vibration, washing) for disposal
    • Up to 99% efficiency for > 1 µm
    • high efficiency and low maintenance but high initial cost and high power costs
66
Q

fabric filters

A
  • ‘bag house’ technology
  • Gas stream passed through elongated filter bags and PM is trapped on the surface of the bags as gas passes through.
  • Nearly 100% for > 0.01 µm PM
  • expensive and requires frequent cleaning
67
Q

Removal of Gases

A
  • absorption and chemical reaction
  • adsorption
  • incineration
  • water injection
  • SCR
68
Q

absorption and chemical reaction

A
  • Transfer of gaseous pollutant into a contacting liquid such as water or chemical slurries (scrubbing/bath)
  • gas must be soluble or a reactive in order for this to work
  • FGD - flue gas desulphurization - SO2 removal through the use of scrubbing liquid
69
Q

adsorption

A
  • Gases are sorbed (attracted to and held) on the surface of a solid
  • Activated carbon
  • good for VOC’s and odors
  • (>95% removal efficiency)‏
70
Q

incineration

A
  • VOCs and other gaseous HCs burned => CO2 & H2O products
  • Afterburner required (gas stream well mixed, with sufficient T°C and residence time to achieve up to
  • 99.98% removal (for VOCs)‏
  • Flammable gas streams- no additional fuel gas required
71
Q

water injection

A
  • mix water with fuel to reduced combustion temp and increased surface area of fuel droplet
  • can reduce NOx emissions from burning light weight oils by as much as 15%
72
Q

SCR

A
  • selective catalytic reduction
  • Removal of Nox (catalyst reduces combustion temp)
  • NH3 injected in gas stream, then mixture flows through a structure coated with a catalyst
  • emission result is N2 and H2O
73
Q

Mobile Sources of Emission Reduction Control

A
  • clean fuels - leaded gas phased out
  • catalytic convertors (gas engines)
  • diesel particulate filters
  • diesel oxidation catalysts
  • VOC
74
Q

catalytic convertors

A
  • most vehicles now have 3 way type of converter

- controls NOx, CO and HC’s

75
Q

diesel particulate filters

A
  • DPF’s
  • filter which removes PM and other pollutants from the exhaust stream
  • up to 90% reduction in PM emissions
76
Q

diesel oxidation catalysts

A
  • O2 reacts with these pollutants (due to catalyst) resulting in more efficient combustion and more benign emissions.
  • PM reduction ranges from 20-50%
77
Q

VOC

A

-fuel vapours

  • Stage 1
    • Recovers gasoline vapours from the storage tank as it is being filled and returns them to the tanker truck.
  • Stage 2
    • Recovery 95% of all vapours produced during vehicle refueling.
    • Reduce VOCs thereby limiting tropospheric O3 production
  • *Onboard Refueling Vapor Recovery (ORVR)
    • effective at capturing vapors evacuated from the gasoline tank before reaching the pump nozzle and will soon surpass the performance of Stage II vapor recovery systems.
78
Q

Clean fuels

A
  • gasoline has been made cleaner over the years.. limiting the amount of SO2 released over time
  • diesel - decreased sulphur
  • biodiesel - non-toxic, biodegradable
79
Q

Cap & Trade

A

-market-based approach used to control pollution by providing economic incentives for achieving reductions in the emissions of pollutants

80
Q

BOD

A
  • biochemical oxygen demand
  • DO is one of the most important parameters of water quality in freshwater bodies.
  • Bacteria and other microbes require O2 to metabolize organic waste. In water this is DO.
  • BOD is the amount of DO “demanded” by aerobic organisms to break down the amount of organic material in a given water sample at a given temperature over time. Expressed as mg/L oxygen
  • used as an indirect measure of the biodegradable organics in a water sample. i.e. the strength of the sewage
  • High organics content = high BOD strong sewage
  • Low organics content = low BOD weak sewage
81
Q

BOD test

A

-used assay to measure the concentration of biochemically oxidizable organic materials in a liquid sample

Waste Management (3 decks)

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