(1) color change. Natural water is colorless and transparent. Water pollution will change the color of water,

Thereby affecting the senses. For example, the pollution of printing and dyeing wastewater often turns water red, and the pollution of oil refining wastewater turns water black and brown, and so on. The change of water color not only affects the senses and destroys the scenery, but also is sometimes difficult to deal with.

(2) Turbidity change. Water contains suspended matter and colloid of sediment, organic matter and inorganic matter, which leads to turbidity, thus reducing the transparency of water and affecting the senses and even life of aquatic organisms.

(3) bubbles. Many pollutants, such as detergents, will foam when discharged into water. The foam floating on the water surface not only affects the perception, but also harbors bacteria in its pores, causing domestic water pollution.

(4) bad smell. Odor in water is a common pollution phenomenon. The odor of water body mostly belongs to organic matter that decays and stinks under anaerobic condition, which belongs to comprehensive odor and has obvious sewer odor. The harm of stench is that people hold their breath and feel sick, aquatic products are inedible, and water bodies lose their tourism function.

2. What is the organic pollution of water?

Mainly refers to the pollution caused by wastewater containing a lot of organic matter discharged from urban sewage, food industry and paper industry. These pollutants need to consume a lot of dissolved oxygen in the process of biological oxidation and decomposition in water. Once the oxygen supply in water is insufficient, it will stop oxidation, resulting in anaerobic fermentation of organic matter, giving off stench, polluting the environment and poisoning aquatic organisms.

3. What is inorganic pollution in water?

Refers to the pollution of water by acid, alkali and inorganic salts. First, it changes the PH value of water, destroys its natural buffering effect, inhibits the growth of microorganisms and hinders the self-purification of water. At the same time, it will increase the hardness of inorganic salts and water in water, which will bring adverse effects on industrial and domestic water.

4. What is the toxic pollution of water?

After all kinds of toxic substances enter the water body, at high concentration, they will kill the creatures in the water; At low concentration, it can be enriched in organisms, and gradually concentrated through the food chain, and finally affect the human body.

5. What is eutrophication pollution?

When wastewater containing plant nutrients enters the water, it will cause eutrophication, make algae multiply in large quantities, consume a lot of dissolved oxygen in the water, and lead to fish suffocation and death.

6. What is water pollution?

Coastal and estuarine oil development, tanker transportation, wastewater discharge from oil refining industry, etc. However, when oil forms an oil film on the water surface, it will affect oxygen entering the water body and cause harm to living things. In addition, oil pollution has also destroyed the landscape of the resort beaches and scenic spots and the survival of birds.

7. What is the thermal pollution of water?

The cooling water of thermal power plant is the main source of thermal pollution. This kind of wastewater discharged directly into the natural water body will cause the water temperature to rise, reduce the dissolved oxygen in the water and increase the toxicity of some poisons in the water. The increase of water temperature has the greatest influence on fish, which can cause the change and death of fish population.

8. What is the pathogenic microorganism pollution of water body?

Domestic sewage, hospital sewage, slaughter meat processing and other sewage contain all kinds of viruses, bacteria, parasites and other pathogenic microorganisms, which will spread various diseases when they flow into the water.

9. What are the pollution modes and hazards of cyanide?

Electroplating and other industries can produce a lot of cyanide-containing wastewater, and cyanide can be immersed in respiratory tract, esophagus and skin to cause poisoning. Mild symptoms include mucosal irritation, numbness of lips and tongue, asthma, nausea, vomiting and palpitation. In severe cases, the breathing is irregular, the consciousness is gradually unconscious, incontinence occurs, and respiratory disorders can quickly occur and die.

After cyanide poisoning is cured, neurological sequelae may occur. When the concentration of cyanide in water exceeds 0.03 mg/L, fish will be poisoned.

10. What is the pollution mode and harm of chromium?

Chromium has a wide range of industrial uses, mainly used in metal processing, electroplating and leather industry. The waste water and waste gas discharged by these industries are the main pollution sources in the environment.

Chromium is one of the essential trace elements for human body, but excessive chromium is harmful to human health. Hexavalent chromium is more toxic, more easily absorbed by the human body, causing cancer and accumulating in the body. Excessive (more than 10ppm) trivalent chromium and hexavalent chromium are fatal to aquatic organisms.

What is the pollution and harm of detergent?

The effective components of synthetic detergent are surfactant and detergent, and there are many auxiliary components such as bleaching agent. Surfactants can be divided into cationic, anionic and nonionic types according to their molecular configurations and group types. The latter two are widely used in industry and life.

Wastewater containing synthetic detergent mainly includes washing wastewater, industrial detergent cleaning water, laundry drainage and catering industry, and domestic sewage. Discharge into water will consume dissolved oxygen, which is slightly toxic to aquatic organisms and can cause fish deformity, and the phosphate solvent contained in it will cause eutrophication of water body.

12. What is the pollution and harm of organochlorine pesticides?

Organochlorine pesticides are basically divided into two types of compounds based on alkaline substances and cyclic dienes. The structure of chlorobenzene is relatively stable, and the enzymes in organisms are difficult to degrade, so the organochlorine pesticide molecules accumulated in animals and plants disappear slowly. Because of this characteristic, it will further collect and spread pesticide residues in the environment through biological enrichment and food chain. Organochlorine pesticides that enter the human body through the food chain can accumulate in tissues such as liver, kidney and heart, especially because of their high fat solubility, so the positive factors in body fat are more prominent. The accumulated residual pesticides can also be excreted through breast milk, or transferred to tissues such as eggs, affecting future generations.

Since 1960s, China has banned the use of DDT and HCH in vegetables, tea, tobacco and other crops.

13, what is biochemical oxygen demand?

Biochemical oxygen demand (BOD) refers to the amount of oxygen consumed when organic matter contained in water is biodegraded by microorganisms. This is a determination method based on the principle of microbiology. All factors affecting microbial degradation, such as temperature and time, will affect the determination of BOD. The final biochemical oxygen demand refers to the amount of oxygen required for biochemical degradation of all organic substances into simple final products. Generally, the standard is 20℃ and culture for 5 days. As for BOD, it is usually expressed in milligrams per liter or ppm.

14, what is chemical oxygen demand?

Chemical oxygen demand (COD) is the amount of oxidant consumed by treating water samples with a strong oxidant under certain conditions, expressed in milligrams per liter of oxygen. It is the main index to indicate that the water body is polluted by reducing substances, including various organic substances, nitrite, ferrous salts and sulfides. The pollution of water samples by organic matter is very common, so chemical oxygen demand can be used as one of the indexes of relative content of organic matter. The determination of chemical oxygen demand can be divided into potassium permanganate method and potassium dichromate method according to the different oxidants used. potassium permanganate

The four methods are simple in operation and short in time, which can explain the pollution of organic matter to water to a certain extent, and are often used in water samples with less pollution. Potassium dichromate method can completely oxidize organic matter and is suitable for all kinds of water samples.

15. Greenhouse effect and its impact on global climate change?

The temperature and climate of the earth's surface are determined by solar radiation, and the energy absorbed by the earth from the sun must be balanced with the radiation energy released by the earth and the atmosphere, so that the temperature of the earth can be stabilized within a certain range. In order to maintain this balance, part of the energy released from the earth is absorbed by radioactive atmospheric gases (greenhouse gases) and then reflected back to the earth, thus reducing the net energy emission to outer space, which is the greenhouse effect. The main greenhouse gases in nature are carbon dioxide, water vapor, methane, nitric oxide and ozone. Human activities

On the one hand, it emits a lot of carbon dioxide, especially since the industrial revolution, the use of fossil fuels has greatly increased. On the other hand, forests and grasslands have been destroyed, which makes the earth lose its carbon dioxide pool continuously, and the concentration of greenhouse gases in the atmosphere increases rapidly, which slows down the release of energy from the earth and causes abnormal greenhouse effect. The direct harm of abnormal greenhouse effect is to raise the global temperature. According to scientists' calculations, doubling the concentration of carbon dioxide will increase the global average temperature by 1.5 ~ 7℃ and 4 ~ 10℃ in high latitudes. Such a rapidly rising temperature will lead to the melting of glaciers on the earth and the rise of sea level, which will make many coastal cities extinct.

Scientists have observed a lot and think that the abnormal greenhouse effect is an important cause of global climate change, and the most important thing is the excessive carbon dioxide on the earth. In the past 100 years, the surface temperature of the earth has increased by 0.3 ~ 0.6 degrees. Of course, there are still differences in academic circles, but most people think that global warming will cause extremely serious social problems to mankind, so practical prevention and control measures must be taken as soon as possible.

16. What is ozone layer destruction and its harm?

The ozone layer refers to the gas layer composed of ozone in the atmosphere from/kloc-0 to 50 kilometers away from the earth's surface. Ozone is a gas, and its molecular structure is three oxygen atoms, namely O3. The main function of the ozone layer is to absorb ultraviolet rays in the universe and protect everything on earth from ultraviolet radiation. Therefore, the ozone layer is called the umbrella of the earth. But now, the ozone layer has been seriously damaged by human beings. Since the beginning of this century, humans have used a large number of high-stability synthetic compounds in air conditioners, refrigerator industries, solvents, aerospace refrigerants, sprays and cleaning agents. These compounds volatilize through complex physical and chemical processes and react chemically with ozone.

Destroy it accordingly. 1984, scientists first discovered the ozone hole over Antarctica, and recently discovered the ozone hole over the Arctic. The direct consequence of the destruction of the ozone layer is to let the ultraviolet rays radiated by the sun directly come in, which is harmful to human beings and other creatures. Scientists have confirmed that every time ozone in the atmosphere is reduced by 1%, ultraviolet radiation on the ground will increase by 2%, and the incidence of skin cancer will increase by about 4%. In addition, it will damage people's immune system and increase the possibility of people suffering from cataracts and respiratory diseases. At the same time, it will also damage marine life and hinder plant growth. The latest achievements of environmental science research show that ozone layer destruction is also an important factor of global climate change.

17. What are the pollution patterns and hazards of photochemical smog?

Primary pollutants such as hydrocarbons (HC) and nitrogen oxides (Nox) discharged into the atmosphere by pollution sources such as automobiles and factories generate photochemical reactions under the action of sunlight (ultraviolet light) to generate secondary pollutants. The smog pollution phenomenon formed by the mixture of primary pollutants and secondary pollutants participating in the photochemical reaction process is called photochemical smog.

The composition of photochemical smog is complex, and the harm to people and animals is mainly manifested in irritation to eyes and mucous membranes, headache, respiratory disorders, deterioration of chronic respiratory diseases in Hohhot, and abnormal lung function of children.

18, what is the grade and harm of stench?

Odor is a fine substance floating in the air that is harmful to human health, such as hydrogen sulfide, mercaptan, ammonia, methyl sulfur, formaldehyde, phenols and various decomposition products of protein. Smell spreads through the wind, and its intensity can be divided into six levels: 0 level, tasteless; 1 grade, barely feeling a slight odor; Grade 2, easy to feel slight odor; Level 3, obviously stinking; Grade 4, strong odor; Grade 5, unbearable stench will affect people's breathing, digestion, cardiovascular, endocrine and nervous system. High-concentration malodor can also cause pulmonary edema and even suffocation death of contacts. Long-term repeated stimulation by malodorous substances will also cause olfactory fatigue and lead to olfactory failure.

19, sulfur dioxide pollution mode and its harm?

Sulfur dioxide (SO2) is a colorless gas with a pungent smell. When the concentration of SO2 in the atmosphere reaches 1-5 ppm, it will stimulate the respiratory tract, increase airflow resistance and cause respiratory diseases. Children are more sensitive than adults. High concentration of SO2 will make sensitive conifers defoliate or even die, and it will also cause acid rain.

20. What are the ways and hazards of lead pollution?

Lead pollution is one of the most toxic heavy metal pollution. Lead pollution in urban air mainly comes from alkyl lead in automobile exhaust. Lead pollutes the human body through the respiratory tract and diet, and the absorption efficiency through the respiratory tract is high and fast.

Lead affects all organs and systems of human body, but mainly nervous system, blood and cardiovascular system. The most common diseases are anemia, lead colic and lead poisoning hepatitis. The symptoms of nervous system include vegetative neurasthenia (such as headache, head mistake, fatigue, irritability, poor sleep and memory loss). ) and polyneuritis.

2 1. What is polycyclic aromatic hydrocarbon pollution and its harm?

Hydrogen compounds containing more than two benzene are collectively called polycyclic aromatic hydrocarbons. Polycyclic aromatic hydrocarbons in the environment mainly come from the combustion of coal and oil. Most of the polycyclic aromatic hydrocarbons produced by combustion are attached to smoke particles and discharged into the atmosphere. Polycyclic aromatic hydrocarbons exist in the exhaust gas of diesel engines and gasoline engines, as well as in the exhaust gas and wastewater discharged from gas plants and asphalt processing plants. Polycyclic aromatic hydrocarbons also exist in smoked food and smoke.

The harm of polycyclic aromatic hydrocarbons to human body was discovered earlier. 19 15 years, scientists confirmed that coal tar is carcinogenic to rabbits. Polycyclic aromatic hydrocarbons are not direct carcinogens, but the ultimate carcinogens under the action of enzymes in the body.

When carcinogens combine with DNA or RNA, they will cause irreparable damage and lead to cancer.

22, the way of electromagnetic wave pollution and its harm?

Electromagnetic wave is a propagating alternating electromagnetic field, which can be divided into long wave, medium wave, short wave, ultrashort wave and microwave according to wavelength, and low frequency, high frequency, ultra-high frequency and ultra-high frequency according to frequency. Electromagnetic radiation pollution is one of the important environmental pollution factors. Its harm to people is intangible.

The greater the output power of electromagnetic radiation source, the shorter the wavelength, the higher the frequency, the closer to the radiation source, the longer the exposure time, and the higher the ambient temperature and humidity, the greater the impact and harm to human body. If people live in an environment polluted by electromagnetic radiation for a long time, they will have symptoms such as neurasthenia, irritability and menstrual disorder, mainly fatigue and memory loss.

The harm of microwave to human body is mainly thermal effect, especially to visual organs. The use of "mobile phone" will change people's brain and its blood flow. Over time, people's brain will be damaged and get sick.

23. What is toxic chemical pollution?

Toxic chemicals refer to chemicals that damage health and the environment through environmental accumulation, bioaccumulation, biotransformation or chemical reaction after entering the environment, or have serious harm and potential danger to human body through contact.

Due to the increasing variety and quantity of toxic chemicals in the world and the expansion of international trade, the harm of most toxic chemicals to the environment and human body is not completely clear. Their migration in the environment is also difficult to control, posing a serious threat to the human environment; Accidents caused by the leakage and transportation of toxic chemicals have the characteristics of strong suddenness, rapid pollution, large scope and long duration, especially some vicious accidents have caused serious casualties and property losses; As well as the long-term potential harm of hazardous wastes produced by toxic chemicals to human environment, the problem of toxic chemicals has become an important global environmental problem, which has attracted the attention of all countries in the world. In recent years, some developed countries have transferred some wastes to the third world. Although the Basel newspaper has been published, it has been repeatedly banned. Some developed countries in Europe and America often transfer hazardous wastes to developing countries.