Use of membrane bioreactors in treatment and re-use of domestic wastewaters

Komesli, Okan Tarık
This study was carried out to investigate performance of a Vacuum Rotating Membrane (VRM) type membrane bioreactor (MBR). During the study, the VRM plant was erected from scratch and operated in METU campus. The plant was composed of two tanks. First one was about 100 m3 and it was used for biological treatment; the second tank, about 30 m3, was used as filter chamber. The permeate flow rate was adjusted between 6 and 8.5 m3/h giving a hydraulic retention time (HRT) of 18 hours during the study. In the aeration tank, dissolved oxygen (DO) was adjusted to between 4 and 0.1 mg/L to see the effect of the dissolved oxygen concentration on the process. In the filter chamber, total of 540 m2 flat sheet membrane surface were used for the separation of the treated wastewater from the activated sludge. During the 140 days of operation, MLSS concentration increased from 2.5 g/L to 20 g/L. A 99.99% BOD removal and above 95% COD removal were achieved most of the time during the study. At the time when organic loading rate was between 0.35 and 0.1 kg COD/ kgVSS-day, sludge production was very low. Therefore, sludge retention time (SRT) was taken as infinite. The turbidity in the effluent was less than 1 NTU at all the time, and was below that of the tap water. In the aeration tank, 100% Total-N removal was observed when DO was 2 mg/L and MLSS was 8.36 mg/L on 80th day of operation. This indicates that simultaneous nitrification and denitrification was taking place at these conditions. Later, N-removal decreased when DO was deliberately decreased to 0.1 mg/L in the aeration tank to prevent nitrification; for treated wastewaters were intended to be used for irrigation. Since the pores of the membrane were 0.038 æm, treated wastewaters were sterile with respect to bacteria


Investigation of sludge viscosity and its effects on the performance of a vacuum rotation membrane bioreactor
KOMESLİ, Okan Tarık; Gökçay, Celal Ferdi (Informa UK Limited, 2014-03-04)
Sludge characteristics of a full-scale vacuum rotation membrane (VRM) bioreactor having plate-type membranes with 0.038 m nominal pore size and 540 m(2) surface area were investigated. The VRM plant is composed of an aeration tank and a filtration chamber. The sludge floc size distribution, as determined microscopically, was mainly between 0 and 100 m in the filter chamber with very little difference in size distribution between summer (20-25 degrees C) and winter (10-15 degrees C) seasons. Small floc size ...
Highly active, robust and reusable micro-/mesoporous TiN/Si3N4 nanocomposite-based catalysts for clean energy: Understanding the key role of TiN nanoclusters and amorphous Si3N4 matrix in the performance of the catalyst system
Lale, Abhijeet; Mallmann, Maira Debarba; Tada, Shotaro; Bruma, Alina; Özkar, Saim; Kumar, Ravi; Haneda, Masaaki; Machado, Ricardo Antonio Francisco; Iwamoto, Yuji; Demirci, Umit B.; Bernard, Samuel (Elsevier BV, 2020-09-05)
Herein, we developed a precursor approach toward the design of a titanium nitride (TiN)/silicon nitride (Si3N4) nanocomposite with an activated carbon monolith as a support matrix forming a highly micro-/mesoporous component to be used as a Pt support for the catalytic hydrolysis of sodium borohydride (NaBH4) as a model reaction. The experimental data demonstrated that the amorphous Si3N4 matrix, the strong Pt-TiN nanocluster interaction and the synergistic effects between the three components contributed t...
Modeling of nitrogen removal in a membrane biological treatment process
Codal, Ahmet; Gökçay, Celal Ferdi; Department of Environmental Engineering (2008)
Biological nitrogen removal was simulated for a Vacuum Rotating Membrane (VRM) type membrane bioreactor (MBR) operated in METU campus. In order to simulate the biological MBR plant, a dynamic model that describes the process is needed. In this thesis, the Activated Sludge Model No.1 (ASM1), which still is the most widely used model developed by the International Association on Water Quality (IAWQ), has been used to simulate the carbon oxidation, nitrification and denitrification processes occurring in the p...
Effects of membrane electrode assembly components on proton exchange membrane fuel cell performance
Bayrakceken, Ayse; Erkan, Serdar; Turker, Lemi; Eroğlu, İnci (Elsevier BV, 2008-01-01)
The objective of this study is to determine the effects of various factors on the performance of proton exchange membrane (PEM) fuel cell. These factors are membrane thickness, hot-pressing conditions of the gas diffusion layer (GDL) either onto the membrane or membrane electrode assembly (MEA) and Teflon:carbon ratio in the GDL on PEM fuel cell performance. Homemade five-layer and commercial three-layer MEAs were used in the experiments. Nafion (R) 112 and 115 which have nominal thicknesses of 50 and 125 m...
Application of two receptor models for the investigation of sites contaminated with polychlorinated biphenyls : positive matrix factorization and chemical mass balance
Demircioğlu, Filiz; İmamoğlu, İpek; Department of Environmental Engineering (2010)
This study examines the application of two receptor models, namely Positive Matrix Factorization (PMF) and Chemical Mass Balance (CMB), on the investigation of sites contaminated with PCBs. Both models are typically used for apportionment of pollution sources in atmospheric pollution studies, however have gained popularity in the last decade on the investigation of PCBs in soil/sediments. The aim of the study is four-fold; (i) to identify the status of PCB pollution in Lake Eymir area via sampling and analy...
Citation Formats
O. T. Komesli, “Use of membrane bioreactors in treatment and re-use of domestic wastewaters,” M.S. - Master of Science, Middle East Technical University, 2006.