WATER :
Today water resources have been the most exploited natural systems since man strode earth.
Pollution of water bodies is increasing steadily due to population growth, industrial proliferations, urbanization, increasing living standards and spheres of human activities.
Water pollutants are characterised as follows:
1) Oxygen Demanding Wastes
Dissolved oxygen is a fundamental requirement for the maintenance of life of all living organisms in water. A water body is said to be polluted when the Dissolved Oxygen (DO) level fall below a certain minimal concentration necessary for sustaining a normal biota for that water, oxygen demanding substances can remove large amount of DO from water, causing changes in their flora and fauna. Biodegradable organic waste demands certain amount of DO for its oxidative biodegradation.
This process is biological process in nature. Therefore, this demand for DO is expressed as Biochemical Oxygen Demand (BOD).
It is necessary, therefore, that any waste water either sewage or industrial effluent should be reduce its BOD of the organic waste load below certain permissible level before it is discharged into a surface water body for its disposal.
Sources of high BOD waste water include municipal sewage and effluents from industries such as Pulp and Paper, Tanneries, Dairies, Sugar and some Chemical manufacturing plants.
2) Disease Causing Agents or Pathogens
Pathogens are disease producing organism, which grow and multiply within the body host. Pathogens associated with water include the following:
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Bacteria: They are responsible for Cholera, Bacillary Dysentery, Typhoid and Paratyphoid fever etc. |
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Viruses: They are responsible for infectious Hepatitis, Polio etc. |
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Protozoa: They are responsible for Amoebic Dysentery. |
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Helminths or Parasitic Worms: They cause diseases such as Schisomiasis and Dracontiasis. These diseases are generally due to faecal
contamination and generally caused by discharging raw sewage in surface water bodies for its disposal. |
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3) Plant Nutrients
Nitrogen as NO 3ˉ and Phosphorous as PO 4ˉˉ are the two important plant nutrients, which cause water pollution in surface water bodies like lakes, reservoir and sluggish rivers.
These plant nutrients find there way into the surface water body by discharge of sewage which contains 1.5% to 2% of N and P compounds. The surface run-offs from animal farms such as Dairies, Pigsties, Poultries etc. also carry plant nutrients to surface water body. Run-offs from agricultural land carried leached nitrates and phosphates from the fertilizers used.
4) Dissolved Inorganic Chemicals and Mineral Substances
This category includes acids, alkalies, ammonia and ionic species such as Clˉ, Fˉ, Sˉ, PO 4 2ˉ, NO 3ˉ, SO 3 2ˉ, SO 4 2ˉ, CNˉ, NH 4 +, Na +, Ca 2+, Mg 2+, Fe 2+, and Cr 3+ etc. These originate from industries such as Tanneries, Metal Finishing and Electroplating industry and large no. of Chemical processes industry including Fertilizer industry. The metals may not be present as simple ions, but in the complex form with different inorganic and organic ligands. Most of these substances are proved to be toxic to different extent to man, animals and vegetations.
5) Dissolved Synthetic Organic Compounds
The organic pollution is mainly due to suspended organic substances and dissolved organic substances.
Organic pollutants enter into water system through domestic sewage, industrial waste from Paper Mills and Tanneries, waste from Slaughter House, Meat Packing Plants, Food Processing Plant, plant nutrients, detergents, biocides, run-off from crop lands and decomposition products of organic compounds. The addition of carbohydrates, fatty acids, proteins, soaps, detergents and oils cause organic pollution of water.
6) Hydrocarbons
Hydrocarbons are those arising due to spillage while considering oil pollution.
7) Suspended Solids and Sediments
Suspended solids in water may be inorganic or organic components present in sewage and most of the industrial waste water. Waste from sand washing, stone quarrying works, china and clay works, acid mines and Paper and Pulp industries contain primary inorganic suspended solids, which are added to running streams. Sewage and coal washery effluent contain organic suspended matter.
Soil erosion by natural process gives rise to sediment pollution in water. Sediments are soil and mineral particles, are washed away from the land by floodwater. An estimate indicates that suspended soil loading entering natural waters are about 700 times as large as the soil loadings from sewage discharge. Sediments are depositions of traces of elements or metals such as; Sb, Hg, Cd, Cu, Cr, Co, Pb, Mn etc.
8) Waste Heat
Water gets polluted when hot effluent, hot air and hot water are added to water systems. Coal Fired Power Plants, Electric Power, Steel and Chemical industries as well as Atomic Energy Plants discharge their heated effluents into nearby lakes or rivers. This process increases the temperature of the water by 10ºC to 15ºC. A single 100 MW Power plant may use one half million gallons cooling water per minutes.
The various standards have been provided by Indian Standard Institution, Indian Council of Medical Research, Central Public Health Engineering Research Organization and Department of Environment (DOEN). In case Indian Standards are not available for any particular parameter then standards provided by World Health Organization (WHO) shall be used.
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Table : General Standards for Discharge of Environment Pollutants :
Effluent(Gazette Notification of MoEF, May 1993)
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S. No. |
Parameter |
Inland
surface water |
Public sewers |
Land
for irrigation |
Marine/coastal areas |
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(a) |
(b) |
(c) |
(d) |
1. |
Suspended solids
mg/l, max. |
100 |
600 |
200 |
(a) For process waste water
(b) For cooling water effluent 10 per cent above total suspended matter of influent. |
3 |
Particle size of
suspended solids |
shall pass 850 micron IS Sieve |
- |
- |
(a) Floatable solids, solids max. 3 mm
(b) Settleable solids, max 856 microns |
4 |
pH value |
5.5 to 9.0 |
5.5 to 9.0 |
5.5 to 9.0 |
5.5 to 9.0 |
5 |
Temperature |
shall not exceed 5°C above the receiving water temperature |
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shall not exceed 5°C above the receiving water temperature |
6 |
Oil and grease,
mg/l max, |
10 |
20 |
10 |
20 |
7 |
Total residual
chlorine, mg/l
max |
1.0 |
- |
- |
1.0 |
8 |
Ammonical nitrogen (as
N),mg/l, max. |
50 |
50 |
- |
50 |
9 |
Total kjeldahl nitrogen (as
N);mg/l, max.
mg/l, max. |
100 |
- |
- |
100 |
10 |
Free ammonia (as NH3),
mg/l,max. |
5.0 |
- |
- |
5.0 |
11 |
Biochemical oxygen demand (3 days at
27°C), mg/l,
max. |
30 |
350 |
100 |
100 |
12 |
Chemical oxygen demand, mg/l,
max. |
250 |
- |
- |
250 |
13 |
Arsenic(as As). |
0.2 |
0.2 |
0.2 |
0.2 |
14 |
Mercury (As
Hg), mg/l, max. |
0.01 |
0.01 |
- |
0.01 |
15 |
Lead (as Pb)
mg/l, max |
0.1 |
1.0 |
- |
2.0 |
16 |
Cadmium
(as Cd)mg/l,
max |
2.0 |
1.0 |
- |
2.0 |
17 |
Hexavalent chro-mium (as
Cr + 6),mg/l,
max. |
0.1 |
2.0 |
- |
1.0 |
18 |
Total chromium
(as Cr) mg/l,
max. |
2.0 |
2.0 |
- |
2.0 |
19 |
Copper (as
Cu)mg/l, max. |
3.0 |
3.0 |
- |
3.0 |
20 |
Zinc (as Zn)
mg/l, max. |
5.0 |
15 |
- |
15 |
21 |
Selenium (as
Se) |
0.05 |
0.05 |
- |
0.05 |
22 |
Nickel (as Ni)
mg/l, max. |
3.0 |
3.0 |
- |
5.0 |
23 |
Cyanide (as CN)
mg/l, max. |
0.2 |
2.0 |
0.2 |
0.2 |
24 |
Fluoride (as F)
mg/l, max. |
2.0 |
15 |
- |
15 |
25 |
Dissolved phos- phates (as
P)
,
mg/l, max. |
5.0 |
- |
- |
- |
26 |
Sulphide (as S)
mg/l, max. |
2.0 |
- |
- |
5.0 |
27 |
Phenolic compounds
(as 6H50H)mg/l, max. |
1.0 |
5.0 |
- |
5.0 |
28 |
Radioactive materials:
(a)Alpha mitters
microcurie mg/l, max.
(b)Beta
emittersmicro curie mg/l |
10 -7
10 -6 |
10 -7
10 -6 |
10 -8
10 -7 |
10 -7
10 -6 |
29 |
Bio-assay test |
90% suivival of fish after 96 hours in 100% effluent |
90% suivival of fish after 96 hours in 100% effluen |
90% suivival of fish after 96 hours in 100% effluen |
90% suivival of
fish after 96 hours
in 100% effluen |
30 |
Manganese |
2 mg/l |
2 mg/l |
- |
2 mg/l |
31 |
Iron (as Fe) |
3mg/l |
3mg/l |
- |
3mg/l |
32 |
Vanadium
(as V)
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0.2mg/l |
0.2mg/l |
- |
0.2mg/l |
33 |
Nitrate Nitrogen |
10 mg/l |
- |
- |
20 mg/l |
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Air Quality
A comprehensive status viz. Air (Prevention and Control of Pollution) Act is promulgated in India 1981. Its corresponding Statement of object and reasons have provided an insight of the driving force viz.
"With the increasing industrialization and the tendency of majority of industries to congregate in areas which are already heavily industrialized, the problem of air pollution has begun to be felt in the country. The problem is more acute in those heavily industrialized areas which are also densely populated."
Air pollution is a chemical, particulate matter, or biological agent that modifies the natural characteristics of the atmosphere. The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.
Worldwide air pollution is responsible for large numbers of deaths and cases of respiratory disease. While major stationary sources are often identified with air pollution, the greatest source of emissions is actually mobile sources, mainly automobiles. Gases such as carbon dioxide contribute to global warming. |
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Table 1: National Ambient Air Quality Standards |
Pollutants |
Time Weighted Average |
Concentration in Ambient Air |
Industrial Areas |
Residential, Rural & Other Areas |
Sensitive Areas |
Sulphur Dioxide (SO 2) |
Annual Average |
80 µg/m 3 |
60 µg/m 3 |
15 µg/m 3 |
24 hours |
120 µg/m 3 |
80 µg/m 3 |
30 µg/m 3 |
Oxides of
Nitrogen as NO x |
Annual Average |
80 µg/m 3 |
60 µg/m 3 |
15 µg/m 3 |
24 hours |
120 µg/m 3 |
80 µg/m 3 |
30 µg/m 3 |
Suspended Particulate
Matter (SPM) |
Annual Average |
360 µg/m 3 |
140 µg/m 3 |
70 µg/m 3 |
24 hours |
500 µg/m 3 |
200 µg/m 3 |
100 µg/m 3 |
Respirable Particulate
Matter (RPM)
(size less than 10
microns) |
Annual Average |
120 µg/m 3 |
60 µg/m 3 |
50 µg/m 3 |
24 hours |
150 µg/m 3 |
100 µg/m 3 |
75 µg/m 3 |
Carbon Monoxide (CO) |
8 hours |
5.0 mg/m 3 |
2.0 mg/m 3 |
1.0 mg/ m 3 |
1 hour |
10.0 mg/m 3 |
4.0 mg/m 3 |
2.0 mg/m 3 |
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| Central Pollution Control Board has specified the air quality criteria, which is given in Table 2. |
S. No. |
Air Quality |
Pollution Concentration |
1. |
Low |
If less than half of the notified standards |
2. |
Moderate |
If between half of the notified standards and the value of standards |
3. |
High |
If between the value of standards and 1.5 times the value of standards |
4. |
Critical |
If greater than the 1.5 times the value of the standards |
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Noise pollution
It is a displeasing human or machine created sound that disrupts the environment. The overarching source of most noise worldwide is generated by transportation systems, principally motor vehicle noise, but also including aircraft noise and rail noise. Besides transportation noise, other prominent sources are office equipment, factory machinery, appliances, power tools, and audio entertainment systems. For instance, noise pollution can cause annoyance and aggression, hypertension, high stress levels, hearing loss, and other harmful effects depending on the level of sound, or how loud it is. Furthermore, stress and hypertension are the leading causes to health problems, it may also lead to forgetfulness, severe depression and at times panic attacks. |
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Table: Ambient Noise Level Standards Specified by Ministry of Environment & Forest |
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Category of Area |
LIMITS (dB) |
Day Time |
Night Time |
Industrial Area
Commercial Area
Residential Area
Silence Zone |
75
65
55
50 |
70
55
45
40 |
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Hazardous waste
Hazardous wasteis a waste that poses substantial or potential threats to public health or the environment and generally exhibits one or more of these characteristics: |
- Ignitable (i.e. flammable)
- oxidizing
- corrosivity
- toxic
- radioactive
- eco-toxic
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| Bio-Medical Waste generated primarily from health care establishments is a relatively recent issue and there are a lot gaps in information. The management of bio-medical waste is still in its infancy all over the world. Bio-medical waste is generated from health care establishments, and also institutions such as blood banks, laboratories and research institutes. |
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| Categories of Bio-medical Waste |
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Option
(1) |
Water Category
(2) |
Treatment & Disposal
(3) |
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Category No. 1 |
Human Anatomical Waste
(human tissues, organs, body parts) |
incineration@/deep burial* |
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Category No. 2 |
Animal Waste
(animal tissues, organs, body parts carcasses, bleeding parts, fluid, blood and experimental animals used in research, waste generated by veterinary hospital colleges, discharge from hospitals, animal house). |
incineration@/deep burial* |
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Category No. 3 |
Microbiology & Biotechnology Waste
(Waste from laboratory cultures, stocks, or specimens of micro-organisms live or attenuated vaccines, human and animal cell culture used in research and infectious agents from research and industrial laboratories, wastes from production of bio-logicals, toxins, dishes and devices used for transfer of cultures) |
local autoclaving/microwaving/
incineration@ |
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Category No. 4 |
Waste sharps
(needles, syringes, scalpels, blades, glass, etc. that may cause puncture and cuts. This includes both used and unused sharps) |
disinfection (2chemical treatment@@/autoclaving/
micro-waving and multilation/
shredding |
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Category No. 5 |
Discarded Medicines and Cytotoxic drugs
(Wastes comprising of outdated, contaminated and discarded medicines). |
incineration@/destruction and drugs disposal in
secured landfills |
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Category No. 6 |
Solid Waste
(Items contaminated with blood and body fluids including cotton, dressings, soiled plaster casts, lines, beddings, other material contaminated with blood) |
incineration@/autoclaving/
microwaving |
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Category No. 7 |
Solid Waste
(Wastes generated from disposable items other than the waste shaprs such as tubbings, catheters, intravenous sets etc). |
disinfection by chemical treatment@@/autoclaving/
microwaving and multilation/shredding## |
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Category No. 8 |
Liquid Waste
(Waste generated from laboratory andwashing, cleaning, housekeeping and disinfecting activities) discharge into drains. |
disinfection by chemical treatment @@ and discharge into drains |
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Category No. 9 |
Incineration Ash
(ash from incineration of an bio-medical waste) |
disposal in municipal land fill |
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Category No. 10 |
Chemical Waste
(Chemicals used in production of biologicals, chemicals used in disinfection, as insecticides etc.) |
Chemical treatment @@ and discharge into drains for liquids and secured land fill for solids. |
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Chemicals treatment using at least1% hypochlorite solution or any other equivalent chemicals reagent. It must be ensured that chemical treatment ensures disinfection. |
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Multilation/shredding must be such so as to prevent unauthorised reuse. |
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There will be no chemical pretreatment before incineration. Chlorinated plastics shall not be incinerated. |
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Deep burial shall be an option available only in towns with population less than five lakhs and in rural areas. |
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