Implications of changes in solids retention time on long term evolution of sludge filterability in anaerobic membrane bioreactors treating high strength industrial wastewater.
Long-term experiments were conducted to assess the impact of changing the solids retention time (SRT) on sludge filterability in anaerobic membrane bioreactors (AnMBRs), treating corn-based bioethanol thin stillage. Well established parameters, such as capillary suction time (CST) and specific resistance to filtration (SRF), developed for sludge dewatering, were used to evaluate the SRT effect on sludge filterability. Our results clearly demonstrated that SRT is one of the most important factors influencing sludge filterability in AnMBRs. SRT effects the accumulation of fine particles and solutes, which were found to affect attainable flux and fouling, in reactor broth. A better filterability was observed at a SRT of 20 days compared to elevated SRTs, i.e. 50 days. A clear correlation between sludge filtration characteristics and membrane filtration resistance could not be established especially at short SRTs, whereas many parameters such as total suspended solids (TSS), CST, soluble microbial products (SMP) and supernatant filterability were found to be mutually correlated. Net membrane fluxes between 9 and 13 L m(-2) h(-1) were obtained at 0.5 m s(-1) cross-flow velocity and the long term fouling was controlled by using frequent filtration and backwash cycles.
Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Watermanagement, Sanitary Engineering Section, Stevinweg 1, 2628 CN Delft, The Netherlands; Istanbul Technical University, Civil Engineering Faculty, Environmental Engineering Department, Maslak 34469, Istanbul, Turkey; Biothane Systems International, Tanthofdreef 21, 2600 GB Delft, The Netherlands. Electronic address: R.K.Dereli@tudelft.nl.
Recep Kaan
RK
Dereli
Biothane Systems International, Tanthofdreef 21, 2600 GB Delft, The Netherlands; Veolia Environnement Recherche et Innovation, Chemin de la Digue, BP 76, 78603 Maisons Laffitte Cedex, France.
Aurelie
A
Grelot
Biothane Systems International, Tanthofdreef 21, 2600 GB Delft, The Netherlands.
Barry
B
Heffernan
Biothane Systems International, Tanthofdreef 21, 2600 GB Delft, The Netherlands.
Frank P
FP
van der Zee
Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Watermanagement, Sanitary Engineering Section, Stevinweg 1, 2628 CN Delft, The Netherlands.
Jules B
JB
van Lier
D019149:Bioreactors; D005374:Filtration / Q000379:methods*; D007220:Industrial Waste; D012722:Sewage; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater
D007220:Industrial Waste; D012722:Sewage; D062065:Wastewater
Anaerobic membrane bioreactor; Corn thin stillage; Membrane fouling; Sludge filterability; Solids retention time