Q.43. What is Waste? Briefly discuss the various criteria for selecting an environmentally safe site for waste disposal. (AKTU. - 2013-14)
Ans. Waste is any material that is not needed by the owner, producer, or processor. Humans, animals, other organisms, and all processes of production and consumption produce waste. It has always been a part of the Earth’s ecosytem, but its nature and scale were such that the ecosystem could use this waste in its many cycles. In fact, is no real waste in nature. The apparent waste from one process an input in another.
Disposal of Solid Wastes :-
Before the solid waste is ultimately disposed of it is processed in order to improve the efficiency of solid waste disposal system and to recover usable resources out of the solid wastes.
The processing techniques such as compaction i.e. mechanical voulume reduction or incineration i.e. thermal volume reduction and manual component separation i.e. manual sorting of the waste are employed to increase the efficiency of solid waste management
Due to heterogeneity of the city refuse it is important to select the most appropriate solid waste disposal method keeping in view the following objectives.
(a) It should be economically viable i.e. the operation and maintenance costs must be carefully assessed.
(b) It should not create a health hazard.
(c) It should not cause adverse environmental effects.
(d) It should not be aesthetically unpleasant i.e. it should not result in offending sights, odours, and noise.
(e) It should preferably provide opportunities for recycling of materials.
Q.44. What is “ water shed” ? Explain with reasons
the importance of water management in our national policy.
Ans. Watershed is the area of land surrounding a river, lake, or pond,
which contributes to the water entering into these water bodies. For example,
when rainfall occurs on a watershed, the water is channelized to the lake or
river or any other water resservoir in the form of smaller streams or small
channels. These streams or channels form a big channel, which ends into the
water body. Thus, watershed is a delineated area with a well- defined
topograhic boundary and a water outlet. The size of the watershed depends upon
the geographical location. It may range from few square kilometres to few
thousand square kilometres.
Benefits
of watershed Management:-
Proper utilization of land and water resouraces for optimum
production without damaging the natural resources is know as an watershed
management. It is a holistic approach. It includes soil and moisture
conservation, afforestation, water haravesting, horticulture, silviculture,
grassland development, and increase of soil fertility. Watershed management
enhances the water table by increasing the soil
moisture retention. It also helps facilitate water conservation for
domestic water supply, irrigation, hydropower generation, and other beneficial
developmental activities. Watershed management utilizes the natural resources
in sustainable agriculatural practices with a view to improve rural economy of
the region and socio- economic conditions of rural people. Above all,
watershed management helps to ensure ecological balance. It is an economical
and environmentally sound way to prevent flood damage and store more water for
future. The main objectives of watershed development can be summarized as:
- Soil and water conservation
- Regeneration of vegetation
- Fodder production
- Fuel wood plantation
- Horticulture plantation
- Income - generation activities
- Drought proofing
Ans. Biogeochemical Cycles (Material Cycles): -
The producers of an ecosystem
take up several basic inorganic nutrients from their non-living environment.
These material get transformed into the bio mass of the producers. Then they
are utilised by the consumer population and are ultimately returened to the
environment with the help of the reducers or decomposers. This cyclic exchange
of nutrient material between the living organisms and their non - living
environment is called biogeochemcial cycle. As indicated by the name the
nutrients circulate through life (bio) and through earth (geo )repeatedly
(cycle).
The biogeochemical (material or
nutrient) cycles conserve the limited source of raw materials in the
environment.