The purification and concentration of amoxicillin by novel alkali-sensitive polypiperazine amide/polysulfate composite nanofiltration membranes

Abstract

The recovery of amoxicillin from the mother liquor is crucial in reducing production costs and preventing environmental contamination. Amoxicillin separation was enhanced under an alkaline filtering environment. Therefore, the novel alkali-sensitive polypiperazine amide (PPA)/polysulfate (PSE) composite nanofiltration membranes were fabricated via interfacial polymerization for the concentration and purification of the amoxicillin crystalline mother liquor. The alkali sensitivity of the PPA/PSE composite nanofiltration membrane was investigated. The long-term stability of the membrane was also evaluated. Purification and concentration experiments of amoxicillin mother liquor were also carried out. The separation efficiency of amoxicillin was improved due to the pH sensitivity of amoxicillin and the pH sensitivity of the developed nanofiltration membrane. The results indicate 92.2% rejection of amoxicillin and 45.4 L⋅m−2⋅h−1 of flux at pH 10. In addition, PPA/PSE nanofiltration membranes exhibit good mechanical properties and long-term stability. This indicates its remarkable application potential and its use is expected to result in the large-scale recovery of amoxicillin from the crystalline mother liquor.