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Excessive nutrients result in excessive algal growth or eutrophication in the water body. Thus, the water quality becomes poor as the oxygen level decreases.

• They may be inhaled deep into the – lungs and cause breathing and respiratory problems.
• Irritation of lungs.
• Inflammation of lungs.
• Premature death.

1. Yes.

2. Higher BOD lower the D.O. content of water. D.O. is the dissolved 02 content of water. When organic content is increased in water the D.O. is consumed for its oxidation by bacteria which is referred as BOD (Biochemical Oxygen demand) when B.O.D. is greater the D.O. becomes low.

Electrode wire at thousand volts, produce corona to release electrons, electrons attach to dust particules giving them net negative charge, charged dust particules attracted/collected by collecting plates which are grounded. 

Economical procedure as recycling takes place. 

Waste not accumulated but recycled Efficiency and utilization of resources increased Does not lead to eutrophication.

In a coal-red power plant, electrostatic precipitators are installed to control emission of SPM

1. BOD – Biochemical Oxygen Demand

2. Polluted water contains microorganisms they consume lot of oxygen from water for the bio degradation of organic material that Causes sharp decline in dissolved oxygen.

1. Bio magnification. Bio magnification refers to increase in concentration of the toxicant at successive trophic levels.

2. Non biodegradable toxic substance accumulated by an organism cannot be metabolised or excreted and it is passed to the next higher trophic level.

• As the sewage is discharged into water bodies, there is an increase in the biodegradable organic matter.
• The micro organisms multiply fast with the increase in organic matter, which Is used as its substrate for them.
• These microbes consume a lot of oxygen and there is a sharp decline in the dissolved oxygen content of the water body, this leads to fish mortality.

(b) particulate matter

1. CNG is compressed natural gas.

2. advantages of CNG:

• CNG is better than diesel
• It burns most efficiently
• CNG is cheaper than petrol or diesel
• It cannot be adulterated like petrol or diesel.

A sustainable system for handling human excreta, using dry composting toilets. Practical, Hygienic, efficient and cost-effective solution to human waste disposal Human excreta can be Recycled into manure Used in Kerala and Sri Lanka.

It is sustainable system for handling human excreta without using water but by composting Method. 

Advantages :

Hygienic, practical and efficient, Conserves water can be recycled and, Acts as a natural fertilizer. 

CNG is compressed natural gas. It burns more efficiently than Petrol and diesel, thus brings down the amount of pollutants from automobiles (unburnt hydrocarbons).

CNG is cheaper than petrol or diesel. It cannot be siphoned out by thieves and adultered like petrol or diesel.

The problem in using CNG as fuel is the difficulty of laying down pipelines to deliver CNG through distribution points.

• This allows maximum utilization of resources.
• It increases the efficiency of production.
• There is no need for chemical fertilizers for crops, as cattle excreta, can be used as manures.
• Crop wastes are also decomposed and used as manures.
• Cattle dung and crop wastes are used to generate bio gas, that is used for cooking and lighting.

• Biodegradable:

These are the waste which can be broken down into simpler harmless substances by the activity of decomposers. These substance are used as manures.

• Non-biodegradable: 

The substances which cannot be broken down into simpler substances by microbes and they start accumulating in the biosphere.
This causes pollution and can lead to bio magnification.

(b) air pollution

• Ecological sanitation is a subtain able system for handling human excreta, using dry composition toilets.
• This is a practical, hygienic, efficient and cost effective solution to human waste disposal.
• In this method, human excreta an be recycled into manures that reduce the need for chemical fertilizers.
• There are working ecosans in Kerala and Sri lanka.

Major pollutant present in automobile exhaust is CO

1. Active chlorine

2. Dob son (Du)

3. Two diseases affects men due to ozone depletion: 

• snow blindness
• cataract

1. Ozone is found in the stratosphere It acts as shield by absorbing UV radiation from the sun. UV rays are injurious to living organisms since DNA & proteins of living organism are affected by UV rays. The refrigerators use CFC.

The CFC’s discharged into the atmosphere it reaches the stratosphere. In stratosphere UV rays act on them releasing chlorine atom. Chlorine degrade ozone and releasing molecular oxygen. As the chlorine atom are not consumed in this reaction they remain in the stratosphere & will have permanent & continuing effect on ozone level.

2. Recognizing the deleterious effects of ozone depletion an international treaty known as Montreal Protocol was signed at Montreal(canada) in 1987 & is effective from 1989. This protocol emphasizes to control the emission of ozone depleting substances.

Answer is (d) -150 c

About 150 liters of wastewater at an average is generated by an Indian individual daily, and a large amount of it is generated from toilets. Ecological sanitation (EcoSan) is a sustainable system for handling human excreta by using dry composting toilets. EcoSan toilets not only v reduce wastewater generation but also generate the natural fertiliser from recycled human .excreta, which forms an excellent substitute for chemical fertilisers. This method is based on the principle of recovery and recycling of nutrients from excreta to create a valuable supply for agriculture. ‘EcoSan’ toilets are being used in several parts of India and Sri Lanka.

1. Algal bloom:

Excessive growth of planktonic algae due to the presence of large amount of nutrients in water.

2. Eutrophication:

Natural aging of a lake by nutrient enrichment of its water.

1. CNG -Compressed Natural Gas

2. Air pollution can be controlled by using lead free petrol & by using catalytic converters. The catalytic converters convert unburned hydro carbons into CO₂ , H₂O, CO & nitric oxide are converted to CO₂ & N₂ gas.

3. CPCB (Central pollution control board).

1. Scrubber

2. CPCB (Central pollution control board)

Use of catalytic converter.

Use of lead-free petrol or diesel.

Merits of CNG 

(1) It burns most efficiently, 

(2) It is cheaper than petrol or diesel, cannot be siphoned off by thieves and adulterated like petrol or diesel.

Demerits of CNG

It is difficult of laying down pipelines to deliver CNG through distribution points/pumps and ensuring uninterrupted supply.

(d) none of the above

Chlonofluoro carbons.

1. The refrigerators emit CFC (Chloro flora carbon). 

2. The CFC’s discharged into the atmosphere reaches the stratosphere. In stratosphere UV rays act on them releasing chlorine atom, chlorine Degrade ozone releasing molecular oxygen. As the chlorine atom are not consumed in this reaction they remain in the stratosphere and have permanent and continuing effect on ozone level.

3. Montreal protocol and Kyoto protocol.

1. greenhouse gases 1,2 and write their percentage of contribution to total global warming:

• CO₂ – 60%
• CFCs 14%

2. four measures to control global warming: 

• Cutting down use of fossil fuel
• Improving efficiency of energy usage 
• Reducing deforestation
• Planting trees

(b) Automobile exhausts and chemicals from industry

Scrubber: A Scrubber can remove gases like sulphur dioxide.

It is Hygienic efficient, cost effective and human excreta can be recycled into a natural fertilizer.

Amrita Devi Bishnoi Wildlife Protection Award.

1. Joint Forest Management.

2. Participation by local communities for protecting and managing forest and these communities get benefit of various forest products.

In 1980s Government of India has introduced the concept of Joint Forest Management (JFM).

(d) All of these

Irrepairable computers and other electronic wastes. 

Recycling in developing countries involves manual participation thus exposing workers to toxic substances. In developed countries its mechanised so less dangerous.

Catalysts : platinum - palladium and Rhodium 

Motor vehicles equipped with catalytic converters should use unleaded petrol as lead inactivates the catalysts.

1. Banagudi Shola 

2. Thirukurungudi 

3. Udaiyankudikadu 

4. Sittannavasal

Two sources of e-wastes are : 

(i) Televisions 

(ii) Computers 

They can be disposed by : 

(i) Land filling : Soil is excavated from the trenches and waste material is buried in it, which is covered by a thick layer of soil. 

(ii) Recycling : Recycling is the practice of reusing items that would otherwise be discarded as waste.

Discarded unusable electronic gadgets such as computers, mobile phones, circuits, television sets, etc., form electronic waste. These contain harmful toxic substances like heavy metals to which the unskilled manual workers are directly exposed.

1. Sanitary land fills.

2. The Solid wastes can be categorised into 3 types 

• bio degradable 
• Recyclable 
• non-biodegradable.

The biodegradable waste material can be disposed in deep pits for natural break down. Recycling of material is made easy by the separation done by rag pickers.

Non-biodegradable waste should reduced by using eco-friendly packaging & natural fiber carry bags. State government can play important role by applying laws for reducing the use of plastics.

Methyl isocyanate (MIC) and phosgene.

Water pollution can be defined in many ways. Usually, it means one or more substances have built up in water to such an extent that they cause problems for animals or people. Oceans, lakes, rivers, and other inland waters can naturally clean up a certain amount of pollution by dispersing it harmlessly. If you poured a cup of black ink into a river, the ink would quickly disappear into the river's much larger volume of clean water. The ink would still be there in the river, but in such a low concentration that you would not be able to see it. At such low levels, the chemicals in the ink probably would not present any real problem.

Domestic sewage and industrial effluents:

• A mere 0.1 percent impurities make domestic sewage unfit for human use 
• Sewage contains dissolve salts like nitrates, phosphates, and other nutrients, and toxic metal ions and organic compounds. 
• The amount of organic matter in water is estimated by BOD
• Biochemical oxygen demand: the amount of Oxygen required oxidizing all organic matter present in one liter of water.

Changes take place on discharge of sewage into the river. 

• Micro-organism involved in biodegradation of organic matter in the receiving water body consume a lot of oxygen, hence there is sharp decline in dissolved oxygen downstream from the point of discharge.
• Due to low DO there is mortality of fish and other aquatic animals.

(c) R explains A.

(b) Dobson units

(d) R explains A