What are the chemical pollutions, what are the chemical pollutions?

Chemicals enter the environment through accidents or through direct application; It also enters the environment through the discharge of exhaust gas, waste residue and waste liquid. For example, sulfur dioxide, nitrogen oxide and polycyclic aromatic hydrocarbons in the atmosphere mainly come from exhaust gases; Heavy metals in rivers, lakes and seas mainly come from wastewater and waste residue; Exposure to occupational environments is also a major way chemicals can harm the human body.

Chemical contamination includes a variety of hazardous metals, non-metals, organic compounds, and inorganic compounds.

1 Pesticide contamination.

Common pesticides include fumigants, insecticides, herbicides, fungicides, etc., which are contaminated or have certain residues in food if they are used improperly or excessively.

2. Industrial waste pollution.

The wastewater, waste gas, and waste residue (commonly known as the "three wastes") discharged from industrial production contain various toxic and harmful substances, which can pollute aquatic organisms, crops, pastures, etc., and then pollute various foods.

3 Contamination of packaging materials.

Harmful substances in containers, instruments, packaging materials and means of transport that do not meet hygienic requirements contaminate the food when they come into contact with it.

4 Contamination of additives.

In order to achieve a certain processing purpose, food additives are consciously added to food, if the food additives themselves do not meet the hygiene requirements, or contain harmful impurities, they can cause food contamination.

Chemical Pollutants : Generally refers to chemical substances that cause pollution when they enter the environment. Such as DDT, polychlorinated biphenyls, potassium dichromate, acrylonitrile and vinyl chloride.

Environmental pollution due to chemical substances (chemicals) entering the environment. That is, environmental pollution caused by chemical pollutants. These chemicals are organic and inorganic, and they are mostly products made by human activities or artificial creation, and there are also secondary pollutants.

According to the damage caused, chemical pollution is mainly divided into environmental hormonal damage, carcinogenic and teratogenic and mutagenic chemical damage, and toxic chemical sudden pollution damage.

According to environmental factors, it can be divided into: air pollutants, water pollutants and industrial pollutants.

According to the form of pollutants, they can be divided into: gaseous pollutants, liquid pollutants and solid pollutants;

According to the nature of pollutants, they can be divided into: chemical pollutants, physical pollutants and biological pollutants.

The main chemical pollutants are:

1.Elements: such as lead, cadmium, metalloids, etc. 2.Inorganics: oxides, carbon monoxide, hydrogen halides, halogen compounds, etc.

3.Organic compounds and hydrocarbons: alkanes, unsaturated aliphatic hydrocarbons, aromatic hydrocarbons, PAH, etc.;

4.Organometallic and metalloid-organic compounds: e.g., tetraethyl lead, diphenyl chromium, dimethylarsonic acid, etc.;

5.Oxygenated organic compounds: such as ethylene oxide, ether, aldehyde, organic acids, anhydrides, phenols, etc.;

6.Nitrogen-containing organic compounds: amines, eyeballs, nitrobenzene, trinitrotoluene, nitrosamines, etc.;

7.Organohalides: carbon tetrachloride, polychlorinated biphenyls, chlorinated dioxane;

8.Organic sulfides: mercaptans, dimethyl sulfone, dimethyl sulfate, etc.;

9.Organophosphorus compounds: phosphate compounds, organophosphorus pesticides, organophosphorus military toxic gases, etc.

There are three main types of chemical pollution:

1. The water temperature of heat-polluted sewage is one of the important physical properties of sewage water quality. As far as sewage treatment itself is concerned, how low (e.g. below 5) or too high (e.g. above 40) of the water temperature will affect the biological treatment effect of the effluent.

Hotter effluents mainly come from cooling water from thermal power plants and various heat-generating plants. After the untreated cooling water is discharged into the water body, the water temperature of the receiving water body increases, the toxicity of toxic substances in the water increases, the dissolved oxygen decreases, and the growth of aquatic organisms is endangered and even leads to death.

2. Suspended matter pollution suspended solids refer to insoluble substances contained in water, including solid substances, plankton and emulsified oils (foams). They mainly come from domestic sewage, garbage and sewage from industries such as mining, building materials, food, papermaking, etc., or soil erosion caused by surface runoff. The presence of suspended matter causes turbidity and deterioration of the water and changes the color of the water.

3. The radioactive substances in radioactive contaminated sewage mainly come from the production and use of radioactive metals such as uranium and radium, such as radioactive mineral deposits, nuclear tests, nuclear power plants and isotope laboratories in hospitals.

The decay of radioactive substances releases radioactive nucleophiles (r-rays) to constitute a special kind of pollution, that is, radioactive pollution, which carries out chronic radiation to the human body and can accumulate for a long time, causing potential effects and inducing anemia, cancer, etc.