Characteristics of physical contamination:
Suspended matter pollution
Suspended solids refer to insoluble substances contained in water, including solid substances and foamed plastics. They are caused by the leakage of domestic sewage, garbage and waste from mining, quarrying, construction, food processing and paper making into water or farmland soil erosion. Suspended matter affects the appearance of water, hinders the photosynthesis of plants in water and reduces the dissolution of oxygen, which is unfavorable to aquatic organisms.
thermal pollution
If the cooling water of various industrial processes is directly discharged into the water body without taking measures, it may cause the water temperature to increase, the dissolved oxygen content to decrease, and the toxicity of some toxic substances in the water to increase, thus endangering the growth of fish and aquatic organisms.
noise pollution
Noise destroys the original tranquility of nature, damages people's hearing, harms people's health and affects people's life and work. Strong noise can also cause damage to buildings and even lead to biological death. Noise has become the third public hazard after air pollution and water pollution.
traffic noise
Mainly refers to all kinds of motor vehicles, planes, trains, ships, etc. There is vibration and horn noise during driving. It is characterized by fluidity and instability. It has the greatest impact on residents on both sides of traffic trunk roads and near ports and airports.
industrial noise
Refers to the noise generated during the operation of machinery in the factory and the noise generated during the construction of the site. It is characterized by a stable noise source. People who work in factories and construction sites are direct victims, and residents near them are also deeply affected.
Social life noise
Mainly produced in commercial areas. In addition, entertainment, sports venues, parades, assemblies, publicity and other social activities will also produce noise. Others, such as the operation of household appliances, the barking of pets, the footsteps upstairs and downstairs, noise, slapstick and so on. All belong to the noise of social life.
Radioactive contamination
Radioactive pollution mainly refers to the pollution caused by man-made radiation sources, such as radioactive substances produced during nuclear weapon tests and nuclear waste discharged by enterprises that produce and use radioactive substances. In addition, due to the development of atomic energy industry, the exploitation of radioactive mineral deposits, the establishment of nuclear tests and nuclear power plants, and the application of isotopes in medicine, industry, scientific research and other fields, radioactive wastewater and waste have increased greatly, causing certain radioactive pollution.
Pollution to the atmosphere: After radioactive substances enter the atmosphere, there are usually three ways to cause radiation damage to people: ① Immersion irradiation: when the human body is immersed in the air with radioactive pollution, the whole body skin will be exposed to external irradiation. ② Inhalation radiation: Inhalation of radioactive gas will cause internal radiation to the whole body or organs such as thyroid and lungs. (3) Subsidence radiation: refers to the radiation generated by radioactive substances deposited on the ground. Such as gamma-ray external irradiation emitted by radioactive substances or internal irradiation generated by transmission into human body through food chain. The dose of subsidence radiation is generally less than that of immersion radiation and inhalation radiation, but the harmful effect lasts for a long time.
Water pollution: The fallout from nuclear tests will increase the content of radioactive substances in surface water all over the world. The radioactive waste water discharged by nuclear enterprises and the water used to wash radioactive pollutants are easy to cause radioactive pollution to the nearby sea areas. The main ways of radioactive pollution of groundwater are: direct injection of radioactive waste water into underground aquifer, discharge of radioactive waste water into ground infiltration pond and burial of radioactive waste. Radioactive substances in groundwater will also migrate and spread to surface water, causing surface water pollution. Radioactive substances pollute surface water and groundwater, affect the quality of drinking water, pollute aquatic organisms and soil, and produce internal radiation to people through the food chain.
Pollution to soil: Radioactive substances can pollute soil in many ways. For example, radioactive waste water is discharged to the ground, radioactive solid waste is buried underground, and radioactive discharge accidents of nuclear enterprises will cause serious soil pollution in some areas.
light pollution
Visible light pollution: glare is common in visible light pollution, such as headlights used for lighting when cars are driving at night, and unreasonable lighting arrangement in factory workshops will make people's vision drop instantly. The intense flash produced by a nuclear explosion can hurt people's eyes within a few kilometers. The strong light generated during electric welding will also hurt people's eyes if there are no proper protective measures. People who work under strong light for a long time (such as smelting, melting and burning, blowing glass, etc.). ) will also encounter strong light.
Pollution prevention and control:
Noise pollution protection
Noise control: At present, many countries in the world have promulgated noise control standards through legislation, and formulated strict noise control standards for aircraft and airport noise, urban traffic noise, building construction noise, factory machinery noise and social life noise. For example, the noise of factories and construction sites should not exceed 85 decibels to 90 decibels. Residential areas shall not exceed 50 decibels during the day and 40 decibels at night.
Noise is a kind of sound wave, and noise pollution is produced by noise sources and then affects people through propagation media. Noise control includes reducing the noise of noise sources, controlling the propagation path of noise and personal protection;
(1) Mechanical equipment and various vehicles controlled by sound sources are the main noise sources, and there are two ways to control their noise:
First, improve the structure, improve the machining accuracy and assembly quality of each component, and adopt reasonable operation methods to reduce the noise emission power of the sound source.
The second is to use the characteristics of sound wave absorption, reflection and interference, adopt sound absorption, sound insulation, vibration reduction and vibration isolation technologies, and install silencers to control noise radiation. Therefore, vigorously developing science and technology, developing new materials, new technologies and new processes, and popularizing the use of low-noise equipment are long-term strategies to control noise pollution.
(2) The main measures to control noise transmission are:
① Reasonable layout in urban construction. According to the planning of different functional areas, residential areas should be as far away from noise sources as possible.
(2) Build sound barriers on both sides of traffic trunk roads with large traffic volume and dense population, or use natural barriers (slopes and hills) and other sound insulation materials and structures to block the spread of noise.
(3) The application of sound-absorbing materials and sound-absorbing structures can transform the propagating noise acoustic energy into the internal energy of the object.
(3) Personal protection reduces the exposure time in noise environment. People who work in factories or construction sites can wear ear protectors (earplugs, earmuffs, etc. ) to reduce the impact of noise.
Radioactive pollution protection
Prevention and control of radioactive pollution: the prevention and control of radioactive pollution is mainly to control the source of radioactive substances. The sources of radioactive substances are mainly nuclear tests and nuclear industry (such as nuclear power plants and the mining, refining, storage and transportation of radioactive minerals).
The main measures to prevent radioactive pollution are:
(1) nuclear power plants (including other nuclear enterprises) should generally be located in areas with low population density, meteorological and hydrological conditions conducive to the diffusion and dilution of waste water and waste gas, and low earthquake intensity to ensure the lowest radiation dose to residents during normal operation and accidents.
② The selection of process flow and equipment should consider the generation and operation safety of waste.
(3) Waste gas and waste water should be purified, and the emission concentration and quantity of radioactive elements should be strictly controlled. Wastes containing alpha rays and wastes with high radiation intensity should be finally disposed of and permanently stored.
(4) Establish monitoring institutions around nuclear enterprises and areas that may suffer from radioactive pollution.
Light pollution protection
Light pollution protection: Light pollution protection mainly includes the following aspects:
① Strengthen urban planning and management, strengthen the management of decorative materials with high reflection coefficient such as glass curtain walls, and reduce their negative impact on the urban environment. Improve the lighting conditions of the factory and reduce the sources of light pollution.
② Take necessary safety protection measures for places polluted by infrared rays and ultraviolet rays.
③ Personal protection. Mainly wear protective glasses and protective masks.
Electromagnetic wave pollution protection
First, keep your distance. The distance from the TV should be multiplied by 6, the distance from the microwave oven should be 2.5 ~ 3 meters, and the distance from the high-voltage transmission line is generally regarded as a safe area.
Second, reduce contact. People who often use computers should take a break every 1 hour 15 minutes and work no more than 32 hours a week.
Third, improve the environment. Pay attention to air circulation, moderate temperature and humidity, and it is best not to put household appliances in the bedroom.
Fourth, personal protection. Pregnant women, children, the infirm, people who are allergic to electromagnetic radiation, and people who have been in an environment where electromagnetic wave pollution exceeds the standard for a long time should choose to use protective equipment that suits them.
Fifth, use mobile phones less. Minimize the use of mobile phones, walkie-talkies and cordless phones, and make a long story short when using them; Don't hang your mobile phone on your body often.
Sixth, use less electric blankets. The electromagnetic wave pollution of electric blanket is serious, which is harmful to human body after long-term use. When it is needed in cold weather, it is suggested to cut off the power supply immediately after heating the bed to reduce electromagnetic wave pollution.
Seven, the use of shielding to reduce electromagnetic wave pollution. For facilities that produce electromagnetic pollution, shielding materials that shield, reflect or absorb electromagnetic waves, such as copper, aluminum, steel plate, polymer film, etc. , you can use.
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