SEPARATION OF AMOXICILLIN FROM PHARMACEUTICAL WASTEWATER BY SYNERGISTIC EXTRACTION

Abstract

The contamination of amoxicillin from pharmaceutical wastewater into aquatic environment adversely affects ecosystem as well as the increasing the treatment difficulty of bacterial infection in human. Hollow fiber supported liquid membrane (HFSLM) is a promising method for amoxicillin removal and recovery in a single unit. Based on the polyprotic property of amoxicillin, several extractants are selected to perform the reactive liquid-liquid extraction of amoxicillin including trioctylmethylammonium chloride (Aliquat 336), di-(2-ethylhexyl)-phosphoric acid (D2EHPA), tributyl phosphate (TBP), trioctylamine (Alamine 336) as well as the binary mixture of the mentioned extractant as means to achieve synergistic amoxicillin extraction. The results of the experiment indicated that the initial pH of amoxicillin solution should be adjusted to 10. The mixture of Aliquat 336 and TBP (AqT) prepared at the molar ratio of 10:2 provided the synergistic amoxicillin extraction with the maximum extraction percentage of 90.4 ± 0.39% while the optimal pH and concentrations of KCl stripping solution should be maintained at 5 and 6 mM, respectively. The obtained condition was subsequently applied to HFSLM, resulting in the steady state extraction and stripping percentages of 31.8% and 9.7%, respectively, when the flow rates of feed and stripping streams were 62.5 mL/min. Low magnitudes of extraction and stripping percentages were likely related to short contact time.