I. Atmospheric Pollution
Definition of Atmospheric Pollution
In the dry and clean atmosphere, the composition of trace gases is insignificant. However, in a certain range of the atmosphere, the appearance of trace substances that were not originally present, in quantities and for a sustained period of time, may adversely affect and jeopardize people, animals, plants, and objects and materials. When the concentration of pollutants in the atmosphere reaches a harmful level, to the extent of destroying the ecosystem and the conditions for the normal survival and development of human beings, the phenomenon of causing harm to people or things is called air pollution. The causes of atmospheric pollution are both natural and man-made, especially man-made factors, such as industrial exhaust, combustion, automobile exhaust and nuclear explosions. With the rapid development of human economic activities and production, while consuming large amounts of energy, a large amount of exhaust gases and soot substances are also discharged into the atmosphere, which seriously affects the quality of the atmospheric environment, especially in densely populated cities and industrial areas. The so-called dry clean air refers to the atmosphere in the natural state (composed of mixed gases, water and impurities) to remove water and impurities in the air, its main component is nitrogen, accounting for 78.09%; oxygen, accounting for 20.94%; argon, accounting for 0.93%; and a variety of other content of less than 0.1% of the trace gases (such as neon, helium, carbon dioxide, krypton).
Classification of Atmospheric Pollutants
Atmospheric pollutants can be divided into two main categories, namely, natural pollutants and anthropogenic pollutants, causing public health is often anthropogenic pollutants, which are mainly from fuel combustion and large-scale industrial and mining enterprises.
Particulate matter: refers to liquid, solid-like substances in the atmosphere, also known as dust.
Sulphur oxides: A general term for oxides of sulphur, including sulphur dioxide, sulphur trioxide, sulphur trioxide, sulphur monoxide, etc.
Sulphur oxides: A general term for oxides of sulphur.
Carbon oxides: mainly carbon dioxide and carbon monoxide.
Oxides of nitrogen: A general term for oxides of nitrogen, including nitrous oxide, nitric oxide, nitrogen dioxide, nitrogen dioxide, nitrogen dioxide, and nitrogen trioxide.
Hydrocarbons: Compounds formed by carbon and hydrogen, such as methane, ethane and other hydrocarbon gases.
Other harmful substances: such as heavy metals, fluorine gas, chlorine gas and so on.
Hazards of atmospheric pollution
Atmospheric pollution has a great impact on the climate, air pollution emissions of pollutants on the local area and the global climate will have a certain impact, especially on the global climate, from a long-term point of view, this impact will be very serious.
One is the increase of carbon dioxide content in the atmosphere, the fuel contains a variety of complex components, after combustion to produce a variety of harmful substances, even if the fuel does not contain impurities to achieve complete combustion, but also to produce water and carbon dioxide, just because the fuel combustion so that the concentration of carbon dioxide in the atmosphere continues to increase, and disrupt the balance of carbon dioxide in the natural world to the point of possibly triggering the "Greenhouse effect", resulting in an increase in the earth's temperature. Second, the ozone layer is destroyed .
After the atmosphere is polluted, due to the source of pollutants, the nature and duration of the different pollutants, the polluted area of the meteorological conditions, geographic environment and other factors, as well as the age of the people, the different state of health, the harm caused to the human body is not the same. Harmful substances in the atmosphere mainly invade the human body through the following three ways to cause harm:
(1) through the person's direct respiration and enter the human body;
(2) attached to the food or dissolved in water, so that the food and drink and invade the human body;
(3) through the contact or stimulation of the skin and enter into the human body. Among them, through breathing and invasion of the human body is the main way, the harm is also the greatest.
The harm of air pollution can be roughly divided into acute poisoning, chronic poisoning, carcinogenic three.
Atmospheric protection
Many environmental problems are transnational, or even global, such as the greenhouse effect and the destruction of the ozone layer and other atmospheric pollution, the need for the world's countries **** with efforts to gradually solve. People began to recognize in the early 1970s that HCFCs could be harmful to the environment and began to look for substitutes. By the mid-1980s, evidence of ozone layer depletion was becoming clearer, and calls for concerted action were growing. By 1987, representatives of many countries gathered in Montreal, Canada's second largest city, to sign the Montreal Protocol on Substances that Deplete the Ozone Layer. This Protocol is a pioneering international agreement to deal with the world's environmental hazards, with the aim of controlling the consumption of HCFCs and other ozone-depleting substances, protecting the Earth's "coat", and also protecting human beings themselves.
The amended Montreal Protocol is a binding international agreement. Under the terms of the agreement, industrialized countries must immediately reduce their emissions of HCFCs and other restricted substances, and phase out their use completely by the year 2000. Developing countries can continue to increase their consumption of these substances to a limited extent until 1996, after which it should be phased down to a point where the use of these hazardous substances must be completely eliminated by 2010. In addition to the time preference, the Protocol contains two provisions in favor of developing countries: one is the establishment of an interim multilateral fund to help developing countries to adopt technologies to replace HCFCs, and the other is a technology transfer clause, which requires the signatories to transfer the best technology on "fair and most favorable terms".
China has acceded to the amended Montreal Protocol and has formulated a national action program to fulfill its international obligations, including the establishment of a management body to protect the ozone layer, the formulation of management norms for the relevant industries, the active development of research on alternatives and alternative technologies, and the arrangement of matching funds for the transformation of enterprises into alternative technologies, and so on.
Acid rain
Some people believe that acid rain is a silent crisis, and is the most serious environmental threat ever to hit them, an invisible enemy. This is not alarmist talk.
As industrialization and energy consumption increase, so do acidic emissions, which enter the air and through a series of actions form acid rain.
Acidic emissions have been controlled, but there is still acid rain. Atmospheric dust may be another cause of the acid rain problem.
Acidic emissions
Water vapor condensation occurs in the free atmosphere due to the presence of condensation nuclei in the range of 0.1-10 μM, which then grows through processes such as conjugation and agglomeration, resulting in the formation of clouds and raindrops. Inside the cloud, the cloud droplets touch each other or aerosol particles, while absorbing gaseous pollutants in the atmosphere, and a chemical reaction occurs inside the cloud droplets, this process is called the removal of pollutants from the cloud or rain. During the descent of raindrops, the raindrops flush the gases and aerosols in the air through which they pass, and chemical reactions also occur within the raindrops, a process called under-cloud removal or flushing of pollutants. These processes are also the process of removing particulate matter from gaseous substances in the atmosphere by precipitation, and acidification is formed during these processes.
Atmospheric dust
Recent discoveries have shown that acid rain is a much more complex phenomenon than originally thought. The results obtained from the study show that the presence of alkali compounds in the atmosphere plays an unexpected and crucial role. Alkalis counteract the effects of acid rain by neutralizing acidic pollutants. We found that the focus on atmospheric acidity has obscured the fact that alkali emissions have also declined. It appears that a number of factors are reducing the amount of these bases in the atmosphere, thus exacerbating the ecological impact of acid rain. Ironically, several of these factors are the very things that governments are doing to improve air quality.
Most of the bases in the atmosphere are found in airborne particles called atmospheric dust. These dust particles are rich in minerals such as calcium carbonate and magnesium carbonate, which act as alkalis when dissolved in water. Atmospheric dust particles are formed from a variety of sources***. Combustion of fuels and industrial activities such as cement production, mining and metal smelting produce alkali containing particles. Construction sites, farms, and vehicle travel on unpaved roads also contribute to dust particles.
Three, ozone layer destruction
The ozone layer is the Earth's best umbrella, which absorbs most of the ultraviolet light from the sun. However, nearly two decades of scientific research and atmospheric observations have found that the ozone layer in the Antarctic atmosphere has been thinning every spring, and in fact there is an ozone "hole" in the polar atmosphere.
Is this ozone depletion, an anomaly, an indication that this ultraviolet absorber is in the midst of a global catastrophe? Through ongoing scientific research, it has been found that the ozone layer is severely damaged by substances released by human activities, but also by the unique meteorological conditions of the region (polar vortex, cold stratospheric temperatures, polar stratospheric clouds).
The discovery process
Atmospheric scientists from the British Antarctic Survey (BAS) conducted a program of research in Antarctica, both on the ground and in the air. Spherical instruments generally examine the composition of the atmosphere in which the instrument is traveling and its chemical properties. Land-based and satellite-based instruments perform telemetry missions. These research activities take an international cooperative approach. For example, in 1987, some 150 scientists and support staff representing 19 organizations and four countries met in Punta Arenas, Chile, to conduct an unprecedented study, the Airborne Antarctic Ozone Experiment (AAOE). The experiment showed that the size of the ozone hole reached an all-time high in 1987. This discovery shocked the scientific community.
Mechanism of formation
The cause of the Antarctic "ozone hole" is still not conclusive, and the most convincing is the theory of pollutants. In addition: NASA Hampton Chili Center CALLIS et al. proposed the destruction of the Antarctic ozone layer and strong solar activity; TUNG et al. of the Massachusetts Institute of Technology that there is a unique atmospheric environment in Antarctica caused by the depletion of ozone in late winter and early spring, according to atmospheric dynamics, pointing out that a large number of chlorofluorocarbon compounds, as well as Antarctica in early spring, there is not enough sunlight to produce a large number of oxygen atoms, and therefore the cycle of oxygen atoms is not needed. proposes a cyclic mechanism that does not require oxygen atoms.
Through the analysis, we seem to be able to come up with the following main points: (1) The Antarctic "ozone hole" is a special phenomenon caused by the participation of polar stratospheric clouds and non-homogeneous chemical reactions under the special temperature and circulation conditions in the Antarctic spring. (2) The influence of other factors, such as the polar vortex, on the transportation of gas components is not a determining factor for the formation of the Antarctic "ozone hole", but only affects the intensity of the ozone hole. (3) The influence of solar cycle changes on the strength of the Antarctic "ozone hole" through photochemical reactions can be ignored.
Four, water pollution
Human activities will make a large number of industrial, agricultural and domestic waste discharged into the water, so that water pollution. Definition of "water pollution": the water body due to the intervention of a substance, and lead to its chemical, physical, biological or radiological characteristics of the change, thus affecting the effective use of water, endangering human health or damage to the ecological environment, resulting in the deterioration of water quality phenomenon known as water pollution.
There are two types of water pollution: one is natural pollution; the other is man-made pollution. The current harm to the water body is more man-made pollution. Water pollution can be divided into chemical pollution, physical pollution and biological pollution according to the different impurities of pollution.
1, seawater pollution
Sewage, slag, waste oil and chemical substances constantly flowing into the sea. In many seas, it is illegal to dump sewage mixed with oil, but it still happens from time to time, and the real oil disaster occurs when a giant tanker leaks or sinks. Nowadays, chemicals are used to precipitate the oil in the water in order to remove it.
Dumping chemical and radioactive waste into the ocean has been going on for years. One day, the containers will corrode and the hazardous materials will enter the water. We don't know much about the circulation of deep water to surface water, and it may be happening faster than we previously thought. So the harmful substances will spread into the layers of water where the organisms live.
2. Surface water pollution
More than 500 years ago, it was thought that it was dangerous to drink water from rivers that flowed through large cities, and industrialization, population growth, and new toxic chemicals have made the situation worse.
Drainage systems and the unabated use of detergents have increased phosphate levels in our waterways and lakes. This over-nutrition leads to rapid algal blooms. Depletion of oxygen in the water kills fish and degrades ecosystems. Serious water pollution is also caused by the improper disposal of mercury compounds and other heavy metals by industry. Mercury gradually concentrates through the course of the food chain and eventually causes severe neurological damage to birds or humans who eat fish.
3, groundwater pollution
With surface water, groundwater is also threatened by pollution, mainly from the surface or soil water seepage, agricultural nitrogen fertilizers as well as oil in the garbage, phenol contamination of groundwater, nitrogen fertilizers in the nitrate once into the ground, it will be transformed into nitrites, which in the human body can be transformed into a carcinogen. Destruction of ground vegetation and drainage of wetlands reduces infiltration of surface water, thus lowering the diving surface. Further reductions in the diving surface can also occur as a result of excessive urban and industrial demand, where freshwater is continuously pumped out for domestic and industrial use and then re-discharged as surface water effluent. On the other hand, extensive and frequent irrigation can enhance infiltration and raise the submerged surface all the way to the surface. And in arid areas, the land infiltrated by water will sooner or later become uncultivable saline land due to the unusual evaporation effect that causes the precipitation of salts in the groundwater.
Water Conservation
The water on earth seems to be inexhaustible, but in fact, in terms of the current use of human beings, only fresh water is the main water resource, and only a small part of fresh water can be used by people. Fresh water is a renewable resource, and its renewability depends on the Earth's water cycle. With the development of industry and the increase in population, a large number of water bodies have been polluted; in order to extract river water, many countries have built dams in the upper reaches of rivers, which have altered the flow of water, so that the water cycle and self-purification have been seriously affected.
V. Solid Waste
All human activities generated by the process, and the owner no longer has the value of the use of solid or semi-solid substances that are discarded, commonly known as solid waste. Various types of production activities in the solid waste commonly known as slag; living activities in the generation of solid waste is called garbage." The term "solid waste" actually refers only to the original owner. In any production or life process, the owner of raw materials, goods or consumer goods, often only utilized some of the active ingredients, and for the original owner no longer has the value of the majority of solid waste still contains other production industries in the need for ingredients, after a certain technical aspects, can be transformed into the relevant sectors of the industry in the production of raw materials, or even can be used directly. It can be seen that the concept of solid waste at any time, space changes and has a relative nature.
Solid waste generation pathway
Maintaining all the activities of human society, materials, in a dynamic equilibrium process, and follow the law of conservation of quality, the social material flow can be used to describe this law.
1. All human activities, relative to the external environment, but the development and utilization of materials, and ultimately in the form of waste equal amount of return to the environment. This material "use and return" is often in a cross state. In the production and consumption of products, all forms of waste are generated, and part of this waste is recycled and reused in production and consumption. The other part, which happens to be equal to the amount of raw materials developed in the environment, returns to the environment in the form of waste, forming a closed loop system.
2. In modern society, every aspect of human activity generates various states of waste, from the development of raw materials in the environment to the utilization of products, without exception. Therefore, the only way to seek to reduce the production of waste is to reduce the development of raw materials and reduce the consumption of raw materials for products.
Classification of solid waste
The classification of solid waste is based on the pathway and nature of its generation. In economically developed countries, solid waste is divided into four categories: industrial, mining, agricultural solid waste and municipal waste. The Solid Waste Management Law enacted by the State, solid waste is divided into industrial solid waste (slag) and municipal garbage two categories. Which contains toxic and hazardous components, a separate sub-category of toxic and hazardous solid waste.
The hazards of solid waste
Garbage is becoming a major problem plaguing human society, the world to produce more than 1 billion tons of garbage every year, a large number of living and industrial waste due to the lack of treatment systems and open piles, garbage around the city phenomenon is becoming more and more serious, piles of garbage stinks, germs breeding, toxic substances contaminate the ground surface and groundwater, a serious danger to human health!
This phenomenon, if not curbed, human beings will be buried by their own production of garbage.
Six, ground subsidence
Ground subsidence refers to a certain surface area within the ground level of the phenomenon of lowering. The phenomenon of ground subsidence has long been recorded in the history books. As a natural disaster, the occurrence of ground subsidence has certain geological reasons. However, with the economic development of human society and the expansion of population, the phenomenon of ground subsidence has become more and more frequent and the area of subsidence has become larger and larger. In densely populated cities, the phenomenon of ground subsidence is particularly serious. Now when we study the causes of ground subsidence, it is not difficult to find that man-made factors have greatly exceeded natural factors. Now the phenomenon of ground subsidence rather than a natural disaster, it is better to call it a man-made scourge.
The geological causes of ground settlement
From the geological factors, the natural ground settlement occurs roughly the following three reasons:
1, the surface of the loose strata or semi-loose strata, etc. under the action of gravity, in the loose layer into a dense, hard or semi-hard rock layer, the ground will be due to the thickness of the stratum of the ground becomes smaller and subsidence occurs.
2. Subsidence occurs when the ground is sunken due to geological structure.
3. Earthquakes cause the ground to settle.
Man-made causes of ground subsidence
The phenomenon of ground subsidence is closely related to human activities. Especially in recent decades, human over-exploitation of oil, natural gas, solid minerals, groundwater, etc. has directly led to today's global ground subsidence. As all large and medium-sized cities are under enormous population pressure, the over-exploitation of groundwater is even more serious, leading to ground subsidence in most cities, and in coastal areas it has also caused seawater intrusion.
VII. Changes in Biodiversity
Biomes are diverse, and can be divided into several types from different perspectives. The meaning of biodiversity is very broad, that is, including the diversity of biological species, but also includes ecological adaptability, morphology, physiological ecological diversity and other broad content.
Different geographical and climatic environments have different biological communities. With the development of industrial civilization, the gradual expansion of human society has changed the biological environment in a wide range of areas, seriously affecting biodiversity, and species are decreasing from the earth at an unprecedented rate.
It is estimated that thousands of species of plants and animals go extinct every year around the world.
Deforestation
The greatest threat to the world's plants and animals is ecological destruction. It is very difficult for most living things to leave the environment to which it has adapted. One of the most species-rich places in the world is the tropical rainforest region, but it is now being destroyed at an increasing rate. Virtually all of the world's natural forests are seriously threatened. To the least extent, rainforests have been replaced by monoculture economic forests, and in the worst cases they have been destroyed by erosion into barren scrubland.
The World Conservation Fund (WWF) estimates that forests are disappearing globally at a rate of 2% per year, and that at this rate, people will not see natural forests in 50 years.
Reclamation of grasslands
Much of North America's grasslands have already disappeared to a greater or lesser extent. In Africa, savannas rich in animal resources are being burned in large numbers as a solution to the problem of feeding a growing population. The use of traditional agricultural methods in arid regions is both unreliable and dangerous. Efforts to reclaim the inland steppes of Central Asia have suffered many unfortunate setbacks.
Drainage wetlands
Swampy wetlands are not only a living environment for organisms, but also play an important role in the hydrological cycle. It regulates the flow of rivers and improves groundwater recharge. But in order to develop industry and build housing, many wetlands are either drained or filled with water. Attempts to convert wetlands to cropland often result in poor soil and low yields.
Urbanization
Cities and towns developed in good agricultural areas, and urbanization often meant sacrificing arable land for homes, streets, and parking lots. In this way arable land becomes waste land that cannot produce living things. From a natural or economic point of view, it is difficult to restore such land to farmland.
Animal extinction
Many animal species are endangered, and the number of vertebrates at risk alone is staggering. The nature of the threat is varied: Europe's raptors are being threatened by egg collectors, while tigers are in danger of having the dense forests in which they roam cut down. Many endangered animals are beyond saving, while others could survive if protected.
Eight, red tide
Red tide is a body of water in some of the tiny phytoplankton, protozoa or bacteria, in certain environmental conditions, the sudden proliferation and aggregation, caused by a certain range of a period of time in the body of water in the phenomenon of discoloration. Usually the color of the water body due to the number of red tide organisms, species and red, yellow, green and brown.
Although red tide since ancient times, but with the rapid development of industrial and agricultural production, water pollution is increasing, red tide is also increasingly serious.
The causes of red tide
Red tide is a natural phenomenon that originally existed, or caused by man-made pollution, so far there is no conclusion. However, according to a large number of investigations and research found that the occurrence of red tide must have the following conditions:
① high trophic sea water;
② some special substances involved as triggering factors, known as vitamin B1, B12, iron, manganese, deoxyribonucleic acid;
③ environmental conditions, such as water temperature, salinity and so on, but also determines the occurrence of the type of biology of the red tide. The type of organisms that occur red tide is mainly algae, 63 kinds of plankton have been found, 24 kinds of diatoms, 32 kinds of methanogens, 3 kinds of cyanobacteria, 1 kind of golden algae, 2 kinds of cryptobacteria, and 1 kind of protozoa.
Hazards of red tide
Red tide not only causes serious harm to the marine environment, marine fisheries and mariculture, but also has an impact on human health and even life. Mainly includes two aspects:
① cause marine anomalies, local interruption of the marine food chain, so that the sea once became the Dead Sea;
② some red tide organisms secrete toxins, these toxins are ingested by certain organisms in the food chain, if humans eat these organisms, it will lead to poisoning or even death.
Nine, soil erosion
Land resources is one of the three major geological resources (mineral resources, water resources, land resources), is the most basic human production activities of resources and labor objects. The degree of human use of land reflects the development of human civilization, but at the same time also cause direct damage to land resources, which is mainly manifested in unreasonable cultivation caused by soil erosion, land desertification, land secondary salinization and soil pollution, etc., of which water and soil erosion is particularly serious, is now the world is facing another serious crisis.
Overview of soil and water erosion
Soil and water erosion refers to the whole process of soil erosion, transportation and sedimentation under the action of water flow. In the natural state, the process of surface erosion caused by purely natural factors is very slow, often in relative balance with the process of soil formation. Thus the sloping land remains intact. This type of erosion is called natural erosion, also known as geological erosion. Under the influence of human activities, especially after the serious destruction of human vegetation on slopes, the surface soil damage caused by natural factors and the movement of land material, the loss process accelerated, that is, soil erosion occurs.
Soil and water erosion is the most common geologic disaster that destroys the resources of the land, which is most serious in the Loess Plateau region. The country's current situation of soil erosion is: point on the governance, the surface has expanded, governance can not catch up with the destruction. At the beginning of the liberation of the country's soil erosion area of 1.74 billion mu, to 1980 about 600 million mu of governance. Because the treatment could not catch up with the destruction, the area of soil erosion expanded to 2.25 billion mu, accounting for about 1/6 of the total area of the country, involving nearly 1,000 counties. The country's mountainous and hilly areas have about 400 million mu of sloping farmland, of which about 100 million mu of terracing, while the other 300 million mu of sloping land is suffering from the dangers of soil erosion.
Soil and water erosion hazards
Soil fertility decline, soil erosion can make a large number of fertile topsoil loss.
Siltation of reservoirs, elevation of river beds, reduced navigability and flooding.
Threaten the safety of industrial and mining transportation facilities. In the deep valleys of the mountains, soil erosion often causes mudslide disasters, endangering the safety of industrial and mining transportation facilities.
Deterioration of the ecological environment. 30 ~ 60 years in the 20th century, people for the erosion disaster is still stuck in the land caused by direct economic losses, but in the 1960s, began to link to the human environment as a whole, including the pollution of sediment, the deterioration of the ecological environment, etc.
The soil and water erosion disaster is the first time in the world to cause a disaster, but it is also the first time in the world to cause a disaster.
Causes of soil erosion
Geomorphologic and climatic conditions that predispose to soil erosion are the main reasons for the occurrence of soil erosion.
With a large population and great pressure on the demand for food and fuel for civilian use, the land was reclaimed in a predatory manner when the productivity level was not high, emphasizing one-sidedly on food production, neglecting the integrated development of agriculture, forestry and animal husbandry according to local conditions, and turning land that was only suitable for forestry and animal husbandry into farmland. A large number of reclamation of steep slopes, and even steep slopes more open the more poor, the more poor the more reclamation, the ecosystem of the vicious circle; indiscriminate cutting of forests, and even digging up tree roots, lawn, trees sharply reduced, so that the surface of the ground is bare, which have aggravated soil erosion. In addition, certain capital construction does not meet the requirements of soil and water conservation, for example, irrational construction of roads, building factories, coal digging, quarrying, etc., which destroys the vegetation and reduces the stability of the slopes, causing landslides, landslides, mudslides, and other more serious geological disasters.
Soil and water erosion control
Soil and water erosion is caused by the movement of surface runoff on slopes. The basic principle of each prevention and control measure is to reduce the runoff volume on the slope, slow down the runoff speed, improve the soil water absorption capacity and slope resistance, and raise the erosion datum as much as possible. In taking preventive and control measures, should start from the surface runoff formation section, along the runoff movement route, according to local conditions, step by step set up prevention and treatment, the implementation of prevention and treatment combined to prevent the main; treatment of slopes and gully combined to treat the slope as the main; engineering measures and biological measures combined to biological measures as the main. Only by adopting various measures of integrated and centralized management, continuous management, in order to be effective.
I hope to adopt