Present situation and countermeasures of air pollution

College:

Instructor:

Specialized courses:

Student name:

Student number:

Present situation and countermeasures of air pollution

Abstract: We human beings live in the bottom of the earth's atmosphere, and we can't live without it for a moment. The atmosphere provides an ideal environment for the reproduction of life on earth and the development of human beings. Its state and changes always affect human activities and survival everywhere. With the development of economy and people's lack of awareness of atmospheric protection, air pollution is becoming more and more serious. It is more and more important to improve the environmental awareness of the whole people and prevent and control air pollution.

Keywords: air pollution prevention, healthy environment, sustainable development

Present situation and countermeasures of air pollution

Summary:

We humans live at the bottom of the earth's atmosphere, and there is no atmosphere at all. The atmosphere provides an ideal environment for life reproduction and human development on earth. Its status and changes always affect human activities and survival. along with

Economic development and people's lack of awareness of protecting the atmosphere, air pollution is

It's getting worse Raise people's awareness

Environmental protection to prevent air pollution.

Pollution is becoming more and more important.

Key words:

Air pollution prevention

Control a healthy environment

sustainable development

1 The concept of air pollution is defined by the International Organization for Standardization (ISO). Air pollution usually refers to the phenomenon that some substances enter the atmosphere due to human activities or natural processes, showing sufficient concentration and reaching sufficient time, thus endangering human comfort, health and welfare or environmental pollution.

Atmospheric pollutants are mainly divided into harmful gases (carbon dioxide, nitrogen oxides, hydrocarbons, photochemical smog halogen elements, etc. ) and particulate matter (dust, acid mist, aerosol, etc.). Their main sources are factory emissions, automobile exhaust, land reclamation, forest fires, kitchen smoke (including roadside barbecues) and dust (including construction sites).

2 the current situation of air pollution

2. 1. Current situation of total emission of air pollutants At present, the air pollution situation in China is very serious, mainly manifested as soot pollution. The concentration of total suspended particles in urban atmospheric environment generally exceeds the standard; Sulfur dioxide pollution remains at a high level; The total emission of motor vehicle exhaust pollutants increased rapidly; The pollution of nitrogen oxides is becoming more and more serious; There are many acid rain areas in Central China, Southwest China, East China and South China, especially in Central China. 2.2 Weak awareness of environmental protection. Lack of understanding of sustainable development strategy. When formulating some comprehensive economic policies, industrial policies and urban construction and development plans, people only consider short-term and local economic development needs, but lack consideration of protecting the atmospheric environment. Therefore, the introduction of local policies that lack environmental protection considerations is itself an inducement to aggravate air pollution, and the environmental harm and losses caused are irreparable. 2.3 Energy, unreasonable use and serious waste of energy is one of the causes of serious air pollution in China, mainly including: (1) In China's primary energy consumption structure, coal accounts for 75%, while coal for power generation only accounts for 35% of the total coal, and other coal is used for industrial and civil combustion, and coal for direct combustion accounts for 84%, which constitutes this coal consumption. (2) China's coal production pays too much attention to the increase of output and not enough attention to the control of high-sulfur coal, which is mainly manifested in the low coal washing rate and the rapid growth of coal output in high-sulfur coal areas. . (3) The technology and manufacturing level of all kinds of combustion equipment are low, and the energy utilization rate is not high. It is quite common to use combustion equipment with high energy consumption, large sewage discharge and extended service. (4) With the rapid development of township industries, the production technologies and processes adopted by most enterprises are relatively backward, the production equipment is crude, and the utilization rate of resources and energy is extremely low, resulting in amazing air pollution. 2.4. Insufficient investment in air pollution prevention and control (1) The starting point of China's industrial development is low, the overall level of basic industries is slow to improve, technological transformation is difficult, and there are many pollution debts. (2) The national investment in implementing the clean coal policy and improving the energy structure, such as coal washing and processing, briquette, coal desulfurization and the use of clean energy, is too weak to meet the needs. (3) Urban central heating, gas and other infrastructure projects are the main measures to solve urban atmospheric environmental pollution. However, many areas are still developing slowly, and the key is the problem of insufficient capital investment. (4) The standard of sewage charges is too low, which makes polluting enterprises prefer to pay sewage charges rather than spend money on treatment. 2.5 lax enforcement, inadequate supervision and management. Although great progress has been made in the construction of laws and standards for the prevention and control of air pollution in China, the phenomenon of non-compliance with laws, lax enforcement and impunity is still very serious. (1) Some local governments intervene in the law enforcement of environmental protection departments and approve the construction of industrial projects with good short-term economic benefits but high energy consumption and serious air pollution; Failure to implement the national regulation of "evaluation first, then construction" has led to some new unreasonable layout and construction projects with excessive pollution. (2) local power plants, local cement plants and township enterprises are lax in law enforcement, and the phenomenon of exceeding the standard is more common. (3) Due to the limitation of funds, local monitoring institutions generally can't conduct regular supervision and monitoring of pollution sources, thus weakening the daily supervision and management of pollution sources by environmental protection departments. The operation and management of environmental protection facilities are poor, and the actual operation rate is low. Although many projects can reach the standard at the time of acceptance, they have exceeded the standard in actual operation. It is estimated that the average over-standard rates of smoke and dust emissions from industrial boilers, industrial kilns and local cement industries are 30%, 50% and 40% respectively. (4) The prevention and control of motor vehicle pollution started late, and the tail gas supervision and management mechanism has not really been established. The supervision and law enforcement departments have unclear responsibilities and weak supervision, especially in the whole process of automobile manufacturing, sales, use and scrapping. 2.6 Lack of practical control technology. Although China has done a lot of work in the research, development, popularization and use of air pollution control technology and equipment, there is still a big gap with the demand of air pollution control. The investment of capital and manpower and the weak field are clean coal technology; Pollution control technology of industrial furnaces and production facilities in metallurgy, chemical industry, building materials and other industries; Purification technology in motor vehicles, etc. The lack of practical technology directly affects the process and effect of air pollution control.

3 Harm of air pollution

3. 1 Harm to human health

3. 1. 1 acute poisoning

When the concentration of pollutants in the atmosphere is low, it usually does not cause acute poisoning, but under some special conditions, such as special accidents in the production process of factories, a large number of harmful gases leaking out, and sudden changes in external meteorological conditions. It can cause acute poisoning. For example, methyl isocyanate leaked from Pabor pesticide plant in India directly harms human body, with 2,500 people killed and1100,000 injured.

3. 1.2 Chronic poisoning

The chronic toxic effect of air pollution on human health is mainly manifested in the increase of morbidity after long-term low-concentration exposure of pollutants to human body. In recent years, the incidence of lung cancer among urban residents in China is very high, the highest of which is Shanghai, and the respiratory diseases of urban residents are significantly higher than those in suburbs.

3. 1.3 Carcinogenesis

This is the result of long-term effects, because pollutants act on the body for a long time, destroying the genetic material in the body and leading to variation. If germ cells mutate, all kinds of abnormalities will appear in offspring, which is called teratogenesis. If the genetic material and genetic information of organism cells suddenly change, it is also called mutagenicity; If the tumor is induced, it is called canceration. The "cancer" mentioned here includes benign tumors and malignant tumors. Carcinogens in the environment can be divided into chemical carcinogens, physical carcinogens and biological carcinogens. The canceration process is quite complicated, generally including the initial stage and the growth promotion stage. Factors that can induce tumors are collectively referred to as carcinogenic factors. Tumors caused by long-term exposure to carcinogenic factors in the environment are called environmental tumors.

3.2 Harm to industrial and agricultural production

Air pollution is very harmful to industrial and agricultural production, which will affect economic development and cause a lot of loss of manpower, material resources and financial resources. There are two kinds of hazards of atmospheric pollutants to industry: one is the corrosion of industrial materials, equipment and building facilities by acidic pollutants, sulfur dioxide and nitrogen dioxide in the atmosphere; Second, the increase of floating dust has brought adverse effects on the production, installation, debugging and use of precision instruments and equipment. The harm of air pollution to industrial production, from an economic point of view, is to increase production costs, raise costs and shorten the service life of products.

Air pollution is also very harmful to agricultural production. Acid rain can directly affect the normal growth of plants, and can also cause acidification and dissolution of toxic components in soil and water by infiltrating into soil and water, thus causing toxicity to animals, plants and aquatic organisms. Severe acid rain will make forests decline and fish disappear.

3.3 Impact on the atmosphere and climate

Air pollutants can also affect weather and climate. Particulate matter will reduce atmospheric visibility and reduce the amount of solar radiation reaching the ground. Especially in large industrial cities, the sunshine is 40% less than normal when the smoke and dust are not scattered. The pollutants in the upper atmosphere, such as nitrogen oxides, hydrocarbons and chlorofluorocarbons, decompose ozone in large quantities, resulting in the "ozone hole" problem, which has become the focus of global attention.

Most of the particles discharged into the atmosphere by factories, power stations, automobiles and small domestic coal stoves have the function of condensation nuclei or freezing nuclei of water vapor. These particles can adsorb water vapor in the atmosphere and condense into water droplets or ice crystals, thus changing the original precipitation (rain and snow) in this area. It is found that in the downwind area not far from big industrial cities, the precipitation is more than other surrounding areas, which is the so-called "laporte effect". If acidic pollutants are entrained in the center of particles, they may be attacked by acid rain in the downwind area.

Air pollution not only has a bad influence on the weather, but also on the global climate has gradually attracted people's attention. The greenhouse effect caused by the increase of carbon dioxide concentration in the atmosphere is the most important influence on the global climate. Global warming will bring many adverse effects to human ecological environment, and human beings must fully realize this.

4 air pollution protection measures

4. 1. Reasonably arrange industrial layout and urban functional zoning.

The rational layout of industry should be comprehensively considered in combination with urban planning. General industrial areas should be located on the edge of the city or in the suburbs, and the location should be on the downwind side of the local maximum frequency wind direction, so that the number of times waste gas is blown into residential areas is the least. No harmful industrial enterprises shall be built in residential areas.

4.2. Strengthen greening

Plants not only beautify the environment, but also have the functions of regulating climate, blocking, filtering and adsorbing dust and absorbing harmful gases in the atmosphere.

4.3. Control coal pollution

① About 40%-60% of inorganic sulfur in coal can be removed by using raw coal desulfurization technology. Give priority to low-sulfur fuels, such as low-sulfur coal and low-sulfur natural gas. (2) Improve coal burning technology to reduce the emission of sulfur dioxide and nitrogen oxides during coal burning. For example, liquid coal combustion technology is one of the new technologies welcomed by all countries. Limestone and dolomite are mainly used to react with sulfur dioxide, and the generated calcium sulfate is discharged with ash. The flue gas formed after coal combustion is desulfurized before being discharged into the atmosphere. ③ Develop new energy sources, such as solar energy, wind energy, nuclear energy and combustible ice. However, the current technology is not mature enough. If it is used, it will cause new pollution and the consumption cost is high.

4.4. Strengthening process measures

(1) strengthening process. Replace toxic raw materials with non-toxic or low-toxic raw materials. Closed-loop circulation is adopted to reduce the removal of pollutants. ② Strengthen production management. Prevent all possible exhaust gases from polluting the atmosphere. ③ Comprehensive utilization turns waste into treasure.

4.5. Transport waste gas treatment

Reduce automobile exhaust emissions. Mainly to change the engine combustion design, improve the combustion quality of oil products and strengthen traffic management. In order to solve the problem of automobile exhaust, automobile catalytic converter is usually installed to make the fuel burn fully and reduce the emission of harmful substances. The catalyst in the converter is a high-temperature porous ceramic carrier with finely dispersed palladium and platinum on its surface, which can convert NOX, HC and CO into harmless substances such as nitrogen, water and carbon dioxide. In addition, we can also develop new fuels, such as methanol, ethanol and other oxygenated organic matter, vegetable oil and gas fuel, to reduce the emission of tail gas pollution. Effectively controlling the development of private cars, expanding the transportation scope and capacity of subways, and using green buses (using liquefied petroleum gas and compressed gas) are also effective ways to solve environmental pollution.

4.6. Chimney dust removal

The control technology of sulfur dioxide in flue gas can be divided into dry method (using solid powder or particles as absorbent) and wet method (using liquid as absorbent). The higher the chimney, the more conducive to the diffusion and dilution of flue gas. Generally, when the chimney height exceeds 100m, the effect is very obvious, and it is not economical to increase the cost greatly if it is too high. It should be pointed out that this is a way to reduce local ground pollution at the expense of expanding the pollution range.

5 air pollution and sustainable development 1 local governments are responsible for environmental quality and take the road of sustainable development. Governments at all levels should be responsible for the quality of atmospheric environment in their respective jurisdictions and fully understand the importance of taking the road of sustainable development. When studying major strategies and major projects of economic and social development, we should fully consider the requirements of environmental protection. The quality of urban atmospheric environment should generally reach the national second-class standard. Take measures to implement the cross-century green project planning and the total emission control plan of major pollutants, decompose the total indicators according to the local atmospheric environmental quality control objectives, and guarantee them from the aspects of funds, supervision and management. Especially for large, medium and small projects that emit sulfur dioxide and dust, effective measures must be taken to control the total amount of pollutants, or the project construction unit or the local people's government is responsible for reducing the emissions of other pollution sources in the region to ensure that the emissions of atmospheric pollutants are controlled within the regional total control index. 2. Develop clean energy and improve the energy consumption structure. Gradually reduce the direct consumption of coal and increase the consumption ratio of clean energy such as gas and electricity. Gradually improve the quality and grade of vehicle fuel, accelerate the elimination of leaded gasoline, and make China's gasoline develop to lead-free and high-grade as soon as possible. In 2000, the production, sale and use of leaded gasoline were banned. Actively develop various low-pollution vehicles, such as natural gas vehicles, liquefied gas vehicles, methanol vehicles and electric vehicles. 3. Carry out coal washing and processing to control coal pollution with high sulfur and ash. Strictly controlling the mining of high-sulfur and high-ash coal and carrying out coal washing are important measures to reduce sulfur dioxide emissions. It is stipulated (1) that coal mines with sulfur content greater than 3% will no longer be approved, and existing coal mines with sulfur content greater than 3% will be limited in production, mixed mining or shut down; (2) Vigorously improve the raw coal washing rate. New coal mines with sulfur content greater than 1.5% need to build coal washing facilities. In 2005, coal washing facilities will be built for existing coal mines with sulfur content greater than 2% and inorganic sulfur content greater than 50% of total sulfur content; (3) The coal grindstone that has not recovered pyrite after coal washing cannot be used as fuel for power generation; 4. Eliminate backward production processes, prevent and control industrial waste gas pollution, eliminate backward processes and equipment that seriously pollute the environment, adopt clean processes with high technical starting point, minimize the waste of energy and resources, fundamentally reduce the generation and discharge of pollutants, and reduce the capital investment required for terminal pollution control. 5. Strengthen the practical technology of air pollution prevention and control. Based on the national conditions, we should develop and popularize practical technologies for air pollution prevention and control as soon as possible, which are technically reliable, economical and reasonable, and the supporting equipment can meet the standards. Key areas include coal washing to remove organic sulfur, industrial briquette, circulating fluidized bed boiler, coal gasification and liquefaction, flue gas desulfurization, converter steelmaking and dust removal, coke oven flue gas control, ceramic tile kiln black smoke control and so on. 6. Improve the environmental supervision and management system: it mainly includes: (1) All the units that discharge air pollutants exceeding the standard will reach the standard by 2000, formulate the implementation plan, implement the governance funds, and complete the governance tasks within a time limit by stages. (2) Allocate the total pollutant discharge indicators to the pollutant discharge units and implement the pollutant discharge permit system, so that the pollutant discharge units can clearly define their respective total pollutant discharge control targets and effectively control the total pollutant discharge. Sewage units must organize production according to the requirements of environmental quality and the allowable discharge approved by the environmental protection department. (3) The supervision mechanism of environmental protection in industrial departments has been established, and all departments are required to take practical measures to implement the Ninth Five-Year Plan for environmental protection in this industry. (4) The pilot area of sulfur dioxide pollution charge has been expanded from "two provinces" and "nine cities" to "two control areas". Raise the charging standard of sulfur dioxide pollution discharge, so that it will gradually reach a level higher than the cost of treatment, and urge pollutant discharge enterprises to actively increase investment and take the initiative to control pollution.

Ten most advanced air pollution control technologies

1, clean HEPA filter.

Ultrafine glass fiber absolute filter is more effective than fiber filter. Continuous cleaning technology enables it to be used for pollution control. The new air toxicity law will make the emission of the most toxic substances only a few pounds a year. This can only be achieved through clean HEPA filters, while traditional fiber filters emit hundreds of pounds of toxic substances every year.

2. Condensing heat exchanger

The test results in Europe and the United States show that the condensing heat exchanger can greatly reduce the emission of toxic substances and reduce the power cost. It can get more heat from waste gas, improve the efficiency of converting coal or oil into electricity by 4%, and reduce the consumption of greenhouse gases. Its greater advantage is to condense heavy metals and remove various air toxins.

3, the pollution is small, and a complete incineration system is used.

This new technology is being adopted in Europe at present. The primary dust collector produces industrial hydrochloric acid, and the secondary dust collector produces gypsum for wallboard. Heavy metals are sealed in vitrified products made of mountain ash (inert material). This so-called gas mask technology also includes the final activated carbon filter, which can eliminate all dirt.

4. Continuous emission monitoring technology for quality measurement

Several new technologies in Europe can continuously measure the weight of discharged particulate pollutants. It is much more accurate than opaque monitors and fully complies with the new air pollution regulations.

5. Improvement of pulse jet engine for utility boiler.

Replacing internal dust collector with pulse jet filter or replacing related dust collector with small high-speed tail pulse jet filter opens up a new way to reduce particulate matter.

6. Sulfur dioxide separation system in sulfur and sulfuric acid production

The technology of converting sulfur dioxide in furnace gas into useful sulfur and sulfuric acid at low cost is constantly improving. Catalyst conversion, separation and on-site ammonium sulfate production technology will soon enter commercialization.

7. Solid and semi-solid filter media

Many new materials, from low-temperature plastics to high-temperature ceramics, are gradually used to make solid and semi-solid filter media, providing various advanced properties, including high efficiency, long life and high temperature resistance.

8. wesp

This ancient technology has a new application, which can be used in terminal devices to remove a lot of heavy metals and moisture. The development of new materials, especially plastics, has brought this technology into full play.

9, the use of particulate medium to remove SO2 technology

The United States has allowed the application of liquid or solid lime or limestone beds in the drying systems of power station boilers and industrial boilers to remove SO2. This technology can remove more than 90% SO2 with a relatively small amount of calcium.

10, zeolite technology

Zeolite has been proved to have many new uses in adsorption and catalysis, and has outstanding performance in capturing NO2 and VOCS, so it has a very broad application prospect.

References:

Yang; Laser telemetry of air pollution [J]; Laser magazine; 1980 03

Gao yuan; Present situation and countermeasures of air pollution in China [J]; The influence of science on society; 1994 0 1

Mao Zhiping; On air pollution [A]: the second annual academic meeting of China Cultural Relics Protection Technology Association [c]; In 2002

Huang Zhenzhong. Overview of air pollution control technology in China [J]. World Science and Technology Research and Development, 2004,26 (2): 30-35.

Huang cheng. Present situation of urban air pollution in China and its control countermeasures [J]. Science and Technology Information, 2008 (2 1): 136, 13.

Shao Hong, this is Lin Yue. Prevention and control of air pollution by ecological control method [c] ∑ Excellent paper of the annual meeting of natural science in Inner Mongolia Autonomous Region in 2003. Hohhot: 2003 Inner Mongolia Autonomous Region Natural Science Annual Meeting, July 2003.

Zhang and Liu Wei. On urban air pollution in China [J]. Silicon Valley, 2008( 19): 18.