Effect of sludge retention time on the performance and sludge filtration characteristics of an aerobic membrane bioreactor treating textile wastewater


Yilmaz T., Demir E. K., Asik G., Başaran S. T., Çokgör E. U., Sözen S., ...More

Journal of Water Process Engineering, vol.51, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 51
  • Publication Date: 2023
  • Doi Number: 10.1016/j.jwpe.2022.103390
  • Journal Name: Journal of Water Process Engineering
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, INSPEC
  • Keywords: Textile wastewater, Membrane bioreactor, Filtration characteristics, Sludge retention time, Water reuse
  • Istanbul Technical University Affiliated: Yes

Abstract

© 2022 Elsevier LtdIn this study, the impact of different sludge retention times (SRTs) on the wastewater treatment performance of an aerobic membrane bioreactor (MBR) was investigated using real textile industry wastewater. For this purpose, two laboratory-scale membrane bioreactors were operated in parallel. Under the same conditions, one of the systems was operated at an SRT of 30 d and, the other at SRTs of 20 d, and 10 d, respectively. The total chemical oxygen demand (COD), color and soluble total nitrogen (TN) of the wastewater averaged 927 ± 277 mg/L, 910 ± 287 Pt–Co and 39 ± 10 mg/L, respectively. COD removal efficiency remained above 90 % in all the tested SRTs. While the color removal efficiency was 55 % and 60 % at SRTs of 30 d and 20 d, respectively, it decreased to 50 % at SRT of 10 d. In addition, the impact of different SRTs on membrane filtration performance was studied. With the reduction of SRT to 10 d, an increase was observed in specific resistance to filtration (SRF) and supernatant filterability (SF) values, while viscosity decreased due to lower suspended solid (SS) concentration. According to gel permeation chromatography (GPC) analysis, the molecular weights of organic substances in the permeate distributed over a wide spectrum as SRT decreased. Also, signals given by the low molecular weight organic compounds were higher.