The source and prevention of chemical pollution

With the development of society, the problem of environmental pollution has become more and more serious, and industrial pollution has occupied a large proportion of environmental pollution. The more developed countries, the more rapid the development of chemical industry, chemical pollution is more serious.

Chemical pollution refers to the waste gas and pollutants produced in the production process of the chemical industry. Most of these wastes are harmful above a certain concentration, and some are highly toxic substances, which will cause pollution when entering the environment. Some chemical products in the process of use will cause some pollution, even more serious than the pollution caused by the production itself, more extensive.

Chemical industry development process

From the perspective of the development process of chemical industry, foreign chemical pollution can be generally divided into three stages.

The occurrence period of chemical industry pollution

The early chemical industry (about the end of the 19th century) was based on the production of inorganic chemical raw materials such as acids and alkalis, so the pollutants in the chemical industry at that time were mainly inorganic pollutants such as acids, alkalis and salts. In addition, the scale of inorganic chemical production in this period can not be compared with the current chemical industry, and the variety is relatively small, so the pollutants generated are relatively single, which is not enough to constitute a large area of regional pollution, and the environmental pollution problem is not obvious.

The development period of chemical industry pollution

From the beginning of the 20th century to the 1940s, due to the rapid development of metallurgy and coking industry, the chemical industry also developed, and entered the period of coal chemical industry that uses coal as raw materials to produce chemical products. Coal can not only be burned as fuel, but also become the main raw material of the chemical industry. A series of organic chemical industrial products with coal, coke and coal tar as raw materials began to mass production, a large number of new chemical enterprises continue to build, the world chemical industry has a rapid development. At the same time, the scale and quantity of the inorganic chemical industry are also expanding during this period, so the inorganic pollution caused by the quantity and the degree of harm have been intensified, and the organic chemical industry has also begun to develop, resulting in the increased impact of organic pollution on environmental pollution, and sometimes there is a synergistic effect with inorganic pollutants. Therefore, the phenomenon of chemical industry pollution is more important.

A period of widespread pollution from the chemical industry

Since the 1950s, countries in the world have discovered rich reserves of oil and gas fields, since the rapid development of the petroleum industry, the petroleum industry has become an important part of modern energy and national economy, the rise of the petroleum industry, caused the fuel structure of countries in the world gradually from coal to oil and gas. Thus, the chemical industry has also entered the "petrochemical era" with oil and natural gas as the main raw materials, and the petrochemical industry has begun to develop rapidly, and environmental pollution has been flooded, reaching an unprecedented point. The pollution type has also undergone a qualitative change, from the original coal smoke type to oil type pollution.

Chemical pollution is an important problem to be solved urgently in the process of chemical industry development. If it cannot be solved properly, it will inevitably restrict the sustainable development of chemical industry. Now has entered the era of control and prevention of chemical pollution, environmental protection requirements are constantly harsh, pollution-free biochemical and green chemical industry has been advocated, and has been rapidly developed.

The source of chemical pollution

The types of chemical pollutants can be divided into inorganic chemical industry and organic chemical industry pollution according to the nature of pollutants. According to the form of pollutants, there are waste gas, waste water and waste residue. The main sources of chemical pollutants can be roughly divided into two aspects, namely raw materials, semi-finished products and products of chemical production; Waste released during chemical production.

Raw materials, semi-finished products and products for chemical production

(1) The chemical reaction is incomplete

In all chemical production, there is a conversion rate problem, that is, it is impossible to convert all raw materials into semi-finished or finished products. Although unreacted raw materials can be recycled, a part of them is always discharged due to incomplete or impossible recycling. If the chemical raw materials are harmful substances, they will cause environmental pollution after discharge.

(2) Raw materials are not pure

Sometimes the chemical raw materials themselves are not pure enough, which contain impurities. In general, these impurities do not need to participate in chemical reactions and are finally discharged. However, most of the impurities are harmful chemicals that can cause environmental pollution. Some chemical impurities even participate in the reaction, and the resulting reaction product is also an impurity of the desired product. It is also a harmful pollutant to the environment.

(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.

(2) Both biological oxygen demand (BOD) and chemical oxygen demand (COD) are higher

Chemical wastewater, especially petrochemical production wastewater, contains a variety of organic acids, alcohols, aldehydes, ketones, ethers and epoxides, which are characterized by high biochemical and chemical oxygen demand. Some as high as tens of thousands of milligrams per liter. Once this waste water is discharged into the water body, it will be further oxidized and hydrolyzed in the water, thus consuming a large amount of dissolved oxygen in the water, and directly threatening the survival of aquatic organisms.

(3) pH is unstable

The wastewater discharged from chemical production is sometimes strongly acidic and sometimes strongly alkaline, and the pH is very unstable, which has great harm to aquatic organisms, structures and crops.

(4) More nutritive substances

Some of the chemical production wastewater contains too much phosphorus and nitrogen, resulting in eutrophication in the waters, causing algae and microorganisms to proliferate in the water, and in serious cases, forming a "red tide", causing fish to suffocate and die in large numbers.

(5) High wastewater temperature

Because the chemical reaction is often carried out at high temperatures, the water temperature of the discharged wastewater is higher. After this high temperature water is discharged into the water, it will cause thermal pollution of the water body, reduce the dissolved oxygen in the water, and destroy the living conditions of aquatic organisms. Thermal pollution will affect the fishery production, on the one hand, the increase of water temperature can reduce the dissolved oxygen in the water, on the other hand, it will increase the metabolic rate of fish and require more dissolved oxygen, and the development of fish under the action of thermal stress is hindered, and even die.

(6) Oil pollution is more common

Petrochemical wastewater generally contains oil, which not only endangers the survival of aquatic organisms, but also increases the complexity of wastewater treatment.

(7) Recovery is difficult

Even if the water polluted by chemical harmful substances is reduced or stopped, it will still take a long time to return to the raw material state of the water, especially for heavy metal pollutants that can be enriched by organisms, and it is still difficult to eliminate the pollution state after stopping the discharge.

Ways of prevention and control

To prevent and control chemical pollution effectively, we should consider two aspects. One is to reduce emissions; Second, we will strengthen governance. Management includes the proper treatment, recycling and utilization of waste.

Control tool

In the process of recycling waste liquid, leakage and rollover events will inevitably occur, and waste liquid will flow out, causing re-pollution. In this regard, anti-leakage tray came into being. Anti-leakage tray, also known as leakage tray, anti-spill tray, anti-spill tray, anti-spill tray, oil drum tray, anti-leak tray, oil tray tray, oil tray, is a polyethylene material container designed and developed to prevent and control the leakage of oil drums and chemical drums and other oil and chemical containers used in modern factories, warehousing, logistics, transportation industry. It is mainly used for chemical packaging and storage, which can prevent environmental pollution and protect personal safety.

Bikon Industries is committed to providing solutions for the production and processing of rotomized containers. Committed to providing automation and information products and services for water treatment dosing equipment; It is committed to preventing the leakage of oil hazardous chemicals and improving the safety protection level of industrial production.