Environment & Ecology: Environmental Pollution

Categories
Environment & Ecology
Published
10-Feb-2020

SATAT Initiative

Context

The government recently handed over the 100th Letter of Intent (LOI) to the Compressed Bio-Gas(CBG) Entrepreneur (producer) under the SATAT scheme.

About SATAT Initiative:

SATAT initiative is aimed at providing a Sustainable Alternative towards Affordable Transportation (SATAT) as a developmental effort that would bene?t both vehicle-users as well as farmers and entrepreneurs.
Compressed Bio-Gas plants are proposed to be set up mainly through independent entrepreneurs. CBG produced at these plants will be transported through cascades of cylinders to the fuel station networks of OMCs for marketing as a green transport fuel alternative.
The entrepreneurs would be able to separately market the other by-products from these plants, including bio-manure, carbon-dioxide, etc., to enhance returns on investment.
It is planned to roll out 5,000 Compressed Bio-Gas plants across India in a phased manner.
This initiative is expected to generate direct employment for 75,000 people and produce 50 million tonnes of bio-manure for crops.

‘Highest number of wetland species in Kaziranga’

Context

Kaziranga recorded 96 species of wetland birds — one of the highest for wildlife reserves in India, according to the second wetland bird count conducted recently.

Key-highlights of the Survey:

The survey registered a total of 19,225 birds belonging to 96 species under 80 families. It covered four ranges of the park:

Agoratoli
Bagori
Kohora
Burapahar

More than half the birds (9,924) and 85 of the 96 species were recorded in Agoratoli Range. This was because Sohola, the largest of Kaziranga's 92 perennial wetlands, is in this range.
With 6,181 individuals, the bar-headed goose led the species count, followed by the common teal at 1,557 and northern pintail at 1,359. All three belong to the family
The other species with sizeable numbers include gadwall, common coot, lesser whistling duck, Indian spot-billed duck, little cormorant, ferruginous duck, tufted duck, Eurasian wigeon, Asian openbill, northern lapwing, ruddy shelduck and spot-billed pelican.

Background:

The first wetland bird survey in Kaziranga, a UNESCO World Heritage Site since 1985, was conducted in 2018.
The first waterfowl census in 2018 had yielded 10,412 birds covering 80 species, belonging to 21 families.

What are the Wetlands?

Wetlands are areas where water covers the soil or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season.
The primary factor that distinguishes wetlands from other landforms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique hydric soil.
Wetlands play a number of ecological functions, such as water purification, water storage, processing of carbon and other nutrients, stabilization of shorelines, and support of plants and animals.

Ramsar Convention on Wetlands:

The Conventionon Wetlands, called the Ramsar Convention, is the intergovernmental treaty that provides the framework for the conservation and wise use of wetlands and their resources.
It is the only global treaty that focuses specifically on wetlands.
The Convention was adopted in the Iranian city of Ramsar in 1971 and came into force in 1975.
At present, there are 27 Ramsar Wetlands Sites in India

Quick facts on Kaziranga National Park:

Important species: Kaziranga National Park a world heritage site is famous for the Great Indian one-horned rhinoceros. Besides rhinoceros, it is inhabited by tigers, elephants, panthers and bears, and thousands of birds.
Location: It is located fairly in the Golaghat and Nagaon regions of Assam in India and also placed beside the Brahmaputra River on the North and the Karbi Anglong mounts on South India. Kaziranga National Park is the abode of 37 highways which is passed through the park.
It has been declared as National Park in 1974. It has been declared as a world heritage site by UNESCO.
Legal protection: The property receives the highest legal protection and strong legislative framework under the provisions of the Indian Wildlife (Protection) Act, 1972 and Indian Forest Act, 1927/Assam Forest Regulation 1891.

A Giant fish is declared extinct

Context

One of the largest freshwater fish has been declared extinct in a study published in the journal Science of the Total Environment.

About

The Chinese paddlefish (Psephurus gladius) was an iconic species, measuring up to 7 m in length, dating back from 200 million years ago, and therefore swimming the rivers when dinosaurs ruled the Earth.
Its ancestral home was the Yangtze River.
Chinese researchers made this conclusion based on the Red List criteria of the International Union for Conservation of Nature (IUCN).

The Red List has several categories for extinction

“Extinct in the wild” means a species survives only in a captive environment
“Locally extinct” means a species has ceased to exist in a particular area but may exist in other areas.
“Functionally extinct”, which means the species continues to exist but it has too few members to enable to reproduce meaningfully enough to ensure survival.
“Globally extinct”, it means a species has no surviving member anywhere. Such a conclusion is reached when there is no reasonable doubt left that its last member has died.

Other facts

Declaring a species extinct is an elaborate process. It involves a series of exhaustive surveys, which need to be taken at appropriate times, throughout the species’ historic range and over a time-frame that is appropriate to the species’ life cycle and form.
Once declared extinct, a species is not eligible for protective measures and conservation funding; therefore, the declaration has significant consequences.
In the case of the Chinese paddlefish, the researchers made the conclusion over long-term surveys. It was once common in the Yangtze, before overfishing and habitat fragmentation — including dam building — caused its population to dwindle from the 1970s onwards.
Between 1981 and 2003, there were just around 210 sightings of the fish.
The researchers estimate that it became functionally extinct by 1993, and extinct sometime between 2005-2010

Pollution and Mitigation Efforts

Pollution is defined as an addition of undesirable material into the environment as a result of human activities.
The agents which cause environmental pollution are called pollutants.
Pollutants may be defined as a physical, chemical or biological substance unintentionally released into the environment which is directly or indirectly harmful to humans and other living organisms.

Classification of Pollutants

According to the form in which they persist after being released into the environment:

Primary Pollutants: These are pollutants persisted in the environment in the form it is released from the source. e.g., Carbon Dioxide, Nitrogen Oxide, Sulphur dioxide,DDT.
Secondary Pollutants: These are formed from primary pollutants through change or reaction after primary pollutants being released into atmosphere. e.g., Nitrogen oxide and hydrocarbons react photochemically to produce PAN (Peroxyacyl nitrates) and Ozone is formed.

According their Nature of Degradation:

Biodegradable Pollutants: Those pollutants which can be broken down into simpler, harmless, substances in nature in due course of time (by the action of micro-organisms like certain bacteria) are called biodegradable pollutants.

Example: Domestic wastes (garbage), urine, sewage, agriculture residues, paper, wood, cloth, cattle dung, animal bones, leather, wool, vegetable stuff or plants are biodegradable pollutants.

Non-Biodegradable Pollutants: Those pollutants which cannot be broken down into simpler, harmless substances in nature are called non-biodegradable pollutants.

Example: DDT, plastics, polythene, bags, insecticides, pesticides, mercury, lead, arsenic, metal articles like aluminum cans, synthetic fibers, glass objects, iron products and silver foils are non-biodegradable pollutants.

According to their Existence in Nature:

Quantitative Pollutants: These are those substances normally occurring in the environment, which acquire the status of a pollutant when their concentration gets increased due to the activities of man.

For example, carbon dioxide, if present in the atmosphere in concentration greater than normal due to automobiles and industries, causes measurable effects on humans, animals, plants or property, and then it is classified as a quantitative pollutant.

Qualitative Pollutants: These are those substances which do not normally occur in nature but are manmade.

For example: Insecticides, Fungicides, Herbicides, DDT, etc.

According to the Origin of Pollutants:

Natural Pollutants: These are the pollutants emitted by natural processes.
Anthropogenic Pollutants: These are pollutants caused by manmade activities.

Pollution Indicator Species

A species of organism that can indicate an area of pollution by its presences or absence in that specific area.

Lichen

Lichens are plants that grow in exposed places such as rocks or tree bark.
They need to be very good at absorbing water and nutrients to grow there.
Rainwater contains just enough nutrients to keep them alive.
Air pollutants dissolved in rainwater, especially sulfur dioxide, can damage lichens and prevent them from growing.
This makes lichens natural indicators of air pollution.

Indicator of Water Pollution

Water pollution is caused by the discharge of harmful substances into rivers, lakes and seas.
Many aquatic invertebrate animals cannot survive in polluted water, so their presence or absence indicates the extent to which a body of water is polluted.

Fish Survival and Water Oxygen

One simple way to measure the health of a given water source is to examine the survival of fish in that source of water.
Fish rely heavily on the dissolved oxygen in water to survive, so if oxygen levels are low due to pollution, no varieties of fish will survive.

AIR POLLUTION

Rising issue of air pollution has increasingly been becoming a serious concern, particularly in metro cities.
A large number of cities and towns do not meet the standards for pollutants specifically for particulate matter.
In a few cities including Delhi, the ambient particulate matter concentrations are much above the standards i.e. three to four times or even higher.
Air quality regulation and actions for abatement of air pollution is undertaken under various provisions of Air (Prevention and Control of Pollution) Act, 1981 and Environment (Protection) Act, 1985 which prescribes the mechanism and authorities for handling the issue.
The major impact is highlighted with reference to health of people.
As per the available data for Delhi and NCR for last five years, Particulate Matter (PM10 and PM2.5) concentrations are the major concern for the entire area, however a few violations are observed in NO2 concentrations in Delhi, Meerut and Faridabad.
The concentration of SO2 is within the standard limit at all the locations in all the last five years.
PM10 are inhalable coarse particles, which are particles with a diameter between 2.5 and 1O micrometers (um) and PM2.5 are fine particles with a diameter of 2.5 um or less.

Indoor Air Pollution and Health

Indoor Air Quality (IAQ) refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. Understanding and controlling common pollutants indoors can help reduce your risk of indoor health concerns.

Health effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later.

Immediate Effects

Some health effects may show up shortly after a single exposure or repeated exposures to a pollutant.
These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable.
Sometimes the treatment is simply eliminating the person's exposure to the source of the pollution, if it can be identified.
Soon after exposure to some indoor air pollutants, symptoms of some diseases such as asthma may show up, be aggravated or worsened.
The likelihood of immediate reactions to indoor air pollutants depends on several factors including age and preexisting medical conditions.
In some cases, whether a person reacts to a pollutant depends on individual sensitivity, which varies tremendously from person to person.
Some people can become sensitized to biological or chemical pollutants after repeated or high level exposures.
Certain immediate effects are similar to those from colds or other viral diseases, so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution.
For this reason, it is important to pay attention to the time and place symptoms occur. If the symptoms fade or go away when a person is away from the area, for example, an effort should be made to identify indoor air sources that may be possible causes.
Some effects may be made worse by an inadequate supply of outdoor air coming indoors or from the heating, cooling or humidity conditions prevalent indoors.

Long-Term Effects

Other health effects may show up either years after exposure has occurred or only after long or repeated periods of exposure.
These effects, which include some respiratory diseases, heart disease and cancer, can be severely debilitating or fatal.
It is prudent to try to improve the indoor air quality in your home even if symptoms are not noticeable.
While pollutants commonly found in indoor air can cause many harmful effects, there is considerable uncertainty about what concentrations or periods of exposure are necessary to produce specific health problems.
People also react very differently to exposure to indoor air pollutants.
Further research is needed to better understand which health effects occur after exposure to the average pollutant concentrations found in homes and which occurs from the higher concentrations that occur for short periods of time.

Primary Causes of Indoor Air Problems

Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the area. High temperature and humidity levels can also increase concentrations of some pollutants.

Pollutant Sources

There are many sources of indoor air pollution. These can include:

Fuel-burning combustion appliances
Tobacco products
Building materials and furnishings as diverse as:
- Deteriorated asbestos-containing insulation
- Newly installed flooring, upholstery or carpet
- Cabinetry or furniture made of certain pressed wood products
Products for household cleaning and maintenance, personal care, or hobbies
Central heating and cooling systems and humidification devices
Excess moisture
Outdoor sources such as:
- Radon
- Pesticides
- Outdoor air pollution.

Initiatives on Air Pollution Mitigation:

National Ambient Air Quality Standards envisaging 12 pollutants have been notified under EPA, 1986 and 115 emission/effluent standards for 104 different sectors of industries, besides 32 general standards for ambient air have also been notified.
Government is executing a nation-wide programme of ambient air quality monitoring known as National Air Quality Monitoring Programme (NAMP). The network consists of Six hundred and Ninety-One (691) manual operating stations covering Three Hundred and three (303) cities/towns in twenty-nine (29) states and four (6) Union Territories of the country. In addition, there are 86 real-time Continuous Ambient Air Quality Monitoring stations (CAAQMS) in 57 cities. Delhi has 10 Manual Stations and 18 CAAQMS. 20 additional CAAQMS are at various stages of installation in Delhi.
With reference to Vehicular pollution the steps taken include introduction of cleaner / alternate fuels like gaseous fuel (CNG, LPG etc.), ethanol blending, universalization of BS-IV by 2017; leapfrogging from BS-IV to BS-VI fuel standards by 1st April, 2020; ongoing promotion of public transport network of metro, buses, e-rickshaws and promotion of carpooling, streamlining granting of Pollution Under Control Certificate, lane discipline, vehicle maintenance etc.
National Air Quality index (AQI) was launched by the Prime Minister in April, 2015 starting with 14 cities and now extended to 34 cities.
A Graded Response Action Plan for control of air pollution in Delhi and NCR region has been notified. This plan specifies actions required for controlling particulate matter (PM emissions from various sources and prevent PM10 and PM2.5 levels to go beyond ‘moderate’ national Air Quality Index (AQI) category. The measures are cumulative. Emergency and Severe levels include cumulatively all other measures listed in the lower levels of AQI including Very Poor, Poor and Moderate. Actions listed in the Poor to Moderate category need to be implemented though out the year.
Central Pollution Control Board (CPCB) has issued a comprehensive set of directions under section 18 (1) (b) of Air (Prevention and Control of Pollution) Act, 1986 for implementation of 42 measures to mitigate air pollution in major cities including Delhi and NCR comprising of action points to counter air pollution in major cities which include control and mitigation measures related to vehicular emissions, re-suspension of road dust and other fugitive emissions, bio-mass/municipal solid waste burning, industrial pollution, construction and demolition activities, and other general steps.
In order to involve people in the effort, Government had launched a campaign called ‘Harit Diwali and Swasth Diwali’ during September 2017 involving over 2000 schools in Delhi and over two lakh schools in the country. The Government had also organized a Mini Marathon for ‘Swachh Hawa for Swachh and Swasth Bharat’ on 15th October 2017 at India Gate in which nearly 15,000 school children had participated.
Regular co-ordination meetings are held in the Ministry at official and ministerial level with Delhi and other State Governments to avoid the emergency situation. In this regard several meetings have been held this year under the chairmanship of Hon’ble Minister for Environment Forest and Climate Change and Secretary (EF&CC) involving Environment Minister of the States and Senior State Functionaries including Chief Ministers, Ministers, Chief Secretaries and Additional Chief Secretaries.
CPCB had taken a number of Proactive steps to help improve ground implementation .40 CPCB teams deployed for ground feedback on air polluting activities in Delhi –September 01, 2017 onwards Field visit to four pollution hotspots (Anand Vihar, ITO, Punjabi Bagh and DTU) and suggested interventions July 2017 .On the spot reporting to DPCC, and weekly summary reports to Delhi Govt.
During air pollution emergency period from 7.11.2017 to 14.11.2017 and measures like ban on construction, sprinkling of water, ban on entry of truck etc. which are there under GRAP were implemented.
A High Level Task Force (HLTF) headed by Principal Secretary to PM has been constituted by the government for management of air pollution in Delhi and NCR. First meeting of Task Force was held on 4th December 2017. On the basis of direction of the Task Force, Sub-Committee of High Level Task Force for Prevention of Stubble Burning in Haryana, Uttar Pradesh and Punjab has been constituted and report has been submitted for consideration by the HLTF. The Task Force has proposed a draft Air Action Plan on Abatement of Air Pollution in the Delhi National Capital Region in which time bound activities have been outlined. This has been put in the public domain for suggestions/comments from citizens and experts for possible refinements.

WATER POLLUTION

India consists 1/25th of world’s water resources. The total utilizable water resources of the country are assessed as 1086 km3.

Sources of Water Pollution

There are various classifications of water pollution. The two chief sources of water pollution can be seen as Point and Non Point:

Point Source refers to the pollutants that belong to a single source. An example of this would be emissions from factories into the water.
Non Point Source on the other hand means pollutants emitted from multiple sources. Contaminated water after rains that has traveled through several regions may also be considered as a Non point source of pollution.

Sources are:

- Chemical fertilizers and pesticides
- Industrial waste: Industries produce huge amount of waste which contains toxic chemicals and pollutants such as lead, mercury, sulphur, asbestos, nitrates and many other harmful chemicals.
- Mining activities
- Marine dumping: The garbage produce by each household in the form of paper, aluminum, rubber, glass, plastic, food if collected and deposited into the sea in some countries.
- Accidental Oil leakage
- Burning of fossil fuels
- Radioactive Waste
- Animal waste- contributes to the biological pollution of water streams
- Construction activities
- Leaking landfills

Measurement of Water Pollution

Biological Oxygen Demand (BOD)

BOD is the amount of dissolved oxygen needed by bacteria in decomposing the organic wastes present in water. It is expressed in milligrams of oxygen per litre of water.
The higher value of BOD indicates low Dissolved Oxygen content of water. Since BOD is limited to biodegradable materials. Therefore, it is not a reliable method of measuring pollution load in water.

Chemical Oxygen Demand (COD)

COD measures the amount of oxygen in parts per million required to oxidize organic (biodegradable and non- biodegradable) and oxidizable inorganic compounds in the water sample.

Total Organic Carbon

Organic matter content is typically measured as total organic carbon and dissolved organic carbon, which are essential components of the carbon cycle. The Total Organic Carbon test measures all organic carbon as CO2. Therefore, all inorganic CO2, HCO3-, etc. must be removed prior to the analysis.
TOC is often used when levels of organic matter (OM) are low. Total organic carbon is a good parameter to measure and actually a more accurate indication of some of the pollutants that cause the most problems than a BOD test. TOC doesn’t differentiate between that portion of organic carbon, which can be metabolized (assimilated).

Harmful Effects of Water Pollution

Some polluted water looks muddy, smells bad, and has garbage floating in it. Some polluted water looks clean, but is filled with harmful chemicals you can’t see or smell.
Polluted water is unsafe for drinking and swimming. Some people who drink polluted water are exposed to hazardous chemicals that may make them sick years later. Others consume bacteria and other tiny aquatic organisms that cause disease. The United Nations estimates that 4,000 children die every day from drinking dirty water.
Sometimes, polluted water harms people indirectly. They get sick because the fish that live in polluted water are unsafe to eat. They have too many pollutants in their flesh.
There are some natural sources of water pollution. Oil and natural gas, for example, can leak into oceans and lakes from natural underground sources. These sites are called petroleum seeps. The world’s largest petroleum seep is the Coal Oil Point Seep, off the coast of the U.S. state of California. The Coal Oil Point Seep releases so much oil that tar balls wash up on nearby beaches. Tar balls are small, sticky pieces of pollution that eventually decompose in the ocean.
Human activity also contributes to water pollution. Chemicals and oils from factories are sometimes dumped or seep into waterways. These chemicals are called runoff. Chemicals in runoff can create a toxic environment for aquatic life. Runoff can also help create a fertile environment for cyanobacteria, also called blue-green algae. Cyanobacteria reproduce rapidly, creating a harmful algal bloom (HAB). Harmful algal blooms prevent organisms such as plants and fish from living in the ocean. They are associated with “dead zones” in the world’s lakes and rivers, places where little life exists below surface water.
Mining and drilling can also contribute to water pollution. Acid mine drainage (AMD) is a major contributor to pollution of rivers and streams near coal mines. Acid helps miners remove coal from the surrounding rocks. The acid is washed into streams and rivers, where it reacts with rocks and sand. It releases chemical sulfur from the rocks and sand, creating a river rich in sulfuric acid. Sulfuric acid is toxic to plants, fish, and other aquatic organisms. Sulfuric acid is also toxic to people, making rivers polluted by AMD dangerous sources of water for drinking and hygiene.
Buried chemical waste can also pollute water supplies. For many years, people disposed of chemical wastes carelessly, not realizing its dangers. In the 1970s, people living in the Love Canal area in Niagara Falls, New York, suffered from extremely high rates of cancer and birth defects. It was discovered that a chemical waste dump had poisoned the area’s water. In 1978, 800 families living in Love Canal had to abandon their homes.
If not disposed of properly, radioactive waste from nuclear power plants can escape into the environment. Radioactive waste can harm living things and pollute the water.
Sewage that has not been properly treated is a common source of water pollution. Many cities around the world have poor sewage systems and sewage treatment plants. Delhi, the capital of India, is home to more than 21 million people. More than half the sewage and other waste produced in the city are dumped into the Yamuna River. This pollution makes the river dangerous to use as a source of water for drinking or hygiene. It also reduces the river’s fishery, resulting in less food for the local community.
A major source of water pollution is fertilizer used in agriculture. Fertilizer is material added to soil to make plants grow larger and faster. Fertilizers usually contain large amounts of the elements nitrogen and phosphorus, which help plants grow. Rainwater washes fertilizer into streams and lakes. There, the nitrogen and phosphorus cause cyanobacteria to form harmful algal blooms.
Rain washes other pollutants into streams and lakes. It picks up animal waste from cattle ranches. Cars drip oil onto the street, and rain carries it into storm drains, which lead to waterways such as rivers and seas. Rain sometimes washes chemical pesticides off of plants and into streams. Pesticides can also seep into groundwater, the water beneath the surface of the Earth.
Heat can pollute water. Power plants, for example, produce a huge amount of heat. Power plants are often located on rivers so they can use the water as a coolant. Cool water circulates through the plant, absorbing heat. The heated water is then returned to the river. Aquatic creatures are sensitive to changes in temperature. Some fish, for example, can only live in cold water. Warmer river temperatures prevent fish eggs from hatching. Warmer river water also contributes to harmful algal blooms.
Another type of water pollution is simple garbage. The Citarum River in Indonesia, for example, has so much garbage floating in it that you cannot see the water. Floating trash makes the river difficult to fish in. Aquatic animals such as fish and turtles mistake trash, such as plastic bags, for food. Plastic bags and twine can kill many ocean creatures. Chemical pollutants in trash can also pollute the water, making it toxic for fish and people who use the river as a source of drinking water. The fish that are caught in a polluted river often have high levels of chemical toxins in their flesh. People absorb these toxins as they eat the fish.
Garbage also fouls the ocean. Many plastic bottles and other pieces of trash are thrown overboard from boats. The wind blows trash out to sea. Ocean currents carry plastics and other floating trash to certain places on the globe, where it cannot escape. The largest of these areas, called the Great Pacific Garbage Patch, is in a remote part of the Pacific Ocean. According to some estimates, this garbage patch is the size of Texas. The trash is a threat to fish and seabirds, which mistake the plastic for food. Many of the plastics are covered with chemical pollutants.
Eutrophication

- Eutrophication refers to the addition of artificial or non-artificial substances, such as nitrates and phosphates, through fertilizers or sewage, to a fresh water system.
- It can be anthropogenic or natural. It leads increase in the primary productivity of the water body or “bloom” of phytoplankton.
- The overgrowth causes the loss of oxygen in the water leading to severe reductions in fish and other animal populations.
- Eutrophication escalates rapidly when high nutrients from fertilizers, domestic and industrial wastes, urban drainage, detergents and animal, sediments enter water streams.
- The cultural eutrophication process consists of a continuous increase in the contribution of nutrients, mainly nitrogen and phosphorus (organic load) until it exceeds the capacity of the water body (i.e. the capacity of a lake, river or sea to purify itself) , triggering structural changes in the waters.

Some Water Treating Measures

Septic Tanks and Sewage Treatments:

Septic tanks treat sewage at the place where it is located, rather than transporting the waste through a treatment plant or sewage system.
Septic tanks are usually used to treat sewage from an individual building.
Solid material is separated depending on their density. Heavier particles settle at the bottom of the tank whereas lighter particles, such as soap scum, will form a layer at the top of the tank.
Biological processes are used to help degrade the solid materials. The liquid then flows out of the tank into a land drainage system and the remaining solids are filtered out.

Industrial Water Treatment:

In a water treatment plant, sewage goes through a number of chambers and chemical processes to reduce the amount and toxicity of the waste.
Primary Phase: This is where some of the suspended, solid particles and inorganic material is removed by the use of filters.
Secondary Phase: Involves the reduction of organic, this is done with the use of biological filters and processes that naturally degrade the organic waste material.
Tertiary Phase: This stage must be done before the water can be reused. Almost all solid particles are removed from the water and chemical additives are supplied to get rid of any left-over impurities.

Ozone Wastewater Treatment:

It is a method that is increasing in popularity. An ozone generator is used to break down pollutants in the water source.
The generators convert oxygen into ozone by using ultraviolet radiation or by an electric discharge field.
Ozone is a very reactive gas that can oxidise bacteria, moulds, organic material and other pollutants found in water. Using ozone to treat wastewater has many benefits:
- Kills bacteria effectively.
- Oxidises substances such as iron and sulphur so that they can be filtered out of the solution.
- There are no nasty odours or residues produced from the treatment.
- Ozone converts back into oxygen quickly, and leaves no trace once it has been used

Denitrification:

It is an ecological approach that can be used to prevent the leaching of nitrates in soil, this in turn stops any ground water from being contaminated with nutrients.

MARINE POLLUTION

The 1982, United Nations Convention on the Laws of the Sea defined Marine Pollution, “the introduction by man, directly or indirectly, of substances or energy into the marine environment which results or is likely to result in such deleterious effects as harm to living resources and marine life”.

Sources of Marine Pollution

The three main sources of marine pollution are direct discharge as effiuents and solid wastes from land or human activities at sea (like shipping), run off mainly via rivers, and atmospheric fall out.

Effects of Marine Pollution

The effects of Marine Life
Ghost Fishing
Creation of Dead Zones
Increase in Algal Blooms
Acidification of Oceans
Leads to loss of marine life (choking of marine life, depletion of oxygen)

Concept of Algal Bloom

Algal bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems, and is recognized by the discoloration in the water from their pigments.
Algal blooms are the consequence of Eutrophication.
Eutrophication is the response to the addition of nutrients such as nitrates and phosphates naturally or artificially, fertilizing the aquatic ecosystem.

Concept of Ghost Fishing

‘Ghost Fishing’ is what fishing gear does when it has been lost, dumped or abandoned. Imagine a fishing net that gets snagged on a reef or a wreck and gets detached from the fishing vessel. Nets, long lines, fish traps or any man made contraptions designed to catch fish or marine organisms are considered capable of ghost fishing when unattended, and without anyone profiting from the catches, they are affecting already depleted commercial fish stocks. Caught fish die and in turn attract scavengers which will get caught in that same net, thus creating a vicious circle.

Concept of Dead Zone

Dead zones are the areas in oceans and large bodies of freshwater like lakes where the level of dissolved oxygen is too low to sustain marine life.
In such zones, most marine life either dies or migrates to other areas, thus turning these hypoxic zones into biological deserts. The largest dead zone is present in Gulf of Mexico.

Causes

Human Activities:

Increased use of chemical fertilizers, mainly nitrogenous fertilizers. ?
Chemical fertilizers, as well as pesticides and insecticides used in intensive farming, escape into water bodies like rivers and eventually end up in the ocean.
Runoff from sewage and landfills ?
Burning of gasoline ?
Oil spills can further reduce the level of dissolved oxygen in water

Natural Causes:

Apart from human activities, some naturally occurring changes also contributes to the phenomenon of dead zones:
- coastal upwelling ?
- changes in wind ?
- water circulation patterns

Effects

Leads to reproductive problems in marine life
Dead zone is an invisible trap, there is no escaping for marine life
Great impact on benthic biomass and biodiversity
Contributes to climate change

Concept of Ocean Acidification

When carbon dioxide (CO2) is absorbed by seawater, chemical reactions occur that reduce seawater pH, carbonate ion concentration, and saturation states of biologically important calcium carbonate minerals.
These chemical reactions are termed “ocean acidification”. Burning of fossil fuels releases CO2 and other gases which upon absorption by ocean are directly contributing to ocean acidification.
Release of NO2 and SO2 also cause acid rain which can contribute to ocean acidification.

Impact:

The impacts of ocean acidification could be enormous.
The change in ocean chemistry leads to collapsing food webs, corrosive polar seas, dying coral reefs and mass extinctions – which could alter our food, water and air forever.
Acidity is measured using pH measurements.
The higher a pH value is, the more basic, or non-acidic the substance is. The lower the pH value is the more acidic a substance is.

Oil Spill

An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially marine areas, due to human activity, and is a form of pollution.
The term is usually applied to marine oil spills, where oil is released into the ocean or coastal waters, but spills may also occur on land.
Oil spills may be due to releases of crude oil from tankers, offshore platforms, drilling rigs and wells, as well as spills of refined petroleum products (such as gasoline, diesel) and their by-products, heavier fuels used by large ships such as bunker fuel, or the spill of any oily refuse or waste oil.

Oil Zapping

Oil Zapping is a bio-remediation technique involving the use of ‘oil zapping’ bacteria.

How does Oil Zapper Work?

There are five different bacterial strains that are immobilized and mixed with a carrier material such as powdered corncob. This mixture of five bacteria is called Oil Zapper. Oil zapper feeds on hydrocarbon compounds present in crude oil and the hazardous hydrocarbon waste generated by oil refineries, known as Oil Sludge and converts them into harmless CO2 and water. The Oilzapper is neatly packed into sterile polythene bags and sealed aseptically for safe transport. The shelf life of the product is three months at ambient temperature.
The oil zapping bacteria was developed over a period of seven years by TERI and the project was supported by the Department of Biotechnology (Government of India) and the Ministry of Science and Technology

LAND POLLUTION

Article 1 of the UN Convention to Combat Desertification defines land degradation as a “reduction or loss in arid, semi-arid and dry sub-humid areas of the biological or economic productivity and complexity of rain-fed cropland, irrigated cropland, or range, pasture, forest and woodlands resulting from land uses or from a process or combination of processes, including processes arising from human activities and habitation patterns, such as: (i) soil erosion caused by wind and / or water; (ii) deterioration of the physical, chemical, and biological and economic properties of soil; and (iii) long-term loss of natural vegetation” (Ministry of Environment, Forests and Climate Change, GoI, 2014).
Land degradation is the process of deterioration of soil or loss of fertility of soil.

Causes of Land Degradation

Population;
Human Activities;
Urbanization;
Soil erosion;
Soil contamination;
Soil salinization;
Soil sealing;
Overgrazing;
Acidification of Soil;
Mining and quarrying activities;
Improper crop rotations;
Use of Chemical Fertilizer and pesticides.

Harmful Effects of Land Pollution

Many of the same pollutants that foul the water also harm the land. Mining sometimes leaves the soil contaminated with dangerous chemicals.
Pesticides and fertilizers from agricultural fields are blown by the wind. They can harm plants, animals, and sometimes people. Some fruits and vegetables absorb the pesticides that help them grow. When people consume the fruits and vegetables, the pesticides enter their bodies. Some pesticides can cause cancer and other diseases.
A pesticide called DDT (dichlorodiphenyltrichloroethane) was once commonly used to kill insects, especially mosquitoes. In many parts of the world, mosquitoes carry a disease called malaria, which kills a million people every year. Swiss chemist Paul Hermann Muller was awarded the Nobel Prize for his understanding of how DDT can control insects and other pests. DDT is responsible for reducing malaria in places such as Taiwan and Sri Lanka.
In 1962, American biologist Rachel Carson wrote a book called Silent Spring, which discussed the dangers of DDT. She argued that it could contribute to cancer in humans. She also explained how it was destroying bird eggs, which caused the number of bald eagles, brown pelicans, and ospreys to drop. In 1972, the United States banned the use of DDT. Many other countries also banned it. But DDT didn’t disappear entirely. Today, many governments support the use of DDT because it remains the most effective way to combat malaria.
Trash is another form of land pollution. Around the world, paper, cans, glass jars, plastic products, and junked cars and appliances mar the landscape. Litter makes it difficult for plants and other producers in the food web to create nutrients. Animals can die if they mistakenly eat plastic.
Garbage often contains dangerous pollutants such as oils, chemicals, and ink. These pollutants can leech into the soil and harm plants, animals, and people.
Inefficient garbage collection systems contribute to land pollution. Often, the garbage is picked up and brought to a dump, or landfill. Garbage is buried in landfills. Sometimes, communities produce so much garbage that their landfills are filling up. They are running out of places to dump their trash.
A massive landfill near Quezon City, Philippines, was the site of a land pollution tragedy in 2000. Hundreds of people lived on the slopes of the Quezon City landfill. These people made their living from recycling and selling items found in the landfill. However, the landfill was not secure. Heavy rains caused a trash landslide, killing 218 people.
Sometimes, landfills are not completely sealed off from the land around them. Pollutants from the landfill leak into the earth in which they are buried. Plants that grow in the earth may be contaminated, and the herbivores that eat the plants also become contaminated. So do the predators that consume the herbivores. This process, where a chemical builds up in each level of the food web, is called bioaccumulation.
Pollutants leaked from landfills also leak into local groundwater supplies. There, the aquatic food web (from microscopic algae to fish to predators such as sharks or eagles) can suffer from bioaccumulation of toxic chemicals.
Some communities do not have adequate garbage collection systems, and trash lines the side of roads. In other places, garbage washes up on beaches. Kamilo Beach, in the U.S. state of Hawaii, is littered with plastic bags and bottles carried in by the tide. The trash is dangerous to ocean life and reduces economic activity in the area. Tourism is Hawaii’s largest industry. Polluted beaches discourage tourists from investing in the area’s hotels, restaurants, and recreational activities.
Some cities incinerate, or burn, their garbage. Incinerating trash gets rid of it, but it can release dangerous heavy metals and chemicals into the air. So while trash incinerators can help with the problem of land pollution, they sometimes add to the problem of air pollution.

Sustainable Land Management (SLM)

It is crucial to minimizing land degradation, rehabilitating degraded areas and ensuring the optimal use of land resources for the benefit of present and future generations.
SLM is based on four common principles:
- Land-user-driven and participatory approaches;
- Integrated use of natural resources at ecosystem and farming systems levels
- Multilevel and multi-stakeholder involvement; and
- Targeted policy and institutional support, including development of incentive mechanisms for SLM adoption and income generation at the local level.

Some of the methods for sustainable management of land are:

Management on overgrazing: Management practices like water development, placement of salt and supplements, fertilizer application, fencing, burning can control the overgrazing.
Managing irrigation: Irrigation system can be controlled like drip irrigation to reduce soil erosion. Using high and low salt water was most effective in maintaining the productive capacity of the clay soil.
Managing urban sprawl: The urban planning is the most important factor, to control the urban sprawl. Fertile field near by the urban area need to be protected by the local government rules. There should be a proper waste management system dumping of these waste generated as part of urban sprawling will degrade the land, can cause soil salinity, acidity and loss of it vegetative properties.
Managing mining and quarrying: The impact can be reduced by proper management of mining process, using advanced technologies rather than conventional methods. After mining by proper back filling, spreading the soil back over the top, the land can be reclaimed.
Managing agricultural intensification: Agricultural intensification need to be managed properly to reduce the environmental effect. This can be done through education of the farmers.

NOISE POLLUTION

Noise pollutionis generally defined as regular exposure to elevated sound levels that may lead to adverse effects in humans or other living organisms.
According to the World Health Organization, sound levels less than 70 dB are not damaging to living organisms, regardless of how long or consistent the exposure is.
Exposure for more than 8 hours to constant noise beyond 85 dB may be hazardous.
If you work for 8 hours daily in close proximity to a busy road or highway, you are very likely exposed to traffic noise pollution around 85dB.

Various Causes of Noise Pollution

Industrialization

Most of the industries use big machines which are capable of producing a large amount of noise.
Apart from that, various equipment like compressors, generators, exhaust fans, grinding mills also participates in producing big noise.
Therefore, you must have seen workers in these factories and industries wearing earplugs to minimize the effect of noise.

Poor Urban Planning

In most of the developing countries, poor urban planning also plays a vital role.
Congested houses, large families sharing small space, fight over parking, frequent fights over basic amenities leads to noise pollution which may disrupt the environment of society.

Social Events

Noise is at its peak in most of the social events.
Whether it is marriage, parties, pub, disc or place of worship, people normally flout rules set by the local administration and create nuisance in the area.
People play songs on full volume and dance till midnight which makes the condition of people living nearby pretty worse.
In markets, you can see people selling clothes via making a loud noise to attract the attention of people.

Transportation

A large number of vehicles on roads, airplanes flying over houses, underground trains produce heavy noise and people get it difficult to get accustomed to that.
The high noise leads to a situation wherein a normal person loses the ability to hear properly.

Construction Activities

Under construction activities like mining, construction of bridges, dams, buildings, stations, roads, flyovers takes place in almost every part of the world.
These construction activities take place every day as we need more buildings, bridges to accommodate more people and to reduce traffic congestion.

Household Chores

We people are surrounded by gadgets and use them extensively in our daily life.
Gadgets like TV, mobile, mixer grinder, pressure cooker, vacuum cleaners, washing machine and dryer, cooler, air conditioners are minor contributors to the amount of noise that is produced but it affects the quality of life of your neighborhood in a bad way.

Effect of Noise Pollution on Human Health

Hypertension is, in this case, a direct result of noise pollution caused elevated blood levels for a longer period of time.
Hearing loss can be directly caused by noise pollution, whether listening to loud music in your headphones or being exposed to loud drilling noises at work, heavy air or land traffic, or separate incidents in which noise levels reach dangerous intervals, such as around140 dB for adult or 120 dB for children.
Sleep disturbances are usually caused by constant air or land traffic at night, and they are a serious condition in that they can affect everyday performance and lead to serious diseases.
Child development. Children appear to be more sensitive to noise pollution, and a number of noise-pollution-related diseases and dysfunctions are known to affect children, from hearing impairment to psychological and physical effects. Also, children who regularly use music players at high volumes are at risk of developing hearing dysfunctions. In 2001, it was estimated that 12.5% of American children between the ages of 6 to 19 years had impaired hearing in one or both ears
Various cardiovascular dysfunctions. Elevated blood pressure caused by noise pollution, especially during the night, can lead to various cardiovascular diseases.
Dementia isn’t necessarily caused by noise pollution, but its onset can be favored or compounded by noise pollution.
Psychological dysfunctions and noise annoyance. Noise annoyance is, in fact, a recognized name for an emotional reaction that can have an immediate impact.

Effects of Noise Pollution on Wildlife and Marine Life

Our oceans are no longer quiet. Thousands of oil drills, sonars, seismic survey devices, coastal recreational watercraft and shipping vessels are now populating our waters, and that is a serious cause of noise pollution for marine life.
Whales are among the most affected, as their hearing helps them orient themselves, feed and communicate.
Noise pollution thus interferes with cetaceans’ (whales and dolphins) feeding habits, reproductive patterns and migration routes, and can even cause hemorrhage and death.
Other than marine life, land animals are also affected by noise pollution in the form of traffic, firecrackers etc., and birds are especially affected by the increased air traffic.