Industrial thermal pollution

Water pollution continues on a large scale. The Dnieper region is the worst affected among its counterparts in Ukraine. Here, the situation is disastrous because of a combination of energy-intensive industries, thermal power generation, and intensive agriculture, further aggravated by Chernobyl. 

A number of methods can he used to control thermal pollution. Many environmentalists point out that one approach is for consumers and industries simply to reduce the amount of electricity they use and waste, allowing power plants to reduce the amount of electricity they generate. Another approach is to discharge heated water in places that are less ecologically sensitive, that is, bodies of water that contain fewer hsh, shellhsh, and other aquatic organisms that are affected by heated water. For example, heated water can he used to heat homes, office buildings, and other structures. 

New applications of zeolite adsorption developed recently for separation and purification processes are reviewed. Major commercial processes are discussed in areas of hydrocarbon separation, drying gases and liquids, separation and purification of industrial streams, pollution control, and nonregenerative applications. Special emphasis is placed on important commercial processes and potentially important applications. Important properties of zeolite adsorbents for these applications are adsorption capacity and selectivity, adsorption and desorption rate, physical strength and attrition resistance, low catalytic activity, thermal-hydrothermal and chemical stabilityy and particle size and shape. Apparent bulk density is important because it is related to adsorptive capacity per unit volume and to the rate of adsorption-desorption. However, more important factors controlling the raJtes are crystal size and macropore size distribution. 

THERMAL POLLUTION] (Vol 23) industrial hygiene concern [INDUSTRIAL HYGIENE] (Vol 14)... 

Many industries use water as a coolant. Suggest the sorts of problems that may be created by this thermal pollution. ... 

The behavior of gases dissolving in water appears to be less complex. The solubility of a gas in water typically decreases with increasing temperature, as shown for several cases in Fig. 17.6. This temperature effect has important environmental implications because of the widespread use of water from lakes and rivers for industrial cooling. After being used as a coolant, the water is returned to its natural source at a higher-than-ambient temperature (thermal pollution has occurred). Because it is warmer, this water contains less than the normal concentration of oxygen and is also less dense it... 

Thermal pollution the oxygen-depleting effect on lakes and rivers of using water for industrial cooling and returning it to its natural source at a higher temperature. (17.3)... 

Fish are ectothermic vertebrates, and as such are susceptible to fluctuations in temperature of their immediate environment. This has relevance to sewage and industrial effluents, which can be significant sources of thermal pollution in aquatic environments. Recent evidence demonstrating that heat shock can induce apoptosis in a variety of fish tissues21,111,136 suggests that some deleterious effects of thermal pollution may be mechanistically linked to increased apoptosis of susceptible cell types. 

This behavior can lead to an environmental problem known as thermal pollution. During many industrial processes, large amounts of water are taken from a nearby river or lake, pumped through the system to cool liquids, gases, and equipment, and then returned to the body of water at a higher temperature. The metabolic rates of fish and other aquatic animals increase in the warmer water released near the plant outlet thus, their need for O2 increases, but the concentration of dissolved O2 is lower at the higher temperature. Farther from the plant, the water temperature returns to ambient levels and the O2 solubility increases. One way to lessen the problem is with cooling towers, which lower the water s temperature before it exits the plant. 

Thermal pollution from industrial wastewater causes the temperature of river or lake water to increase, which can affect fish survival as the concentration of dissolved O2 decreases. Use the following data to find the molarity of O2 at each temperature (assume the solution density is the same as water) ... 

Radiometer for measuring thermal radiation. (From Baukal, C.E., Industrial Combustion Pollution and Control, New York Marcel Dekker, 2004.)... 

Sulphites rarely occur in natural waters. They are chiefly of artificial origin (wastewaters from the production of sulphite cellulose and thermal processing of coal). They are washed out into atmospheric waters from urban and industrial air pollutants. In waters, sulphites are slowly oxidized into sulphates, consuming dissolved oxygen. Chemical oxidation is accelerated by catalytic effects of various metals, particularly the Co(II) compounds. In water treatment, sulphites are used for dechlorination, removal of oxygen from feed waters for steam boilers, and in the technology of wastewaters for reduction of Cr(VI) to Cr(III). 

Thermal pollution is heated water discharged into lakes and rivers. By raising the ambient water temperature, aquatic plant and wildlife are often threatened. The industry that dumps the greatest amount of heat into lakes and rivers is thermoelectric power, which consists of coal, oil, and natural gas-combusting plants, and nuclear reactors. Because of the laws of thermodynamics, this waste heat cannot be eliminated, but it can be kept from waterways by means of cooling towers or cooling ponds or used in cogeneration industrial parks. 

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