Alibekova A.R, Agilbaeva M.J

Ecological problems of thermal power plants.

Three «E» characterizes the modern period of human development: energy, economics, and ecology. Energy in this series has a special place. It is decisive for the economy and for the environment. From it depends crucially on the economic potential and well-being of people. She has the strongest impact on the environment, ecosystems and the biosphere as a whole. The most acute environmental problems (climate change, acid rain, general pollution and others) directly or indirectly related to the production or energy use. Energy primacy belongs not only to the chemical, but also in other types of pollution: heat, aerosol, electromagnetic and radioactive. Therefore, it is no exaggeration to say that from the solution of energy problems depends on the possibility of solving major environmental problems. Energy - it is the branch of production, which develops an unprecedentedly rapid pace. If the population in today's boomers doubles in 40-50 years, the production and consumption of energy that happens every 12-15 years. At that rate of population growth and energy, power- avalanche increases not only in cumulative terms, but also in per capita terms.

TPP produce electricity (up to 75% of total electricity production of the world) and thermal energy, with all the material mass of the fuel has converted into waste entering the environment in the form of gaseous and particulate combustion products (Fig. 1). These wastes time (the combustion gas 5, when burning anthracite 4 times) greater than the mass of fuel consumed. Released into the environment combustion determined by the type and quality of fuel, as well as by its combustion. Currently, about 70% of total electricity production TPP provided condensing power.

All the thermal energy of the world annually emits Earth more than 200 million tons of carbon dioxide, more than 50 million tons of various hydrocarbons, nearly 150 million of sulfur dioxide, more than 50 million tons of nitrogen oxide, 250 million tons of fine aerosols. No one doubts that this "activity" thermal power contributes significantly to the imbalance of steady circular processes in the biosphere, which began to manifest itself more clearly in recent years. Imbalance is marked not only harmful substances (oxides of sulfur and nitrogen), but also for carbon dioxide. This imbalance include increasing energy production based on fossil fuels may, as many now believe, in the long term lead to significant environmental consequences for the entire planet.

Fig. 1. Effect of TPP on the environment:

1 - boiler, 2 - smoke pipe 3 - turbine 4 - generator 5 - substation, 6 - condenser 7 - condensate pump, 8 - feed pump 9 - transmission line, 10 - electricity consumers.

The process of the production of electricity at thermal power plants also accompanies the emergence of various polluting effluents associated with the process water treatment, conservation and washing equipment, hydraulic transport evils slag waste, etc. These wastewater discharges into water bodies with detrimental impact on their flora and fauna. The establishment of the closed water systems this effect has reduced or eliminated.

Large amount of water used in various TPP heat exchangers for condensing exhaust steam, water, oil, gas and air-cooling. For this purpose, water has abstracted from a surface source and ramjet circuit after use in these devices has returned to the same sources. This makes the water in the pond is used a lot of heat and creates a so-called thermal pollution it. This kind of pollution affects the biological and chemical processes, that determine the livelihoods of plants and animals, that inhabit the natural reservoirs, and often leads to their death, intense evaporation of water from the surface of reservoirs, changes in hydrological flow characteristics, increases the solubility of the rocks in the boxes of reservoirs, the deterioration of their health state and climate change in some areas.

The main sources of water pollution are thermal turbine condensers. Among them has given approximately half to two thirds of the total quantity of heat obtained from the combustion of fossil fuel, which is equivalent to 35-40% of the energy of the fuel used.

Serious environmental problems associated with solid waste TPP - ash and slag. Although ash has collected in bulk various filters, yet the atmosphere as emissions TPP annually receives about 250 million tons of fine aerosols. The latter can significantly alter the balance of solar radiation at the earth's surface. They are the condensation nuclei for water vapor and precipitation formation, and getting into the human respiratory system, and other organisms to cause various respiratory diseases.

Table 1. Influence of extraction of fuels on the environment and biosphere

The technological process	Influence on the elements of environment and the biosphere				Examples of chain reactions
	Air	Soils and subsoils	Water	Ecosystems and human
1	2	3	4	5	6
- liquid (oil)	Hydrocarbon contamination on evaporation and leakage	Damage or destruction of soils in the exploration and production	Oil pollution due to leaks	Destruction and damage ecosystems in mining areas and oilfield construction	Soil pollution, water pollution by oil and chemical reagents.
- Solid (coal, shale, peat, etc.)	Dust from blasting and other works, combustion products, etc.	Destruction and severe contamination of soils near businesses	Strong violation of the aquifers	Basically through the water pollution and hydrobionts	Loss of the consumer taste or properties of water and fishery products

Serious problem TPP is near storage of ash and slag. This requires large areas that has not used for a long time, and are centers of heavy metal accumulation and increased radioactivity.

There is evidence that if all of today's energy based on carbon, the emissions of CO, would amount to 20 billion tons per year (now they are close to 6 billion tons / year). This is the limit beyond which such projected climate change, which will determine the disastrous consequences for the biosphere.

Some solutions to the environmental problems of thermal power plants.

1. Use and improvement of treatment facilities. Currently, many trapped in the TPP mostly solid emissions by using different types of filters. The most aggressive pollutant - sulfur dioxide in many TPP has not captured or trapped in limited quantities.

2. Reducing income sulfur compounds into the atmosphere through the preliminary desulfurization (desulfurization) coal and other fuels (oil, gas, shale oil) by chemical or physical methods. These methods could extracted from the fuel from 50 to 70% of the sulfur prior to its combustion.

3. Big and real opportunities to reduce or stabilize contaminants in revenues associated with environment saving.

Conclusion

This article discussed the main sources of pollution, their types, and their impact on the biosphere. After reviewing, the authors have proposed solutions to these problems.

List of literature

1. V.I. Kormilitsyn, M.S. Tsitskshivili, Y.I. Yalamov "Fundamentals of Ecology", publishing house - Interstyle, Moscow 1997.

2. N.A. Voronkov "Ecology - general, social, applied", publishing - Agar, Moscow 1999.

3. V.M. Garin, I.A. Klenow, V.I. Kolesnikov "Ecology for technical colleges", publishing - Phoenix, Rostov-on-Don in 2001.