Nanofiltration Membrane Technology Improves Drawbacks in Antibiotic Production

Nanofiltration membranes and their related processes have greatly promoted the application of membrane technology in liquid separation field. Nowadays, most major membrane companies are involved in the production of nanofiltration membranes, but they have different names. Based on the characteristics of the membrane, those membranes called loose reverse osmosis, low-pressure reverse osmosis, hyperfiltration, and charged reverse osmosis/ultrafiltration should be classified as nanofiltration.

Understanding nanofiltration membranes

The pore size of nanofiltration membranes is above 1nm, generally between 1 and 2nm. It is a functional semipermeable membrane that allows solvent molecules or certain low molecular weight solutes or low-valence ions to pass through. It is a special and promising variety of separation membrane because its name comes from its ability to screen substances that are about the size of a nanometer. It is used to remove organic matter and color from surface water, remove hardness from groundwater, partially remove dissolved salts, concentrate juice, and separate useful substances in drugs.

Nanofiltration membranes have strong selective screening properties, and the differences in screening abilities for different valence ions are significant, reflecting its highly selective permeability performance. Nanofiltration membrane products with customized performance matching customer needs can solve high-difficulty concentration and separation requirements. They can be used for water quality softening in municipal water supply, groundwater, surface water, industrial wastewater systems, and separation and concentration in various industries such as food and medicine.

Application of nanofiltration membranes in antibiotic production

The relative molecular weight of most drugs is within this range at antibiotic concentrations. Nanofiltration technology is energy-saving and environmentally friendly, so it is increasingly used in various separation, purification, and concentration processes in the pharmaceutical industry. The relative molecular weight of antibiotics is usually between 300 and 1200. The production process is to clarify the fermentation broth, extract it with a selective solvent, and then distill it under reduced pressure. Antibiotic concentration and purification technology does not require heating, has no phase change, and does not destroy biological activity. It is suitable for substances with relative molecular weight less than 1000.

Nanofiltration membrane technology can improve the concentration and purification processes of antibiotics in two ways：

Use nanofiltration membranes to concentrate the unextracted antibiotic fermentation filtrate, remove water and inorganic salts, and then extract it. This can greatly increase the production capacity of the equipment and greatly reduce the amount of extractant used.

After extracting antibiotics with solvents, concentrate the extract with a solvent-resistant nanofiltration membrane and then recycle the permeated extractant. Nanofiltration membranes have been successfully used in the concentration and purification of antibiotics, such as erythromycin, streptomycin, and penicillin.