Encyclopaedia of water treatment chemicals

Lack of water resources has been a major problem facing China, especially in recent years, with the rapid development of the domestic economy, water consumption has risen rapidly, and pollution of water resources has become increasingly serious. Industrial water treatment technology is of great significance for saving water resources, reducing water pollution and prolonging the service life of equipment. Therefore, with the continuous improvement of industrial water treatment and environmental protection requirements, the variety of water treatment agent in our country is constantly enriched, and the performance is continuously improved. There are various kinds of water treatment agents. In order to help you know more about water treatment chemicals, we have collected and sorted out the most complete water treatment chemicals in the history:
Corrosion inhibitor
The utility model has the advantages of good effect, small amount of use and convenient use, and can prevent or slow down the corrosion of water to metal materials or equipment after being added to the water in an appropriate concentration and form.
There are many kinds and kinds of inhibitors. According to their kinds, they can be divided into inorganic inhibitors and organic inhibitors. The inhibition reaction is anodic reaction, cathodic reaction, or both. They can be divided into anodic inhibitors, cathodic inhibitors or mixed inhibitors. Inhibitors can also be divided into passive film type, precipitation film type and adsorption film type according to the mechanism of forming protective film on the metal surface. At present, in the water treatment of passivation film type commonly used inhibitor such as chromate, nitrite, molybdate; precipitation of membrane type commonly used inhibitor with polymeric phosphate and zinc salt; adsorption of membrane type commonly used inhibitor such as organic amine etc..
Two. Scale inhibitors
Also known as anti fouling agents, refers to a class of chemicals that can inhibit calcium, magnesium and other forms of scale, salt and scale formation in water. There is a natural inhibitor such as tannin, lignin derivatives; inorganic inhibitor such as six partial sodium phosphate, sodium tripolyphosphate, etc.; organic polymer scale inhibitors, which polymer scale inhibitors are best, promising. Widely used in water treatment, organic polymer scale inhibitors have two types: the organic phosphonic acid EDTMP (ethylenediamine four methylene phosphonic acid (HEDP), hydroxyl ethyl phosphonic acid two times); the poly carboxylic acid, such as acrylic acid, hydrolyzed polymaleic anhydride etc.. The scale inhibition of these two types of scale inhibitors is usually realized by lattice distortion and dispersion condensation, which is widely used in oilfield water, boiler water and industrial cooling water system.
Three. Bactericide
Also known as bactericidal algae or sludge stripping agent, anti sludge agent, etc., refers to a class of chemicals used to inhibit the growth of microorganisms in water, algae and other microorganisms in order to prevent the formation of microbial slime. They are usually divided into two categories: oxidizing bactericide and non oxidizing bactericide. Oxidizing bactericide, such as chlorine, sodium hypochlorite, bleaching powder; non oxidizing bactericide has good effect, is widely used to destroy bacterial cell wall and cytoplasm of chemicals, such as quaternary ammonium salt. Such as quaternary ammonium chloride twelve alkyl two methyl benzyl ammonium bromide or twelve alkyl two methyl benzyl ammonium, often with sterilization, peeling, corrosion and other effects, promising, has been applied in oil field water, industrial cooling water etc..
Four flocculant
A class of chemicals used to remove or reduce turbidity or suspended matter in water and to accelerate the rate of settling of impurities and sludge in water. Flocculant is the earliest application of inorganic flocculants, such as alum, ferric chloride and so on. Organic and polymeric flocculants are widely used in water supply and wastewater treatment in the future. Can be divided into anionic flocculant, such as carboxymethyl cellulose, sodium polyacrylate and so on; cationic flocculant, such as polyethylene amine, etc.; there are non-ionic flocculant, such as polyacrylamide. Their flocculation is mainly achieved by charge neutralization and adsorption bridging.
Five. Purifying agent
A special chemical application of oilfield water treatment, can remove mechanical impurities and oil in wastewater, its role in addition to the flocculant has suspended solids separation or mechanical impurities, also has the purification effect of oil-water separation. Therefore, in addition to such a general flocculant ingredients, such as aluminum salts, polyacrylamide, etc., often contain some surfactant. For the purification effect of the purifying agent, the membrane filter is usually used to determine the purification factor, and the size of the filter factor (see filter) is the size of the purification effect.
Six, cleaning agent
A class of chemicals having a cleansing effect. In the pretreatment process of water treatment, it is often necessary to use some chemicals to clean the deposits on the surface of metal equipment, such as corrosion products and scale, as well as microbial slime. According to the different requirements of cleaning, cleaning agent can be divided into pickling agents, such as hydrochloric acid, sulfuric acid, hydrofluoric acid, citric acid, etc., such as sodium benzoate passivation agent. At present, the sulfonated succinic acid two (2-ethylhexyl) sodium salt is a surfactant, used as a special cleaning agent, used to clean metal surface oil and rust and other impurities.
Seven. Pre coating agent
In the pretreatment step of water treatment, a kind of chemical that can form protective film beforehand on metal surface. The pre film has two purposes: one is to increase the adding concentration in the early use of chemicals to prevent corrosion; two is the use of a special pre filming agent, to add the inhibitor amount in the normal operation of the CIC, can maintain and repair the protective film, saving reagent and cost. At present, the commonly used precoating agent is six sodium hexametaphosphate, zinc salt, sodium tripolyphosphate and so on.