Severe heavy metal pollution The Ministry of Environmental Protection plans to spend 30 billion yuan on "cultivation of land"

In recent years, with the frequent exposure of heavy metals such as arsenic, cadmium, and lead, this contaminated land, like an invisible killer, has become an anxiety point that the entire society cannot avoid.

This type of land is formed because the land is invaded by mining or industrial waste or agricultural chemical substances, which deteriorates the original physical and chemical properties of the soil. As a result, the potential for land production declines, product quality deteriorates, and humans, plants and animals are seriously damaged. .

As early as 2006, the Ministry of Environmental Protection and the Ministry of Land and Resources jointly launched the first national survey of soil pollution, with a budget of 1 billion yuan, which is planned for completion in 2010. Today, the specific investigation results have not yet been announced, but the current situation of soil pollution is consistent with the official caliber: "The overall situation of soil pollution in China is not optimistic."

According to Chen Tongbin, director of the Ecological Restoration Center of the Chinese Academy of Sciences, soil pollution has severely constrained the development and utilization of land in China and has exerted tremendous pressure on the sustainable use of soil resources. Therefore, it is imminent and inescapable to fully initiate the nationwide soil remediation work.

Recently, the 12th Five-year Plan for National Soil Environmental Protection led by the Ministry of Environmental Protection (hereinafter referred to as the “Planning”) has been approved by the State Council and is expected to be officially announced in the near future. According to the plan, during the “Twelfth Five-Year Plan” period, the central government funding for the restoration of contaminated soil in the country will reach 30 billion yuan.

The soil

In recent years, with the rapid development of industry and agriculture in our country, land has been continuously harmed by various pollutions, mainly concentrated in rural farmland pollution and urban industrial land pollution. According to pollution sources, land pollution can be divided into industrial pollution and traffic. Transportation pollution, agricultural pollution and domestic pollution are four types.

Heavy metal pollution is the most serious piece of industrial pollution. According to a survey conducted by the State Environmental Protection Department on the “Exploration of Soil Environmental Quality in a Typical Region” survey, nearly 40% of the cities in the Pearl River Delta have excessive levels of heavy metal contamination in farmland vegetable soils, of which 10% Seriously exceeded. Some contiguous farmland in the Yangtze River Delta is contaminated with heavy metals, resulting in almost 10% of the soil losing productivity.

Chen Tongbin’s research conclusion is that heavy metal pollution is sporadic in the north and denser in the south.

In February last year, Minister of Environmental Protection Zhou Shengxian stated at the 12th Five-Year Plan for Integrated Prevention and Control of Heavy Metal Pollution that since 2009, there have been more than 30 heavy metal pollution incidents in China. These incidents involved more than 10 provinces such as Anhui, Henan, Hunan, Fujian and Guangdong.

The data from the China National Environmental Monitoring Center indicated that among the heavy metal pollution in China, the most serious are the cadmium pollution, mercury pollution, blood lead pollution, and arsenic pollution. “Among them, the ratio of cadmium pollution and arsenic pollution is the largest, accounting for approximately About 40% of the arable land, more than 700 million mu of fertile land." Chen Tongbin said.

The pollution of pesticides and chemical fertilizers is equally ferocious. Zhang Weili, a researcher at the Chinese Academy of Agricultural Sciences, told Time Weekly that “China’s pesticide use amounted to 1.3 million tons, which is 2.5 times the world average”.

According to a study by the Yunnan Agricultural University, only about 0.1% of the pesticides that are used in large quantities each year can act on target pests, and 99.9% of pesticides enter the ecosystem, causing heavy organic pollution of heavy metals in the soil.

Some experts also pointed out that China is the world’s largest producer and consumer of chemical fertilizers. “In less than one-tenth of the world's total amount of arable land, the total amount of chemical fertilizers applied every year has reached 1/3 of the world's total. The delivery volume is 1.7 times that of the United States."

According to the result of the agricultural sector's monitoring of agricultural environmental quality in the past five years, the area of ​​agricultural production in the Xiangjiang River basin has been contaminated with more than 1.18 million mu of heavy metals, of which about 190,000 mu are heavily polluted, accounting for 16%; and about 390,000 mu are moderately polluted. , accounting for 33%; light pollution of more than 600,000 acres, accounting for more than 50%. The Xiangjiang River Basin has become the hardest hit by heavy metal pollution in Hunan Province. The main pollutants are cadmium and arsenic. The cadmium pollution is the most serious. The over-standard rate of cadmium in soil is as high as 64%.

Urban soil is also the hardest hit by industrial pollution. Accompanied by the acceleration of the urbanization process in China, a large number of contaminated lands left behind after the relocation and reconstruction of industrial and mining enterprises in a large number of cities.

These contaminated industrial sites due to the relocation of factories are called "brown blocks." In these places, the sources of pollutants are mainly heavy metals, electronic wastes, petrochemical organic pollutants and persistent organic pollutants. They can infiltrate into the soil, underground pipes, ground water, etc., with slow volatilization and toxicity, which may harm the human body and may even cause cancer.

The 2010 World Bank's “Analysis of Current Status of Remediation and Redevelopment of Contaminated Sites in China” stated that surveys of relevant experts in cities such as Beijing, Shenzhen, and Chongqing have shown that “in recent years, there have been nearly 1 sites left behind by relocation of industrial companies. /5 There is more serious pollution."

So, what is the total number of contaminated land in China? In 2006, Zhou Shengxian, who was the head of the State Environmental Protection Administration, once disclosed the status of soil pollution: In 2006, there were about 150 million acres of contaminated farmland in China, 32.5 million acres of polluted arable land for sewage irrigation, and land occupied by solid waste and destroyed fields. 200 million mu, which together account for about 1/10 of the total area of ​​cultivated land, most of which are concentrated in economically developed areas. However, there are also a number of experts clearly stated that "these data are based on estimates from the 1990s and are already older, and now the data is much more serious than the above data."

In fact, after several decades of precipitation, heavy metal pollution in China's soil is entering a concentrated and prolonged period. According to Ren Guanping, Secretary-General of the Chinese Society of Environmental Sciences, with the accelerating process of urbanization, serious environmental hazards caused by heavy metal pollution in the soil of China have occurred and have gradually increased.

As early as 2006, the Ministry of Environmental Protection and the Ministry of Land and Resources jointly launched the first national survey of soil pollution and plans to complete it in 2010. The survey focused on areas such as the Yangtze River Delta, the Pearl River Delta, the Bohai Rim region, and the Northeast Old Industrial Base.

It is reported that the investigation has been completed for nearly two years, but the results of the investigation have not been announced yet. On June 5, Wu Xiaoqing, the deputy minister of the Ministry of Environmental Protection, revealed that the Ministry of Environmental Protection will report on the investigation results to the State Council executive meeting in the near future. After the approval of the State Council, the investigation results will be announced in due course.

Huge capital governance

The grim situation of land pollution has prompted the government to invest heavily in governance.

According to the "Planning", during the "Twelfth Five-Year Plan" period, the central government funds for the restoration of contaminated soil in the country will reach 30 billion yuan, and the total investment in the industries that have been promoted may reach hundreds of billions of yuan.

Chen Tongbin introduced that although China's soil remediation business started earlier, it was already proposed during the "6th Five-Year Plan" period, but it did not develop well thereafter.

The plan shows that during the “Twelfth Five-Year Plan” period, 14 provinces, regions and cities including Inner Mongolia, Jiangsu, Zhejiang and Jiangxi, which are currently the most heavily polluted by heavy metals, will be piloted, and the sources of key pollutants such as arsenic, lead, chromium, and mercury will be fully activated. Reductions and soil remediation work, especially for soil pollution left by historical sites of responsible parties, should increase investment in rehabilitation.

In fact, although there are various types of treatment technologies for soil heavy metal pollution, they are mainly divided into three major categories, namely, purification (remediation of contaminated soils by plants such as alfalfa grasses and southeast sedum), passivation (through sepiolite, etc.) Minerals absorb heavy metal elements) and avoid damage (use "guest soil" to convert contaminated soil).

According to the plan, the nationwide soil remediation work will focus on the three major areas of contaminated farmland, urban “brown plots” and contaminated sites in industrial and mining areas.

Among them, urban contaminated soil remediation is mainly divided into two major areas: historical legacy and newly developed pollution. The main operating model of urban soil remediation is to govern the responsibility of the main unit through tendering for the treatment of the project, and the successful bidder repairs the company through soil replacement for off-site rehabilitation. At present, the remediation of urban polluted soil is mainly concentrated in first-tier cities such as Shanghai and Beijing.

The remediation of contaminated soil in farmland is mainly through the planting of plants that do not enter the food chain on the soil to specifically adsorb heavy metal elements in the soil.

This time, the central government’s investment also includes the launch of a major national special project on soil pollution control and rehabilitation. It is understood that the technical R&D and engineering pilots will become the two major players in policy support for soil remediation.

In addition, with the introduction of the "Plan", a series of financial subsidy policies have been introduced around the soil. For example, for the pollution land left behind by the city, the central government proposed to implement a 30%-45% financial subsidy for the governance projects of different original responsible entities.

"Control of soil heavy metal pollution has become the focus of the country's 12th five-year environmental protection work, but soil remediation is currently still in its infancy. With the strong promotion of policies, there will be great potential for industrialization," said Chen Tongbin.

According to media reports, the industrial chain for soil remediation involves major aspects such as the assessment of the pollution status in the early stage, the design and operation of the later stage of the project, and the monitoring of the effects of pollution control. At present, among the A-share listed companies, Yongqing Environmental Protection and Tiehan Ecology in the field of engineering services, and pollutant detection, and Chinese testing and testing are involved in these businesses. With the acceleration of the industrialization of soil remediation, these leading companies with project and technology reserves are expected to focus on benefits.

Ren Guanping, Secretary-General of the Chinese Society of Environmental Sciences, said: "In general terms, the decision for remediation of contaminated soils in China has evolved from a remediation target based on the total amount of pollutants to a rehabilitation-based assessment based on pollution risk assessment; it has been technically restored from physical and chemical sources. The development of bioremediation and natural attenuation has evolved from a single technology to a multi-technical joint, integrated and integrated engineering remediation technology; equipment has also evolved from on-site repair based on stationary equipment to on-site repair of mobile equipment."

However, some people in the industry do not recognize the government’s practice of spending money on current soil remediation. In their view, the move is for polluting companies to "polluterize money and walk, government pays bills."

According to the above-mentioned experts, many state-owned and collectively-owned enterprises that have polluted the soil have gone bankrupt, regardless of “whoever benefits from pollution control” or “whoever pollutes”. The government, as owner of property rights, should assume responsibility for repairs. At the same time, soil pollution should be incorporated into the regulation of environmental normals.

Prevention and control problems

Due to the time-delayed nature of soil contamination, if the soil is not repaired, soil heavy metals will continue to accumulate, and problems that do not arise now will gradually appear in the future. However, under realistic circumstances, there are many kinds of governance problems, both in terms of pre-prevention and post-event control.

First of all, the soil is heavy and the repair cost is high. Where does the money come from? Yang Jide, director of the Suzhou Institute of Environmental Science, told reporters that Suzhou Chemical Plant had 600 mu of land and was treated with 60% of the contaminated area, 666 square meters per mu, such as 5 meters deep, ie 3330 cubic meters, per cubic meter. 1.9 tons of rice, such as 1,000 yuan per ton of soil repair, governance should be 2 billion. If you manage by 3 meters deep, it will cost more than 1 billion yuan. This is true of only one factory, which can be imagined throughout the country.

The reporter learned that the U.S., with almost the same land area, invested almost 100 billion U.S. dollars in contaminated soil remediation in the 1990s, reaching a huge investment scale of an average of 10 billion U.S. dollars per year. If we count inflation, This investment is equivalent to 30 billion to 40 billion U.S. dollars today. "It's definitely not enough for 300 million *** in five years."

In addition to financial factors, the lack of land-control technology is the second difficult issue facing the treatment of poisonous land. Because soil remediation is time consuming, costly, and the disposal process is more complex, and it is prone to secondary pollution, the types of soil pollution currently vary, presenting both old and new pollutants coexisting and inorganic-organic compound pollution.

According to Jiang Lin, deputy director of the Beijing Research Institute of the Central Academy of Sciences, there are few domestic specialized rehabilitation companies, and most of them are still in the initial stage of development.

According to the procedure of soil remediation, the remediation company must first conduct an environmental assessment of the contaminated sites, and follow the same procedures as the “medical treatment, diagnosis, and treatment”. Soil sampling, laboratory tests, and analysis and diagnosis are all necessary links.

The lack of relevant laws and national technical standards is the third problem. "China's soil lacks corresponding standards for heavy metals, and there is no evaluation index system for arable land heavy metals, and we cannot correctly evaluate the environmental quality of arable land," said Chen Mengyu, a researcher at the Nanjing Institute of Soil Science, Chinese Academy of Sciences.

In his opinion, the state must issue the relevant laws of the "Remediation Law" and the national technical standards for soil remediation as soon as possible, so that soil remediation can be justified.

The situation held by our reporter is that Beijing, Wuhan, Chongqing, Guangxi and other provinces, autonomous regions, and municipalities that have already carried out repairs follow the standards issued by local environmental protection agencies.

According to some industry insiders interviewed, in addition to the aforementioned difficulties, the most critical aspect of land governance is still the rationalization of the management system and the determination of the local government.