pramitha after mid sem Flashcards
Ozone Hole
The ozone hole is defined as the area having less than 220 dobson units (DU)
One Dobson Unit is
the number of molecules of ozone
that would be required to create a
layer of pure ozone 0.01 millimeters
thick at a temperature of 0 degrees
Celsius and a pressure of 1
atmosphere
CFCs
CFCs (Chlorofluorocarbons) escape into the atmosphere from devices like refrigeration units and aerosol propellants.
Stability in lower atmosphere: CFCs are extremely stable, allowing them to persist for years to decades in the troposphere (lower atmosphere) without degrading.
Migration to stratosphere: Due to their stability, some CFC molecules eventually drift upward to the stratosphere.
UV radiation breaks CFCs: In the stratosphere, ultraviolet (UV) light causes the breakdown of CFCs by splitting off a chlorine atom (Cl) from the molecule.
Chlorine’s destructive role: The free chlorine atom reacts with ozone (O₃), breaking it down into oxygen (O₂) and leaving the chlorine atom free to continue reacting with more ozone molecules.
Polar Stratospheric Clouds
Polar vortex formation: In the Antarctic winter, a whirlpool of stratospheric winds, called the polar vortex, isolates the air over the continent.
Cold temperatures and darkness: The polar vortex causes temperatures to drop extremely low in the absence of sunlight, leading to cloud formation despite the thin, dry Antarctic air.
Special chemical reactions: These polar stratospheric clouds (PSCs) enable chemical reactions that convert inactive chlorine reservoir compounds (e.g., HCl, ClONO₂) into more reactive forms, primarily chlorine gas (Cl₂).
Sunlight in spring: When sunlight returns to Antarctica in October, UV light breaks the bond between the two chlorine atoms in Cl₂, releasing free chlorine (Cl).
Ozone destruction: Free chlorine enters a catalytic cycle, where each chlorine atom destroys thousands of ozone (O₃) molecules, contributing to ozone depletion.
Bromine’s role: Bromine atoms (Br) also participate in a second catalytic cycle, amplifying ozone loss when combined with chlorine.
Ozone hole growth: The ozone hole grows in early spring (October) as the polar vortex continues isolating the ozone-depleting chemicals.
Polar vortex weakening: As temperatures rise and the vortex weakens in late spring, air from other latitudes mixes with the polar air, dispersing the chlorine.
Researchers flew high-altitude aircraft equipped with sensitive instruments into the region of the ozone hole. This allowed for in-situ measurements of both ozone concentrations and reactive chlorine species (the chemicals thought to be driving ozone loss).
Reactive chlorine species, particularly chlorine monoxide (ClO), were measured. These species are released from chlorofluorocarbons (CFCs) in the stratosphere when they are broken down by ultraviolet radiation.
Once released, reactive chlorine catalytically destroys ozone (O₃), converting it into oxygen (O₂). This reaction is particularly effective in the cold conditions of the Antarctic stratosphere.
The data collected during the flight helped substantiate the hypothesis that the breakdown of CFCs, releasing reactive chlorine, was responsible for the ozone hole.
This evidence contributed to the Montreal Protocol (1987), an international treaty aimed at phasing out the production and use of CFCs and other ozone-depleting substances.
GWP quantifies the radiative forcing (the change in energy balance in the atmosphere due to greenhouse gas emissions) caused by a particular gas relative to the radiative forcing from an equivalent mass of carbon dioxide (CO₂).
It is expressed as a dimensionless number, indicating how much more (or less) effective a gas is at warming the Earth compared to CO₂ over a specified timeframe.
soil pollution
Soil pollution can be defined as introduction of undesirable substance in soil which adversely affects its physical, chemical and biological properties.
Soil pollution is the contamination of the soil with pollutants, toxic chemicals or
any contaminant in such a quantity that reduces soil quality and makes it
inhabitable to organisms such as insects and other microbes. Or it can be
referred to as the addition of chemicals to the soil in quantities that are toxic to
the environment and its residents.
This addition is mostly by human activities such as mining, modern practices
in agriculture, deforestation, indiscriminate dumping of human-generated trash
and unregulated disposal of untreated wastes of various industries
Crop yield is greatly affected by this form of pollution. In China, over 12 million tons of
grain (worth approximately 2.6 billion USD) is found to be unfit for human consumption
due to contamination with heavy metals (as per studies conducted by the China
Dialogue).
from a flight into the Antarctic ozone hole in 1987, comparing the abundance of ozone (measured in parts per billion on the left vertical axis) and reactive chlorine (measured in parts per billion on the right vertical axis) across different latitudes (degrees south).
The blue dashed line represents the abundance of ozone, which begins around 2500 parts per billion at latitudes closer to 63 degrees south, and significantly decreases near 67-68 degrees south.
The red solid line represents the abundance of reactive chlorine, which shows a sharp rise at around 67-68 degrees south, peaking at over 1 part per billion.
This correlates with the Antarctic polar air and the region affected by the ozone hole, where higher levels of reactive chlorine are associated with a decrease in ozone.
how ozone depletion and its effect
CFCs Released: CFCs, which are human-made compounds, are released into the atmosphere from sources like aerosol sprays and refrigeration systems.
CFCs Rise into the Ozone
Layer: These CFC molecules gradually rise into the stratosphere, where the ozone layer is located.
UV Radiation Releases
Chlorine from CFCs: When exposed to ultraviolet radiation from the sun, the CFC molecules are broken down, releasing chlorine (Cl) atoms.
Chlorine Destroys Ozone: The released chlorine reacts with ozone (O₃), breaking it apart into oxygen (O₂), which reduces the amount of ozone available in the ozone layer.
Depleted Ozone Leads to More UV Radiation: With less ozone to absorb UV radiation, more UV reaches the Earth’s surface, increasing the potential for harmful effects.
Increased UV Causes More Skin Cancer:
Halons
contain: Br, Cl (in some but not all), F, H (in some but not all), C
Br many times more effective in destroying O3
ODPs range up to 10
used in fire extinguishers
Causes of Soil Pollution
Soil erosion:But the erosion enhances by
human activities like mining, construction, new land for agricultural practices,
deforestation, overgrazing etc. Due to erosion, soil become less fertile.
Excess use of fertilizers:
Acid Rain:
Salinity of water:
Industrial waste:
effects
Exposure to high levels of lead can result in permanent damage to the nervous system.
Children are particularly vulnerable to lead., Depression of the CNS (Central Nervous
System)., Damage to vital organs such as the kidney
Plants that are grown in polluted soil may accumulate high concentrations of soil
pollutants through a process known as bioaccumulation.
Crop yield is greatly affected by this form of pollution. In China, over 12 million tons of grain (worth approximately 2.6 billion USD) is found to be unfit for human consumption
due to contamination with heavy metals
Green Revolution “Father of the Green Revolution,”
Norman Borlaug, the “Father of the Green Revolution,” who won
the Nobel Prize in 1970, credited with saving over a billion people from
starvation,
high-yielding varieties of cereal grains,
expansion of
irrigation infrastructure,
distribution of hybridized seeds,
synthetic fertilizers, and
pesticides to farmers.
india green revol
Indian minister of agriculture C. Subramaniam. Despite bureaucratic
hurdles imposed by India’s grain monopolies, the Ford Foundation and Indian
government collaborated to import wheat seed from the International Maize and Wheat
Improvement Center (CIMMYT).
1960s, rice yields in India were about two tons per hectare; by the mid-1990s, they
had risen to six tons per hectare. India became one of the world’s most successful rice
producers, and is now a major rice exporter, shipping nearly 4.5 million tons in 2006.
She claims that the Green
Revolution’s reliance on heavy use of chemical inputs and monocultures has resulted in
water scarcity, vulnerability to pests, and incidents of violent conflict.
Good Agricultural Practices are a collection of principles
They are applied through sustainable agricultural methods, such as
integrated pest management, integrated fertilizer management and
conservation agriculture. The implementation of GAP should contribute to
Sustainable Agriculture and Rural Development (SARD).
Good Agricultural Practices
Soil Management:
Use of soil testing to determine nutrient needs.
Prevention of soil erosion through contour farming,
cover crops.
Water Management:
Efficient irrigation systems to reduce water waste.
Monitoring water quality to prevent contamination.
Proper drainage to prevent waterlogging and salinization.
Crop Protection:
Integrated Pest Management (IPM) strategies to minimize the use of chemical pesticides.
Use of biological controls and resistant crop varieties.
Animal Welfare:
Providing adequate space, feed, and water for livestock.
Maintaining good health and hygiene practices to prevent disease.
Post-Harvest Handling:
Proper harvesting techniques to reduce damage to produce.
Safe storage and transportation of products to maintain quality and safety.
Food Safety:
Ensuring the use of safe inputs (seeds, fertilizers, water).
Preventing contamination of food products during production and processing.
Adhering to national and international food safety standards.
biodegradable
Biodegradable materials can be decomposed naturally
The decomposition of such materials takes place in presence
of air, sunlight, water, soil, microorganisms,
Faster Rate of Decomposition.
waste is useful for the production of fertilizers, manure,
compost, biogas,
e.g. Kitchen waste, Human waste, Manure, Sewage sludge,
Dead animals and plants,
non biodegradable
e.g. Kitchen waste, Human waste, Manure, Sewage sludge,
Dead animals and plants,
can not decay in the
ecosystem naturally and create pollution.
Slower Rate of Decomposition.
This waste is needed to be separated first and get recycled,
which is expensive and time-consuming.
Hazardous wastes
Toxicity: Can cause harm to human health or the environment through ingestion, inhalation,
or skin absorption. Examples include heavy metals (lead, mercury), solvents, pesticides, and
chemicals.
Flammability: Easily ignitable, which poses a fire hazard. Examples include gasoline,
alcohol, or certain solvents.
Reactivity: Can react violently with water or other substances, potentially causing
explosions or toxic fumes. Examples include sodium, lithium batteries..
Corrosivity: Can corrode or dissolve metals and other materials. Examples include strong
acids (like sulfuric acid) and bases (like sodium hydroxide).
Characteristics of Non-Hazardous Waste:
Characteristics of Non-Hazardous Waste:
Inert: Non-hazardous waste typically doesn’t react chemically with other
substances or cause damage to the environment under normal conditions.
Safe for landfill disposal:
Non-hazardous waste can usually be safely disposed of in a landfill or by other
conventional means without special handling.
Acute Toxicity
Symptoms: Depending on the substance, symptoms can range from mild irritation (such
as skin or eye irritation) to severe effects like vomiting, respiratory distress, organ failure,
or even death.
Treatment: Immediate medical intervention is typically required, including
decontamination (e.g., flushing the skin or eyes), administering antidotes, or providing life
support in severe cases.
Chronic Toxicity
develop over time
Symptoms: Chronic toxicity can lead to long-term health issues such as cancer, liver or
kidney damage, reproductive problems, neurological disorders, or weakened immune systems.
Treatment: Managing chronic toxicity often involves long-term medical care, lifestyle
adjustments, and sometimes specific treatments to address the affected organs or systems.
Preventing further exposure is crucial.
according to their origin and type
Municipal Solid wastes:
Solid wastes that include household garbage, rubbish, construction &
any municipality manages demolition debris, sanitation residues, packaging materials etc..
Bio-medical wastes:
Solid or liquid wastes including containers, intermediate or end products
generated during diagnosis, treatment & research activities of medical sciences.
Industrial wastes: Liquid and solid wastes that are generated by manufacturing & processing
units of various industries like chemical, petroleum, coal, metal gas etc.
Agricultural wastes: Wastes generated from farming activities. These substances are mostly
biodegradable.
Fishery wastes: Wastes generated due to fishery activities. These are extensively found in
coastal & estuarine areas.
Radioactive wastes: Waste containing radioactive materials. Usually these are byproducts of
nuclear processes. Sometimes industries that are not directly involved in nuclear activities, may
also produce some radioactive wastes, e.g. radioisotopes.
E-wastes: Electronic wastes generated from any modern establishments. They may be described
as discarded electrical or electronic devices. Some electronic scrap components, such as CRTs,
may contain contaminants such as Pb, Cd, Be etc.
methods
- Recycling: A sustainable e-waste disposal method that recovers valuable materials and safely handles hazardous components.
- Materials Recycled: Includes printed circuit boards, plastics, CRTs, metals, mobile phones, hard drives, fax machines, wires, and memory chips.
- Benefits: Reduces the presence of hazardous heavy metals (e.g., mercury, cadmium, beryllium, lead) to protect health and the environment.
- Mercury Handling: E-waste with mercury is manually dismantled, and components are heated in a controlled environment to vaporize the mercury.
- Mercury Processing: Vaporized mercury is condensed for reuse; non-reusable mercury is stabilized and securely stored.
Support Brands with EPR Policies: Choose to buy electronics from brands that have implemented Extended
Producer Responsibility (EPR) policies. These brands are committed to taking responsibility for properly
disposing and recycling their products.
Seek Authorised Recyclers and Collection Centers: Look for certified e-waste recyclers or official collection
centres. These organisations follow environmentally responsible practices in handling and disposing of
e-waste.
Utilise Producer Responsibility Organizations (PROs): PROs are entities designated to manage and
oversee the recycling and disposal of e-waste on behalf of manufacturers. Collaborate with PROs to
ensure your e-waste is managed responsibly.
Government-Approved Dismantlers: If possible, give your e-waste to government-approved dismantlers
who adhere to regulations and environmentally sound practices.
Community-Level Initiatives: Encourage and participate in community-level e-waste collection drives.
Organise events or partner with local organisations to raise awareness and promote responsible
e-waste disposal within your community.
effects of noise pollution
Hearing: Prolonged exposure to noise pollution can damage the eardrum, leading to permanent hearing impairment.
General Health Effects:
Increases heart rate, cholesterol, and blood pressure.
Causes blood vessel constriction and pupil dilation.
Disrupts communication, peace of mind, and behavior.
Leads to headaches, irritability, nervousness, and fatigue, reducing work efficiency.
Can affect the embryo in pregnant women.
Sleeping Disorders: Noise disrupts sleep patterns, leading to fatigue and poor performance.
Effect on Wildlife: Animals suffer more from noise pollution since they depend on sound for survival. It disturbs their ability to hear threats
solid waste management
SWM refers to the systematic handling
and disposal of solid waste materials
generated by human activities to ensure
public health, environmental protection,
and resource conservation.
six Elements of Solid Waste Management:
Solid waste generation
On-site handling and storage
Collection
Transfer and transport
Material and resource recovery
Disposal
Solid Waste Management
Waste Generation = Population × Per Capita Waste Generation Rate.
Solid waste generation results from natural, human, and animal activities.
“collection” encompasses more than just the act of gathering or picking up solid
wastes from different origins; it also involves the transportation of these wastes to transfer
stations and the unloading process there.
The design of efficient collection systems considers factors such
as population density, waste generation rates, and transportation logistics.
Recycling: The separation and processing of recyclable materials, such as paper, metal, and glass, to
facilitate their remanufacturing into new products.
Composting: The decomposition of organic waste materials, such as food scraps and yard waste, leading to
the production of nutrient-rich compost used for soil amendment.
Energy Recovery: The utilization of waste as a fuel source through various processes like waste-to-energy
(WTE) or anaerobic digestion, thereby generating electricity or heat.
