Mukherjee Arun B, Zevenhoven Ron
Department of Biological and Environmental Sciences, Helsinki University, P.O. Box 27, FIN-00014 Helsinki, Finland.
Sci Total Environ. 2006 Sep 1;368(1):384-92. doi: 10.1016/j.scitotenv.2005.08.022. Epub 2005 Sep 22.
In the Indian subcontinent power generation is mainly dependent upon the thermal power units and coal is burnt as a fuel for the production of heat and electricity. In India, bituminous and sub-bituminous coals are used which contain over 40% of ash. At present, 80-90 million tons of fly ashes are generated from 85 existing coal based thermal power plants. Coal contains trace metals of which mercury is most toxic for humans and aquatic fauna. The problem of mercury in the society is not new, but in recent years the Indian subcontinent has gained the reputation of being "a dumping ground for mercury". This study focuses on mercury in fly ash and its releases to the atmosphere and soils cross the country. The utilisation of coal ash in India is also addressed although it is still in its nascent stage. About 10% of produced fly ashes are used in India whereas in Western countries its use is typically over 70%. Regulations from India's Ministry of Environment and Forestry should increase coal fly ash utilisation, although this would require that cost-effective new technology is put to use. As to the release of Hg from ashes disposed of in the environment, the scarce literature suggests that this is negligible or zero, and less problematic than wet or dry deposition of Hg from flue gases.
在印度次大陆，发电主要依赖火力发电机组，煤炭作为燃料燃烧以产生热量和电力。在印度，使用的烟煤和次烟煤含灰量超过40%。目前，85座现有的以煤炭为基础的火力发电厂产生8000万至9000万吨粉煤灰。煤炭含有微量金属，其中汞对人类和水生动物毒性最大。社会中的汞问题并非新鲜事，但近年来印度次大陆赢得了“汞倾销地”的名声。本研究聚焦于粉煤灰中的汞及其向大气和全国土壤的释放。印度粉煤灰的利用也在讨论范围内，尽管仍处于起步阶段。在印度，约10%的生产粉煤灰被利用，而在西方国家其利用率通常超过70%。印度环境与林业部的相关规定应提高粉煤灰的利用率，不过这需要采用具有成本效益的新技术。至于环境中处置的灰渣释放汞的情况，稀少的文献表明这种释放可忽略不计或为零，且比烟气中汞的湿沉降或干沉降问题更小。
