< General Studies Home Page

Content

• World Air Quality Report, 2023
• Swatch Vayu Survekshan, 2023
• Cloud Seeding
• Coal Fired Power Plants
• Nitrogen Pollution
• Solid Waste
• Treatment and Disposal of Solid Waste
• Landfills in Delhi and Key Concerns
• Landfill Fire – Causes
• Solid Waste management Rules, 2016
• Domestic Hazardous Waste

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1)  WORLD AIR QUALITY REPORT, 2023

• Published by a Swiss Air Purifier Company IQAIR.
• Key Highlights (March 2023)
  • Delhi ranked 4th out of 50 of the world’s most polluted cities in terms of PM 2.5 in 2022.
  • India ranked 8th with a population weighted average of PM2.5 level of 53.3 micrograms/m3 in 2022.
  • Chad, Iraq, Pakistan, Bahrain and Bangladesh are the most polluted countries in 2022.
• Situation after Diwali 2023
  • The Day after Diwali (13h Nov 2023), Delhi was the most polluted city in the world with an AQI of 287.
• Live Situation: https://iqair.com/in-en/world-air-quality-ranking

 2)  SWATCH VAYU SURVEKSHAN, 2023

• “Swatch Vayu Survekshan” is an initiative by MoEF&CC to rank cities on the basis of implementation of activities approved under city action plan and air quality in 131 NCAP cities.
• Objectives:
  • Create Awareness; Inform citizens about the health impacts related due to exposure; comparing air quality conditions at different locations/cities; to achieve the goal of NCAP “Clean Air for All”.

• All 131 cities covered under NCAP are assessed based on ranking framework submitted by cities/ULBs on PRANA portal (Dashboard to capture progress of NCAP program).
• Air Quality is improving on the basis of PM10 data.

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3)  CLOUD SEEDING

• Understanding Cloud Seeding:
  • How clouds are formed naturally?
    • Clouds are made up of tiny water droplets or ice crystals that form when water vapor in the atmosphere cools and condenses around a tiny particle of dust or salt floating in the atmosphere. Without these tiny particles raindrops or snow flakes can’t form and precipitation will not occur.
  • What is cloud seeding?
    • It is a weather modification technique aimed at enhancing precipitation from clouds. The idea of cloud seeding was first conceived during WW-II and has since then become a much practiced activity in different dry regions of the world.
  • How does it work?
    • In cloud seeding, clouds are injected with salts like silver iodide, potassium iodide, or sodium chloride which act as seed. These salts provide additional nuclei around which more cloud droplets would form.
  • There are two principal cloud seeding techniques:
    1. Hygroscopic Cloud Seeding: It aims at speeding up droplet coalescence in liquid clouds, leading to production of large droplets that start to Here seeding material is generally large salt particles.
    2. Glaciogenic Cloud Seeding: In this method the idea is to trigger ice production in supercooled clouds, leading to It is usually done by dispersing efficient ice nuclei, such as silver iodide particles or dry ice (solid carbondioxide) into the cloud, causing heterogeneous ice nucleation.
  • How is cloud seeding done?
    • It is done using ground based generators or aircraft.

• • What are the conditions required for cloud seeding to be done?
    • Moisture laden clouds: Cloud seeding can only happen if there is sufficient cloud and sufficient depth of cloud.
    • Wind speed below a certain level
    • Temperature – cloud should be cold enough to contain supercooled liquid water
• Application/advantages
  • Fighting water scarcity: Rainfall in drought prone areas.
  • Increasing winter snowfall – which can supplement the natural water supply for communities in the surrounding area.
  • It can also be done to prevent hailstorm, dissipate fog etc.
  • Increasing hydro power generation (for e.g. in Tasmania, Australia)
  • Fighting air pollution and Water pollution
    • Rainfall can wash off pollution from air
    • More rainfall can also ensure ecological flow in rivers leading to reduced scope of pollution.
  • Controlling forest fires
  • Atmospheric studies – Studying cloud seeding can help scientists understand how normal cloud formation would occur.
• Could cloud seeding be used to fight air pollution in Delhi?
  • In India, cloud seeding hasn’t been tried for fighting pollution.
    • China has tried this option.
    • In winters, cloud from over Delhi due to Western Disturbances and thus some experts suggested cloud seeding for rainfall to occur.
• Has Cloud seeding been done before in India, and has it been successful?
  • It has been attempted in Monsoon, in places such as Karnataka, Maharashtra, and Tamil Nadu.
  • A recent experiment, the fourth phase of the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX-IV) that took place in monsoon seasons of 2018 and 2019. It was conducted in drought-prone Solapur in Maharashtra. It pointed to relative enhancement of 18% in rainfall.
    • The cost of producing water through this method was 18 paisa per litre, the cost will drop by more than 50% if we use indigenous seeding aircraft.

4)  COAL FIRED POWER PLANTS

• Why in news?
  • Only 5% of India’s coal-based thermal power capacity meets SO2 emission norms: CSE report (June 2023)
• Introduction:
  • Coal is the most important and abundant fossil fuel in India. It accounts for 55% of India’s energy needs. Infact, India’s industrial heritage was built upon Indigenous coal.
• Environmental Impacts of Coal Based Thermal Power Plants:
  • Air Pollution: Burning of coal produces air pollutants like NO2, SO2, CO, PM, Mercury etc. which are primary air pollutants in the world.
  • Acid Rain: Pollutants like NO2, SO2 etc. are primary contributor of Acid rain. It can harm forests, aquatic ecosystems, and buildings and it can also lead to soil and water acidification.
  • Climate Change due to global warming
  • Excessive water Extraction: Coal based thermal power plants require huge quantities of water which is often drawn from nearly rivers, lakes, or groundwater sources.
  • Water Pollution: Leakage of heavy metals and acids from the exposed coal seams may cause water pollution. They can leach into the groundwater and nearby waterbodies, posing risks to drinking water source and health of aquatic ecosystem. In addition, the release of warm water from the thermal power plant also causes thermal pollution.
  • Other issues created by mining of coals
• Emission Norms:
  • The MoEF&CC had notified the emission norms for coal-based power plants in Dec 2015.
  • In 2021, MoEF&CC divided the power plants on the basis of distance from polluted cities to enforce deadlines and extended the deadlines.
    1. Category A – coal based power plants within 10 kms radius of NCR and of cities with million+ population. (deadline changed from 31st Dec 2022 to 31st Dec 2024)
    2. Category B – power plants within 10 kms radius of critically polluted areas or non- attainment cities. (deadline changed from 31st Dec 2023 to 31st Dec 2025)
    3. Category C – remaining plants throughout the (deadline changed from 31st Dec 2024 to 31st Dec 2026)
       • This has the longest deadline and most of the country’s coal based power plants fall in this category.
  • Even after multiple extension, only 5% of the coal fired power plants have installed FGD (Flu Gas Desulfurization) systems, which are air pollution control devices for SO2 emissions (June 2023 : CSE Analysis)
  • Similarly, another analysis by the Centre for Research on Energy and Clean Air (CREA) has found less than 8% of India’s coal based power plants have installed the SO2 emission reduction technology recommended by MoEF&CC (Dec 2023)
• Problems caused by Coal Based power plants
  • Older technology -> Larger emissions of CO, NOx, SOx, Ozone etc.
  • Lesser Fly ash Utilization due to weak fly ash guidelines and poor implementations.
  • Difficulty in achieving the Paris Agreement Targets.
• Why moving away from coal based power plants may be difficult?
  • Very large dependency -> 75% of India’s annual power output.
  • Phasing in renewable energy sources and phasing out conventional sources rapidly may lead to instability in the electricity grid which may potentially cause blackout.
  • Political Economy Risk: Aggressive early retirement of coal based capacity, without detailed analyses, could result in real or perceived electricity shortage in some states.

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A) FLUE GAS DESULFURIZATION (FGD)

• FGD is a set of technologies that remove SO2 from exhaust flu gases of fossil fuel power plants, and from the emissions of other sulfur dioxide emitting processes such as waste incineration, petroleum refineries, cement and lime kilns.
• FGD systems use a scrubbing solution to absorb SO2.
  • The most common type of FGD is wet scrubber which uses a limestone slurry or seawater to absorb SO2.
    • The SO2 reacts with the scrubbing solution to from sulfate particles which can then be
    • The removal efficiency is upto 99%.
  • Drug scrubbers can also be used. It uses sorbent such as sodium bicarbonate or calcium oxide to absorb SO2,
  • Regenerative scrubbers, use a chemical solvent to absorb SO2 and then regenerate the solvent for reuse.

B) CIRCULATING FLUIDIZED BED COMBUSTION (CFBC)

• CFBC is a type of combustion technology used in thermal power plants to increase the efficiency of combustion and reduce emissions.
• It works by suspending a bed of inert particles (like sand or limestone) in a stream of air, creating a fluid like Fuel is injected in the bed and burned, with the heat transferred to the particles and then to a heat exchanger to produce steam or hot water.

C) CENTRE FOR RESEARCH ON ENERGY AND CLEAN AIR

• It is an independent organization focused on revealing trends, causes, and health impacts as well as the solutions to air pollution.
• It uses scientific data, research and evidence to support the efforts of government, companies and campaigning organizations worldwide in their efforts to move towards clean energy.
• It is registered in Finland with staff across Asia and Europe.
• It is funded by philanthropic grants and revenue from commissioned research

 2. NITROGEN POLLUTION

• Introduction
  • While nitrogen is the dominant gas in the atmosphere, it is inert and doesn’t react. However, when it is released as part of compounds from agriculture, sewage and biological waste, nitrogen is considered ‘reactive’ and may be polluting and causing greenhouse effect.
  • The release of these reactive nitrogen compounds in the atmosphere have increased over the years because of increased use of fertilizers for agriculture and increased industrial pollution. NOx emissions grew at 52% from 1991 to 2001 and 69% from 2001-2011.
  • In fact, a study in 2017 showed that we have breached the planetary boundary of N (Nitrogen). This planetary boundary is set at 44 Tg (Tera-grams) per year globally. But currently we use 150 Tg N per year, primarily through fertilizer usage.
  • Key Forms of Nitrogen

• • More Details about N2O: It is a greenhouse gas 300 times more potent that CO2. It has the third highest concentration – after CO2 and methane – in our atmosphere among greenhouse gases. It can live in our atmosphere for upto 125 years.
• 2020 Study about N2O published in Nature:
  • Human emission of N2O increased 30% in 36 years.
  • 43% of the total emissions came from human sources.
  • The increase means that climate burden from non-carbon sources is also increasing.
  • Dichotomy between Climate Crisis and Food Security – Major proportion of the N2O emissions in the last four decades came from the agricultural sector, mainly because of the use of nitrogen- based fertilizers.
  • Most of the emission have come from developing countries like China, India and Brazil.
• Key causes of Nitrogen Pollution
  • Emission from chemical fertilizer –
    • About 50% of the nitrogen used in global agri sector is released in environment (atmosphere, water bodies etc.).
    • Most important source.
    • Difficult to control (non-point source, food security concerns )
  • Sewage and organic solid wastes (second largest source):
  • Burning of fossil fuels: Vehicular pollution, mostly from road transport is another major NOx producer.
  • Industries
• Key threats due to nitrogen pollution
  • Air Pollution: Emissions of Ammonia, nitrogen oxide and nitrous oxide contribute to particulate matter and acid rain. These cause respiratory problems and cancers for people and damage to forests and building
  • Water Pollution – Eutrophication
  • Negatively hampers soil health -> brings down the yield of agri-
  • Climate Change: Nitrous Oxide (N2O) -> GWP: 300 times of CO2; Also contributes to Ozone
  • Negative impact on Health, economy and livelihood
    • Deteriorating soil quality impacts Agri output and livelihood. Further, particulate matter and acid rains have adverse impact on health.

A) UNEP’S COLOMBO DECLARATION ON SUSTAINABLE NITROGEN MANAGEMENT (OCT 2019)

• Sri Lanka, with support from the UNEP, convened an event at which member states came together to adopt what is called the “Colombo Declaration“.
• Key Highlights
  • Halve nitrogen waste by 2030.
  • The member countries also endorsed UN’s plan for a sustainable nitrogen management called “Nitrogen for Life“, which stems from the Sustainable Nitrogen Management Resolution which was adopted during the fourth session of the UN environment Assembly held from 11-15th March 2019, at the UNEP headquarter in Nairobi.
• Analysis
  • This is the first-time governments have agreed to work together on a major quantitative global goal for improved nitrogen management.

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3. SOLID WASTE

• Introduction
  • Solid waste is the unwanted or useless solid materials generated from human activities in residential, industrial or commercial areas.
• Solid waste may be categorized in three ways:
  • Origin (domestic, industrial, commercial, construction or institutional)
  • Contents (organic material, glass, metal, plastic, paper, hazardous chemical)
  • Hazard Potential (toxic, non-toxin, flammable, radioactive, infectious)
• As per org the total MSW generated in urban India has been estimated at 68.8 million tons per year (TPY).
  • This is expected to go to 165 million tonnes by 2030.
• But the Solid waste collection efficiency in India is around 70% at present, while it is 100% in many developed countries.
• Therefore, around 30% of MSW is not collected and thus lies littered around in Indian cities. Even the waste which is collected is not treated and thus is highly hazardous.
• Problems of unscientific MSW disposal -> Untreated, unprocessed and indiscriminately dumped waste causes air, water and soil pollution which have adverse impact on health situation. Further, this type of dumping goes against the 4Rs principle of environment Protection.
• Factors for increasing Solid Waste in India
  • Population, Urbanization, Increasing Per-Capita Income
  • Increased Consumerism, Use and throw culture.
  • Plastic waste -> non availability of good alternative
  • Technology change -> Increasing electronic waste.
  • COVID-19 also led to shooting up of domestic hazardous waste.
• Proper Solid waste management
  • SWM reduces or eliminates the adverse impact on the environment & human health. It includes a number of processes including segregation, collection and treatment and disposal in an environmentally sound manner.
  • The local authorities are responsible for the development of infrastructure for collection, storage, segregation, transportation, processing and disposal of MSW.

5)  TREATMENT AND DISPOSAL OF SOLID WASTE

A) OPEN DUMPING, LANDFILLS AND SANITARY LANDFILL

• Advantage: Waste limited to well defined area; Reduces contact between waste and
• Disadvantages – Open dumps get exposed to natural elements, stray animals and birds and may cause air pollution, water pollution and soil pollution.

B) THERMAL TREATMENT

• ­Incineration plants (Waste to Energy Method)
  • Incineration is combustion of waste in the presence of oxygen. Waste gets converted in CO2, Water Vapor and Ash along with heat.
  • Advantages – reduction in volume; kills many diseases causing germs.
  • Limitations – Air pollution -> Health issues; Climate Change
• Pyrolysis
  • Here material is exposed to very high temperatures in an inert (oxygen less) environment. The material decomposes due to the limited thermal stability of chemical bonds of material, which disintegrates.
  • Pyrolysis is thus a thermo-chemical treatment, which can be applied to any organic (carbon-based) product. It produces volatile products and leaves a solid residue enriched in carbon, char.
• Plasma Arc Gasification (PAG) process
  • It is a waste treatment technology that uses a combination of electricity and high temperature to turn municipal waste (garbage or trash) into usable by-products without combustion.
    • It shouldn’t be confused with incineration. This technology doesn’t combust the waste as happens in incinerators. It converts the organic waste into gas that contains all its chemical and heat energy and converts the inorganic waste into an inert vitrified glass called slag.
    • This process reduces the volume of waste reaching the landfills and also generate electricity.

C) BIOLOGICAL TREATMENT METHODS – USE OF MICROORGANISMS

• ­Bio-Gasification
  • It is a waste-to-Energy technique where biological decomposition of organic matter of biological origin under un-aerobic condition is done to produce methane and other secondary gases.
• Composting
  • In this process, the organic waste is converted into compost through decomposition. Compost is rich in nutrients and can be used as soil conditioner, a fertilizer, addition of vital humus and humic acids and as a natural pesticide in soil.
  • It can also be used for erosion control, land and sea reclamation, wetland construction, and as landfill cover.
• Vermiculture/Vermicomposting: It is the process of making compost through decomposition process. But here, decomposition is done by using various species of worms, usually red wigglers, white worms, and other earthworms.
• ­Bioremediation
  • It involves use of bio-culture or microorganisms to degrade organic waste and contaminants that pose environmental and human risks. Here the environment is altered to stimulate the growth of micro-organisms and degrade pollutants. The organic waste is eventually converted into soil.
  • Various approaches – Biostimulation; Bioaugmentation; a combination of both etc.

D) BIOMINING

• Biomining involves use of separator machines or large sieves to separate waste material of different sizes, thereby obtaining soil, plastic, wood and metal components in isolation for appropriate processing.

6)  LANDFILLS IN DELHI AND KEY CONCERNS

• Why in news?
  • Our target is to clear all three landfill sites in Delhi by December 2024: CM Kejriwal (March 2023)
• Chronic negligence of sustainable and scientific treatment has resulted in an ever-growing mass of municipal solid waste (MSW) making its way into dumpsites in India.
• There are three main landfills in Delhi – Bhalswa in north, Ghazipur in east and Okhla in south with total estimated waste of 20 million tonnes (as of Oct 2022)
  • Note: In 2019, the total legacy waste at these three sites totaled to 28 million tonnes.
• Present Situation of Landfills:
  • Bhalswa (36 acres): 8 million tonnes.
  • Gazipur (70 acres): 14 million tonnes
  • Okhla (46 acres): Currently the site contains around 4 million tonnes of legacy waste. In last few years, around 2.5 lakh tonnes have been removed from it. (at its peak it contained around 6.5 million tonnes of waste)
• Harmful Impacts of landfills:
  • Ground Water and River Water Pollution: Leachate from these landfills are not only contaminating ground water but are also reaching Yamuna River.
  • Other concerns due to landfills -> Air Pollution (methane); Odour Pollution; Wastage of Resources; breeding ground for diseases.
  • Prolonged exposure to compounds such as dioxins which are carcinogenic.

Dioxin:

Dioxins are a group of chemically-related compounds that are persistent environmental pollutants. They are found throughout the world in environment and they accumulate in the food chain, mainly in the fatty tissue of animals.

More than 90% of human exposure is through food, mainly meat and dairy products, fish, and shellfish. Many national authorities have programs in place to monitor the food supply.

They are highly toxic and can cause reproductive and developmental problems, damage the immune system, interfere with hormones and also cause cancer.

Due to omnipresence of dioxins, all people have background exposure, which is not expected to affect human health. However, due to the highly toxic potential, efforts need to be undertaken to reduce current background exposure.

Prevention or reduction of human exposure is best done via source-directed measures, i.e., strict control of industrial processes to reduce the formation of dioxins.

• Ecological Loss: A study conducted by experts from the NEERI, CPCB and IIT Delhi assessed that ecological damage due to these three landfill sites is 450 crore rupees per annum.

 7)  LANDFILL FIRE – CAUSES

Methane Gas; Sabotage; collection of scrap metals; difficult to extinguish.

8)  SOLID WASTE MANAGEMENT RULES, 2016

• In 2016, The Environment ministry had revised the solid waste management rules after 16 years.
• Salient Features
  • Extended Beyond Municipal Areas – Covers urban agglomerations, census towns, notified townships, areas under control of railways, airports, airbases, port and harbour, SEZ etc.
  • Source Segregation of waste has been mandated to channelize the waste to wealth by recovery, reuse, and recycle.
    • Waste generators have to segregate the waste in three streams – Wet (biodegradable; Dry (plastic, paper, glass, metal etc.) and Domestic Hazard wastes (diapers, napkins, empty containers etc.)
      • They should handover the waste to authorized rag pickers or waste collector or local bodies.
    • Street vendors to keep separate containers for separate wastes.
    • Sanitary napkins and diapers manufacturers or brand owners explore the possibility of using recyclable material in the product and shall provide a pouch or wrapper for disposal of each napkin or diapers along with packet of their sanitary products.
      • Educate masses in wrapping and disposal of their products.
  • The rules emphasized on integration of waste pickers/ rag pickers and waste dealers in the formal system by state governments, SHGs or any other group to be formed.
  • Ban on open throwing burning or burying; Provisions for User Fee for waste collectors and ‘Spot Fine’ for Littering and non-segregation
  • Provisions for Bulk and institutional generators -> directly responsible for segregation and sorting the waste and manage in partnership with local bodies.
  • The developers of SEZs, Industrial estate, industrial parks etc. to earmark 5% of the total area of the plot or minimum 5 plots/sheds for recovery and recycling facility.
  • All manufacturers of disposable products such as tin, glass, plastics packaging etc. or brand owners who introduce such products in the market should provide necessary financial assistance to local authorities for the establishment of waste management system.
  • The Biodegradable waste -> processed through composting, bio-methanation etc.
  • Promoting Waste to Energy
    • Industrial units within 100 km of Solid waste RDF plants should get at least 5% of their fuel from them.
    • Non-recyclable waste with high calorific value (1500 K/cal/kg or more) should not be disposed of and should only be utilized for refuse-derived fuel or by giving away the feedstock for preparing refused derived fuel.
    • High calorific wastes shall be used for co-processing in cement or thermal power plants.

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 5. DOMESTIC HAZARDOUS WASTE           

• Details
  • A lot of harmful chemicals are used for domestic purposes
    • Chemicals to sanitize houses.
    • Power bulbs, CFLs, Tube lights
    • Medicines, ointments etc.
  • Caution is not applied while they are thrown in garbage.
  • Current Concerns:
    • India hasn’t estimated how much domestic hazardous waste do we generate.
    • Traces of toxic waste can be found in most landfills.
    • Absence of robust framework and infrastructure
    • Segregation of domestic hazardous waste remains a distant dream for most cities.
• Indore Municipal Corporation has shown the way:
  • It has introduced a 3-way source segregation in 2018-19: Wet, Dry and Domestic Hazardous. Later, it has asked its residents to follow a five-way source segregation (wet, dry, hazardous, e- waste, and sanitary) to improve the purity levels of waste that can be recycled.
  • In Jan 2021, they added plastic waste as the sixth category.
  • The municipal corporation has taken an authorization of sending 1,000 tonnes of domestic hazardous waste to a treatment facility every year.
• Bhopal has brought similar initiatives and is making citizens segregate wastes into 4 categories (wet, dry, hazardous and sanitary)