Coal-Fired Power Station Effluents
AUTHOR: Deborah M B Adams, Rohan Fernando
DATE: November 1998
The use of water in power plants, both in relation to the quantity required and the quality of that discharged is of growing concern in a number of countries. Many countries have legislation which sets limits on the composition of pollutants in the effluent. The larges volume of water is used by cooling systems and another major stream is associated with the water/steam cycle. Other streams are related to the FGD plant, boiler cleaning, ash transport. Demineraliser plant regeneration and coal stockpile run-off. More recently the trend is towards water conservation and the attainment of zero discharge.
This report considers issues relating to the discharge of effluent from power plant. The different affluent streams in power plants are described - the role they play in the operation of the plant, how the pollutants arise in the effluent and the typical composition. The legislation applicable to the discharge of power plant effluent in a number of countries is discussed. The report considers the general treatment technologies available for effluent treatment and describes the systems utilised most commonly in power plants. It describes methods of minimising water usage and discharge, particularly how clean coal technologies such as IGCC plant achieve zero water discharge.