- Cultural or Accelerated Eutrophication:
- Pollutants from man’s activities like effluents from the industries and homes can radically accelerate the aging process. This phenomenon is called Cultural or Accelerated Eutrophication.
Causes:
- Sewage and agricultural and industrial wastes.
- Prime contaminants are nitrates and phosphates.
Effects:
Thermal pollution:
- Unsightly scum and unpleasant odors.
- Robbing the dissolved oxygen form water.
- Pollutant inflow kills the fish.
- Decomposition of dead fish causes further depletion of DO.
- Finally a lake can literally choke to death.
Cause:
- Heated (thermal) waste waters flowing out of electricity-generating units. E.g. thermal power plants.
Effects:
- Thermal wastewater eliminates or reduces the number of organism sensitive to high temperature.
- Enhance the growth of plants and fish in extremely cold areas but only after causing damage to the indigenous flora and fauna.
A case study of integrated waste water treatment:
- Wastewater including sewage can be treated in an integrated manner, by utilizing a mix of artificial and natural process.
- It has been done in town of Arcata, in the northern coast of California.
- The treatment is done in two stages:-
- The conventional sedimentation, filtering and chorine treatment are given.
- The biologist developed a series of six connected marshes over 60 hectares of marshland.
- Appropriate plants, algae, fungi and bacteria were seeded into this area, which neutralize, absorb and assimilate the pollutant
- The water flows through the marshes, it get purified naturally.
- The marshes also constitute a sanctuary, with high level of biodiversity in the form of fishes, animals and birds that now reside there.
- A citizens group called Friends of the Arcata Marsh (FOAM) is responsible for the upkeep and safeguarding of this project.
Ecological sanitation:
- Ecological sanitation is a sustainable system for handling human excreta, using dry composting toilets.
- This is a practical, hygienic, efficient and cost-effective solution to human waste disposal.
- With this composting method human excreta can be recycled into are source (as natural fertilizer).
- ‘EcoSan’ toilets are being used in Kerala and Srilanka.
SOLID WASTES:
- Solid wastes refer to everything that goes out in trash.
- Municipal solid wastes are wastes from homes, offices, stores, schools, hospitals etc. It comprises paper, food wastes, plastics, glass, metals rubber, leathers, textiles etc.
- Open damp of these wastes serve as the breeding ground for rats and flies.
- Sanitary landfills were adopted as substitute for open-burning dumps.
Sanitary landfills:
- Wastes are dumped in a depression or trench after compaction and covered with dirt everyday.
Disadvantages:
- Shortage of space for huge garbage’s.
- Danger of seepage of chemicals, polluting the ground water resources.
Solution to solid wastes:
- All solid wastes are categorized into thee types:
- Bio-degradable.
- Recyclable.
- Non-biodegradable.
- All the garbage generated is sorted first.
- Recyclable material to be separated and send for recycles.
- Biodegradable wastes can be put into deep pits in the ground and be left for natural breakdown.
- Only Non-biodegradable wastes are left and required to be disposed.
Prevention:
- The need to reduce our garbage generation should be a prime goal.
- Reduction in use of plastics and use of eco-friendly packaging.
- Carrying cloth or other natural fiber carry bags when we go shopping.
- Refusing polythene bags.
Case study of Remedy for Plastic wastes: (Ahmed Khan)
- Polyblend, a fine powder of recycled modified plastic, was developed by his company.
- Polyblend is mixed with bitumen that is used to lay roads.
- It increases the water repelling property of bitumen, and helped to increase road life by a factor of three.
- The raw material used for polyblend is plastic film waste.
CBSE Biology (Chapter Wise) Class XII ( By Mr. Hare Krushna Giri )
Email Id : [email protected]
