SEMINAR ON

ENVIRONMENTAL IMPACT OF POWER SECTOR ON LAND AND WATERPresented By :S.K. AgrahariDepartment :Environment Science& Engineering HBTI KANPUR

INTRODUCTIONIMPACT OF POWER PLANTS ON WATER RESOURCTHERMAL POLLUTIONMETAL CONTAMINATION OF SURFACE AND WATERIMPACT ON LAND THERMAL POWER PLANT STANDARDS FOR LIQUID EFFLUENTCASE STUDIESSTEPS FOR CONTROLLING THE IMPACT REFERENCES

INTRODUCTION More demand of power require more generation, which lead to more pollution through power plants. It effects very badly to our environment as well as our natural resources like water resources and land resources.

IMPACT OF POWER PLANTS ON WATER RESOURCES

Water consumptionThermal water pollutionphysical and chemical changesMetal contaminant of surface and ground water

Water consumption

Chart1

59.2coal 59.2%coal 59.2%

13.9oil 13.9%oil 13.9%

6.03gas 6.03%gas 6.03%

2.5nuclear 2.5%nuclear 2.5%

17.8hydro 17.8%hydro 17.8%

0.3others 0.3%others 0.3%

Source: CPCB, Paper presented at Yogykarta, Indonesia,2006

Electric Power Generation in india

Sheet1

Electric Power Generation in india

coal 59.2%59.2

oil 13.9%13.9

gas 6.03%6.03

nuclear 2.5%2.5

hydro 17.8%17.8

others 0.3%0.3

Water consumption

[source:Greenwire, 10/4/07,USA]

Thermal water pollution

Thermal water pollution is increase of water temperature in a stream, lake and ocean due to the discharge of heated water from power plants and other industries.This is harmful to the fisheries and other aquatic biota in the water body.

Effects of Increased Water Temperature Thermal shock aquatic life adapted to a certain water temperature can go into shock when the temp is changed even 1 or 2 degrees.Oxygen dissolved in water decreasesIncreases the rate of photosynthesis, which increases the amount of plant growthIncreases the metabolic rate of fish, which increases their need for oxygen

physical and chemical changes

Increased turbidity higher Biological Oxygen Demand reduce levels of Dissolved Oxygen

Metal contaminant of surface and ground water The major part of fly ash is disposed off in unmanaged landfills or lagoons, leads to environmental pollution in the area through fly ash erosion and leachate generation. Heavy metals like Arsenic, Lead, Nickel, Cobalt, Chromium, Boron and Antimony found in fly ash are hazardous for living organisms.

Return flow of power plant waste

IMPACT ON LANDThe land requirement per mega watt of installed capacity for coal, gas and hydroelectric power plants is 0.1-4.7 ha., 0.26 ha. and 6.6 ha. Respectively.Due to enormous quantity of ash content in Indian coal, approximately 1 acre land per MW of installed thermal capacity is required

Due to this, natural soil properties changes. It becomes more alkaline due to the alkaline nature of fly ash. [Source:Performance Review of Thermal Power Stations 2004-05 Section 14]

THERMAL POWER PLANT : STANDARDS FOR LIQUID EFFLUENT

[Source :EPA Notification (S.O., 844 (E), dt. 19.11.86)]

PARAMETERS STANDARDS MAX. LIMITING CONCENTRATION mg/lCondenser Cooling Water (once through cooling system) PH Temperature 6.5 to 8.5 Not more than 7deg. C higher than the intake Boiler Blowdown Suspended Soilds Oil & Grease Copper (Total) Iron (Total) 100 20 1.0 1.0 Cooling Tower Blowdown Free available Chlorine Zinc Chromium (Total) 0.5 1.0 0.2Ash Pond Effluent PH Suspended Solids Oil & Greases 6.5 to 8.5 100 20

SOURCE

CASE STUDIES

Leaching of soluble ions from ash ponds into the ground water was reported near Vijayawada Thermal Power Station. Leachability of metals such as cadmium, chromium, zinc, lead, mercury, and silver (cations) increases with decreasing pH or under acidic conditions. [Suresh et.al, 1998]

Al, Fe, Mn and Pb are the major contaminants contributed from the ash pond effluent to the river water in Orissa and their enrichment with respect to the respective prescribed limits confirmed that the river water is contaminated to varying degrees and therefore not potable. [Tripathy et.al, 2002]

STEPS FOR CONTROLLING THE IMPACT

power plants can be designed or refitted to be more efficient and to produce less waste heat using cooling towers or cooling ponds.Cogeneration.waste hot water can be used for heating and hot water supply.Fly ash can be beneficially used for brick making, toy and decorative items making and cement manufacturing.

REFERENCES

World coal association http://www.worldcoal.org/resources/coal-statistics. Central Electricity Authority (CEA). Performance Review of Thermal Power Stations report march 2012Greenwire,10/4/07,USASci. Revs. Chem. Commun.: 2(3), 2012, 212-215 ISSN 2277-2669CPCB, Paper presented at Yogykarta, Indonesia,2006Performance Review of Thermal Power Stations 2004-05 Section 14 Page no. 14.15 EPA Notification (S.O., 844 (E), dt. 19.11.86)Suresh, I.V., Padmakar, C. and Venkata Rao, K. 1998. Effect of ash pond on ground water quality: a case study. Env. Manage. Health., 9(5): 200-208.Tripathi, Gupta, D.K., Rai, U.N. R.D. and Inouhe, M. 2002. Impacts of fly ash on soil and plant responses. J. Plant Res., 115(6): 401-409.

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