Performance of a high-rate membrane bioreactor for energy-efficient treatment of textile wastewater

Tülay Yilmaz; Emir Kasım Demir; Gulfem Aşık; Senem Teksoy Başaran; Emine Cokgor; Seval Sözen; Erkan Sahinkaya

doi:10.1016/j.jenvman.2024.120845

Performance of a high-rate membrane bioreactor for energy-efficient treatment of textile wastewater

J Environ Manage. 2024 Apr 9:358:120845. doi: 10.1016/j.jenvman.2024.120845. Online ahead of print.

Authors

Tülay Yilmaz¹, Emir Kasım Demir², Gulfem Aşık³, Senem Teksoy Başaran², Emine Cokgor⁴, Seval Sözen⁴, Erkan Sahinkaya²

Affiliations

¹ Environmental Engineering Department, Istanbul Technical University, Maslak, 34469, Istanbul, Turkey; Science and Advanced Technologies Application and Research Center (BILTAM), Istanbul Medeniyet University, Istanbul, 34700, Turkey. Electronic address: tulayylmaz@outlook.com.
² Science and Advanced Technologies Application and Research Center (BILTAM), Istanbul Medeniyet University, Istanbul, 34700, Turkey; Department of Bioengineering, Istanbul Medeniyet University, Istanbul, 34700, Turkey.
³ Department of Bioengineering, Istanbul Medeniyet University, Istanbul, 34700, Turkey.
⁴ Environmental Engineering Department, Istanbul Technical University, Maslak, 34469, Istanbul, Turkey.

PMID: 38599093
DOI: 10.1016/j.jenvman.2024.120845

Abstract

High-rate membrane bioreactors (MBR), where the wastewater undergoes partial oxidation due to the applied short sludge retention time (SRT) and hydraulic retention time (HRT) values, retain the majority of the organic substances in the sludge through growth and biological flocculation. Thus, a raw material source with a high biomethane production potential is created for the widespread use of circular economy or energy-neutral plants in wastewater treatment. While high-rate MBRs have been successfully employed for energy-efficient treatment of domestic wastewater, there is a lack of research specifically focused on textile wastewater. This study aimed to investigate the textile wastewater treatment and organic matter recovery performances of an aerobic MBR system containing a hollow fiber ultrafiltration membrane with a 0.04 μm pore diameter. The system was initially operated at short SRTs (5 and 3 d) and different SRT/HRT ratios (5, 10, and 20) and subsequently at high-rate conditions (SRT of 0.5-2 d and HRT of 1.2-9.6 h) which are believed to be the most limiting conditions tested for treatment of real textile wastewater. The results showed that chemical oxygen demand (COD) removal averaged 77% even at SRT of 0.5 d and HRT of 1.2 h. Slowly biodegradable substrates and soluble microbial products (SMP) accumulated within the MBR at SRT of 0.5 and 1 d, which resulted in decreased sludge filterability. The observed sludge yield (Y_obs) exhibited a considerable increase when SRT was reduced from 5 to 1 d. On the other hand, the SRT/HRT ratio displayed a decisive effect on the energy requirement for aeration.

Keywords: Filtration performance; High-rate membrane bioreactor; Membrane fouling; Sludge retention time; Textile wastewater.