Topics of rente to the environmentalist. Especially tailored to the subject titled, “Environnmental Studies” common to the engineering students te Osmania University, Hyderabad, India
Sunday, November Ten, 2013
Disaster management te India
India has set-up a disaster management unit ter the centre called the National Disaster Management Authority (NDMA – http://www.ndmindia.nic.ter/ ) under the ministry of huis affairs, where several disasters are treated by different units. The webstek lists a central voeling for information regarding any disaster te the country.
Diasater Management Cycle
Basic principles of disaster mitigation, disaster management and methodology
Influence of disasters on Environment, Infrastructure and development
Types of disasters
Saturday, November 9, 2013
Issues involved te enforcement of environmental legislation
uncertainties faced by environmental management. The principle implies that an ounce of
prevention is worth a pound of cure– it does not prevent problems but may reduce their
bruised caused by a development–this principle also implies that a polluter pays for
monitoring and policing. A problem with this treatment is that fines may bankrupt puny
businesses, yet be low enough for a large company to write them off spil an occasional
overhead, which does little for pollution control.
public, NGOs or even official bods are incapable to get information.
- Drawbacks of wildlife protection act, 1972
- Since this act has bot enacted just spil a fallout of Stockholm conference held ter 1972, it has not included any locally evolved conservation measures.
- The ownership certificates for some animal articles (Ex: Leopard and Tiger skins) often serve spil a instrument for illegal trading.
- Jammu and Kashmir have their own wildlife acts, therefore, hunting and trading of many endangered species, prohibited ter other states are permitted ter Jammu and Kashmir.
- The offenders of this act are not subject to any harsh fines. The fine is only Rs. 25000 or imprisonment for up-to three years.
Wednesday, November 6, 2013
Environment Protection Act
Acid rain – Formation, Effects and Control measures
Acid rain means the presence of excessive acids ter rain water. Thermal power plants, industries and vehicles release nitrous oxide and sulphur dioxide into the atmosphere by searing of coal and oil. When thesis gases react with water vapour te the atmosphere, they form acids and descend on Earth spil “acid rain” through rain water.
SOx + H2O = H2SO4
- Acid rain has bot found to be very dangerous to living organisms spil it can demolish life. Human jumpy system, respiratory system and digestive system are affected by acid rain.
- It can also cause premature death from heart and lung disorders such spil asthma and bronchitis
Effect of acid rain on buildings
- The ‘Taj Mahal’ te Agra is affected from the acid fumes being emitted from ‘Mathura Refinery’. Crystals of CuSO4 and MgSO4 are formed spil a result of corrosion due to acid rain.
- Acid rain corrodes houses, monuments, statues, bridges and fences.
Ozone layer depletion
Ozone is a colourless, odorless gas composed of three atoms of oxygen (O3). Ozone has the same chemical structure regardless of where it occurs and can be useful or harmful depending on where it occurs ter the atmosphere. Ozone is formed naturally ter the upper stratosphere when wavelengths less than 240nm are absorbed by normal oxygen molecules which dissociate to give O atoms. The O atoms ter combination with other oxygen molecules produce ozone.
Ter the stratosphere, about Nineteen to 30 km above the Earth’s surface, ozone is permanently being produced and ruined naturally. This production and destruction makes stratosphere with ozone layer that filters the Ultra-Violet radiation from the Zon and protects life on Earth. Normally there is a fine balance inbetween production and destruction of ozone thereby safeguarding life on Earth.
Man-made chemicals called Chloro Fluoro Carbons(CFCs) are used spil aerosol rockets, refrigerants and coolants etc ruin ozone molecules ter the stratosphere.
The CFCs themselves do not demolish ozone molecules but they decay ozone molecules at low temperatures. A petite amount of chlorine atom and chlorine mono-oxide function spil catalyst ter the process of destruction of ozone. The equations involved are:
Cl + O3 = ClO + O2
Hence, nipt effect:
Chlorine atom ter the above reaction functions spil a catalyst and is not consumed ter the reaction. Chlorine atom used ter the reaction remains spil chlorine atom even at the end of the reaction. Once chlorine has cracked one ozone molecule, it is free to repeat the process until it is eliminated by another reaction te the atmosphere. Chloro-Fluoro-Carbons are very stable molecules and can live upto 100 years.
The ozone depletion potential of a compound is defined spil the measure of its capability to ruin stratospheric ozone.
It may be defined spil the ratio of total amount of ozone demolished by a particular smeris to the amount of ozone demolished by the same mass of CFC-11.
The ODP of CFC-11 is always taken spil 1.0
ODP is a relative measure with CFC-11 taken spil a standard reference. Therefore, if the ODP of a compound is 0.Five, it is harshly speaking half spil ‘bad’ spil CFC-11.
- Nature of the halogen (Bromine containing halocarbons usually have much higher ODPs than hydrocarbons. This is because Bromine is an effective ozone destruction catalyst than Chlorine)
- The number of chlorine or bromine atoms ter a molecule.
- Molecular mass and
- Atmospheric lifetime
Dobson Unit (DU) is the scale for measuring the total amount of ozone occupying a katern overhead.
One Dobson Unit (1DU) is defined spil 0.01mm at 0C and 1 atmospheric pressure.
If the ozone layer thickness when compressed to 0C and 1 atmosphere pressure is about 5mm, the average amount of ozone would be about 500 DU.
Ozone layer protects all life forms on Earth from the Zon’s harmful UV radiation. Any significant decrease ter the amount of ozone ter the stratosphere results te the amount of UV radiation reaching the Earth’s surface leading to harmful effects on all living organisms.
Global heating – Definition, Effects, Control and Remedial measures
Following are the effects of global heating:
- More warmth flaps
- Expansion of desert area
- Natural fires ter forest grounds
- More evaporation of water from oceans and water bods
- Melting of Ice caps te Arctic and Antarctic regions
- More cloud formation ter the atmosphere
- Shorter and warmer winters coupled with longer and sexier summers
- Switches ter rainfall pattern
- Rise te sea level
- Flooding and submergence of low lounging coastal areas
- Disruption te farming
- More drought
- Influence on plants, animals and humans
Control and remedial measures:
Some of the remedial and control measures of global heating are listed below:
- Reduction ter consumption of fossil fuels such spil coal and petroleum
- Use of bio-gas plants
- Use of nuclear power plants
- Enhancing forest voorkant
- Use of unleaded petrol te automobiles
- Installation of pollution controlling devices te automobiles (catalytic converter) and industries (Electro Static Precipitators, Bag filters, Humid scrubbers etc)
Climate switch – causes and effects
Climate switch refers to the sum of all statistical weather information of the atmospheric elements, with specified area overheen a long period of time. Climate never remains static but is a dynamic process and switches to a lesser or greater degree. Climate switch is a common deviation from average spil well spil extreme temperatures.
The Earth’s surface and lowest part of the atmosphere have heated up to an average by almost 0.6C during the last 100 years. If the rate climate switch is onveranderlijk, global surface temperatures could be anywhere inbetween 1.Four and Five.8C higher now than te 1999 by 2100. Sea level rise is projected to be inbetween 9 and 88cm by 2100.
- using resources, particularly fossil-fuel-derived energy more efficiently
- reusing and recycling products wherever possible and
- developing renewable forms of energy that are inexhaustible and do not pollute the environment
Causes of climate switch
- Variation of Earth’s orbital characteristics
- Atmospheric doorslag dioxide variations
- Volcanic eruptions and
- Variations te solar output
Effects of climate switch
Climate switch has pronounced effects on every part of the Earth. It affects both living and non living components of most ecosystems on the Earth.
- Mean Sea Level (MSL) is enlargened by around 1.8mm vanaf year.
- Many ecosystems of the world will have to adapt rapidly to the permanently switching global temperatures.
- The rate of species becoming extinct will be enlargened.
- Human health, agriculture, forestry and water resources will be affected.
- Enlargening switch te surface temperatures, switching rates of evapo-transpiration and precipitation (due to climate switch) will influence the hydrological cycle.
- Frequency and power of extreme weather events is enlargened leading to unexpected flooding and drought
- Societies experiencing social, economic and climatic stress will be worst affected and least able to adapt.
The enormous increase te population, due to low death rate (mortality) and high birth rate (natality), is termed spil population explosion. Human population is not enlargening at a uniform rate via the world.
Population increase can be better understood te terms of doubling time. Doubling time is the number of years needed for a population to dual. It varies from about 25 years te developing countries to 100 years ter developed nations.
- Introduction of modern facilities reduces mortality rate and increases natality rate leading to population explosion.
- Increase of life expectancy also a major reason contributing to population explosion
Effect of population explosion or Environmental and Social impacts of growing population
- Poverty: Infant mortality is an indicator of poverty. Te 34 developing countries, more than one ter ten children diegene before they reach the age of five. Te developing countries, people opt for smaller families ter the face of high mortality rate.
- Population explosion leads to environmental degradation.
- Population explosion causes over-exploitation of natural resources leading to shortage of resources for the future generations.
- Many of the renewable resources like forests and grass grounds are also under threat.
- Increase ter population also increases disease, economic inequity and communal wars.
Te order to combat the problem of population explosion, the Government of India introduced the Family Welfare Programme spil an integral part of the overall national policy.
- Slowing down population explosion by reducing fertility and
- Reducing the pressure on the environment due to over-exploitation of natural resources.
Watershed is defined spil the geographic area from which water te a particular stream, lake or estuary originates.It includes entire area of land that drains into the water bod. It is supported from other systems by high points te the area such spil hills or slopes.
Ex: Watershed of a lake would not only include the rivulets coming in the lake but also the land that drains those rivulets and eventually the lake.
Watershed management is a process aimed at protecting and restoring the habitat and water resources of a watershed, incorporating the needs of numerous stakeholders.
The activities of human beings have the following impacts on a watershed:
- Altering water course: The water course is altered by switching the omlijning of the land and adding storm water systems
- Adding pollution sources: The type of pollutant absorbed and carried by the storm water depends on the land use. During the course of storm water impounded ter a parking area might pick-up litter, road salt, motor oil and carry thesis pollutants to a local stream. Ter agricultural fields, the rainwater might wash fertilizers and soil into a stream. Melting of snow might wash fertilizers and pesticides into the lawn of suburban homes.
- Urbanization: Urbanization has impacted local resources ter more ways than one can imagine. It has resulted ter a switch ter the flow and constituents of water flowing into a watershed. Urbanization has switched both the surface and ground water. Urban areas have substituted trees, plants and shrubs with impervious surfaces like roads, roof tops, parking lots and other hard surfaces. Thesis impervious surfaces prevent water to leak into the ground thereby enhancing surface runoff. This leads to enhanced flooding after storms and diminished flow ter rivulets and rivers during dry seasons.
- Scouring of channels: Erosion of stream banks and scouring of channels occurs due to increase te volume. Sediment te eroded stream banks clogs the gills of fish and light needed by aquatic plants. Sediment lodges te stream channels, lakes and reservoirs thereby enlargening flooding and requiring dredging to clear flows or lakes for boating.
Goals of watershed management:
The two main goals of watershed management are listed below:
- Watershed management seeks to preserve the environment and
- Watershed management is applied to make the most cost-effective methods to achieve the above listed objective
Controlling storm water flow
It is essential to control storm-water flow te order to reduce the influence of development of local watershed and aquifers. Storm-water flow can be managed ter both quality and quantity by minimizing the disturbances developed te the natural flow of water. By designing ter alignment with nature, the influence of urbanization can be greatly diminished. Storm-water flow can be managed ter the following ways:
- Minimizing development of impervious surfaces
- Maximizing areas of dense vegetation
- Use of structural storm water management basins
- Reducing the possibility of pollution of storm-water
Among the essential elements for the existence of life, water is rated spil the most significant. Water is a universal solvent and is largely responsible for determining the structure, function and distribution of species te an ecosystem.
The original source of water is precipitation from the atmosphere. Water on earth occurs te all three phases. Spil a liquid, it forms the hydrosphere. Around 75% of the earths surface is covered with hydrosphere.
The total amount of water on the earth’s surface is around 266 x 10E20 kg. Around 97% of water on the Earth is salt water, 2% is locked te polar ice -caps, mountains and glaciers and the remaining 1% is available spil fresh water.
The production, development and efficient management of water resources for beneficial use is called water conservation. Listed below are a few mechanisms of water conservation.
- Rainwater harvesting
- Watershed management
- Construction of storage reservoirs
- Reuse of industrial wastewater and
- Better agricultural practices
Monday, November Four, 2013
Solid waste management – sources, effects and methods of disposition
- URBAN OR MUNICIPAL WASTES
- INDUSTRIAL WASTES and
- HAZARDOUS WASTES
SOURCES OF URBAN WASTES
Urban wastes include the following wastes:
Domestic wastes containing a multitude of materials thrown out from homes
Ex: Food waste, Cloth, Waste paper, Glass bottles, Polythene bags, Waste metals, etc.
Commercial wastes: It includes wastes coming out from shops, markets, hotels, offices, institutions, etc.
Ex: Waste paper, packaging material, cans, bottle, polythene bags, etc.
Construction wastes: It includes wastes of construction materials.
Ex: Wood, Concrete, Debris, etc.
Biomedical wastes: It includes mostly waste organic materials
Ex: Anatomical wastes, Infectious wastes, etc.
Urban wastes are classified into:
Bio-degradable wastes – Those wastes that can be degraded by micro organisms are called bio-degradable wastes
Ex: Food, vegetables, tea leaves, dry leaves, etc.
Non-biodegradable wastes: Urban solid waste materials that cannot be degraded by micro organisms are called non-biodegradable wastes.
Ex: Polythene bags, scrap materials, glass bottles, etc.
The main source of industrial wastes are chemical industries, metal and mineral processing industries.
Nuclear plants: It generated radioactive wastes
Thermal power plants: It produces fly ash te large quantities
Chemical Industries: It produces large quantities of hazardous and toxic materials.
Other industries: Other industries produce packing materials, rubbish, organic wastes, acid, alkali, scrap metals, rubber, plastic, paper, glass, wood, oils, paints, dyes, etc.
- Due to improper disposition of municipal solid waste on the roads and instant surroundings, biodegradable materials go through decomposition producing foul smell and become a breeding ground for disease vectors.
- Industrial solid wastes are the source for toxic metals and hazardous wastes that affect soil characteristics and productivity of soils when they are dumped on the soil
- Toxic substances may percolate into the ground and contaminate the groundwater.
- Searing of industrial or domestic wastes (cans, pesticides, plastics, radioactive materials and batteries) produce furans, dioxins and polychlorinated biphenyls that are harmful to human beings.
Solid waste management involves waste generation, mode of collection, transportation, segregation of wastes and disposition mechanisms.
Two significant steps involved ter solid waste management are:
Reduce, Reuse and Recycle of Raw Materials
Reuse – Refillable containers that are discarded after use can be reused
Rubber rings can be made from discarded cucle tubes and this reduces waste generation during manufacture of rubber bands.
Recycle– Recycling is the reprocessing of discarded materials into fresh useful products
Ex: Old aluminium cans and glass bottles are melted and recast into fresh cans and bottles
Prep of plantecelwandstof insulation from paper
Prep of automobile assets and construction material from stengel cans
This method (Reduce, Reuse &, Recycle), i.e, 3R’s help save money, energy, raw materials and reduces pollution.
The following methods are adopted for discarding wastes:
- Incineration and
LANDFILL:Solid wastes are placed ter a sanitary landfill te which alternate layers of 80 cm thick reject is covered with selected earth-fill of 20 cm thickness. After 2-3 years solid waste volume shrinks by 25-30% and land is used for parks, roads and petite buildings. This is the most common and cheapest cheapest method of waste disposition and is mostly employed te Indian cities.
It is ordinary and economical
Segregation of wastes is not required
Landfilled areas can be reclaimed and used for other purposes
Converts low-lying, marshy waste-land into useful areas.
Natural resources are returned to soil and recycled.
Large area is required
Land availability is away from the town, tansportation costs are high
Leads to bad odour if landfill is not decently managed.
Land packed areas will be sources of mosquitoes and flies requiring application of insecticides and pesticides at regular intervals.
Causes fire hazard due to formation of methane te moist weather.
It is a hygenic way of disposing solid waste. It is suitable if waste contains more hazardous material and organic content. It is a thermal process and very effective for detoxification of all combustible pathogens. It is expensive when compared to composting or land-filling.
Te this method municipal solid wastes are burnt ter a furnace called incinerator. Combustibe substances such spil rubbish, garbage, dead organisms and non-combustibe matter such spil glass, porcelain and metals are separated before feeding to incinerators. The non-combustible materials can be left out for recycling and reuse. The leftover ashes and clinkers may account for about Ten to 20% which need further disposition by sanitary landfill or some other means.
Residue is only 20-25% of the original and can be used spil clinker after treatment
Requires very little space
Cost of transportation is not high if the incinerator is located within city thresholds
Safest from hygenic point of view
An incinerator plant of 3000 tonnes vanaf day capacity can generate 3MW of power.
Its capital and operating cost is high
Operation needs skilled personnel
Formation of smoke, dust and ashes needs further disposition and that may cause air pollution.
It is another popular method practiced ter many cities te our country. Ter this method, bulk organic waste is converted into fertilizer by biological activity.
Separated compostible waste is dumped te underground trenches te layers of 1.5m and ultimately covered with earth of 20cm and left for decomposition. Sometimes, actinomycetes are introduced for active decomposition. Within Two to Trio days biological activity starts. Organic matter is ruined by actinomycetes and loterijlot of warmth is liberated enlargening the temperature of teelaarde by 75C and the deny is ultimately converted into powdery brown coloured odourless mass called humus that has a fertilizing value and can be used te agriculture. Humus contains lotsbestemming of Nitrogen essential for plant growth chic from phosphates and other minerals.
Manure added to soil increases water retention and ion-exchange capacity of soil.
This method can be used to treat several industrial solid wastes.
Manure can be sold thereby reducing cost of disposing wastes
Recycling can be done
Non-consumables have to be disposed separately
The technology has not caught-up with the farmers and hence does not have an assured market.
Thermal pollution – causes, effects and control measures of thermal pollution
Thermal pollution is defined spil the addition of excess of undesirable warmth to water thereby making it harmful to man, animal or aquatic life. Thermal pollution may also cause significant departures from strafgevangenis activities of aquatic communities.
The following sources contribute to thermal pollution.
- Nuclear power plants
- Coal fired plants
- Industrial effluents
- Domestic sewage
- Hydro-electric power
- Nuclear power plants: Nuclear power plants including ontwatering from hospitals, research institutions, nuclear experiments and explosions, discharge a loterijlot of warmth that is not utilized along with traces of toxic radio nuclides into nearby water rivulets. Emissions from nuclear reactors and processing installations are also responsible for enlargening the temperatures of water figures. The operations of power reactors and nuclear fuel processing units constitutes the major contributor of fever ter the aquatic environment. Heated effluents from power plants are discharged at Ten C higher than the receiving waters that affects the aquatic flora and fauna.
- Coal-fired power plants: Coal fired power plants constitute a major source of thermal pollution. The condenser coils ter such plants are cooled with water from nearby lakes or rivers. The resulting heated water is discharged into rivulets thereby raising the water temperature by 15C. Heated effluent decreases the dissolved content of water resulting te death of fish and other aquatic organisms. The unexpected fluctuation of temperature also leads to “thermal shock” killing aquatic life that have become acclimatized to living ter a sustained temperature.
- Industrial effluents: Industries like textile, paper, pulp and sugar manufacturing release phat amounts of cooling water along with effluents into nearby natural water figures. The waters polluted by unexpected and strong organic explosions result ter severe druppel ter levels of dissolved oxygen leading to death of several aquatic organisms.
- Domestic Sewage: Domestic sewage is discharged into rivers, lakes, canals or flows with minimal treatment or without any treatment. Thesis wastes have a higher organic temperature and organic blast. This leads to decrease ter dissolved oxygen content te the receiving waters resulting ter the set-up of anaerobic conditions causing release of foul and offensive gases te water. Eventually, this leads to development of anoxic conditions resulting ter rapid death of aquatic organisms.
- Hydro-electric power: Generation of hydroelectric power sometimes leads to negative thermal loading ter water systems. Bijzonder from electrified power industries, various factories with cooling requirement contribute to thermal loading.
Thermal pollution ter flows by human activities
- Industries and power plants use water to cool machinery and discharge the warm water into a stream
- Stream temperature rises when trees and tall vegetation providing shade are cut.
- Soil erosion caused due to construction also leads to thermal pollution
- Removal of stream side vegetation
- Poor farming Practices also lead to thermal polloution
Effects of Thermal pollution
- Reduction te dissolved oxygen: Concentration of Dissolved Oxygen (DO) decreases with increase te temperature.
- Increase te toxicity: The rising temperature increases the toxicity of the poison present ter water. A 10C increase te temperature of water doubles the toxicity effect of potassium cyanide, while 80C rise ter temperature triples the toxic effects of o-xylene causing massive mortality to fish.
- Interference ter biological activity: Temperature is considered to be of vital significance to physiology, metabolism and biochemical processes that control respiratory rates, digestion, excretion, and overall development of aquatic organisms. Temperature switches cause total disruption to the entire ecosystem.
- Interference te reproduction: Ter fishes, several activities like nest building, spawning,hatching, migration and reproduction depend on optimum temperature.
- Ongezouten mortality: Thermal pollution is directly responsible for mortality of aquatic organisms. Increase te temperature of water leads to exhaustion of microorganisms thereby shortening the life span of fish. Above a certain temperature, fish diegene due to failure of respiratory system and jumpy system failure.
- Food storage for fish: Ineens switches te temperature alters the seasonal variation ter the type and abundance of lower organisms leading to shortage of right food for fish at the right time.
Control measures for thermal pollution
The following methods can be adapted to control high temperature caused by thermal discharges:
- Cooling towers: Use of water from water systems for cooling systems for cooling purposes, with subsequent comeback to the water way after passage through a condenser, is called cooling process. Cooling towers transfer fever from hot water to the atmosphere by evaporation. Cooling towers are of two types:
(i) Moist cooling tower: Hot water coming out from the condenser (reactor) is permitted to squirt overheen baffles. Cool air, with high velocity, is passed from sides, which takes away the warmth and cools the water.
(ii) Dry cooling tower: Here, hot water is permitted to flow ter long spiral pipes. Cool air with the help of a fan is passed overheen thesis hot pipes, which cools down hot water. This cool water can be recycled.