Air Pollution FE

Primary Air pollutants

from direct sorce, Carbon Monoxide (CO), Nitrogen Oxides (NOx), Sulfur dioxide (SO2), PM and VOCs

CO

colorless, odorless, from incomplete combustion, fuel burning, causes tissue hypoxia, binds to hemoglobin stronger than Oxygen, reduces oxygen to tissures

Where does NOx come from

gases from burning fossil fuels at high temps (Cars, power plants), smog and acid, NO2 is formed in the atmosphere from NO secondarily

Where does Sulfur Dioxide come from (SO2)

From coal/oil burning, major contributer to acid rain

where does PM come from '

combustion (gas and diesel engines), Industrial (cememt manuf. mining), Construction, Wood fireplaces

PM 2.5

fine PM very small, can penetrate deep in lungs and enter the bloodstream, more harmful than larger PM, from combustion and secondary PM

PM 10

diameter less than 10 micrometers, from dust, crushing, and construction, can pentrate the respirotory tract

A coal-fired power plant is located in a nonattainment area for fine particulate matter (PM₂.₅). Which of the following pollutants is most likely to contribute to secondary PM₂.₅ formation downwind of the plant?

SO2 or NOx

Which of the following conditions will most likely increase NOₓ formation in a combustion process?

A. Low flame temperature
B. Excess air reduction
C. High combustion temperature
D. Incomplete combustion

C, high-temperature combustion” = NOₓ

Sulfur Dioxide Characteristics

high odor, colorless, forms sulfate aersols (PM 2.5) makes sulfric acid (H2SO4) acid rain if it oxidies in the atmosphere

VOCs

• VOCs = Organic chemicals that evaporate easily at room temperature

• Examples: benzene, toluene, xylene, formaldehyde

• Primary pollutant (emitted directly)

• evaporates from paint or fuels

• forms ozone with sunlight and NOx

Photochemical Smog

Ozone, formed from sunlight, NOx and VOCs

Stable atmosphere

little vertical mixing, pollutants stay concentrated, higher ground level conc

higher wind speed = ____ dilution

faster

low wind speed

poor dispersion, higher concentrations

Low Mixing height

pollutants get trapped in ground

Point source

stack, chimney

area source

parking lot dust, fields

line source

roadway

taller stacks + hot emissions

pollutants disperse more before reaching ground

Inversion

bad air quality, very stable

A factory emits a pollutant from a 20 m stack. On a calm day, a temperature inversion occurs near the ground. Which of the following statements is most likely true?

A. Pollutants will disperse quickly and concentrations at ground level will be low.
B. Pollutants will be trapped near the ground, leading to high concentrations.
C. Pollutants will rise higher than normal due to unstable conditions.
D. Wind will carry pollutants away, so dispersion is unaffected.

B

Two factories emit the same pollutant at the same rate. Factory A has a 50 m stack, and Factory B has a 20 m stack. All other conditions (wind, stability, emission rate) are the same.

Which factory will likely have higher ground-level pollutant concentrations nearby?

A. Factory A
B. Factory B
C. Both will have the same concentrations
D. Cannot be determined without wind data

B, taller stacks promote better mixing

Unstable conditions

Sunny days, strong surface heating, mixes rapidly

in guassian plume modeling with fixed emissions, increasing wind speed generally..

decreases centerline ground concentarction

what is a Baghouse

Fabric filter, removes fine particular matter, Industrial

what is cyclone

best for large PM, uses centrifugal force

What is an Electrostatic Precipitator

best for fine PM, Fly ash, high effeciency for large volume gases

Wet scrubber

SO2 and some PM, reacts with lime gypsum,, removes acidic gases

what makes something hazardous

ignitable, corrosive, reactive, toxic

Ignitable

flash point is less than 60 C (140F)

Corrosive

pH is less than 2 or greater or equal to 12.5

Reactive

explosive, unstable, reacts violently with water

toxic

fails TCLP test

F-list

non specific sources (solvents) most common (TCE)

K-list

Specific industrial

P list

acutely hazardous

TCLP

toxicity characteristic leaching procedure, simulates landfill leaching

Metals used in TCLP

Lead, mercury, cadnium

What are the three types of generators

CESQG/VSQG, SQG, LQG

CESQG/VSQG

less than 100 kg/month

SQG

100-1000 kg/month

LQG

more than 1000 kg/month

what is the max storage rule for LQG

90 days

what is the max storage days for SQG

180 days

what are the storage rules for containers

labeled, closed, compatilble with waste

Cradle to Grave

Generation, transport, treatment, storage, disposal

who is responsible in cradle to grave

generator

Incineration

good for treating organices

Stabillization/solidification

immobolizes metals

secure landfill

double liner, leachate collection

Nuetralization

treating corrosives

A liquid waste has a flash point of 50°C and a pH of 6.5. It is not listed under RCRA.
How should this waste be classified?

A. Non-hazardous waste
B. Corrosive hazardous waste
C. Ignitable hazardous waste
D. Reactive hazardous waste

C

RCRA

resource conservation and recovery act, regulates haz waste from craddle to grave

nitrification

Ammonia to nitrite(NO2-) then nitrite to nitrate (NO3-)

what is produced during denitrification

N2 gas

Nitrogen Fixation

makes nitrogen available to plants. Converts atmos N2 gas to ammonia

ammonification

organic nitrogen to ammonia (decomposition)

logistic growth

growth slows as carrying capacity (K) is approached limited resources

linear growth

population increases by a fixed number not proportionatly

Exponential

unlimited resources, rapid growth

What is Growth primary productivity

total energy captired by producers through photosynthesis

Net primary productivity

GPP minus the energy used by producers for respiration

secondary productivity

biomass produced by herbivores and carnovores

what do wetlands provide

flood control, water filtration, habitat, carbon sequestration

what are the three soil phases

solids, water, air

porosity (n)

fraction of void spaces

void ratio (e)

voids / solids

bulk density

total mass over total V

moisture content

mass of water over mass of dry soil

hydralic conductivity (K)

measures how easily water flows through soild and depends on grain size, soil structure, and fluid viscosity

Hydralic conductivity trends

gravel = very high, silt and clay = low

darcys law

Discharge = K*Cross sectional Area* hydralic gradient

ground water velocity

K/n * Hydralic gradient

Unconfined aquifer

water table at top

Confined aquifer

bounded by low K-vale layers (Clay)

Water Table

where pore pressure = atmospheric, drops during pumping, rises with recharge

Groundwater Flow direction

high hydralic head to low

Head

elavation head + pressure head

contour maps

flow lines are perpendicular to equipotential lines

Gravel diameter

greater than 2 mm

Sand diameter

between 0.075 - 2mm

silt diameter

0.002-2mm

clay diameter

less than 0.002 mm

advection

movement with groundwater

dispersion

spreading due to velocity differences

diffusion

concentration gradient driven

sorption

attachment to soil

decay

chemical/biological breakdown

Retardation Factor

contaminants move slower than groundwater due to sorption, metals and organics have high R

CEC

Cation exchange capacity

Verturi throat

high velocity and low pressure

hagen poiseuille relation

steady imcompressible, laminar flow of a newtonian fluid in a circular pipe

density of water

1000 kg/m³

specific weight

=desity * gravity (N/m3)

dynamic viscosity

Pa*s

kinematic viscosity

v=dynamic v(u)/density, water = 1×10^-6 m²/s

Manometer equation

change in pressure = pgDh

Continuity Equation

Q=AV

continuity equation for imcompressible flow

A1V1=A2V2