Biological treatment of wastewater from fruit juice production using a membrane bioreactor: parameters limiting membrane performance

2003 ◽  
Vol 3 (5-6) ◽  
pp. 253-259
Author(s):  
C. Blöcher ◽  
T. Britz ◽  
H.D. Janke ◽  
H. Chmiel
Keyword(s):  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Fruit Juice ◽  
Operating Conditions ◽  
Production Plant ◽  
Permeate Flux ◽  
Produce Water ◽  
Membrane Performance ◽  
Test Operation

The application of a membrane bioreactor (MBR) was investigated to treat polluted process water from fruit juice processing. The aim was either direct discharge or further treatment by nanofiltration/low pressure reverse osmosis to produce water of drinking quality. The results of a one-year test operation of the process in industrial scale at a fruit juice production plant are presented. Focus was centred on the influence of activated sludge characteristics on membrane performance. Under the operating conditions in place, neither solids content, particle size distribution nor addition of nutrient significantly affected the permeate flux which was considerably lower than expected (based on municipal wastewater treatment with MBRs). Instead, evidence was obtained that the insufficient permeate flux was most likely due to the high content of extracellular polymeric substances. However, it was impossible to relate in detail the substantial flux variations during the test run to AS characteristics or changes in microbial population.

Operation of a submerged aerobic membrane bioreactor for decentralised municipal wastewater treatment in North Africa

2012 ◽  
Vol 7 (3) ◽  
Author(s):  
George Skouteris ◽  
Tom C. Arnot ◽  
Firas Feki ◽  
Mouna Jraou ◽  
Sami Sayadi
Keyword(s):  
Wastewater Treatment ◽  
North Africa ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Domestic Wastewater ◽  
Permeate Flux ◽  
Mixed Liquor ◽  
Membrane Performance ◽  
Energy Benchmarking ◽  
Crop Irrigation

A pilot-scale aerobic membrane bioreactor (MBR) was operated for 6.5 months, alongside a full-sized conventional activated sludge (AS) plant, treating high-strength domestic wastewater originating from Sfax in Tunisia. The main target was to investigate whether or not the MBR could produce effluent suitable for unrestricted crop irrigation in Tunisia, a target that the AS plant fails to achieve. Membrane performance analysis and energy benchmarking were also carried out. The MBR did produce irrigation quality water regardless of the mixed-liquor suspended solids (MLSS) or feed concentrations. The average chemical oxygen demand (COD) removal efficiency was 88% at an average MLSS concentration of 4.59 g L−1, and 89.7% at an average MLSS concentration of 9.52 g L−1. During membrane performance evaluation, a maximum sustainable membrane permeate flux of 12.81 L m−2 h−1, at an average mixed-liquor temperature of 24 °C and an average MLSS concentration of 9.21 g L−1 was maintained. Finally, energy benchmarking was carried out; the average energy consumption rate was 8.95 kWh d−1, corresponding to an average specific energy demand (SED) of 3.82 kWh m−3. This is a relatively high value compared to the AS plant, whose SED value is always lower than 3 kWh m−3, but further energy reduction is possible for the MBR as well as the AS plant effluent requires further treatment in order to be acceptable for unrestricted human crop irrigation; hence, additional energy input. The work demonstrates the potential impact of MBRs in decentralised domestic wastewater treatment in North Africa.

scholarly journals Membrane Fouling Controlled by Adjustment of Biological Treatment Parameters in Step-Aerating MBR

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 553
Author(s):  
Dimitra C. Banti ◽  
Manassis Mitrakas ◽  
Petros Samaras
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Aeration Tank ◽  
Filamentous Bacteria ◽  
Membrane Performance ◽  
Low Concentrations ◽  
Fouling Reduction

A promising solution for membrane fouling reduction in membrane bioreactors (MBRs) could be the adjustment of operating parameters of the MBR, such as hydraulic retention time (HRT), food/microorganisms (F/M) loading and dissolved oxygen (DO) concentration, aiming to modify the sludge morphology to the direction of improvement of the membrane filtration. In this work, these parameters were investigated in a step-aerating pilot MBR that treated municipal wastewater, in order to control the filamentous population. When F/M loading in the first aeration tank (AT1) was ≤0.65 ± 0.2 g COD/g MLSS/d at 20 ± 3 °C, DO = 2.5 ± 0.1 mg/L and HRT = 1.6 h, the filamentous bacteria were controlled effectively at a moderate filament index of 1.5–3. The moderate population of filamentous bacteria improved the membrane performance, leading to low transmembrane pressure (TMP) at values ≤2 kPa for a great period, while at the control MBR the TMP gradually increased reaching 14 kPa. Soluble microbial products (SMP), were also maintained at low concentrations, contributing additionally to the reduction of ΤΜP. Finally, the step-aerating MBR process and the selected imposed operating conditions of HRT, F/M and DO improved the MBR performance in terms of fouling control, facilitating its future wider application.

Investigation of long-term operation and biomass activity in a membrane bioreactor system

2011 ◽  
Vol 63 (9) ◽  
pp. 1906-1912 ◽  
Author(s):  
Simos Malamis ◽  
Andreas Andreadakis ◽  
Daniel Mamais ◽  
Constantinos Noutsopoulos
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Operating Conditions ◽  
Term Operation ◽  
Solids Retention ◽  
Biomass Activity ◽  
Long Term Performance ◽  
Term Performance

The aim of this work was to evaluate the long-term performance of a Membrane Bioreactor (MBR) that operated continuously for 2.5 years and to assess membrane fouling and biomass activity under various operating conditions. Furthermore, a method for the characterisation of influent wastewater was developed based on its separation into various fractions. The MBR system operated at the solids retention times (SRT) of 10, 15, 20 and 33 days. The increase of SRT resulted in a decrease of the fouling rate associated with the reduction of extracellular polymeric substances. Moreover, the SRT increase resulted in a significant reduction of the Oxygen Uptake Rate (OUR) due to the lower availability of substrate and in a notable decrease of the maximum OUR since high SRT allowed the development of slower growing microorganisms. Biomass consisted of small flocs due to extensive deflocculation caused by intense aeration. Finally, the method developed for wastewater characterisation is straightforward and less time consuming than the usual method that is employed.

scholarly journals Treatment of Liquid Phase of Digestate from Agricultural Biogas Plant in a System with Aerobic Granules and Ultrafiltration

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 104 ◽  
Author(s):  
Piotr Świątczak ◽  
Agnieszka Cydzik-Kwiatkowska ◽  
Magdalena Zielińska
Keyword(s):  
Liquid Phase ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Substantial Reduction ◽  
Oxygen Demand ◽  
Aerobic Granular Sludge ◽  
Permeate Flux ◽  
Granule Formation ◽  
Nitrogen Loads ◽  
Cycle Lengths

Management of digestate from manure co-digestion with a very high chemical oxygen demand (COD) to nitrogen ratio and high nitrogen loads are a major bottleneck in the development of agricultural biogas plants. The liquid phase of digestate mixed with municipal wastewater was treated in aerobic granular sludge batch reactors at cycle lengths (t) of 6 h (GSBR6h), 8 h (GSBR8h), and 12 h (GSBR12h), corresponding to nitrogen loads of 1.6, 1.2, and 0.8 g/(L·d). Thauera sp., Lacibacter sp., Thermanaerothrix sp., and Planctomyces sp. predominated in granules favoring effective granule formation and nitrogen removal. Increasing cycle lengths (t) significantly decreased proteins in soluble fraction of extracellular polymeric substances (EPS) in granules and increased polysaccharides in tightly bound EPS that resulted in higher granule diameters and higher COD removal. In GSBR6h, heterotrophic nitrification/denitrification was very efficient, but ammonium was fully oxidized in the last hour of the cycle. So in further studies, the effluent from GSBR8h was subjected to ultrafiltration (UF) at transmembrane pressures (TMPs) of 0.3, 0.4, and 0.5 MPa. A GSBR8h-UF system (TMP of 0.4 MPa) ensured full removal of total Kjeldahl nitrogen (TKN), suspended solids, and substantial reduction of COD and color with good permeate flux. The NOx-rich (about 250 mg/L), clear permeate can be reused in line with assumptions of modern circular economy.

Performance of membrane bioreactor combined with pre-coagulation/sedimentation

2004 ◽  
Vol 4 (1) ◽  
pp. 143-149 ◽  
Author(s):  
T. Itonaga ◽  
Y. Watanabe
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Suspended Solids ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Term Operation ◽  
Made In

This paper deals with the performance of a hybrid membrane bioreactor (MBR) combined with pre-coagulation/sedimentation. Primary clarifier effluent in a municipal wastewater treatment plant was fed into the hybrid MBR to investigate its performance during long-term operation. Pre-coagulation/sedimentation process efficiently removed the suspended solids including organic matter and phosphorus. Comparison of the hybrid MBR and conventional MBR was made in terms of the permeate quality and membrane fouling. As the organic loading to the MBR was significantly reduced by the pre-coagulation/sedimentation, production and accumulation of extracellular polymeric substances (EPS) may be limited. Therefore, the mixed liquor viscosity in the hybrid MBR was much lower than that in the conventional MBR. These effect caused by pre-coagulation/sedimentation brought a remarkable improvement in both permeate quality and membrane permeability.

Modification of submerged membrane bioreactors (MBRs) by inserting baffles: pilot scale study

2007 ◽  
Vol 55 (7) ◽  
pp. 119-126 ◽  
Author(s):  
K. Kimura ◽  
M. Enomoto ◽  
Y. Watanabe
Keyword(s):  
Phosphorus Removal ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Feed Water ◽  
Simple Modification ◽  
Anoxic Conditions ◽  
Scale Experiment

Submerged membrane bioreactors (MBRs) have been gaining in popularity in various types of wastewater treatment. One drawback of submerged MBRs is difficulty in removing nitrogen as they are accompanied with intensive aeration inside the reactor and therefore principally operated under aerobic conditions. In order to address this problem, a simple modification for submerged MBRs, insertion of baffles to create alternative aerobic/anoxic conditions, was proposed. In this study, the performance of the proposed baffled membrane bioreactor (BMBR) was investigated based on a pilot-scale experiment using a real municipal wastewater. With appropriate operating conditions, the BMBR could remove more than 70% of total nitrogen contained in the feed water without any external carbon source. The BMBR demonstrated a good treatment performance in terms of TOC and phosphorus removal as well. Increase of trans-membrane pressure difference was subtle, which might be attributed to the alternative creation of aerobic/anoxic conditions.

Effect of upflow velocity on the performance of an inclined plate membrane bioreactor treating municipal wastewater

2011 ◽  
Vol 64 (5) ◽  
pp. 1102-1107 ◽  
Author(s):  
P. M. Fontanos ◽  
K. Yamamoto ◽  
F. Nakajima
Keyword(s):  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Operating Conditions ◽  
Inclined Plate ◽  
Concentration Difference ◽  
Inclined Plates ◽  
Aerobic Zone ◽  
Sludge Concentration

An inclined plate membrane bioreactor (iPMBR) was introduced to meet the challenge of handling high mixed liquor suspended solids when operating at long sludge retention times. During the first 407 days of operation, the iPMBR was able to rezone more sludge (1.5–10.5 times greater) in its upstream, anoxic tank compared to its downstream, aerobic tank. This could extend membrane filtration by diverting most of the sludge from the aerobic zone. During this period, the upflow velocities through the inclined plates of the anoxic tank ranged from 2.3 × 10−4 to 7.7 × 10−4 m/s. After Day 407, the operating conditions were changed to determine whether the iPMBR would fail to create a sludge concentration difference between its two tanks. When the upflow velocity was increased to 1.8 × 10−3 m/s, the sludge concentration difference between the two zones was removed. This indicated that the upflow velocity had increased sufficiently to overcome the settling velocities of most flocs, resulting in more solids being carried from the anoxic to the aerobic tank. For the configuration of this iPMBR, operating at flow rates where the upflow velocity through the inclined plates was less than 1.0 × 10−3 m/s would be necessary to keep a significant sludge concentration difference between its two zones.

Optimal sludge retention time for a bench scale MBR treating municipal sewage

2008 ◽  
Vol 57 (3) ◽  
pp. 319-322 ◽  
Author(s):  
A. Pollice ◽  
G. Laera ◽  
D. Saturno ◽  
C. Giordano ◽  
R. Sandulli
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Process Conditions ◽  
Physical Parameters ◽  
Municipal Wastewater Treatment ◽  
Bench Scale ◽  
Conventional Activated Sludge

Membrane bioreactors allow for higher sludge concentrations and improved degradation efficiencies with respect to conventional activated sludge. However, in the current practice these systems are often operated under sub-optimal conditions, since so far no precise indications have yet been issued on the optimal operating conditions of MBR for municipal wastewater treatment. This paper reports some results of four years of operation of a bench scale membrane bioreactor where steady state conditions were investigated under different sludge retention times. The whole experimental campaign was oriented towards the investigation of optimal process conditions in terms of COD removal and nitrification, biomass activity and growth, and sludge characteristics. The membrane bioreactor treated real municipal sewage, and four different sludge ages were tested (20, 40, 60, and 80 days) and compared with previous data on complete sludge retention. The results showed that the the biology of the system, as assessed by the oxygen uptake rate, is less affected than the sludge physical parameters. In particular, although the growth yield was observed to dramatically drop for SRT higher than 80 days, the biological activity was maintained under all the tested conditions. These considerations suggest that high SRT are convenient in terms of limited excess sludge production without losses of the treatment capacity. Physical characteristics such as the viscosity and the filterability appear to be negatively affected by prolonged sludge retention times, but their values remain within the ranges normally reported for conventional activated sludge.

Numerical Simulation of Hollow Fiber Ultrafiltration Membrane

2009 ◽  
Author(s):  
Nina Zhou ◽  
A. G. Agwu Nnanna
Keyword(s):  
Numerical Model ◽  
Hollow Fiber ◽  
Membrane Fouling ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Operating Conditions ◽  
Permeate Flux ◽  
High Productivity ◽  
Design And Optimization ◽  
Membrane Performance

Low pressure driven ultrafiltraion (UF) processes has been applied in various industries due to its economical and easy operated benefits. Hollow fiber membrane is one of the most used membrane configuration in industry, membrane fouling is the major challenge for widely usage. Most of the investigation of UF was carried out by experiments to determine the effect of different operating conditions on permeate flux. However, experiments provide limited insight information on the membrane performance. In addition, the prediction of permeate flux under different operating conditions is necessary for experimental design and optimization. The purpose of the present study is to develop a numerical model to simulate the UF process and investigate the UF mechanism. A numerical model was developed using commercial CFD package (FLUENT). The effects of various operating conditions on permeate flux were determined by experiments and simulations, the comparison of the experimental and CFD results shows good agreements. Controlling membrane fouling will maintain a high productivity. The simulations were carried out to investigate the efficiency of removing accumulated particles on membrane surface by installing spacer filaments in membrane channels. The results suggested that the zigzag type spacer has d/h = 0.5 and l/h = 5 is more economical and efficient in reducing fouling.

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