1 Introduction
Environmental chemistry is a science that studies the various forms and characteristics of chemical substances, especially chemical pollutants in the environment, the laws of migration and transformation, and the effects of pollutants on the ecological environment and human beings. This paper mainly studies the chemical principles and methods of the existence, chemical characteristics, behavior and influence of harmful chemicals in environmental media. It is one of the basic contents of environmental science research and environmental science.
2 overview
The factors that cause environmental pollution can be divided into physical, chemical and biological aspects, and the pollution caused by chemical substances accounts for about 80%-90%. Environmental chemistry is to explore the changing law of environmental quality caused by human activities and the methods and principles of protecting and governing the environment from the chemical point of view. As far as its main content is concerned, environmental chemistry not only studies the detection methods and principles of environmental pollutants (belonging to the category of environmental analytical chemistry), but also discusses the chemistry, chemical engineering principles and chemical processes in environmental pollution and treatment technology. It also needs to further study the sources, migration and distribution, mutual reaction, transformation mechanism and state structure changes of chemical pollutants in the environment at the atomic and molecular levels by means of physical chemistry.
Pollution impact and final destination. With the deepening of environmental chemistry research, it has laid a solid foundation for the development of environmental science and provided an important scientific basis for controlling environmental pollution [1].
As far as the task of subject research is concerned, the characteristic of environmental chemistry is to study macro-environmental phenomena, chemical mechanism of change and its prevention and control ways from the microscopic atomic and molecular level, and its core is to study the chemical transformation and effect of chemical pollutants in the environment. The environment it studies is an open system with multi-factors, multi-variables and complex conditions, and many chemical principles and methods are not easy to be directly applied.
3 Main research fields and contents
3. 1 study the basic laws of migration and transformation of pollutants (mainly chemical pollutants) in the environment (including the atmosphere, hydrosphere, soil lithosphere and biosphere), and form a new marginal branch of environmental pollution chemistry between environmental science and chemistry.
3.2 Study the types, components and quantitative analysis methods of pollutants in the environment to form environmental analytical chemistry (often called environmental analysis). It is a branch of environmental chemistry.
3.3 Study the migration and transformation law of natural and artificial chemical properties in the environment and their relationship with environmental quality and human health, and form environmental geochemistry. It is a new marginal branch between environment and geochemistry.
4 Environment Overview and Solutions
4. 1 Pollution hazards of harmful chemicals
Hazardous chemicals refer to any chemicals that are determined to be harmful to human health and the environment.
With the rapid development of industry and agriculture, toxic and harmful pollution sources can be seen everywhere, and the most harmful to human beings is toxic and harmful chemicals. The ways of chemical substances invading the environment are almost omni-directional, and the most important ones can be divided into four types.
4. 1 1 artificial application directly into the environment;
4. 12 in the process of production, processing and storage, waste water, waste gas and waste residue are discharged into the environment as chemical pollutants;
4. 13 Due to sudden chemical accidents such as fire, explosion and leakage during production, storage and transportation, a large number of harmful chemicals leaked into the environment;
4. 14 In the combustion process of fuels such as oil and coal, and in daily life such as home decoration, it is directly discharged into the environment or used as waste.
Harmful chemicals entering the environment have caused serious harm or potential danger to human health and the environment.
Taking pesticides as an example, with the rapid development of pesticide technology and agriculture, the use of pesticides is becoming more and more common, from natural agriculture that never uses pesticides to modern agriculture that uses pesticides. For China, a big country with a large population and tight arable land, pesticides have played an important role in solving natural disasters of crops and promoting grain production. However, because pesticides are toxic chemicals and people put them into the environment on their own initiative, long-term and large-scale use will definitely have a greater adverse impact on environmental biological safety and human health. This raises an unavoidable practical problem for people. While fully affirming the beneficial effects of pesticides, we need to fully understand the harm of pesticides to the ecological environment and human health [2].
At the same time, industrial wastewater is also one of the biggest pollution sources of the environment. For example, cyanide and other harmful substances in industrial wastewater have seriously polluted the main rivers and lakes in China, which has worsened the water quality, especially the Huaihe River, Haihe River, Liaohe River, Dianchi Lake, Chaohu Lake and Taihu Lake (referred to as "Three Rivers and Three Lakes"), which has seriously affected the local economic development and people's lives. Cyanide discharged from industrial wastewater is more harmful to fish, and phenol-containing wastewater can inhibit the growth of bacteria, algae and molluscs in water. Irrigation of farmland with phenol-containing wastewater will inhibit photosynthesis and enzyme activity, destroy the formation of crop auxin and reduce yield. Domestic sewage and some industrial wastewater often contain a certain amount of nitrogen and phosphorus, which will make closed lakes and bays eutrophic after entering the water body, lead to a large number of phytoplankton proliferation, reduce the transparency of the water body, reduce dissolved oxygen, threaten the survival of fish, stink the water quality and appear "red tide". Improper disposal of chemical waste will cause soil hardening and groundwater pollution, which directly threatens human health and human survival. At present, cancer has become one of the diseases that seriously threaten human health and life. According to the estimate of the World Health Organization, there are 6 million cancer patients in the world every year, and about 5 million people die of cancer every year, accounting for110 of the total number of deaths. Every year, there are10.5 million new cancer patients and10/10,000 deaths in China. The cause of human cancer is 15% related to chemical factors.
Furthermore, the chlorofluorocarbon gas released by refrigeration and air conditioning equipment leads to the destruction of stratospheric ozone layer, which leads to the enhancement of ultraviolet radiation on the earth's surface and the increase of skin cancer incidence. Sulfur dioxide emitted from coal-fired power plants leads to acid rain, acidification of rivers and lakes, fish reproduction and even population disappearance. The increase of soil acidity will reduce the species and fertility of bacteria and affect crop growth. Acid rain also converts heavy metals such as manganese, copper, lead, cadmium and zinc into soluble compounds and transfers them to rivers and lakes, causing water pollution.
The harm of harmful chemicals to human health and the environment is an important problem to be solved urgently in China's environmental protection, which must be highly valued by the whole society.
4.2 Environmental Pollution Control of Chemicals
China is a big chemical producer, and the chemical industry has formed a relatively complete system. In order to control or reduce environmental pollution, pollution control in chemical production should be considered. First of all, we should understand the pollution situation of chemical plants, including the types of pollution sources, main pollutants, emissions, environmental protection measures and sensitivity to the surrounding environment. In particular, it is necessary to investigate the distribution of pollution sources and count the emissions of pollutants. At the same time, we should know the types of pollution effects, such as primary pollution or secondary pollution, long-term pollution or short-term pollution, reversible pollution or irreversible pollution, local pollution or large-scale pollution, single-factor pollution or multi-factor compound pollution. The following main measures should be taken to control the pollution hazards of chemicals:
4.2 1 Formulate and improve environmental legislation and strengthen environmental law enforcement.
1979 China has promulgated the Environmental Protection Law of People's Republic of China (PRC), which is a comprehensive law of environmental protection in China and a basic law in the field of environmental protection, mainly stipulating the state's environmental policies, principles and measures of environmental protection, etc. The State Council has also formulated environmental protection laws such as the Detailed Rules for the Prevention and Control of Water Pollution, the Detailed Rules for the Prevention and Control of Air Pollution and the Law for the Prevention and Control of Environmental Pollution by Solid Waste, and promulgated the Regulations on the Safety Management of Hazardous Chemicals and the Regulations on the Management of Pesticides. The state has also specially formulated environmental protection standards, pollutant discharge standards, basic environmental protection standards and environmental protection method standards. For example, published environmental quality standards include ambient air quality standards and surface water environmental quality. Pollutant discharge must have the Industrial "Three Wastes" Discharge Standard and the Integrated Wastewater Discharge Standard, etc. At the same time, local environmental protection laws and regulations and normative documents of environmental protection departments have been clearly defined. The promulgation and implementation of these laws and regulations have played an important role in strengthening the safety management of dangerous chemicals, preventing chemical substances from polluting the environment and ensuring people's health. However, China has not yet established a complete system of laws and regulations on environmental management of chemical substances to effectively manage the whole process of production, storage, transportation, sales, use, import and export of chemical substances [3].
China's current chemical environmental legislation needs to be supplemented and improved in view of the weak links in the current chemical management laws and regulations, and be in line with the international chemical management system. In addition, it is urgent to strengthen the enforcement of laws and regulations on chemical management. Enterprises that cause serious pollution to environmental protection should be investigated and dealt with according to law, and those that cause harm to people due to environmental pollution should be punished and compensated according to law. This is a legal management system that Japan and other industrialized countries have already implemented. Through publicity and education, it is also necessary to improve the awareness of law-abiding of units and individuals engaged in the production, storage, management, transportation and use of hazardous chemicals, and strengthen the safety and environmental management of hazardous chemicals. Especially dangerous chemicals, should be strictly managed in accordance with China's Environmental Protection Law.
4.22 Strengthen the environmental management of key hazardous chemicals
Establish a corresponding registration management system, and take measures to prohibit or strictly restrict the use, elimination and substitution of chemicals known or suspected to be carcinogenic, teratogenic, mutagenic or seriously harmful to the environment, so as to effectively reduce the pollution hazards of these chemicals.
4.23 Carry out cleaner production and strictly control the discharge of harmful chemicals to the environment.
An important reason for serious chemical pollution is that a large number of old enterprises have not carried out technical transformation for a long time, the consumption of resources and energy is too high, and the sewage discharge is too large. It is the fundamental way to change the backward situation of high consumption and high pollution in chemical production by comprehensively carrying out clean technology transformation, reducing the burden of terminal treatment and eliminating the "three wastes" in the production process as much as possible by transforming process equipment. To actively promote cleaner production, it is necessary to choose clean raw materials, replace harmful raw materials with non-toxic and harmless substances, design clean processes and produce clean products. At the same time, measures such as improving and strengthening the internal safety management of enterprises are taken to reduce the generation of pollutants and wastes at the source of pollution and realize the recycling of wastes. Minimize or reduce the emission of harmful substances. For pollutants that cannot be solved by prevention, source control measures should be taken for safe treatment and disposal, so that pollutants can meet national or local emission standards.
4.24 Strengthen hazardous waste management
Hazardous waste refers to waste with one of the hazardous characteristics such as flammability, corrosiveness, reactivity, explosiveness, acute toxicity and infectivity. According to the Law on the Prevention and Control of Environmental Pollution by Solid Wastes, units engaged in the collection, storage and disposal of hazardous wastes must be approved by the competent administrative department of environmental protection and obtain a business license.
4.25 Public supervision
Through the establishment and implementation of the system of safety labels and safety technical specifications for dangerous chemicals, the knowledge of chemical safety and environmental protection will be popularized among enterprise employees and chemical users. And actively publicize the knowledge about chemical safety and environmental protection in the whole society, improve the public's understanding of harmful chemical hazards, safety protection measures and environmental protection, and vigorously encourage the public to participate in the supervision of the prevention and control of harmful chemical pollution.
5 conclusion
We should always pay attention to the performance of the ecosystem, find out the unbalanced information as soon as possible and reverse the unfavorable situation in time. Actively improve the anti-interference ability of the ecosystem, protect the ecosystem and prevent ecological imbalance.
refer to
[1] Yuan Jiacheng. Environmental chemistry. Chemical Industry Press, 20 10
[2] Zhang Jin. Introduction to environmental chemistry. Chemical Industry Press, 2008
Zhou Qixing, Li Peijun. Pollution ecology, science press, 200 1
1. According to environmental factors: air pollution, water pollution and soil pollution.
According to human activities: industrial environmental pollution, urban environmental pollution, agricultural environmental pollution.
3. According to the nature and source of pollution: chemical pollution, biological pollution and physical contamination (noise, radioactivity, heat, electromagnetic waves, etc.). ), solid waste pollution, energy pollution.
As long as there are the following kinds of chemical pollution in life:
1, factory smoke
2. Cars, planes, trains, ships and other means of transportation emit a lot of harmful gases and dust.
3. Burning sulfur-containing fuel
4. Burning garbage, leaves and waste plastics.
5. Burning industrial waste
Step 6 smoke
7. Smoking in the kitchen while cooking.
8. The decay of garbage will release harmful gases.
9, factory toxic gas leakage
10, indoor decoration materials slowly release toxic gases.
1 1, road dust
12, spraying toxic pesticides on agriculture
13, products using chemical diluents such as hair gel.
14, harmful gases produced by electrical appliances such as photocopiers and televisions.
15. Sulfur oxides and nitrogen oxides are the main causes of acid rain, so it is necessary to adjust the energy structure and reduce the direct use of fossil fuels such as coal, oil and natural gas. The waste gas produced in industrial production can only be discharged into the atmosphere after purification.
16, the ozone layer is destroyed by gases such as chlorofluorocarbons and nitrogen oxides. Gases such as carbon dioxide, ozone, methane and chlorofluorocarbons will have a "greenhouse effect", which will warm the world and have a great impact on human normal life. In order to prevent the ozone layer from being destroyed and the "greenhouse effect" from being further enhanced, the following measures can be taken: First, save energy, reduce the use of fossil fuels such as coal, oil and natural gas, and make more use of clean energy such as solar energy, wind energy and geothermal energy. Restrict and gradually stop the production and use of HCFCs, vigorously plant trees, prohibit deforestation and protect wetlands.
17. The air in the kitchen contains gases such as carbon dioxide, carbon monoxide and sulfur dioxide released during fuel combustion, as well as gases and suspended matter (lampblack) generated during frying food. Therefore, it is necessary to keep indoor air circulation and install a range hood in the kitchen. Newly built and renovated rooms will also contain a lot of harmful gases.
18, smoking is harmful to health and pollutes the environment.
19, Source, harm and treatment of air pollution.
Main pollutants: sulfur dioxide, carbon oxides, nitrogen oxides, hydrocarbons, floating dust, coal dust, radioactive substances, etc.
Sources: coal and oil combustion, ore smelting, automobile exhaust, industrial waste gas, etc.
20. Source, harm and treatment of water pollution.
Main pollutants: inorganic substances, alkali, salt, etc. , heavy metal oxygen-consuming substances, plant nutrients, petroleum, refractory organic matter, etc.
There are cyanide, phenols, pathogens, radioactive substances, suspended solids and so on.
Sources: petroleum refining, industrial wastewater, domestic sewage, farmland drainage using pesticides and fertilizers, rainfall leaching of atmospheric pollutants and ground leaching of solid waste, etc.
2 1, the source, harm and prevention measures of indoor pollution
Main pollutants: CO, CO2, SO2, nitrogen oxides, NH3, aldehydes (such as formaldehyde), phenols, smoke and dust, radioactive rare gas radon, electromagnetic waves, mites, bacteria and viruses.
Sources: Smoke generated in the burning of coal, petroleum, liquefied gas and natural gas, frying, frying, baking and other high-temperature cooking processes, tobacco burning, electromagnetic waves emitted by electrical appliances, mites in carpets, formaldehyde generated by building decoration materials, radioactive rare gas radon, cosmetics, daily necessities, domestic pets, etc.
22. Batteries contain a lot of heavy metal ions, which will pollute water and soil.
For example: "red tide" and water eutrophication.
"Red tide" is a very harmful natural disaster, which will cause the deterioration of water quality and a large number of fish deaths. Since the 20th century, red tides have occurred frequently all over the world. Seto Inland Sea in Japan is a high incidence area, with 1976 occurring 326 times. Recently, it has also occurred from time to time in China, among which 1989 is the largest red tide event in Huanghua sea area, with the heaviest loss (up to 300 million yuan). 1998 In the spring, another raging red tide swept through the Hong Kong Sea and the waters near the Pearl River Estuary in Guangdong. When the red tide passed, the sea was red and smelly, and a large number of animals such as fish died in the water. The local farms suffered heavy losses. According to the report of Economic Daily on May 3rd 1998, fishermen in Hong Kong lost nearly HK$ 1 billion in this red tide incident. More than 300 tons of precious cultured fish died in the mainland, with a loss of more than 40 million yuan. For a time, the news media have been speculating, and people can't help but ask, what is a "red tide"? How did it happen?
The mechanism of red tide is still inconclusive. It is generally believed that moderate water temperature, salinity, nutrients and growth-promoting substances (substances that promote algae growth) are all proliferation factors of red tide organisms. Eutrophication of water, that is, the enrichment of nitrogen and phosphorus nutrients, is an indispensable prerequisite for the occurrence of red tide.
Eutrophication of water body is not a new event, it has always existed in nature. The so-called ocean change is partly due to eutrophication of water bodies. It turns lakes into swamps and finally grasslands and forests, but it is a process of thousands of years. Nowadays, human activities make it extremely intense. A large number of industrial wastewater from the production and use of nitrogen and phosphorus fertilizers, food processing and livestock products processing, as well as a large number of urban domestic sewage, especially sewage from phosphorus-containing detergents, have become an important material source in the process of eutrophication of water bodies. Excessive phosphorus and nitrogen nutrients in water become nutrients of microorganisms and algae in water, which makes blue, green and red algae grow and reproduce rapidly. Their reproduction, growth and corruption lead to a large reduction of oxygen in water, which leads to the suffocation and death of a large number of aquatic organisms such as fish and shrimp. Some algae even release some toxic substances to poison fish. In addition, due to the decomposition of dead algae, some gases, such as CH4 and H2S, will be released, which will make the seawater smelly and the water quality worse. This kind of pollution caused by excessive accumulation of plant nutrients in water is called water eutrophication. This phenomenon is called "red tide" in the bay, and it is also called "water bloom" if it happens in fresh water. Therefore, eutrophication is the precursor of red tide (or water bloom), and red tide is the result of eutrophication.
At this time, it is necessary to emphasize the synthetic detergent, which is composed of surfactants and detergents. Surfactants remain in the environment for a long time, consume dissolved oxygen in water, are toxic to aquatic organisms, and can lead to fish deformity. Purifying agents, such as phosphate, will make water eutrophication. So, how to control water eutrophication?
The most effective and simple method is to intercept the wastewater containing a lot of nitrogen and phosphorus before it enters the natural water body. For example, the production and use of phosphorus-containing detergents are prohibited, urban industrial and domestic sewage is purified, and precipitants such as Ca(OH)2 and Al2(SO4)3 are added to the sewage to remove phosphorus.
May people's actions prevent water eutrophication and eliminate the threat of red tide.
1. China invented papermaking in 100 BC. In A.D. 105, Cai Lun in the Eastern Han Dynasty summarized and popularized papermaking technology, while Europeans still copied books with sheepskin!
2. In 700-800 AD, Sun Simiao recorded three components of black powder (potassium nitrate, sulfur and charcoal) in the Law of Sulfur. Gunpowder was introduced to Arabia in the13rd century and to Europe in the14th century.
3. After 200 BC ... 400 years, alchemy rose in China. Wei Boyang's Zhouyi Shentongqi and Ge Hong's Baopuzi recorded the characteristics and preparation of dozens of drugs such as mercury, lead, gold and sulfur. In 750 AD, China alchemists were introduced into Arabia.
In the Tang Dynasty in 800 AD, Hua Mao was the first person to discover oxygen in the world. He was about 1000 years earlier than priestley in Britain (1774) and Scheler in Sweden (1773).
China is the "king of fiber" ... the hometown of silk. In 2000 BC, China had been able to raise silkworms. In 200 AD, sericulture technology was introduced to Japan.
6. In 600 BC, China had mastered the technology of smelting iron, which was 1900 years earlier than Europe. In 200 BC, China produced ductile iron, 2000 years earlier than Britain and America.
7. 1000 years ago, China was able to smelt zinc, 400 years earlier than Europe.
8. In 2000 BC, China was able to melt and cast copper. China began to smelt and cast bronze in 1700 BC. For more than 900 years, copper leaching from bile in China is the earliest hydrometallurgical technology (replacement method) in the world.
9. 1700 years ago, China was able to smelt lead and copper-lead alloys.
10. From 8000 to 6000 BC, China made pottery. In 200 AD, China mastered the porcelain-making technology.
1 1.3000 years ago, China used natural dyes for dyeing.
12. China is the first country in the world to discover pigments and make lacquerware, with a history of about 7,000 years.
13. From 4000 BC to 3000 BC, China has been able to make wine. In BC 1000, China had mastered the technology of koji-making, which was more than 2,000 years earlier than the "starch fermentation method" in Europe.
14.3000 years ago, our ancestors discovered oil. The ancient book "there is fire in the river" refers to the oil flowing out of the ground spilling over to the water surface and burning. In Song Dynasty, Shen Kuo recorded the use of oil for the first time in Meng Qian's Bi Tan, and predicted that "it will be popular in the world".
15. Qiongchuan in China and Hong Men in Shaanxi were the first to develop and utilize natural gas in the world.
16. Our ancestors used charcoal and Carboniferous (also called black charcoal, that is, coal) very early, but Europeans began to use coal in16th century.
17. 1939, Chinese chemical expert Hou proposed the "combined soda production method". 1939, Hou completed the world's first monograph on soda production.
18. 1965, China is the first person in the world to synthesize active protein … crystalline bovine insulin by artificial method. (Because of his signature, the Nobel Prize in Chemistry passed by China people. )
19.in 1970s, China's original cyanide-free electroplating process replaced toxic cyanide electroplating, which was a pioneering work in the world electroplating history.
20. 1977 The largest diamond in the world … Chang Lin diamond found in Shandong.
2 1. The world's sea salt output is 50 million tons, of which China's output exceeds130,000 tons, ranking first in the world. As early as 3,000 years ago, China used seawater to make salt, which was the earliest country in the world.
22. There are more than 40 kinds of useful minerals known in the world in China. It is the first country in the world to smelt minerals.