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

Abstract

The viability of treating high-concentration antibiotic wastewater by a membrane bioreactor (MBR) was studied using submerged flat sheet membrane. The major problems for these modules are concentration polarization and subsequent fouling. By using gas-liquid two-phase flow, these problems can be ameliorated. A case study has been identified and the current issues in one of the major pharmaceutical industry (manufacturing cephalosporin drugs) located in Chennai, India, has been discussed for the possible removal of anaerobically transformed intermediates of antibiotic pharmaceutical wastewater. The objective of the study was to determine the effect of organic loading rate and hydraulic retention time on the removal of cephalosporin derivative, viz., cephalexin (C(16)H(17)N(3)O(4)S.H(2)O) and the intermediates [7-amino-3-deacetoxycephalosporanic acid (7-ADCA) and acyl group (Phenyl acetic acid)] in the MBR with enhanced biodegradation using bioaugmentation technique. Based on the critical examination of results, the industry is looking for the alternatives of either direct disposal of 7-ADCA and phenyl acetic acid or for further degradation and disposal, which will essentially require additional cost and maintenance. The present regulatory standard implemented at a global level, (meaning the intermediates which are transformed during its course of travel within the industry and in the treatments plants, i.e., in the present study it is, 7-ADCA and phenyl acetic acid are not allowed to discharge on water bodies), does not envisage such disposal alternatives and hence the present study was aimed at the complete removal of intermediates (7-ADCA) and phenyl acetic acid prior to discharge.

An overview of cephalosporin antibiotics as emerging contaminants: a serious environmental concern

“…The wastewater containing cephalosporin antibiotics contains active pharmaceutical ingredients (API), inorganic salts and toxic organic compounds, thus leading to a high risk to biological survival in the environment (Yang et al 2016;Guo and Chen 2015). Cephalosporin wastewater can be treated by chemical processes (Serna-Galvis et al 2017), physio-chemical processes (Zavareh and Eghbalazar 2017), biological processes (Sundararaman and Saravanane 2010) and combined processes (Gadipelly et al 2014). Recently, the performance and microbial community of an expanded granular sludge bed reactor for the treatment of cephalosporin wastewater has also been reported by Li et al (2019).…”

Fouling analysis of membrane bioreactor treating antibiotic production wastewater at different hydraulic retention times

“…MBR is an attractive choice because stringent discharge standards can be satisfied within a limited footprint (Cheng 2012). Recalcitrant pollutants can be retained and removed by MBR (Sundararaman and Saravanane 2010;Xing and Sun 2009). When SRT is long enough, the retained recalcitrant organics may be biodegraded by the biomass within the limits of the substrates (Hai et al 2010;Raj et al 2013).…”

“…A common operational counter measure for volatile and recalcitrant organic pollutants involves decreasing the organic loading rate by prolonging hydraulic retention time (HRT) (Sipma et al 2010;Sundararaman and Saravanane 2010); however, a definite connection between HRT adjustment and membrane fouling trends is still missing in the treatment of pharmaceutical wastewater using a MBR. Tay investigated the effect of HRT on system performance in a submerged MBR treating simulated high-strength wastewater, and cues of the potential solution for the membrane fouling were studied during optimization of HRT from 6 days to 12 h (Tay et al 2003).…”

Recent developments in hazardous pollutants removal from wastewater and water reuse within a circular economy

“…There are several studies on improving the degradation performance via bioaugmentation. For example, Saravanane and Sundararaman investigated the treatment of pharmaceutical wastewater with a high concentration of Cephalosporin derivative using an AnMBR with a submerged flat sheet membrane 41 . They found an enhanced removal efficiency upon bioaugmentation.…”