China is one of the most important mercury producing countries in the world, and Guizhou Province is one of the most serious areas of mercury pollution in China. Guizhou Province Environmental Science Research Institute which lasted seven years, the province's mercury pollution white spoon three most important source region: the typical regional mercury mining and smelting, coal-fired mercury, mercury emissions from chemical companies and so on a full range of white spoon pollution Multi-disciplinary systematic investigation and research; from the dynamic relationship between food chain and experimental animal vegetative nerve, the harm of mercury to the nervous system of the body is discussed in depth; the prevention and control measures of pollution are put forward. Mercury coal-fired chemical industry: source of mercury pollution Reserves rank third in the world, most importantly in eastern Guizhou. Guizhou takes 10 minutes with 12 mercury mercury mine fields, of which the mountains, Wuchuan, copper benevolence, Danzhai, Songtao and Xingren wood sill plants, and so the main ore field. The most important pollution of mercury in Guizhou comes from the three aspects of mercury mining and smelting, coal burning and chemical industry. The typical mercury-contaminated area of ​​the Wuchuan mercury mine currently produces about 80-120 tons of refined mercury per year. Since the Daping mining area to production, the cumulative total mercury emissions have been approximately 185 tons (including mercury waste gas, industrial waste residue and wastewater). If calculated according to the annual production capacity of 100 tons, the Wuchuan mercury mine will discharge 620.5 kilograms of mercury into the environment every year in the form of slag, water and gas. Hongfeng Lake is one of the most important drinking water sources in Guiyang City. Typical mercury pollution area Guizhou mercury mine is the largest production base of mercury and mercury products in China. In the mid-fifties and mid-1980s, the annual mercury production was 800 tons/year, and the waste residue after smelting reached 476,000 tons / year, not including ore. The tail gas of the smelter is along the diameter of 1 m, the length of the 400 m mountain climbing flue, and the disorderly discharge to the atmosphere at a flow rate of 4,600 m3 / h. Due to process requirements, the two wastewater discharge ports of the machine selection plant and the smelter have a water consumption of about 800 tons/day. Downstream of the two factories, one is the Longjiang Reservoir, and the other is the upper reaches of the Xiahe River. The river directly flows into the Jinjiang River and finally flows into the Dongting Lake and flows into the Yangtze River. Longjiang Reservoir is the largest agricultural irrigation water source in Wanshan Special Zone with an irrigation area of ​​about 8,000 mu. There are about 4,000 acres of paddy fields around the banks of the Xia River, and there are more than 8,000 people living there. With the acceleration of the “West-to-East Power Transmission†pace, the coal consumption of thermal power generation in Guizhou has been increasing year by year. According to statistics, between 1996 and 2000, the coal consumption of thermal power generation increased from 6,636,200 tons to 8,956,200 tons. It is estimated that in 2010, the coal consumption of thermal power generation in Guizhou will reach 35.83 million tons / year. If the average mercury content of coal is 0.62 mg / kg, the annual mercury emissions of power plants will reach about 22 tons / year. The total amount of control of the State Environmental Protection Administration is 800 kg / year. The annual output of waste slag in Qingzhen Power Plant is about 900,000 tons, of which the amount of fly ash is 800,000 tons. The ash slag yard is built on the edge of Hongfeng Lake, only 10 meters away from the water surface. Due to the use of hydraulic ash discharge into the ash yard, the gray water displacement is about 8 million cubic meters / year, the direction of the smoke and dust in the power plant chimney in winter, the most important with the leading wind blowing to the lake area. Hongfeng Lake is one of the most important drinking water sources in Guiyang. The use of mercury also brings pollution to the environment. During the production process of mercury-based acetic acid, Guizhou Organic Chemicals Factory discharged mercury from the Dongmenqiao River Basin, Maotiao River and surrounding farmland in the upper reaches of Baihua Lake, the most important drinking water source in Guiyang City from 1971 to 1997. As many as 100 tons. Through a high-level investigation, the Academy of Environmental Sciences confirmed that there are 117.4 hectares of soil contaminated with mercury in the Qingzhen area, the soil contains mercury in the range of 4.71-723 mg/kg, and the mercury content is above 200 mg/kg. 66 hectares of soil must be disposed of urgently. The surrounding environment of the plant has been polluted by different degrees of mercury. The mercury content in the bottom of the water is 76.9%, and the mercury content in rice is in the range of 0.03-0.13 mg/kg. It also contains certain methyl mercury, which exceeds the national food standard. The mercury content in fish is close to or higher than the standard value of controlling mercury content in Chinese food. Mercury pollution: the unbearable weight of the living environment According to a high-level survey conducted by the Guizhou Provincial Environmental Science Research and Design Institute, mercury is not only polluted by the environment but also enters the food chain due to the migration of mercury in the vicinity of the mercury mining area and the chemical plant. Once the mercury enters the food chain, it will cause animal nerves. The damage of the system brings great harm to animals and humans. The Institute of Environmental Sciences passed the experiment of mice. The results showed that the mice were fed with mercury-contaminated food, and the neurotransmitters in the mice were obviously damaged and mutated in the brain, liver, kidney and blood. The effect of mercury on acetylcholine may have a stimulating effect in a short period of time, and the long-term accumulation will result in the depletion of intracellular acetylcholine accumulation, leading to a complete decline in cholinergic neurotransmitter function. Acetylcholine is closely related to the physiological functions of exercise, learning, memory, etc. The destruction of cholinergic nerve function may lead to the decline of memory function and the coordination of exercise, which is similar to the symptoms of methylmercury-induced poisoning. . Yan Liya, deputy director of the Academy of Environmental Sciences, said that mercury in contaminated soil can be released into the atmosphere without water, and dissolved under water conditions, becoming a secondary source of pollution. The soil is contaminated with mercury and contains more than 180 mg/kg of mercury. After 6 years of natural purification, sun, rain and weeds have not been able to reduce the mercury content of mercury in rice in reclaimed rice fields. It damages the environment in which people depend on survival. Mercury in large areas of soil will diffuse and invade water and aquatic organisms after dissolution. In the investigation and research, the power plant and the mining and smelting mercury area studied by Huanyuan Institute were occupied by people at a distance of 1000 meters from the chimney. If one person breathes 20 cubic meters of air per day, passive inhalation of mercury is 10 micrograms per day. If one person consumes 500 grams of rice per day, passive intake of mercury is 107.3 micrograms per day. If extreme data is used in the study, at least 7.18 mg/g of mercury enters the body (breathing and food only) in a year due to exposure to mercury in the environment, which will cause human health. disease. The downstream of the wastewater discharge port of Guizhou Organic Chemical Plant has a artificial lake of 319 square kilometers in the cat jumping river basin - Baihua Lake. The lake is a multi-functional reservoir that combines power generation, drinking, farming and irrigation. The fish in the library contains mercury in the range of 0.16-0.96 mg/kg, and the sediment in the library contains 19.7-62.1 mg/kg of mercury. This area is home to nearly half a million people. Although the plant is currently preparing to renovate the production process and the source of pollution has been cut off, if the soil that has been seriously polluted is not treated in time, it may become secondary pollution and pollute other rice fields and groundwater. One of the most important drinking water sources in Guiyang City - Baihua Lake In the area polluted by mercury in Qingzhen City, the large livestock are skinny and the villagers' hair is checked. The mercury content is high. The local villagers also know that the soil is contaminated by mercury-containing wastewater. Therefore, the rice and vegetables produced by the local villagers are sold to the surrounding areas at low prices, and then the rice vegetables containing no mercury are purchased. And when selling rice and vegetables, it does not reveal its address and production location. Due to the influence of mercury-containing wastewater, the average annual output of crops such as grain and vegetables is reduced by 3-4%. So far, the area of ​​mercury wastewater pollution has reached 177.4 hectares, and urgent countermeasures are needed, that is, the area of ​​heavily polluted soil is 60 hectares and the depth of the soil layer is 50 cm. Experimental studies have shown that crops can accumulate mercury, and humans can import mercury into the human body through the food chain, which will cause great harm when accumulated to a certain extent. Not only that, the mercury mining and smelting and mercury chemical industry in Guizhou are located in the main stream of the Wujiang River and the Dongting Lake in the upper reaches of the Yangtze River Basin. The waste slag, waste water and mercury contaminated soil are continuously discharged and oozing into the river. Continuous migration will have a certain impact on the water quality of the Yangtze and Three Gorges reservoir areas. According to a research report by the Chinese Academy of Sciences, the water quality of Wujiang River has been affected by the Wuchuan mercury mine. The mercury content of the fish in the Hongdu River is very high. The mercury content of the turtle is 0.458 mg/kg and the carp is 0.613 mg/kg, both exceeding the country. Food hygiene standards. The mercury content in the sediment of the Xiaodukou section of Jiangbin is as high as 10 mg/kg, which will directly affect the water quality and water environment of the Three Gorges reservoir area. Preventing mercury pollution is an urgent task Specializing in the pollution of the mercury environment and the pollution caused by pollution, experts have called on relevant national departments to establish practical and sustainable development laws and regulations, strictly control the total mercury target, and use mercury pollution reduction technology. And increase the management of various mercury industries, etc., while controlling mercury pollution, and prevent new mercury pollution. First, establish practical and sustainable development laws and regulations. At present, environmental pollution is brought about by economic activities and social development. Therefore, in order to alleviate and solve environmental pollution problems, formulate and implement technical and economic policies that are conducive to the coordinated development of the social economy and the environment. Second, improve relevant regulations to control the total amount of mercury emissions. The sewage discharge permit is a legal expression form for the environmental protection management agency to limit the discharge process of pollution sources to achieve the goal of total control. The total amount of control has laid the foundation for the discharge permit, and the discharge permit has become a favorable tool. The formulation and implementation of mercury standards in China should fully consider the total amount of control. Third, increase efforts to control mercury emissions from coal-fired atmospheres. During the “10th Five-Year Plan†period, Guizhou will have an installed capacity of 6.24 million kilowatts and an increase of 16.5 million tons of coal. Chemical industry, light industry, electronics, medical and metallurgical industrial development has a certain scale white spoon. Therefore, during the 10th Five-Year Plan period, Guizhou still needs 1900 tons of mercury per year. Therefore, strengthen scientific and technological research and technological transformation. At present, the first step in the international use of mercury in coal-fired atmospheres is to wash coal and wash away 30%-41% of mercury in coal. The second step is to burn flue gas. This step can remove mercury by 15%-18. %, the third step is desulfurization, using desulfurization technology, adding certain equipment, can remove about 30.35% of mercury. At present, the proportion of coal washing in China is too low, accounting for only 5%. Therefore, we should vigorously increase the proportion of coal washing, and there should be policy support in this regard. Fourth, strengthen the management of mercury sources and mercury pollution sources. Fifth, research and standardize new sources of pollution. At present, in addition to industry emissions, the new source of mercury pollution is coal-fired emissions, and the discharge of coal into the atmosphere is difficult to control. As China's research on mercury emissions from coal combustion has just started, further research on mercury emissions from coal combustion is needed to provide a scientific basis for the development of mercury emission standards for coal combustion. WEISS MACHINERY CO., LTD. , https://www.weissmachinerys.com
Mercury pollution in Guizhou Province