Membrane fouling and performance evaluation of conventional membrane bioreactor (MBR), moving biofilm MBR and oxic/anoxic MBR.
In this study, three laboratory scale submerged membrane bioreactors (MBRs) comprising a conventional MBR (C-MBR), moving bed MBR (MB-MBR) and anoxic-oxic MBR (A/O-MBR) were continuously operated with synthesized domestic wastewater (chemical oxygen demand, COD = 500 mg/L) for 150 days under similar operational and environmental conditions. Kaldnes(®) plastic media with 20% dry volume was used as a biofilm carrier in the MB-MBR and A/O-MBR. The treatment performance and fouling propensity of the MBRs were evaluated. The effect of cake layer formation in all three MBRs was almost the same. However, pore blocking caused a major difference in the resultant water flux. The A/O-MBR showed the highest total nitrogen and phosphorus (PO4-P) removal efficiencies of 83.2 and 69.7%, respectively. Due to the high removal of nitrogen, fewer protein contents were found in the soluble and bound extracellular polymeric substances (EPS) of the A/O-MBR. Fouling trends of the MBRs showed 12, 14 and 20 days filtration cycles for C-MBR, MB-MBR and A/O-MBR, respectively. A 25% reduction of the soluble EPS and a 37% reduction of the bound EPS concentrations in A/O-MBR compared with C-MBR was a major contributing factor for fouling retardation and the enhanced filtration capacity of the A/O-MBR.
Institute of Environmental Sciences and Engineering (IESE), School of Civil and Environmental Engineering (SCEE), National University of Sciences and Technology (NUST), Sector H-12, Islamabad, Pakistan E-mail: s.jamal@iese.nust.edu.pk.
Sher Jamal
SJ
Khan
Institute of Environmental Sciences and Engineering (IESE), School of Civil and Environmental Engineering (SCEE), National University of Sciences and Technology (NUST), Sector H-12, Islamabad, Pakistan E-mail: s.jamal@iese.nust.edu.pk.
Aman
A
Ahmad
Institute of Environmental Sciences and Engineering (IESE), School of Civil and Environmental Engineering (SCEE), National University of Sciences and Technology (NUST), Sector H-12, Islamabad, Pakistan E-mail: s.jamal@iese.nust.edu.pk.
Muhammad Saqib
MS
Nawaz
Department of Engineering Science, Centre for Sustainable Water Engineering, The University of Oxford, Parks Road, Oxford OX1 3PJ, UK.
Nicholas P
NP
Hankins
D018441:Biofilms; D057219:Biofouling; D019149:Bioreactors; D008567:Membranes, Artificial; D010100:Oxygen
D008567:Membranes, Artificial; D010100:Oxygen