ENVIRONMENT MANAGEMENT IN POWER PLANTS

摘要

Thermal Power Plants use fuels for power generation. Water is used for process, cooling, as well as for service/drinking requirements. Chemicals are used for conditioning of water, corrosion-control and sometimes for conditioning of fuel as well. Lubricants are used for machinery. These inputs generate waste products. Human related wastes (sewage etc.) are also generated along with the process wastes. These pollutants/wastes need to be treated before their disposal from the plants. The treated effluents are required to meet the limits set by Central / State Pollution Control Boards. The regulations, issued by these agencies, specify the maximum allowable limits applicable to the pollutants discharged from the Power Plants. BHEL has executed many Power Plants wherein the wastes generated in the plants have been treated before disposal, resulting in the savings in the now scarce fresh water, for plant use, and also protecting the water bodies from the polluting effect of the wastewater. This paper deals with the nature and quantities of the effluents, generated in Thermal Power Plants, the treatment practices being followed by BHEL and the state of art. Effluents, in the context of pollution, are fluids, such as wastewater and chemicals, smoke, dust and solid /semi-solid materials like ash/sludge. These effluents affect the quality of the environment. The extent of effect depends on their quality, quantities and location of disposal. Effluents are generated in all types of power stations. Their nature and quantities differ significantly with the type of power station. However these are most serious for the coal fired power plants. Oil and gas fired plants are less environment degrading, where as the hydro plants have minimum impact, if at all, due to the pollutants. The nature and seriousness of the pollutants from nuclear plants are of entirely different type and these have not been considered in this paper. Following are the important regulations related to pollution control in power plants: 1. Water (Prevention and control of Pollution) act, 1974 2. Air (Prevention and control of pollution) Act, 1981 3. Environment Protection Act, 1986 4. Minimal National Standards (MINAS) Center/State Pollution Control Boards are the regulatory bodies to implement the stipulations of the pollution control laws. Power plant authorities are required to obtain clearance from the concerned Pollution Control Board.