A pharmaceutical freeze dryer is a device that converts liquid pharmaceuticals into solid products. It is particularly suitable for the production and manufacturing of pharmaceuticals, health supplements, foods, and other cosmetics. Compared to other drying processes, freeze drying technology can maintain the original chemical properties and activity of pharmaceuticals while extending their shelf life, thereby increasing their utilization efficiency.

Sludge is a byproduct of sewage treatment, a composite product containing various bacterial colloids, organic matter, and inorganic substances. Untreated sludge has a complex composition. In addition to ash, it also contains large amounts of organic matter, refractory organic matter, various trace elements, pathogenic microorganisms, parasitic eggs, heavy metals, and salts. The complex sewage and sludge system and the many interfering components pose certain difficulties for analysis. Therefore, it is necessary to use reasonable and effective methods to remove impurities and other components. In addition, due to the low content of the target compound (usually at trace or ultra-trace levels), in addition to ensuring the sensitivity of the analytical method, the impurity removal method must also be safe for the target research components. Because conventional drying methods have a certain destructive effect on some research components, vacuum freeze-drying technology is considered an effective method for drying sludge and is used in such research.

Hydrogels, polymers that form a macromolecular network in water, are widely used in medicine, biochemistry, materials science, and other fields. Hydrogels possess excellent water absorption, foaming, and water retention properties, and can be made into products such as hydrogel patches, dressings, and fillers. They are widely used in wound dressings, bioengineering, environmental remediation, and cosmetics.