Effect of loading rate and HRT on the removal of cephalosporin and their intermediates during the operation of a membrane bioreactor treating pharmaceutical wastewater

摘要

The viability of treating high-concentration antibiotic wastewater by a membrane bioreactorn(MBR) was studied using submerged flat sheet membrane. The major problems for these modulesnare concentration polarization and subsequent fouling. By using gas-liquid two-phase flow, thesenproblems can be ameliorated. A case study has been identified and the current issues in one ofnthe major pharmaceutical industry (manufacturing cephalosporin drugs) located in Chennai, India,nhas been discussed for the possible removal of anaerobically transformed intermediates ofnantibiotic pharmaceutical wastewater. The objective of the study was to determine the effectnof organic loading rate and hydraulic retention time on the removal of cephalosporin derivative,nviz., cephalexin (C16H17N3O4S·H2O) and the intermediates [7-amino-3-deacetoxycephalosporanicnacid (7-ADCA) and acyl group (Phenyl acetic acid)] in the MBR with enhanced biodegradationnusing bioaugmentation technique. Based on the critical examination of results, the industry isnlooking for the alternatives of either direct disposal of 7-ADCA and phenyl acetic acid or fornfurther degradation and disposal, which will essentially require additional cost and maintenance.nThe present regulatory standard implemented at a global level, (meaning the intermediatesnwhich are transformed during its course of travel within the industry and in the treatmentsnplants, i.e., in the present study it is, 7-ADCA and phenyl acetic acid are not allowed tondischarge on water bodies), does not envisage such disposal alternatives and hence thenpresent study was aimed at the complete removal of intermediates (7-ADCA) and phenylnacetic acid prior to discharge.