Use of combined UASB + eMBR treatment for removal of emerging micropollutants and reduction of fouling

Abstract

This study employs a novel combined pilot plant consisting of an anaerobic reactor followed by a membrane electro-bioreactor (eMBR) to treat domestic water containing selected micro-pollutants of emerging concern (CECs) [ibuprofen (IB), carbamazepine, diclofenac (DCF) and 17α-ethinylestradiol (EE2)]. The first phase operated as a conventional membrane bioreactor to achieve the removal of organic matter [chemical oxygen demand (COD)], the CECs and phosphorus. A removal rate of 96.3% for COD, 94.5% for IB, 37.1% for CMZ, 87.1% for DCF and 96% for EE2 was obtained. In the three subsequent phases, current density (CD) of 5, 10 and 15 A/m2 was applied successively in the eMBR with the aim of investigating the effects on the removal of the former components and the fouling of the membrane. After the application of 5 and 10 A/m2 CD, the removal rate of COD decreased. Regarding phosphorus, a CD of 5 A/m2 was enough to achieve the rate of 97% and the membrane fouling suffered a substantial reduction too. Finally, the experimental results were subject to statistical analysis using the Kruskal–Wallis and Wilcoxon tests to validate the influence of each DC.

Anaerobic Treatment of Domestic Wastewater

“…For UASB reactors, the literature also explores HRT beyond the conventionally applied or conjugated technologies, aiming at MP removal. For example, Mora-Cabrera et al (2021) studied a UASB reactor followed by a membrane electrochemical bioreactor to treat domestic wastewater containing ibuprofen (24% removal), carbamazepine (23% removal), diclofenac (29% removal), and 17α-ethinylestradiol (26% removal), whereas Vassalle et al (2020) combined UASB with high-rate algal ponds to remove ibuprofen (65% removal), diclofenac (65% removal), naproxen (71% removal), paracetamol (65% removal), gemfibrozil (39% removal), estrone (95% removal), 17β-estradiol (91% removal), 17α-ethinylestradiol (92% removal), estriol (89% removal), nonylphenol (70% removal), and bisphenol A (43% removal). In both studies, the HRT applied to UASB reactors was commonly applied in domestic WWTPs, in which the focus of the studies was on combining the systems, searching for reliable post-treatment units.…”