Introduction to Macroporous Adsorption Resin Technology

Macroporous adsorption resins are synthetic polymer adsorbents with a porous three-dimensional structure. Developed based on the applications of ion exchangers and other adsorbents, they function by relying on van der Waals forces between themselves and the adsorbed molecules (adsorbates), utilizing their large specific surface area for physical adsorption. In practical applications, they exhibit particularly strong adsorption capacity for molecules with similar skeletal structures, such as aromatic cyclic compounds.

Macroporous adsorption resins are widely used in the extraction and separation of macromolecular compounds such as saponins, flavonoids, lactones, and alkaloids from pharmaceuticals and natural plants. This process demonstrates excellent efficacy in the purification, separation, and recovery of ginsenosides, notoginseng saponins, gynostemma pentaphyllum saponins, diosgenin saponins, steviosides, glycyrrhizin, ginkgo flavonoids, hawthorn flavonoids, astragalus saponins, hesperidin, epimedium flavonoids, soy isoflavones, tea polyphenols, digitalis cardiac glycosides, ephedrine powder, naringin, holly flavonoids, yew alkaloids, various natural pigments, and traditional Chinese medicine compound extracts, as well as biochemical products. It also has wide applications in the purification of antibiotics, vitamins, amino acids, and proteins, and in biochemical pharmaceuticals.

Macroporous resin adsorption separation technology is one of the most influential and far-reaching technologies in the extraction of traditional Chinese medicine. This process is simple to operate, low in cost, and the resin can be reused, making it suitable for industrial production. Therefore, it has strong application value and will promote a leapfrog advancement in traditional Chinese medicine extraction technology. Meanwhile, macroporous adsorption resins also have wide applications in the treatment of industrial wastewater and waste liquids. They exhibit excellent adsorption, recovery, and purification effects on organic compounds in wastewater containing benzene, nitrobenzene, chlorobenzene, fluorobenzene, phenol, nitrophenol, aminophenol, bisphenol A, p-cresol, naphthalene, aniline, o-phenylenediamine, p-phenylenediamine, salicylic acid, 2,3-acid, and naphthalenesulfonic acid. Furthermore, they are highly adaptable to varying concentrations of harmful substances in waste liquids and can achieve one-time compliance. This enables the recovery and reuse of harmful substances in industrial production, turning waste into resources and transforming harmful substances into beneficial ones.

Ion exchange resin application precautions:

1) Storage and transportation

① Store in a sealed container, avoiding exposure to cold or direct sunlight.

② Storage temperature: 4℃-40℃.

③ The resin has a shelf life of 2 years. It can only be used after passing a re-inspection after 2 years. If the resin is found to be dehydrated, do not add water directly; first add an appropriate amount of concentrated saline solution to restore moisture. 2) Pretreatment

The resin must be pretreated according to the following steps before operation.

① Pretreatment of Cation Resin

The pretreatment steps for cation resin are as follows:

First, use saturated saline solution, approximately twice the volume of the resin to be treated, and soak the resin in the saline solution for 18-20 hours. Then drain the saline solution and rinse thoroughly with clean water until the effluent is no longer yellow. Next, use a 2%-4% NaOH solution, the same amount as above, and soak the resin in it for 2-4 hours (or rinse with a small flow rate). After draining the alkali solution, rinse the resin until the effluent is nearly neutral. Finally, use a 5% HCl solution, the same amount as above, and soak the resin for 4-8 hours. Drain the acid solution and rinse with clean water until neutral before use. ② Pretreatment of Anion Resin

The first step in the pretreatment method is the same as the first step in the pretreatment method for cation resin. Then, soak in 5% HCl for 4-8 hours, drain the acid, and rinse with water until neutral. Next, soak in 2%-4% NaOH solution for 4-8 hours, drain the alkali, and rinse with clean water until neutral before use.

3) Prevention of Resin Contamination

Resin contamination can occur in several ways: one is due to organic matter and colloidal silica in the raw water; another is heavy metal contamination; and yet another is the breakdown of high-molecular-weight compounds in the resin itself during long-term operation, causing breakage or a decrease in exchange capacity. Therefore, it is essential to differentiate the causes of contamination and poisoning and treat accordingly.