In recent years, with the development of industry and the increase of means of transportation, air pollution has become more and more serious, causing great harm to the human body and seriously damaging the environment. Therefore, it is necessary to control air pollution, reduce pollutant emissions, and prevent air pollution. So what are the air pollution prevention and control measures? The following editor is introduced in detail in this article.
The concept of air pollution
Air pollution, also known as air pollution, according to the definition of the International Organization for Standardization (ISO), air pollution usually refers to the phenomenon that certain substances enter the atmosphere due to human activities or natural processes, present sufficient concentrations, reach sufficient time, and thus endanger the comfort, health and welfare of the human body or the environment.
The hazards of air pollution
1. Acute poisoning
When the concentration of pollutants in the atmosphere is low, it usually does not cause acute poisoning of the human body, but under some special conditions, such as special accidents in the production process of the factory, a large number of harmful gases leakage and discharge, and sudden changes in external meteorological conditions, it will cause acute poisoning of the population.
2. Chronic poisoning
The chronic toxic effect of air pollution on human health is mainly manifested in the increase in the prevalence of pollutant substances after low concentration and long-term continuous action on the human body. In recent years, the incidence of lung cancer in urban residents in China is very high, and the highest incidence is in Shanghai, where respiratory diseases are significantly higher among urban residents than in suburban areas.
3. Carcinogenicity
This is the result of long-term effects, which are due to the fact that pollutants act on the body for a long time, damage the genetic material in the body, cause mutations, and if the germ cells are mutated, the offspring body will have various abnormalities, which is called teratogenicity; If it causes a sudden change in the genetic material and genetic information of the organism, it is also called mutagenicity; If the effect of inducing a tumor is called carcinogenicity. The process of carcinogenesis is quite complex, and there are generally initiation stages and growth promotion stages. 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. Air pollution can lead to a decrease in a person's lifespan.
Air pollutants are mainly divided into harmful gases (carbon dioxide, nitrogen oxides, hydrocarbons, photochemical smog and halogen elements, etc.) and particulate matter (dust and acid mist, aerosols, etc.). Their main sources are factory emissions, vehicle exhaust, agricultural burning, forest fires, cooking smoke (including roadside barbecues), dust (including construction sites), etc.
Air pollution prevention and control measures
1. Rationally arrange the industrial layout and urban functional zoning. The rational layout of industry should be fully considered in combination with urban planning. Industrial zones should generally be located at the edge of the city or in the suburbs, and should be located on the downwind side of the local maximum frequency wind direction, so that the exhaust fumes blow the residential area with the least number of times. Harmful industrial enterprises shall not be built in residential areas.
2. Strengthen greening. In addition to beautifying the environment, plants also have the functions of regulating the climate, blocking, filtering and adsorbing dust, and absorbing harmful gases in the atmosphere.
3. Strengthen the management of local pollution sources in residential areas. For example, chimneys, waste dumps, garbage bins, etc., such as restaurants, public baths, etc., can emit harmful gases to pollute the atmosphere and affect indoor air, and the health department should cooperate with relevant departments to strengthen management.
4. Control coal pollution.
(1) Using raw coal desulfurization technology, about 40% to 60% of inorganic sulfur in coal can be removed. Priority is given to low-sulphur fuels, such as low-sulphur coal and natural gas, which contain less sulphur.
(2) Improve coal-fired technology to reduce emissions of sulfur dioxide and nitrogen oxides in the process of coal combustion. For example, liquefied coal-fired technology is one of the new technologies that has been welcomed by various countries. It is mainly used to add limestone and dolomite, react with sulfur dioxide, and generate calcium sulfate and discharge with ash. The flue gas formed after coal combustion is desulfurized before it is discharged into the atmosphere.
(3) Develop new energy, such as solar energy, wind energy, nuclear energy, combustible ice, etc., but the current technology is not mature enough, if it is used, it will cause new pollution, and the consumption cost is very high.
5. Strengthen process measures.
(1) Strengthen the process. Non-toxic or low-toxicity raw materials are used instead of highly toxic raw materials. Closed-circuit circulation is adopted to reduce the removal of pollutants, etc.
(2) Strengthen production management. Prevent all possible exhaust gases from polluting the atmosphere. (3) Comprehensive utilization: turning waste into treasure. For example, the large amount of coal ash emitted from power plants can be made into building materials such as cement and bricks. It can also recover nitrogen to make nitrogen fertilizer.
6. The establishment of large electric heating plants and heating stations for district central heating and heating, and the implementation of regional central heating and heating, especially the thermal power plants and heating stations in the suburbs, are very effective measures to eliminate smoke and dust for the northern cities with dense low chimneys and heating in winter.
7. Treatment of waste gas from transportation vehicles. Reduction of vehicle exhaust emissions. The main thing is to change the combustion design of the engine and improve the combustion quality of the oil, and strengthen traffic management. To solve the problem of automobile exhaust, it is common to install automobile catalytic converter to fully burn the fuel and reduce the emission of harmful substances.
In addition, new fuels, such as methanol and ethanol, vegetable oils and gaseous fuels, can also be developed to reduce vehicle exhaust pollution emissions. The adoption of effective control of the development of private cars, the expansion of the transportation scope and capacity of the subway, and the use of environmentally friendly vehicles such as green buses (using liquefied petroleum gas and compressed gas) are also effective ways to solve environmental pollution.
8. Chimney dust removal. Sulfur dioxide control technology in flue gas can be divided into two categories: dry (using solid powder or granules as absorbent) and wet (using liquid as absorbent). The higher the chimney exhaust chimney, the more conducive to the diffusion and dilution of flue gas, the general chimney height of more than 100m effect is very obvious, and it is uneconomical to rise sharply if the cost is too high. It should be noted that this is a way to reduce localized ground pollution at the cost of expanding the scope of pollution.
Source: Shanxi Provincial Department of Ecology and Environment
Editor: Ren Ziqi
Editor: Yu Guoshu Cui Zhikai
Review: Meng Hui
E-mail: [email protected]