Strong acid ion exchange resin is a kind of granular product with sulfonic group on the crosslinked styrene skeleton. It can be used in all pH ranges (0-14), stable at various temperatures and resistant to high temperatures of 100-120℃. Therefore, it is widely used in water treatment for manufacturing pure water and soft water, as well as in pharmaceutical products, food refining, catalyst and other fields.

Strong acid ion exchange resin is a cation exchange resin whose main exchange group is a sulfonic acid group (-SO3H), which can be used repeatedly. The use of ordinary mineral acids is the same. Softening strong acidic ion exchange resins must use special catalyst type resins because it also affects the reaction rate of hydrogen ion release rate, pore size, and crosslinking degree.

Chelating resin is a kind of cross-linking functional polymer materials which can form multi coordination complex with metal ions. The mechanism of metal chelating resin adsorbing metal ions is that a stable structure similar to small molecule chelates is formed after the coordination reaction between functional atoms on resin and metal ions. The adsorption mechanism of ion exchange resin is electrostatic. Therefore, compared with ion exchange resin, the binding force of chelate resin to metal ions is stronger, which is of high selectivity. It can be widely used in the recovery and separation of various metal ions, the separation of amino acids, hydrometallurgy, pollution prevention and so on.

Ion exchange system is a kind of traditional water treatment technology which displaces all kinds of anion and cation in water by anion and cation exchange resin. The anion and cation exchange resins can be combined in different proportion to form cation exchange bed system, anion exchange bed system and mixed bed ion exchange system. The mixed bed ion exchange system is usually used to produce ultra pure water and high pure water after water treatment processes such as reverse osmosis. It is one of the irreplaceable means to prepare ultra pure water and high pure water.

A polypeptide is a kind of compound that is made up of many amino acids connected by peptide bonds.

In the process of evaporation treatment of wastewater from by-product ammonium salt (including organic amine) of chemical industry, some ammonium salt will be hydrolyzed and converted into ammonia gas (or organic amine). They enter into the condensate with the evaporation and condensation of water vapor, resulting in the ammonia nitrogen in the condensate exceeding the standard (according to the evaporation process, the ammonia nitrogen content generally varies from 200-1000 mg/L), unable to be discharged or reused, which brings difficulties to the production enterprises, but also causes waste of resources.

Lactic acid is a kind of multi-purpose organic acid and it is also one of the three recognized organic acids in the world.

Citric acid, scientific name 2-hydroxypropane-1,2,3-tricarboxylic acid, is widely used in food, medicine, cosmetics and other industrial fields. The production of citric acid is mainly through biological fermentation. In the process of fermentation, salt, pigment and other impurities will inevitably be produced. It is necessary to achieve the impurity removal and purification of citric acid through necessary refining process to meet the requirements of relevant standards.