Status, distribution and sources of heavy metal pollution in soil in China 100

According to the national survey of sewage irrigation areas conducted by the Ministry of Agriculture of China, among the sewage irrigation areas of about 1.4 million hm2, the land area polluted by heavy metals accounts for the area of sewage irrigation areas, of which light pollution, moderate pollution accounts for the area, and serious pollution accounts for the area. China's annual grain production is reduced by more than 10 million tons due to heavy metal pollution, and the grain polluted by heavy metals is as much as 12 million tons per year, with a total economic loss of at least 20 billion yuan.

Judging from the current investigation of heavy metal pollution, the soil in the suburbs of most cities in China has been polluted to varying degrees. According to the survey data, within 14,000 km2 of a hilly area in Jiangsu Province, copper, mercury, lead and cadmium were polluted. According to the results of the soil survey conducted by the geological survey department of Guangdong Province, 5,500 km2 of 10,000 km2 of land in the Xijiang River basin were polluted by heavy metals, with a pollution rate of more than 50%, of which 1,257 km2 were contaminated with mercury and the pollution depth reached 40 cm underground.

The State Environmental Protection Administration has carried out land pollution surveys in 26 provinces and cities across the country, focusing on the Yangtze River Delta, the Pearl River Delta, the Bohai Bay Rim, the old industrial base in Northeast China, the Chengdu-Chongqing Plain, the Weihe Plain and major mineral resource-based cities.

Current sources of pollution: Soil pollution mainly comes from waste discharged from human activities. According to the nature of pollutants**, they can be divided into four types: industrial and municipal waste, agricultural fertilizers and pesticides, radioactive materials and harmful microorganisms.

At present, the trend of soil pollution in China is toxic chemical and heavy metal pollution ()aTransfer the vertical beat from upstream to downstream.

b.The bridge is transferred from the surface to the underground.

c.Shift from urban to rural areas.

d.Shift from agriculture to industry.

Correct answer: ABC

1 Universal characteristics With the development of industrial production, heavy metal pollution is becoming more and more common, threatening almost every country, in the 50s of the last century, Japan's Toyama Tsukawa River Basin "bone pain" is caused by cadmium pollution in brown rice excessive cadmium. In 1997, two agricultural areas in Montana, USA, were also contaminated with cadmium, making local wheat inedible. Many of our cities have been affected by the suburbs and irrigation districts.

There are different degrees of heavy metal pollution. Such as the Zhangtu irrigation area in Shenyang.

2.Concealment Characteristics The soil polluted by heavy metals is colorless and odorless, and it is difficult to detect by human sensory organs, and it can only be reflected when plants enter the food chain to accumulate to a certain extent.

3 Characteristics of surface polymerization Most of the heavy metal pollutants in the soil remain in the soil tillage layer and rarely move to the lower layer of the soil. This is due to the existence of organic colloids, inorganic colloids and organic-inorganic composite colloids in the soil, which have strong adsorption and chelation ability for heavy metals, which limits the migration ability of heavy metals in the soil.

4 Irreversibility Characteristics Because heavy metals accumulate in the soil to a certain extent, it leads to changes in soil structure and function, and because heavy metals are difficult to degrade, it is difficult to recover once the soil is polluted.

The main characteristics of heavy metal pollution in mine soil are as follows:

1.Widespread contamination: Mining sites are often excavated over large areas, which can lead to heavy metal contamination of hundreds of hectares of soil.

2.Deep pollution: The soil in mining areas often contains a large number of heavy metals combined with minerals, and the pollution degree is deep, and the pollutants are difficult to remove.

3.There are many kinds of pollutants: The soil pollutants in the mining area mainly include lead, copper, zinc, cadmium, mercury and other heavy metals, and there are many types.

4.Serious ecological damage: Soil pollution in mining areas has a great impact on the ecological environment, affecting crop production and animal husbandry development.

5.Long-lasting consequences: The soil in the mining area is difficult to remove the heavy metal pollutants in the minerals, and the consequences of heavy metal pollution in the soil are long-lasting, and serious mining areas may even be affected by heavy metal pollution for a long time.

Among the following options, the method for controlling heavy metal pollution in soil is () aThermal Huai Lingji desorption method.

b.Electrification.

c.Washing method.

d.Bioremediation and demolition method.

Positive lead firm answer: ABCD

Summary. Pro-<>

The problem of heavy metal contamination of soil can be traced back to the early 19th century, when rapid industrialization and mining produced large amounts of waste and pollutants, resulting in soil contamination by heavy metals and other harmful substances. With the further development of industry and urbanization, the problem of soil pollution is becoming more and more serious.

What year did heavy metal contamination begin? Why.

The problem of <> heavy metal contamination of the soil can be traced back to the early 19th century, when the rapid development of industrialization and mining produced a large amount of waste and pollutants, resulting in the soil being polluted by heavy amounts of money and other harmful substances. With the further development of industry and urbanization, the problem of soil pollution is becoming more and more serious.

The causes of soil heavy metal pollution caused by pro-<> mainly include the following aspects:1Industrial Production:

The waste and wastewater from the factory contain a large amount of heavy metals, and when discharged into the environment, it can pollute the surrounding soil. 2.Agricultural Production:

Agricultural products such as pesticides and fertilizers contain a large amount of heavy metals, and long-term use can lead to soil pollution. 3.Mining:

The tailings and construction waste produced by mines and quarries contain a large amount of heavy metals, which can cause great pollution to the surrounding soil. 4.Car exhaust:

Some harmful substances and heavy metals in automobile exhaust can also lead to soil pollution as the particulate matter in the air settles into the soil. The degree and severity of heavy metal contaminated soil are related to factors such as time, region, industry and management key. In order to reduce the impact of soil pollution, effective control and remediation measures are needed, including strengthening supervision, controlling waste and wastewater discharge, and promoting sustainable agricultural production practices.

Summary. Hello dear, happy to answer your <>

Heavy metal contaminated soil from; Heavy metal pollution is when certain elements or compounds in the soil exceed the concentration limits set by environmental quality standards, posing a potential threat to the environment and human health. The origin of heavy metal polluted soil can be traced back to the development and utilization of natural resources by human beings, but for the specific year when heavy metal pollution begins, it is necessary to take into account various factors, such as the natural environment, economic development level, industrial structure and so on in different regions. In China, with the acceleration of industrialization and the continuous expansion of urbanization, the problem of heavy metal pollution has become increasingly serious.

One of the earliest heavy metal pollution incidents was the June 30 incident in Caohegang Town, Yancheng City, in 1986, when the soil was severely contaminated with cadmium due to wastewater discharge from a small local factory. In addition, China has also experienced some other heavy metal pollution incidents, such as the 2005 lead-zinc mine wastewater incident in Huayuan County, Honghe Prefecture, Yunnan Province, and the 2006 cadmium pollution incident in Changzhutan Town, Nanhai District, Foshan City, Guangdong Province. These incidents have led to a wider focus on the problem of heavy metal contamination in the soil.

What year did heavy metal contamination begin? Why.

Hello dear, happy to answer your <>

Heavy metal contaminated soil from; Heavy metal pollution refers to the fact that certain elements or compounds in the soil exceed the concentration limits specified in the environmental quality standards, and the potential threat to the environment and human health is caused by the good elephant boy. The origin of heavy metal polluted soil can be traced back to the development and utilization of natural resources by human beings, but for the specific year when heavy metal pollution begins, it is necessary to take into account various factors, such as the natural environment, economic development level, industrial structure and so on in different regions. In China, with the acceleration of industrialization and the continuous expansion of urbanization, the problem of heavy metal pollution has become increasingly serious.

One of the earliest heavy metal pollution incidents was the June 30 incident in Caohegang Town, Yancheng City, in 1986, when the soil was severely contaminated with cadmium due to wastewater discharge from a small local factory. In addition, China has experienced a number of other heavy metal pollution incidents, such as the 2005 lead-zinc mine wastewater incident in Yanbang Huayuan County, Honghe Prefecture, Yunnan Province, and the 2006 cadmium pollution incident in Changzhutan Town, Nanhai District, Foshan City, Guangdong Province. These incidents have led to a wider focus on the problem of heavy metal contamination in the soil.

Pollution refers to the act of discharging one or more harmful substances into the environment, resulting in a decrease in environmental quality or causing harm to living organisms. These hazardous substances can be in solid, liquid or gaseous form, including chemicals, microorganisms, radiation, etc.

The main heavy metal pollutants in soil are cadmium, copper, chromium, mercury, lead, zinc and arsenic. These heavy metals cannot be decomposed in water, and will be harmful to human health with the ingestion of animals and plants and the drinking of water. It also combines with other toxins in the water to form more toxic organic matter.

Its first is mainly the development of modern industries such as human mining and smelting technology, and it is stacked at will during the mining process and does not take protective measures around; Some factories do not treat wastewater and waste residue after processing, and discharge them at will; In addition, heavy metals are difficult to degrade in the soil, and accumulate more and more.

Heavy metal pollutants Heavy metals such as mercury, cadmium, lead, arsenic, chromium, and zinc can cause soil pollution. These heavy metal pollutants mainly come from the infiltration of industrial wastewater from smelters, mines, chemical plants and other industrial wastewater, and the sedimentation of automobile exhaust gases. Both sides of the road are susceptible to lead contamination, arsenic is used in large quantities as an insecticide and herbicide, and cadmium is present in phosphate fertilizers.

Waste batteries are discarded at will. Once the soil is polluted by heavy metals, it is difficult to completely remove it, and it is a good habit to wear a mask that is seriously harmful to human beings, which can prevent harmful substances such as particles and droplets from entering your body, and can also prevent yourself from affecting the people around you when you are sick. It's just that many of us are lazy, or most masks are uncomfortable and unsightly to wear, so we don't want to wear them.

In economically developed and densely populated areas such as Hong Kong and Japan, wearing white masks has long been commonplace, and has even developed into a culture. Don't feel that someone looks at you differently and you're not used to it, there are already more and more people around us wearing masks, and it's good after a long time. If you still have concerns about this, you can start with a pure white mask, celebrities wear simple and generous white masks, like a fashion.

Jingdong recommends a high-grade medical mask imported from the United States, which not only has a simple appearance, but also has a powerful protective function, which can not only worry about abruptness but also be safe and allergic.

Soil refers to the loose surface layer of the land surface that is fertile and capable of growing plants, and its thickness is generally about 2 m. Soil not only provides mechanical support for plant growth, but also provides water, fertilizer, gas, heat and other fertility elements required for plant growth and development. In recent years, due to the rapid growth of population and the rapid development of industry, solid waste has been piled up and dumped on the soil surface, harmful wastewater has been infiltrating into the soil, and harmful gases and dust in the atmosphere have also been falling into the soil with rain, resulting in soil pollution.

Any substance that hinders the normal function of the soil, reduces the yield and quality of crops, and indirectly affects human health through grains, vegetables, fruits, etc., is called soil pollutants. There are many types of soil pollutants, which can be roughly divided into two categories: inorganic pollutants and organic pollutants. Inorganic pollutants mainly include acids, alkalis, heavy metals (copper, mercury, chromium, cadmium, nickel, lead, etc.), salts, radioactive elements cesium, strontium compounds, arsenic, selenium, fluorine compounds, etc.

Organic pollutants mainly include organic pesticides, phenols, cyanide, petroleum, synthetic detergents, 3,4-benzo, and harmful microorganisms brought by municipal sewage, sludge and manure. When the soil contains too many harmful substances, exceeding the self-purification ability of the soil, it will cause changes in the composition, structure and function of the soil, microbial activities are inhibited, and harmful substances or their decomposition products gradually accumulate in the soil, and are indirectly absorbed by the human body through "soil, plants, and human body", or through "soil, water, and human body", reaching the degree of endangering human health, which is soil pollution. In order to control and eliminate soil pollution, it is first necessary to control and eliminate soil pollution sources, strengthen the management of industrial "three wastes", and rationally apply chemical fertilizers and pesticides.

At the same time, control measures should be taken, such as planting plants with strong absorption capacity for the types of soil pollutants and reducing the content of toxic substances (for example, plants of the genus Iron Horn Fern can absorb heavy metals in the soil); or purify the soil through biodegradation (for example, earthworms can degrade pesticides, heavy metals, etc.); or apply inhibitors to change the migration and transformation direction of pollutants in the soil, reduce the absorption of crops (such as applying lime), increase the pH of the soil, and promote the formation of hydroxide precipitation of cadmium, mercury, copper, zinc, etc. In addition, soil pollution can also be controlled by increasing organic fertilizer, changing the farming system, changing the soil, and deep ploughing.