Through a semester of study, I have a deeper understanding of the relationship between people and the environment. I also realize that our environment is in danger and needs my treatment urgently. Although a person's strength is insignificant, everyone's responsibility and mission to protect the environment is inescapable. Everyone should consciously understand and protect the environment. The following is my understanding of the present situation of air pollution in China and some prevention and control methods after studying the course of "People and Environment".
At present, the air pollution in China is very serious, mainly characterized by 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. The main sources of air pollutants in China are as follows: (1) Present situation of sulfur dioxide emission With the rapid development of China's economy, coal consumption is increasing. (2) Smoke and dust emissions, national coal-fired emissions and thermal power plant emissions. Because local power plants basically use inefficient dust collectors, the dust emission per ton of coal far exceeds the national standard. In China's industrial dust emissions, there are dust emissions from steel production and dust emissions from cement production. (3) In recent years, township industries have developed rapidly. The results of the national survey of industrial pollution sources in towns and villages show that the emissions of industrial sulfur dioxide, smoke dust and industrial dust in towns and villages accounted for 28.2%, 54.2% and 68.3% of the national emissions of industrial sulfur dioxide, smoke dust and industrial dust respectively. The discharge of pollutants from township industries has become an important factor of environmental pollution in China. (4) Vehicle exhaust pollution. Since 1980s, driven by economic growth, the number of motor vehicles in China has increased rapidly. The annual growth rate of car ownership in China remains at 13%. The total amount of nitrogen oxides, carbon monoxide and hydrocarbons emitted by automobiles.
Rising year by year. Due to the dense population and relatively large traffic volume, the proportion of motor vehicle exhaust pollution in urban air pollution is also rising.
In addition, the awareness of environmental protection is weak and the understanding of sustainable development strategy is insufficient. Atmospheric environment is a precious resource for human survival, and the destruction of atmospheric environment resources is an irreversible process. It is more economical to restore good atmospheric environmental quality than to take measures to fundamentally prevent and control air pollution. In China, unreasonable energy use and serious energy waste are one of the reasons for serious air pollution. Moreover, China's investment in air pollution prevention and control is insufficient. At present, the national investment in pollution prevention and urban infrastructure construction related to pollution prevention only accounts for 0.7% of the gross national product. There is also lax law enforcement and insufficient 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.
We can take some measures to prevent and control air pollution.
The comprehensive prevention and control of air pollution must start with coordinating the relationship between regional economic development and environmental protection, comprehensively investigate and study the types, quantities and temporal and spatial distribution of various pollutants discharged by various pollution sources in this area, and formulate the best pollution control scheme on this basis. The industrial production area should be located in the downwind of the dominant wind direction in the city. The factory should keep a certain distance from the urban living area and plant trees to reduce pollution hazards. For enterprises with serious pollution, waste of resources and hopeless governance, measures such as closing, stopping, merging, transferring and moving should be implemented.
In improving the energy structure and improving the effective utilization rate of energy, coal is the main energy structure in China, accounting for 73% of the total consumption of commodity energy. In the process of coal combustion,
Sulfur dioxide, nitrogen oxides, carbon monoxide, suspended particles and other pollutants are released in large quantities. Therefore, to fundamentally solve the problem of air pollution, we must first improve the energy structure, such as using natural gas and secondary energy sources, such as gas, liquefied petroleum gas and electricity. We should also pay attention to the use of so-called clean energy such as solar energy, wind energy and geothermal energy. China's coal-based energy structure will not change fundamentally in the short term. Therefore, at present, we should first promote the production and use of briquette and coal washing to reduce the emission of smoke and sulfur dioxide.
An effective measure to control air pollution is to plant trees and choose forests to green the environment. Afforestation is an economical and effective measure to prevent and control air pollution. Plants have the function of absorbing all kinds of toxic and harmful gases and purifying the air. Plants are natural filters of air. Dense jungle can reduce the wind speed and reduce the large particle dust carried by airflow. The surface of leaves is rough and fluffy, and the leaves of some tree species also secrete mucus, which can absorb a lot of floating dust. After being washed away by rain, the dusty leaves can restore the functions of adsorption and blocking dust, so that the air can be purified.
There are several ways to remove particulate pollutants from the atmosphere:
① Dry removal of particulate pollutants
Through the gravity and centrifugal force of the particles themselves, the particle pollution in the gas is settled and removed from the gas, such as gravity dust removal, inertia dust removal, centrifugal dust removal, etc. Commonly used equipment includes gravity settling chamber, inertial dust collector and cyclone dust collector.
② Wet removal of particulate pollutants
A method of wetting particles with water or other liquids and capturing and removing them. Such as gas washing, foam dust removal, etc. Common equipment includes: spray tower, packed tower, foam dust collector, venturi scrubber, etc.
③ Filtering to remove particulate pollutants.
A method of passing gas containing particulate pollutants through a filter material with many holes and retaining particulate pollutants, such as packed bed filtration, bag filtration, etc. Commonly used equipment includes granular layer filter and bag filter.
④ It is everyone's responsibility to remove particulate pollutants by electrostatic method and protect the environment. Puweixin Tiantong imported from the United States can effectively prevent smog.