Effects of sulfate on activated sludge characteristics and membrane fouling in membrane bioreactor treating penicillin wastewater

The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8–10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin – at an MLSS of 6–9 g/L – showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected.

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Comparison of Performance of an Intermittent Aeration Membrane Bioreactor and a Conventional Activated–sludge System in the Treatment of Palm Oil Mill Effluent

Journal of Applied Membrane Science & Technology ◽

10.11113/amst.v7i1.53 ◽

2017 ◽

Vol 7 (1) ◽

Author(s):

S. Annop ◽

P. Sridang ◽

P. Chevakidagarn ◽

K. Nopthavorn

Keyword(s):

Activated Sludge ◽

Palm Oil ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Palm Oil Mill Effluent ◽

Oil And Grease ◽

Stage Of Development ◽

Working Volume ◽

Dissolved Oxygen Control ◽

Palm Oil Mill

The main objective was to compare the performances and the removal efficiencies of two biological treatment systems, a submerged membrane bioreactor (SMBR) and a simultaneous activated sludge (AS), for treating Palm Oil Mill Effluent (POME). Two lab scale units of SMBR and AS with a working volume of 24 L were operated under favorable biological conditions and minimized membrane fouling intensity. To achieve both carbonaceous and nitrogen removal, the cyclic air intermittent and dissolved oxygen control were performed into SMBR and AS with the influent flow rate about 16 L/d respectively. In terms of organic removal and membrane performance, the SMBR showed good removal efficiency to treat high strength wastewater with organic loading variation of POME. The average removal rates of TCOD, BOD, Turbidity, Color, Oil and Grease, NH3–N, TKN were 69±2, 76±2, 100±1, 37±21, 92±6, 67±4 and 75±10% respectively. Results pointed out the benefit of membranes retained totally the active compositions of biomass in each stage of development. The AS showed the limitation of sedimentation phase for sludge and oil separation. The characteristics of sludge in SMBR showed healthy floc formations and good settling after 240 h. The concentrations of COD and BOD in permeate were around 870±53 and 37±13 mg/L.

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Exerting ultrasound to control the membrane fouling in filtration of anaerobic activated sludge—mechanism and membrane damage

Water Science & Technology ◽

10.2166/wst.2008.120 ◽

2008 ◽

Vol 57 (5) ◽

pp. 773-779 ◽

Cited By ~ 24

Author(s):

Xianghua Wen ◽

Pengzhe Sui ◽

Xia Huang

Keyword(s):

Activated Sludge ◽

Hydroxyl Radicals ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Chemical Interaction ◽

Membrane Surface ◽

Membrane Damage ◽

Operational Conditions ◽

Fouling Control ◽

Cake Layer

In this study, ultrasound was applied to control membrane fouling development online in an anaerobic membrane bioreactor (AMBR). Experimental results showed that membrane fouling could be controlled effectively by ultrasound although membrane damage may occur under some operational conditions. Based upon the observation on the damaged membrane surface via SEM, two mechanisms causing membrane damage by exerting ultrasound are inferred as micro particle collide on the membrane surface and chemical interaction between membrane materials and hydroxyl radicals produced by acoustic cavitations. Not only membrane damage but also membrane fouling control and membrane fouling cleaning were resulted from these mechanisms. Properly selecting ultrasonic intensity and working time, and keeping a certain thickness of cake layer on membrane surface could be effective ways to protect membrane against damage.

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