Definition and classification of water treatment chemicals

Water treatment chemicals refer to chemicals used in industrial water treatment . Water treatment chemicals , also known as water treatment agents, mainly refer to chemicals used in industrial water treatment, including cooling water, boiler water, sewage, oil field water and other industrial water treatment chemicals. Scale inhibitor, corrosion inhibitor, dispersant, bactericide and algaecide, defoamer, flocculant, oxygen scavenger, sludge conditioner, chelating agent, etc. Coagulants and flocculants for raw water and sewage treatment are also included in water treatment chemicals. In addition, activated carbon and ion exchange resins are also important water treatment chemicals.

1. Water treatment agents include the following three types of products:

(a) General chemicals for water treatment: originally refers to inorganic chemical products used for water treatment, such as aluminum sulfate, sodium hydroxide, sulfuric acid, ferrous sulfate, ferric chloride solution, etc.

(b) Special chemicals for water treatment: ion exchange resins and organic water treatment chemicals including activated carbon, inorganic polyaluminum chloride organic flocculants, lime, alum, etc., including activated carbon, ion exchange resins and organic polymeric flocculants (such as polyacrylamide, potassium acid, polyamine and polyquaternium) etc.

(c) Water treatment formulation chemicals: including corrosion inhibitors, scale inhibitors, bactericides and combustion aids, etc.

2. Water treatment chemicals have strong transfer properties. Water treatment chemicals can be divided into two categories according to the purpose of application.

(a) Purified water: pH regulator, redox agent, adsorbent, activated carbon and ion exchange resin, coagulant and flocculant, etc.

(b) Special industrial purposes: corrosion inhibitor, scale inhibitor and dispersant, bactericidal and algaecide, softener, etc.

3.The compound water treatment agent is the main application form, which has the advantages of multi-function and convenient application.

4.Development history of water treatment chemicals:

In ancient times, human beings at that time did not have advanced water treatment technology. In order to reduce the water transmission of diseases, they used simple grid interception and natural sedimentation methods for water treatment. Later, after years of observation and summary, they also discovered a method of filtering out fine suspended solids with sand, and then a chemical coagulation pretreatment appeared. With the continuous progress of human civilization, the waste generated by human beings and the destruction of the environment have caused serious pollution of water resources. When various infectious diseases are transmitted through water, causing many people to get sick or die, it is only when people find out how important water treatment is. It is precisely because of this that people gradually began to study water treatment technology.

Since the end of the 19th century, industrial technology has developed by leaps and bounds, and the production of industrial sewage has doubled year by year. Moreover, the rivers and lakes of the industrial powers at that time were also seriously polluted and gradually became a social hazard. Typical examples include the near-death of fish in the Thames River in the United Kingdom, the death of a large number of organisms in the Mississippi River in the United States, and the contamination of Minamata Bay in Kumamoto Prefecture, Japan with methylmercury, which has caused the occurrence of bone pain in nearby residents. It has been found that the simple chemical and physical methods and the difficulty in treating these sewages have led to the development of new water treatment technologies. Scientists from all over the world have begun to study water treatment methods. The earliest is the sewage aeration test, then the biofilm method, then the artificial biological treatment method, and now the targeted ion exchange method, electrochemical method and other high-tech methods. 

In the 1990s, with the idea of sustainable development put forward, many countries also began to use the method of systems engineering. Taking economic development and environmental protection into consideration, water treatment is not only to treat the formed sewage, but to control it from the source. Due to the rapid economic development in recent decades, it has been found that the traditional water supply treatment process has been difficult to meet the water demand of the society, so biotechnology has begun to be applied to the water supply process. Not only that, with the emergence of water resources crisis, the process of wastewater reuse has also become a point of concern. In order to improve water quality and improve the current environment, sewage treatment technologies such as land irrigation and oxidation ponds based on ecological principles have also been developed.

Water treatment chemicals, also known as water treatment agents, were also called water quality stabilizers in the 1970s, mainly referring to chemicals used in industrial water treatment, including scale inhibitors for industrial water treatment such as cooling water, boiler water and oil field water. , corrosion inhibitor, dispersant, bactericidal and algaecide, defoamer, flocculant, oxygen scavenger, sludge conditioner and chelating agent, etc. Coagulants and flocculants for raw water and sewage treatment are also included in water treatment chemicals. In addition, activated carbon and ion exchange resins are also important water treatment chemicals.

Worldwide sales of water treatment agents in 1992 were US$2.837 billion (excluding activated carbon, ion exchange resins, combustion additives and general inorganic coagulants), of which US$1.479 billion, Western Europe US$483 million, and Japan US$575 million. According to statistics, there are more than 500 companies engaged in the production and service of water treatment agents in the United States, and they mainly focus on technical services. The Western European water treatment market is mainly controlled by American companies, and there are only a few water treatment companies in Western European countries. Organic polymer flocculants in Western Europe, especially polyacrylamide products, have certain advantages. In addition, the production capacity of powder products in the United States is insufficient, and most of their markets are occupied by Western European companies. In addition, several Western European companies have also taken Korea from Japanese manufacturers. Fresh and Middle Eastern parts of the market. There are also many companies engaged in water treatment agent production and technical services in Japan, among which there are more than 20 companies related to cooling water treatment agent manufacturing and technical services.

China’s water treatment technology started in the 1950s, and inorganic phosphates have been used as water treatment agents while introducing chemical technology from the former Soviet Union. In the 1970s, when the large chemical fertilizer plant was introduced, it began to introduce water treatment technology, mainly the technology of the American Baez Company. In the early 1980s, it introduced the phosphate ester water treatment technology from the American Nalco Company and the T-225 alkaline water from the Japanese Kurita Company. Process recipes.

On this basis, China Central Bank has developed localized water treatment technology and water treatment agent. The sewage treatment technology started from the primary treatment in the 1960s, and most of them adopted the secondary treatment. The flocculant and coagulant started in the 1950s production, but it was only used in industrial production in the 1960s, and many new pharmaceuticals were developed in the 1980s.

The production of organic flocculants in China is mainly based on polyacrylamide series products, the varieties are mainly non-ionic and anionic, and there are few cationic products. Among them,

Envo Industrial Co., Ltd. have larger output and more varieties.

By 2000, in addition to some breakthroughs in the preparation technology of various water treatment agents, the varieties that have been produced and applied are still dominant. The average annual growth rate of various varieties will be around 5%-6%.

5.significance of water treatment chemicals

Water treatment is of great significance for improving water quality, preventing scaling, corrosion, bacteria and algae growth and environmental pollution, ensuring efficient, safe and long-term operation of industrial production, and saving water, energy, materials and environmental protection.