News
Health fears as substandard coal doubles fly ash, Mercury levels
View(s):Amidst environmentalists raising concerns this week that recent substandard coal consignments may contain high levels of mercury, thereby posing a health risk to Norochcholai residents, an energy analyst has calculated that the amount of mercury generally released to the environment due to coal combustion is between 600 and 650kg per year.
Reports point to mercury values of 0.27mg per kilogramme of coal. “Since we are using 2.2 to 2.5mn MT of coal for a year, this comes to 600-650kg of mercury per annum,” said Vidhura Ralapanawe, who has analysed the data.
Mercury is a liquid at room temperature, and becomes a vapour even at moderate temperatures, he said. So, it becomes a vapour at combustion and is therefore not captured with ash in the ash filters (electrostatic precipitators or ESPs).
Part of the mercury gets absorbed into the ocean water in the sulphur filter (FGD), which is a mechanism that sprays ocean water on the flue gas coming out of the combustion chamber via the ESP. The balance is released to the atmosphere in the flue gas via the chimneys.
Only two studies have been conducted on mercury pollution in Sri Lanka, both by the International Pollutants Elimination Network (IPEN), with one in collaboration with the local Centre for Environmental Justice. Further studies have revealed that mercury bioaccumulation is already impacting our fisheries, Dr Ralapanawe said.
“Data obtained from the Lakvijaya coal power plant’s (LVP) Continuous Mercury Emission System (CEMS) reveals that the power plant appears to violate the environmental conditions for mercury emissions,” he asserted. “The stack emission data for LVP’s unit 1, which has a mercury sensor, shows a value of approximately 36 micrograms /Nm3, which is equivalent to 0.036 mg/Nm3.”
However, the plant’s Environment Protection Licence (EPL) shows that the legally permissible limit is 0.01 mg/Nm3. “This is a clear violation of the environmental standards imposed on the plant by North-Western Province’s Provincial Environmental Authority,” he stressed.
Data also shows that the plant is generating high fly ash content from the time the recent South African coal consignments were used, more than doubling the fly ash generation from approximately 800 metric tons per day to 1500-1800 MT per day, Dr Ralapanawe pointed out. This is a clear indication that the coal coming from South Africa under the current contract is high in ash.
“Bottom ash quantums are similarly increased, as well as pyrites, which are impurities in coal that clog the coal grinding mills,” he explained. “These numbers indicate the ash content is indeed above the 16% limit given in the reject values.”
“The plant is unable to sell the full volume to cement companies, and has now resorted to open dumping in the ash yard, a practice that they stopped many years back due to pressure from environmental organisations and the community due to its very high ecological impact,” he said. “This practice has now come back due to the poor coal quality, and the community is the one paying the price.”
“The problem is expected to come to a head as the cement companies close for more than two weeks during the Sinhala and Tamil New Year, forcing the plant to dump the full amount of generated ash to the ash yard,” he warned. “This will increase community impact greatly.”
The best way to say that you found the home of your dreams is by finding it on Hitad.lk. We have listings for apartments for sale or rent in Sri Lanka, no matter what locale you're looking for! Whether you live in Colombo, Galle, Kandy, Matara, Jaffna and more - we've got them all!