There is a Tianjin chemical plant in Hangu. Is the air and river water polluted seriously?

There are two reasons for air pollution: first, natural reasons, such as strong winds in northern China, blow up dust on the ground; Volcanic eruption, ash, sulfur dioxide, etc.; Forest fires produce a lot of carbon dioxide, nitrogen dioxide, sulfur dioxide and some hydrocarbons. The other is caused by human activities, such as exhaust gas from industry and transportation, and household heating and food burning. At present, it is the latter pollution that causes extensive and serious air pollution.

At present, about 1 kinds of atmospheric pollutants have been noticed by people. These pollutants can be roughly divided into two categories, one is dust particles and the other is gas pollutants. See the following table for several major pollutants:

several major pollutants

pollutants include dust particles, carbon particles, fly ash, calcium carbonate, zinc oxide, lead dioxide, etc.

sulfide sulfur dioxide, sulfur trioxide, sulfuric acid, hydrogen sulfide, mercaptan, etc.

nitride nitric oxide, nitrogen dioxide, ammonia, etc.

oxide ozone, peroxide, etc. Among the pollutants such as formaldehyde, organic acids, tar, organic halides and caves, which have a wide range of influences, coal dust, sulfur dioxide, carbon monoxide, hydrogen carbide, hydrogen sulfide and ammonia are the main threats to human beings. The world releases about 1 million tons of coal dust, 146 million tons of sulfur dioxide, 22 million tons of carbon monoxide, 88 million tons of hydrogen carbide, 3 million tons of hydrogen sulfide and 4 million tons of ammonia into the atmosphere every year.

in order to analyze the movement and diffusion of pollutants in the atmosphere, pollutant sources are often divided into two categories: stationary sources and mobile sources. Stationary source refers to the discharge of pollutants from fixed locations, such as various types of factories, especially thermal power plants, steel plants and so on. Mobile sources refer to vehicles, such as cars, planes, trains and ships. Compared with fixed sources (such as factories), they are small, scattered and mobile, but they are large in number and frequent in contact. Therefore, the total amount of pollutants discharged is also very considerable.

The following are the sources of several major air pollutants:

Sulfur oxides: mainly sulfur dioxide and sulfur trioxide, which are mainly generated during the combustion of sulfur-containing coal, petroleum and the smelting of sulfur-containing metal minerals.

nitrogen oxides: mainly nitric oxide and nitrogen dioxide, which mainly come from high-temperature combustion process.

carbon monoxide: mainly comes from the combustion of fossil fuels, petroleum refining, iron and steel smelting, the burning of solid waste and the exhaust of various motor vehicles. Carbon monoxide is the largest air pollutant. It is estimated that the amount of human-caused emissions is about 22 million tons every year, half of which comes from automobile exhaust.

floating particles: non-gaseous substances that can't settle in the atmosphere, which are mainly caused by combustion and mechanical reasons. See the following table for the relationship between various pollutants and their sources

Air pollutants and their sources

Causes of their occurrence

Combustion (thermal power station): dust, smoke, SO, CO, H, C, etc.

heating treatment (smelting, furnace, silicate manufacturing);

mining (mining, quarrying, mineral processing) of dust, SO,

smoke, HS, HF, etc.: dust and smoke

modulation treatment (food industry, leather industry, fish product processing): evil

man-made odor

chemical treatment (chemical industry): dust, Pb, Be. Nuclear explosion): radioactive dust gas

transportation (cars, airplanes, trains, ships, etc.): smoke,

CO, NO, H, C, acid

natural causes, forest fires, volcanic eruptions, dust, smoke, sulfur-containing gases

The atmosphere is an essential substance for human survival.

Sulfur dioxide, hydrogen sulfide, carbon disulfide and other pollutants in the atmosphere have pungent odor in a small amount, which makes people cough and cause respiratory tract inflammation, and in a high concentration, it will cause acute poisoning. If sulfur dioxide meets the water vapor in the air, it can turn into sulfuric acid mist, which can stay in the atmosphere for a long time, and its toxicity is about 1 times greater than that of sulfur dioxide. In the past 2 years, respiratory diseases in Europe, America and Japan have increased nine times, because the area of human lung cells is 25 times that of human body surface, and each person needs 1 ~ 12m air every day. Therefore, the harm of polluted air to human respiratory tract can be imagined.

The floating dust in the atmosphere can adsorb highly carcinogenic hydrocarbons emitted from coal smoke, so people who stay in this environment for a long time can cause lung cancer. According to the survey, in the past 5 years, the incidence of lung cancer in Britain has increased by 4 times compared with the past.

carbon monoxide in the atmosphere is a colorless and odorless gas. The human body inhales carbon monoxide, which combines with hemoglobin to produce carboxyhemoglobin, which hinders the combination of oxygen and hemoglobin. Therefore, when the atmosphere contains a certain amount of carbon monoxide, people will feel dizzy, have a headache and even cause death.

The harm of air pollution to plant growth is much more serious and sensitive than that of animals. This is because people and animals inhale oxygen for gas metabolism. As we all know, the concentration of oxygen in the air is about 21%, but green plants inhale carbon dioxide, and the concentration of carbon dioxide in the atmosphere is very low, about .3%, which is close to the concentration of atmospheric pollutants. Therefore, plants are in closer contact with harmful substances in the air, and the harm is greater.

The harm of pollutants to plants is mostly caused by their entry into plants through stomata on the surface of leaves. The pollutants that are harmful to plants are sulfur dioxide, fluoride, strong oxidant produced by photochemistry and ethylene. Sulfur dioxide will destroy the chloroplast of plants, and fluoride will have a great influence on the buds and young leaves, which will turn brown and die. The harm of ethylene to plants is the phenomenon of defoliation, fruit drop, biased growth and bending of young branches.

air pollution causes corrosion damage to various materials. Especially for metal products, paints, leather products, paper products, textiles, rubber products and buildings, the damage is more and more serious with the intensification of air pollution.

Sulfur dioxide, hydrogen sulfide and chlorine have strong corrosive effects on metal materials; Sulfuric acid smog and photochemical oxidants can make textiles, paper and leather products corrupt and break, and the coatings deteriorate. According to the survey, the residents of big cities in Europe, America and Japan lose $2 ~ 4 each year due to air pollution. Among these losses, buildings and paints account for 1/3, living cleaning expenses account for 1/3, corrosion of factory equipment, products and materials accounts for 1/6, and lighting accounts for 1/6.

As factories, means of transportation and thousands of households burn a lot of coal, oil and natural gas, man-made carbon dioxide is constantly added to the atmosphere. According to statistics, the carbon dioxide caused by the burning of fossil fuels reaches as much as 15 billion tons every year, and this figure is increasing year by year, which causes the carbon dioxide content in the atmosphere to increase at an alarming rate. It is estimated that the concentration of carbon dioxide in the atmosphere was 295ppm in 186, 313ppm in 1958 and 328ppm in 1971, and will increase to 375ppm by the end of this century. Carbon dioxide can penetrate the short-wave radiation of the sun and make it reach the surface warming, but it can absorb the long-wave radiation of the earth, so that most of the long-wave radiation on the ground is trapped in the carbon dioxide in the atmosphere and no longer escapes into space. Carbon dioxide in the atmosphere absorbs the long-wave radiation from the ground, and then the temperature rises, and then it is radiated to the ground with reverse radiation, which makes the ground temperature rise. This is what we usually call the "greenhouse effect". It is estimated that by the end of this century, the average surface temperature in the world will be .4 ~ .5℃ higher than it is now.

another pollutant that has a great impact on the climate is dust. Dust is mainly discharged from factories, transportation tools, domestic stoves, burning garbage, etc. It was estimated in 197 that the amount of dust artificially increased in the world was about 53 million tons per year, accounting for 1/3 of the global atmospheric dust. It is generally believed that dust can reflect solar radiation back into the universe and play the role of a parasol, so it is also called the "parasol effect". In addition, dust can also be used as the condensation core, prompting the surrounding water vapor to condense on it, thus increasing the number of clouds and fog, reducing the thermal radiation of sunlight reaching the ground and lowering the ground temperature. Therefore, dust and carbon dioxide have opposite effects on climate.

It is urgent to protect the atmosphere

To clearly describe the degree of pollution in our atmosphere, space astronauts are the most convincing. Please listen to what they say: "I look at the earth from space, and the dense pollution clouds are turning the earth into a' gray planet'. I am shocked by the extent of air pollution on our earth. The atmosphere has become so dirty, air pollution is spreading, spreading over all continents; The height of the polluted cloud is still rising ... "

Therefore, it is urgent to protect the atmosphere. Many countries and regions have paid great attention to air pollution and taken many measures.

Up to now, the prevention and control of air pollution has mainly gone through three periods. Before the 196s, the control work was mainly focused on smoke and dust removal. After the 196s, the focus of treatment has shifted to solving the pollution of sulfur dioxide; Recently, the control center of air pollution has turned to the control of photochemical smog.

establish a pollution monitoring station. Monitoring is the basis of environmental management, and it is also the basis for formulating and revising environmental standards and evaluating environmental quality standards. At the same time, it is also one of the basic means for environmental research, especially for studying the migration and transformation law of pollutants in the environment and its influence on environmental quality. Many countries have established air pollution monitoring stations. There are more than 1,5 such monitoring stations in Britain. The air pollutants monitored mainly include sulfur dioxide, sulfide, suspended particles, carbon monoxide, carbon dioxide, nitrogen oxides, ozone, photochemical oxides, photochemical hydrocarbons and clay particles.

controlling pollution sources is one of the most important measures to improve the quality of atmospheric environment. According to statistics, at least 8% ~ 85% of solid particles can be shielded before being discharged from the chimney, and electrostatic precipitator can even intercept 98% of dust. Some harmful gases can be purified by the purification method of harmful gases before entering the atmosphere. We know that the burning of fossil fuels (such as coal and oil) is an important cause of air pollution. Therefore, developing harmless energy, changing fuel composition, innovating energy utilization equipment and improving combustion and flue gas purification technology are important ways to reduce air pollution and improve energy utilization.

At present, some countries are actively developing low-cost electric vehicles and vehicles using hydrogen as fuel. Before this kind of car was widely used, many countries stipulated the pollution amount of exhaust gas emitted by cars. As early as 1975, the US Environmental Protection Agency stipulated that carbon monoxide, hydrocarbons and nitrogen oxides emitted by newly produced cars should not exceed 1% of those of old cars. This regulation has received excellent pollution control effect.

afforestation is one of the most effective means to protect the environment, purify the atmosphere and prevent air pollution. In the forest, there is a good name called "natural air purifier". It can not only adjust the air temperature, humidity and microclimate, but also purify the atmosphere. Trees can absorb carbon dioxide and give off oxygen. Usually, a hectare of broad-leaved forest can absorb 1 ton of carbon dioxide and release .73 ton of oxygen a day; A well-grown lawn can absorb 1.5 grams of carbon dioxide per square meter per hour. If adults breathe .75 kg of oxygen and expel .9 kg of carbon dioxide every day, urban residents will have an average of 1 square meters of woodland or 5 square meters of lawn, which can keep the air fresh.

In addition, plants, especially trees, have great blocking, filtering and absorbing effects on smoke and dust. Because of the dense crown of trees, it has a powerful effect on reducing wind speed. With the decrease of wind speed, the smoke carried in the air drops rapidly. In addition, the surface of leaves is fluffy, which can secrete viscous oil and absorb a large amount of floating dust. Trees are like natural filters to filter the atmosphere, and after being washed by rain, they restore their dust retention function. Some trees can also absorb harmful gases in the atmosphere. One hectare of Cryptomeria fortunei can absorb 72 kilograms of sulfur dioxide. The sulfur absorption of citrus can reach .8% of leaf weight. Tomatoes, lentils, etc. have a strong ability to absorb fluorine. One kilogram of tomato leaves can absorb 3 micrograms of fluorine. Platanus acerifolia, Robinia pseudoacacia, etc. have strong absorption capacity for ozone generated by photochemical smog.

Studies are being made at home and abroad to screen the absorption and resistance of various trees and flowers to harmful gases, and the influence of greening layout on air purification. In recent years, in order to prevent air pollution, countries are also increasing the urban greening quota accordingly. For example, Japan plans to increase the number of citizens to 9m, Britain 24m and the United States 4m, and major cities in China are gradually expanding the greening area and improving the living environment.