The source and prevention of chemical pollution

(3) "Running, bubbling, dripping, leaking"

Materials in the storage, transportation and generation process, due to the equipment, pipelines and other sealing is not tight, often cause the leakage of chemical raw materials, products, it is customary to call "running, taking, dripping, leakage" phenomenon. This phenomenon not only causes economic losses, but also may cause serious environmental pollution accidents, and even bring unpredictable consequences.

Waste released during chemical production

(1) Combustion process

The vast majority of chemical production processes need to be carried out under a certain pressure and temperature, so there needs to be an input of energy, which is usually obtained by burning a large amount of fuel. However, in the process of fuel combustion, it is inevitable to produce a lot of waste gas and smoke, which causes great harm to the environment. The content of various harmful substances in the flue gas has a great relationship with the type of fuel.

(2) Cooling water

Chemical production process in addition to the need for a lot of heat, but also need a lot of cooling water. In the production process, there are two ways of cooling with water: direct cooling and indirect cooling. When direct cooling is used, the cooling water is directly in contact with the material being cooled, and this cooling method is easy to make the water contain chemical materials, and become polluting substances. When indirect cooling is used, although the cooling water is not in direct contact with the material, because preservatives, algaecides and other chemical substances are often added to the cooling water, it will cause pollution problems after discharge, even if the relevant chemical substances are not added, the cooling water will also cause thermal pollution problems to the surrounding environment.

(3) Side effects

In chemical production, the main reaction is often accompanied by side reactions, and some unwanted by-products are obtained. Although by-products can be recovered, the number of by-products is often small, and the composition is more complex, so that recycling must face technical and economic problems, so in fact, by-products are often discarded as waste, so it will cause environmental pollution.

(4) Chemical pollution caused by production accidents

The frequent production accidents are equipment accidents. In chemical production, because many raw materials, semi-finished products or finished products are corrosive, containers, pipelines, etc., are easily damaged by corrosion of chemical raw materials or products, such as maintenance is not timely, there will be "running, taking, dripping, leakage" and other phenomena, the loss of raw materials, finished products or semi-finished products will cause pollution to the surrounding environment. Accidental production accidents are process accidents, such as the reaction conditions in the chemical production process are not well controlled, or the catalyst is not replaced in time, or a large amount of exhaust gas and drainage for safety, or the production of unwanted substances. This kind of waste gas, waste liquid and unnecessary substances, the number is more than usual, the concentration is higher than usual, it will cause serious pollution for a while.

In short, the waste discharged by the chemical industry is nothing more than three forms of substances, that is, waste gas, waste water and waste residue, collectively known as the "three wastes" of the chemical industry. However, any waste itself is not an absolute "waste", in a sense, any material is useful to human beings, once people make reasonable use of waste, they can completely "turn waste into treasure".

Characteristics of chemical pollution

The pollutants discharged from the chemical industry will pollute both water and the atmosphere, especially water pollution.

Characteristics of water pollution

Chemical wastewater is the wastewater discharged in the process of chemical production, and its composition depends on the raw materials and processes used in the production process, which can be divided into two kinds of production wastewater and production wastewater. Production wastewater refers to the relatively clean chemical wastewater that can be discharged or reused without treatment, such as condensate water in chemical production. Production sewage refers to those serious pollution, need to be treated before discharge of butyl chemical wastewater. The pollution characteristics of chemical wastewater have the following aspects.

(1) Toxic and irritating

Chemical wastewater contains many pollutants, some of which are toxic or highly toxic substances, such as cyanide, phenol, arsenic, mercury, cadmium and lead, etc. Most of these substances are toxic or highly toxic to organisms and microorganisms at a certain concentration; Some substances are not easy to decompose, long-term accumulation in the biological body will cause poisoning, such as BHC, DDT and other organic chlorides; Some are carcinogens, such as polycyclic aromatic compounds, aromatic amines and nitrogen heterocyclic compounds; In addition, there are some irritating, corrosive substances, such as inorganic acids, bases and so on.