2. Unit I
Types of emissions from chemical industries
and effects of environment
Types of pollution
Environment Legislation
Sources of waste water
Effluent guidelines and standards
7. Inputs and Outputs in Environmental Systems
ACTIVITY
industry, agriculture,
urbanization, mining etc.
Recovery
Raw Material
Energy
Product, Service
By Product
Non-product
output
Hazardous
Waste
Reuse
Waste
Solid
Waste
Air
Emission
Radioactive
Waste
Wastewater Noise Hospital
Waste
11. GASEOUS EMISSION
Most of our cities are highly polluted.
City areas with more than 100 tons of SO2
emission/day, endanger the health of the population.
Due to the diurnal variation of SO2 and other pollutants
in Mumbai, pollution levels are higher during the night,
reaching a maximum before sunrise.
Effect of air pollution on human health (e.g. bronchitis,
asthma), flora and fauna.
12. Some Polluting Process
Industries
Sulfuric Acid Plants
Nitric Acid Plants
Cement Plants
Foundaries
Plastic Industries
Thermal Power
Stations
13. Industrialization and population growth - large
quantities of industrial wastes & sewage and
disposal into either the natural water bodies/air.
Continuous deterioration of the quality of air and
water
Beyond self-assimilation capacity - failed to restore
the original purity of the air and water.
Inadequate infrastructure for sewage collection
and treatment.
LIQUID EMISSION
14. Industrial effluents contain a variety of chemicals,
often very toxic.
These chemicals can be recovered if their
concentration in the waste is fairly high.
Specific treatment methods are required for each
type of industrial waste.
Biological-oxidation methods have their
limitations and should be applied very carefully
when toxic chemicals are present.
15.
16. Effects on Environment
1. Damage to human health by specific chemical substances
present in the air, food, water and radioactive material
2. Damage to natural environment affecting vegetation,
animals, crops, soil and water
3. Damage to visual quality by smoke, fumes, dust, noise and
waste
4. Damage by radioactive materials and excessive noise
17. Broadly, environmental pollution comprises:
(a) water pollution
(b) air pollution
(c) land pollution and
(d) noise pollution
TYPES OF POLLUTION
18. Pollution
Introduction of waste matter into the environment,
which directly or indirectly causes damage to man
and his environment.
19. Pollutant
A pollutant is a substance which adversely alters the
environment:
by changing the growth rate of species,
interferes with the food chain,
is toxic,
or interferes with health, comfort amenities or
property values of people.
23. Water Pollution (Inorganic)
Inorganic pollution (due to alkalis, acids, inorganic salts and
other chemicals)
Inorganic chemicals (such as Cl2, NH3, H2S, and other
sulphides, salts of metals like Cr, Ni, Zn, Cd, Cu, Ag, etc. are
usually found in metal-plating liquid wastes, alkali-producing
units, PVC, coke-oven and fertilizer industries.
Industries like paper-and-pulp, tanneries, textiles and coke-
ovens, among many others, discharge these chemicals.
results in corrosion of metals,
toxic to the aquatic life.
26. Pharmaceutical industries also produce large
quantities of free acids and neutralized chemicals
during different unit processes.
Chromates, phosphates, ammonia and urea are
typical chemicals found in effluents from fertilizer
industries.
27. Industrial Sources Responsible for Organic
Pollution
DO conc. at 0°C = 15 ppm
DO conc. at 15°C = 10 ppm
DO conc. at 20°C = 9 ppm
DO conc. at 30°C = 7.5 ppm
28.
29. Water Pollution (Organic)
Due to the presence of high molecular weight
compounds such as sugars, oils and fats, and
proteins
Industries include distillery, sugar and other food-
processing industries.
Impart a high BOD load to the liquid waste.
These compounds are readily degraded in aqueous
medium by micro-organisms present in the sewage
or soil.
30. Dissolved oxygen depletion in the stream adversely
affects the aquatic life.
Oil spillage from tankers and ships leads to the pollution of
beaches.
Presence of phenol - Wastes from pharmaceutical and
petrochemical industries, and coke-ovens - toxic to fish,
microorganisms and other aquatic life.
Liquid effluents from pharmaceutical, dyestuff, pesticide
and detergent manufacturing industries can be toxic.
Anionic detergents are not-biodegradable.
31. Turbidity of waste water is caused by the presence of
colloidal matter which does not settle readily.
(consists of fine clay particles, milk wastes, sewage, free
peroxides formed from iron and other metal salts, ceramic
industries or paper-and-pulp industries)
Turbidity can inhibit the penetration of light, limiting
photosynthesis by micro-organisms and thereby adversely
affecting oxygenation of the water.
Thermal pollution – another form of physical pollution. This
is due to the high temperatures of liquid wastes from
applications such as power stations.
Increase in temperature of the water decreases the
dissolved oxygen.
34. Air Pollution
Air is considered safe when it contains no
harmful dust and gases.
Polluted air affects:
Humans
Animals
Vegetation
Materials
35. Effects of Air Pollution
Global warming
Ozone depletion
(Ozone hole)
Acid Rain
Various respiratory
illnesses
36. Pollution of air
Particulate Matter
Dust (e.g. cement dust, bagasse, foundry dust and wind
blown solid dust): 1-100 μm
Aerosols (<1 μm)
Smoke (0.01-1 μm): Incomplete combustion of organic
matter
Fume: Sublimation, condensation or cracking of high
MW organics at high temp.
Mist: direct contact between
vapour/gas and liquid,
e.g. Cooling towers
Fog: Formed by temperature inversion
Smog: Smoke + fog
40. Air Pollution
Apart from natural causes (wind, cyclones, volcanic
eruptions and forest fires), pollution of air occurs due to
increased industrialization and urbanization.
A healthy man inhales about 16.5 kg air/day. If this air is
polluted, intake of oxygen is reduced.
Corrosion of materials by acid mist and acidic gases like
SO2, CO2 and oxides of nitrogen can be very significant.
The problems of pollution and its control in process
industries such as H2SO4 plants, power-station boilers,
HNO3 plants, cement plants, foundaries, chlor-alkali,
industries and plastics industries are very diverse and need
to be individually tackled.
41. Pollution of air is due to particulate matter (varying sizes)
and gaseous pollutants dispersed in it.
Gaseous pollutants include CO, NOx, SOx, formaldehyde
and VOCs.
Exhaust from a vehicle in a good condition contains 3.5%
CO, going up to 7% when the engine is idling.
42. Land Pollution
Urbanization and Concentration of Population
Municipal Solid Waste
Industrial Waste and Hazardous Waste
Uncontrolled “Land Treatment”.
Burning open dumps and forest fires
Deforestation
Mining and Erosion
43. The majority of land pollution occurs due to urbanization and
concentration of population.
Garbage, waste paper, packing materials and rejects from
households and industries form solid wastes.
These are scattered in different localities and need to be
collected and disposed of.
In India, the per capita production of solid waste is 0.45
kg/day in urban areas and about half that in rural areas.
In spite of the large expenditure of about Rs 70 to 100
crore/year on collection, transport and disposal of solid
wastes in India, the general aesthetics of many places is far
from satisfactory.
44. Land pollution also occurs when:
deforestation is carried out on a large scale,
agricultural operations are extended to forest and
mountainous areas,
large areas covered with green vegetation are submerged in
water by the construction of artificial barrages or dams or
hundreds of millions of tons of coal, oil, ores, stones, sand
and other construction materials are mined and transported.
Erosion of fertile surface layers by floods and ever
increasing silting of canals.
45. Land Pollution Control
Integrated Solid Waste Management (4R)
Good agricultural practices
Remediation of polluted soils
Prevention of erosion and silting
Containment of hazardous waste and waste
water treatment using land treatment techniques.
46. Noise Pollution
Exposure to prolong noise affects speech,
hearing, general health and behaviour.
Noise Levels _ dB
Intensity
frequency
periods of exposure and
duration
47. Intensity (Loudness)
Measure of acoustic
energy of the sound
vibrations
Expressed in terms of
sound pressure.
Decibels (dB) - unit of
measurement on the
Loudness scale
48. Physical Characteristics of Sound
Measurement and human perception of Sound
involves three basic physical characteristics:
Intensity
Frequency
Duration
56. - Provides a legal tool with which activities affecting
the environment are regulated.
-Three approaches that are generally followed:
1. Legislation that are limited in scope and deal with
only one aspect of environmental protection such
as water pollution control, air pollution control, etc.
The law for prevention and control of water
pollution,1974 and prevention and control of air
pollution,1981 by the Indian Parliament.
Environmental legislation
57. Though this is a piecemeal approach towards
environmental protection, yet in a developing country
like India it is a reasonable policy. It is expected that the
stage-by-stage control of pollution in different spheres
would ultimately form parts of a comprehensive policy. A
proper coordination of different activities and the laws
governing them is, however, important.
2. The second approach to environmental protection is
comprehensive and deals with all types of pollution, viz.
water, air, land, noise, etc. The laws based on this have
to be massive and the organizations implementing them
have necessarily to be big ones.
58. 3.The third approach envisages integration of environmental
protection with national development planning. This,
undoubtedly, is the best approach as the environment, as a
whole, is subjected to national planning. Prohibitive and
restrictive measures, in general, become passive in character
with the passage of time. Legislative measures should,
therefore, built in dynamic character and be in a position to
direct the activities of the country so as to prevent them from
becoming detrimental to the environment. The environment,
therefore, is sought to be protected in a large measure by
national plans of economic development.
59. AIR (PREVENTION AND CONTROLOF
POLLUTION) ACT, 1981
Air pollution, under the act, means the presence of
solid, liquid or gaseous substances in the atmosphere in
such concentrations as may or tend to be injurious to
human beings, living creatures, plants, property or
environment.
The functions of the Central Board for the Prevention
and Control of Air pollution, under this act, will be carried
out by the Central Board for Prevention and Control of
Water Pollution constituted under Section 3 of the Water
(Prevention and Control of Pollution) Act, 1974.
60. Similarly the Functions of the State Boards for the Prevention and
Control of Water Pollution will be carried out by the State Boards
for the Prevention and Control of Air Pollution.
The functions of the Central Board are:
1. To advise the central government on any matter concerning
the improvement of the quality of air and the prevention,
control or abatement of air pollution.
2. To plan and cause to be executed a nation-wide
program for the prevention, control or abatement of air
pollution.
3. To coordinate the activities of the State Boards and
resolve disputes between them.
61. 4. To provide technical assistance and guidance to the
State Boards to carry out and sponsor investigations
and research relating to problems of air pollution and
prevention, control or abatement of air pollution.
5. To plan and organize the training of persons engaged,
or to be engaged, in programs for prevention,
control or abatement of air pollution on such terms
and conditions as the Central Board may specify.
6. To organize through mass media a comprehensive
program regarding the prevention, control and
abatement of air pollution.
62. 7. To collect, compile and publish technical and
statistical data relating to air pollution and the measures
devised for its effective prevention, control or abatement
and to prepare manuals, codes or guides relating to
prevention, control or abatement of air pollution.
8. To lay down standards for the quality of air.
9. To collect and disseminate information concerning
matters relating to air pollution.
10. To perform other prescribed functions.
63. For the large number of small sources of air pollution such
as domestic fires, automobile exhausts, small-scale industries,
etc. the approach will have to be different from that adopted
for water pollution control, viz. granting consent, laying down
permissible concentrations, inspection and monitoring, and
launching prosecutions.
One should reduce air pollution from these sources purely
through improved designs of furnaces, engines and collection
systems.
64. Water (Prevention and Control of Pollution) Act, 1974
The Water (Prevention and Control of Pollution) Act deals with
only one aspect of the environment, viz. water, as we do not have
one comprehensive act for control of all types of environmental
pollution.
The object of the law is to control pollution of water and to
maintain and restore, whenever necessary, the wholesomeness of
water.
The purpose of the law is not to restore water to its pristine
quality but to make the best use of water for development
activities and still preserve its wholesomeness for other uses.
The central and state water-pollution-control boards adopted the
following use based classification of waters:
65.
66. No separate classification exists for water used in
industrial processes as its quality requirement varies
from industry to industry.
Of all the uses of water the one for domestic
consumption is of prime importance. Waterborne
diseases such as infectious hepatitis, dysentry, cholera
and typhoid are caused by the contamination of water by
domestic-waste discharges.
The prevention of pollution of drinking-water sources in
India, by the enforcement of suitable preventive
measures, should have the highest priority.
68. The major sources of pollution of fresh and coastal
waters arc the community wastes generated by cities
and towns where the population is more concentrated.
In the Class I cities of India where 10 per cent of the
population of the country lives, about two-thirds of
the country's pollution, responsible for the deterioration
of the water quality of rivers and streams, is generated.
This pollution renders the water unfit for drinking
purposes, especially in villages where the population is
exposed to water-borne diseases. Only about one-third
of the Class I towns have been provided with sewage
treatment facilities. Other towns in India where the
population is relatively smaller, do not, in many cases,
have sewage collection and or treatment facilities.
69. The main reason for this state of affairs is the paucity
of funds with local bodies.
It becomes necessary, therefore, for the state, central
and other funding agencies to provide adequate financial
help to local bodies so the latter can incorporate the
necessary collection, treatment and disposal facilities.
The provision of sewage-treatment facilities in urban
areas and towns has the following distinct advantages.
70. 1. Industrial liquid effluents can be treated at a small
extra cost.
2. Downstream water quality will improve.
3. General sanitary conditions in the towns will improve.
4. Reuse of water can be planned in a big way,
especially for agriculture.
5. Financial help from industries towards operating costs
would be forthcoming.
71. The water pollution control act has provisions only for
controlling pollution caused by industries or
communities.
It provides only for prohibitive and restrictive measures
and does not empower the regulating agencies to
instruct development authorities to reduce pollution.
The regulating agencies are responsible only for
qualitative aspects of pollution, whereas quantitative
aspects are left out.
This gives very restricted scope for the development of
strategies and policies for achieving the objectives of the
act.
72. The water-quality-management objectives can be met by
four general
approaches:
1. Uniform effluent-standards approach.
2. Using assimilative capacity of receiving water
approach
3. Technology-based effluent standards.
4. Minimum national-standards approach.
73. The central board in India has evolved certain
minimum industry-specific effluent standards at the
national level which are designated the 'Minimum
National Standards' (MINAS).
This would envisage certain minimum standards in the
treatment of all wastes regardless of location.
No relaxation will be permitted, but if the quality
criterion at a certain location so warrants, the state
boards can alter the standards.
This approach is expected to be quite useful in halting
the immediate threat of water and air pollution as well as
providing a measure of flexibility to the state Boards in
the control of pollution.
74. For MINAS, the water treatment envisaged should
include the removal of pathogens (by effective
disinfection), toxic materials, mineral oils, dissolved
organic soilds, suspended materials and a proper control
of pH.
