Pramita Flashcards
Classification based on mode of release
Indoor:
Indoor air quality refers to the air that occupies
confined, non-industrial environments.
Eg:- Dust, mold, fungi spores, cooking gasses,
and cigarette smoke, cleaning and personal
care products, laundry detergents
Outdoor:
Emissions caused by combustion
processes from motor vehicles, solid fuel
burning and industry.
based on degradability
Biodegradable :woods, domestic sewage papers etc
No biodegradable:Mercury compounds of Phenol,
Glass, DDT, Benzene, Pesticides
Health Impact of oullutats
Respiratory and Cardiovascular diseases
Economic Impact
Healthcare costs
Loss of Biodiversity and
Ecosystem services
Damage to property and
infrastructure
Tourism decline
Impact on Labor markets
Environmental Impact of Pollution
Global warming and climate change
● Ozone layer depletion
● Acid rain
● Eutrophication
● Destruction of marine ecosystem
● Deforestation and habitat loss
● Impact on Biodiversity
Water pollution
degrading water quality
and rendering it toxic to
humans or the
environment.
Unsafe water kills more
people each year than war
and all other forms of
violence combined.
Point Sources
● Industrial Discharges
● Sewage and Wastewater Treatment
Plants
● Oil Spills
● Mining Activities
Non-Point Sources
● Agricultural Runoff
● Urban Runoff
● Stormwater Runoff
● Sediment Runoff
Agriculture is the one of the
source of contamination
One of the major
contributor to
contamination to estuaries
and groundwater.
define water quality?
Water quality is a measure of the condition of water relative to the
requirements of one or more biotic species and/or to any human need or
purpose.
Potable water:
It is safe to drink, pleasant to taste and usable for domestic
purposes.
Palatable water:
It is esthetically pleasing; it considers the presence of
chemicals that do not cause a threat to human health.
Contaminated water:
water containing unwanted physical,
chemical, biological, or radiological substances, and it is unfit for drinking
or domestic use
Infected water:
contaminated with pathogenic organism
Parameters of water quality:Physical
4TEC
● Turbidity
● Temperature
● Taste and odor
● Total dissolved solid
● Electrical conductivity (EC)
● Color
Parameters of water quality:Chemical
● Dissolved Oxygen (DO)
● Biochemical Oxygen Demand (BOD)
● Chemical oxygen demand (COD)
● Salinity
● pH
● Alkalinity
● Nutrients (Nitrate, Nitrite, Ammonia, Phosphate)
● Chloride
● Heavy Metals (Lead, Mercury, Cadmium, Arsenic)
● Pesticides and Herbicides
pH water
PH= - log [H+] = - log [H3O+]
POH= - log [OH-]
Normal rainfall
pH of approximately 5.6 (slightly
acidic) owing to atmospheric carbon
dioxide gas.
Safe ranges of pH for drinking water
6.5 to 8.5 for domestic use
BOD
is not an accurate quantitative test, although it is considered as an indication of
the quality of a water source. It is most commonly expressed in milligrams of
oxygen consumed per litre of sample during 5 days of incubation at 20 °C or 3 days
of incubation at 27 °C.
Measure of BOD =
Initial oxygen- Final Oxygen after (5 days at 20 °C) or (3
days at 27 °C)
BOD
BOD is the amount of oxygen (Dissolved Oxygen (DO)) required for the biological
decomposition of organic matter. The oxygen consumed is related to the amount of
biodegradable organics.
P is called as dilution factor
it is the ratio of sample volume (volume of wastewater) to total volume (wastewater plus dilution water).
biological oxygen demand
the saturated value of DO for water at 20o C is 9.1 mg/L only
the oxygen demand for wastewater may be of the order of several hundred mg/L,
therefore, wastewater are generally diluted so that the final DO in BOD test is always ≥ 2 mg/L.
BOD= (DOi -DOf)/P
Modeling BOD as first order reaction
BOD=L(1-e^-kt)
Where k20 is the value of k at 20 o C and is an empirical constant.
theta= 1.135 T => is between 4 - 20 oC;
theta= 1.056 T => is between 20 - 30 o C
test of sewage content
a. Organic matter which can be biologically oxidized is called biologically active
b. Organic matter which cannot be oxidized biologically is called biologically inactive.
COD
oxygen required for the complete oxidation of both biodegradable and
non-biodegradable matter.
● COD is a measure of the oxygen equivalent of the organic matter content of a sample that
is susceptible to oxidation by a strong chemical oxidant.
COD
milligrams per liter (mg/L), which indicates the mass of oxygen
consumed per liter of solution.
Parameters of water quality:Biological
● Bacteria
● Virus
● Parasites
● Algae
Aquatic Pollution: different from water pollution
Encompasses not only the pollution of the water itself but also the impact on the
entire aquatic ecosystem. This includes the water, the organisms living in it (fish,
plants, microorganisms), and the surrounding environment.
Water pollution primarily focuses on the quality of the water itself,
Eutrophication
which occurs when the
environment becomes enriched
with nutrients, increasing the
amount of plant and algae
growth to estuaries and coastal
waters.
NUTRIENTS?
Nutrients are chemical elements found in the food that plants and animals need
to grow and survive. Although there are many kinds of nutrients, two of the most
important and abundant are nitrogen and phosphorus.
Algae can be found in
all types of natural waters,
including salt water, fresh water,
and brackish water (a mix of salt
and fresh water)
T
steps of eutrophication
● Fertilizer Runoff or Leaching
:
● Algae Growth Due to
Presence of Nutrients
:
● Bacteria Use Oxygen to
Break Down the Algae
:
● Oxygen Depletion (Hypoxia)
Due to Lack of Oxygen
Oligotrophic:
Oligotrophic waters are nutrient-poor, with low concentrations of nitrogen and phosphorus.
The water is usually clear with high oxygen levels, particularly in deeper layers. These
ecosystems typically support a variety of fish species,
TP: 5-10 µg/L
TN: 250-600 µg/L
example of oligo
Examples: High-altitude mountain lakes and deep, clear lakes are often oligotrophic.
fish species, including those that require high oxygen levels,
trout.
Moderately Eutrophic:
moderate levels of nutrients, leading to an intermediate
level of biological productivity. Algal growth is more noticeable.
Oxygen
levels can begin to decrease, particularly during warm months or in deeper layers
example Many natural lakes and reservoirs that receive moderate nutrient inputs from surrounding
land use may be classified as moderately eutrophic.
TP: 10-30 µg/L
TN: 500-1100 µg/L
Eutrophic:
water is often green colour due to frequent algal blooms. Oxygen levels in deeper
waters may become depleted (hypoxic), especially during periods of high algal activity and subsequent
decay. This can lead to the death of fish and other aquatic organisms that depend on oxygen.
example - receive high nutrient inputs from agricultural runoff, urban stormwater,
or wastewater discharges are often eutrophic.
TP: 30-100 µg/L
TN: 1000-2000 µg/L
Hyper-eutrophic:
excessive algal blooms, often leading to severe ecological and water quality issues.
turbid and can have a strong, unpleasant odor
These conditions can result in fish kills, loss of biodiversity, and the proliferation of
harmful algal blooms (HABs), which can produce toxins harmful to both aquatic life and humans.
TP: >100 µg/L
TN: >2000 µg/L
dead zones of eutrophication
● The overgrowth of algae
consumes oxygen and blocks
sunlight from underwater plants.
● When the algae eventually dies,
the oxygen in the water is
consumed. The lack of oxygen
makes it impossible for aquatic
life to survive.
● The dead zone is in the United
States – about 6,500 square miles
– is in the Gulf of Mexico and
occurs every summer as a result
of nutrient pollution from the
Mississippi River Basin.
located in thelower part of the Black Sea, forms naturally. Oxygenated water is confined to the upper
layer of the sea, where the Black Sea’s waters interact with those of the Mediterranean
Sea.
“red tide”
common term used for a harmful algal bloom
This bloom, like many HABs, is caused by microscopic algae that produce toxins that kill fish and
make shellfish dangerous to eat. The toxins may also make the surrounding air difficult to breathe. As the name suggests, the bloom of algae often turns the water red.
distribution of CO2 along the depth of water body
● At the surface, photosynthesis
consumes CO2 , so CO2
levels remain relatively low.
In addition, organisms
that utilize carbonate in their shells are common near the surface, further reducing the amount of dissolved CO2
.
● In deeper water, CO2 concentration increases as respiration exceeds photosynthesis, and decomposition of organic matter adds additional CO2
to the water.
Key Features of a Bjerrum Plot:
X-Axis (pH): The pH values ranging typically from around 2 to 12.
Y-Axis (Concentration or Fraction): The relative concentration (or fraction) of each species.
Curves:
The curve for H₂CO₃ (carbonic acid) is dominant at lower pH values.
The curve for HCO₃⁻ (bicarbonate) peaks at a mid-range pH (around 6-9).
The curve for CO₃²⁻ (carbonate) becomes more significant at higher pH levels (above 10).
Recent pH range (highlighted in the blue zone) falls between 7.5 and 8.5, where bicarbonate (HCO₃⁻) is the dominant species.
As the pH drops (moving toward the acidic side), more carbon dioxide (CO₂) remains dissolved in water instead of being converted into other forms like bicarbonate (HCO₃⁻) or carbonate (CO₃²⁻).
A decrease in pH leads to a reduction in carbonate ion (CO₃²⁻)This reduction in carbonate is particularly concerning for marine organisms, such as corals and shellfish, that rely on carbonate ions to build their calcium carbonate (CaCO₃) skeletons and shells.
As pH decreases, the ocean’s buffering capacity weakens. This means that further increases in atmospheric CO₂ will cause larger and faster changes in oceanic pCO₂ (partial pressure of CO₂), accelerating acidification.
link between pollution and ocean acidification
increase by 30%
pH. As pH declines, the amount of carbonate declines, so there is less available for organisms to incorporate into their shells and skeletons. So ocean acidification both dissolves existing shells and
makes it harder for shell formation to occur.
Effects of Water Pollution
Waterborne Pathogens:E. coli and salmonella,
which can cause severe diarrhea, vomiting,
Long-Term:Contaminants conditions such as cancer, neurological disorders,
reproductive issues, and developmental abnormalities.
Impact On The Fishing Industry:
Decreases in fish stocks
Impact On Agricultural Industries
contaminated water used for irrigation which can lead to reduced agricultural productivity and
biomagnification
Cost Of Water Treatment & Restoration
Impact On Tourism & Recreational Activities:
Vertical distribution of Temperature
see the plot
three volatile organic compounds
present in atmosphere due to use of petrol and diesel automobiles
Benzene, Toluene and xylene
Emission from vehicles produces
2⁄3 of CO, 1⁄2 of hydrocarbons and nitrous oxides
Petroleum refineries, paper mill, sugar mill, rubber manufacturing plants are
responsible——— of pollution
Petroleum refineries, paper mill, sugar mill, rubber manufacturing plants are
responsible for 1⁄5 th of the air pollution
2.5% of CO emission
aircraft
——— of CH4
is produced from paddy fields
40%
Air Quality Index (AQI)
CPCB method: AQI range 0-500
transforms the weighted values
of individual air pollution related
parameters (eg: pollutant
concentration) into a single number
or a set of numbers.
To calculate AQI, data for a minimum of three pollutants must be present, of which
one should be either PM10 or PM2.5,
T
Ip=
[( [IHi – ILo ] / [BPHi – BPLo] )* (Cp
– BPLo) ]+ ILo
China and India are major users of coal for energy provision.
T
____________ formed from the remains of marine microorganisms deposited
on the seafloor.
Oil is a liquid fossil fuel that is formed from the remains of marine microorganisms deposited
on the seafloor.
● After millions of years the deposits end up in rock and sediment where oil is trapped in small spaces. It can be extracted by large drilling platforms.
Natural gas is a gaseous fossil fuel that is versatile, abundant and relatively clean
compared to coal and oil.
● Natural gas is formed from the remains of marine microorganisms.
____________ most widely used fossil fuel.
oil
there have been wars on oil
supplies.
the Gulf War of 1991.
like oil, natural gas supplies will run out.
● Some scientists have even predicted this might happen by the middle or end of the 21st
century.
Natural gas has now overtaken coal in developed countries.
Hubbert’s Peak Oil theory
Production curve of any given species of fossil fuel will rise, pass through one or several maxima and then decline asymptotically to zero(Hubbert,
term “Peak Oil” refers to the point at which maximum production is reached. After the peak, oil production enters a permanent decline, and the availability of cheap and easily accessible oil starts to dwindle.
Q(t)=Qtotal [1+e ^−k(t-t0) ]^−1
suess effect
The Suess effect refers to the decrease in the ratio of carbon-14 to carbon-12 in the atmosphere due to the combustion of fossil fuels.
Evidence for the anthropogenic nature of increasing CO2 during the past 200 years.
how does c 12 tell us about fossil
Over time,
14C, a radioactive isotope of carbon, decays to nitrogen-14 because of its half-life of about 5,730 years.
Fossil fuels, therefore, contain almost no 14𝐶 as they are far older than the half-life of the isotope.
When fossil fuels are burned, they release large amounts of 12C (and small amounts of 13C), but virtually no 14 C.
last few slides
“Atom Bomb Effect”
Most of the nuclear explosions and 14C production took place in the
Northern Hemisphere.
The process made ammonia fertilizer widely available,
agriculture industry increased rapidly in a short time.
The Haber-Bosch process, which converts hydrogen and nitrogen to
ammonia.
conditions for haber process
using medium temperature (~500oC)
very high pressure (~250 atmospheres) a catalyst (a porous iron catalyst,
Fe3O4).
● Osmium is a much better catalyst for the reaction but is very expensive.
Industrial ammonia synthesis has resulted
increased in food production by
7∼8 times since the beginning of the 20th century, during which the Earth’s
population has increased by 4.2 times.
Uses of Ammonia( manmade)
Agricultural industries are the major users of ammonia. Ammonia is a very valuable
source of nitrogen that is essential for plant growth.
Ammonia and urea are used as a source of protein in livestock feeds for ruminating
animals such as cattle, sheep and goats.
used as an anti-fungal
agent on certain fruits and as preservative for the storage of high-moisture corn.
drawbacks of largescale ammonium synthesis
In addition to the fossil fuel energy used to drive the reaction, the Haber-Bosch
process uses H2 sourced from steam methane reforming (CH4 + 2H2O →4H2 +
CO2) or coal gasification(C + 2H2O →2H2 + CO2), thereby contributing
enormously to anthropogenic CO2 emissions.
● It is estimated that 1.5% of all anthropogenic CO2 emissions (420 Mt year−1) are
linked to the Haber-Bosch process
luminosity
It represents the total amount of energy a star, such as the Sun, produces and radiates into space in the form of electromagnetic radiation.
Solar Flux Density (Sd):
It is defined as the amount of solar energy per unit area on a sphere centered at the Sun.
Solar Constant (S):
The solar constant represents the solar energy density at the mean distance of Earth from the Sun, approximately
1.5×10-11m.
Solar energy incident on the
Solarenergyincident=(Solarconstant)×(ShadowArea)
Since the shadow area of Earth is a circle, the area can be expressed as:
ShadowArea
=𝜋𝑅𝐸^2
albedo
reflected/incoming sunlight
absorbed energy
solar energy incident - reflected solar flux
Atmospheric window
Solarradiation+Infraredradiationfromtheatmosphere=InfraredradiationemittedbyEarth’ssurface
