Optimising the operation of a MBR pilot plant by quantitative analysis of the membrane fouling mechanism

2005 ◽  
Vol 51 (6-7) ◽  
pp. 19-25 ◽  
Author(s):  
T. Jiang ◽  
M.D. Kennedy ◽  
B.F. Guinzbourg ◽  
P.A. Vanrolleghem ◽  
J.C. Schippers
Keyword(s):  
Membrane Fouling ◽  
Pilot Plant ◽  
Filter Cake ◽  
Municipal Wastewater ◽  
Hollow Fibre ◽  
Critical Flux ◽  
Membrane Pore ◽  
Operational Conditions ◽  
Temperature Conditions ◽  
Filtration Flux

In order to optimize some operational conditions of MBR systems, a MBR pilot plant equipped with a submerged hollow fibre membrane module was employed in this study. The pilot MBR was fed with real municipal wastewater and the filtration flux, backwashing interval, aeration frequency and temperature were varied. A filtration flux below 25 l/m2h is generally recommended, at below this flux, the MBR operated at sub-critical flux conditions, the filter cake was minimized and membrane fouling was mainly attributed to the membrane pore blocking. Moreover, the membrane fouling, at below 25 l/m2h, was more reversible to backwashing; above this value, backwashing became less efficient to clean the membrane. Less frequent backwashing (e.g. 600 s filtration/45 s backwashing) decreased the amount of fouling irreversible to backwashing and its performance was superior to that of frequent backwashing (e.g. 200 s filtration/15 s backwashing). The MBR suffered more fouling at low temperature conditions (e.g. at 13–14 °C) than at high temperature conditions (e.g. at 17–18 °C). A conceptual model was built up and successfully interpreted this temperature effect.

Comparative investigation on the impact of polymeric substances on membrane fouling during sub-critical and critical flux operation of a municipal membrane bioreactor

2008 ◽  
Vol 58 (9) ◽  
pp. 1849-1855 ◽  
Author(s):  
S. Lyko ◽  
T. Wintgens ◽  
T. Melin
Keyword(s):  
Membrane Fouling ◽  
Pilot Scale ◽  
Comparative Investigation ◽  
Hollow Fibre ◽  
Size Exclusion ◽  
Dominant Factor ◽  
Permeate Flux ◽  
Critical Flux ◽  
Operational Conditions ◽  
The Impact

Soluble organic macromolecules are ubiquitous in activated sludge supernatant. For the operation of membrane bioreactors (MBR) this group of substances is considered as the dominant factor causing severe membrane fouling due to the concentration polarisation phenomenon. The well established critical flux concept for the characterisation of membrane bioreactor's operation limits is based on filtration data only. As there is an cause-and-effect relation between the partial retention of organic compounds and the limited flux according the critical flux concept the aim of this study was to draw a comparison between different permeate fluxes on the retention of organic macromolecules. Thus, a municipal pilot-scale MBR with three capillary hollow fibre membrane modules was operated in sub critical, critical and supercritical flux mode, respectively and the retention of macromolecules was quantified by size exclusion chromatography. Three permeate extraction pumps allow a simultaneous operation with different operational conditions for each membrane module and proved the crucial impact of permeate flux on the fouling rate. The interchange of these conditions gave evidence of an optimised start-up procedure for MBRs characterised by higher permeate fluxes. An increased flux causes both a higher retention of soluble macromolecules and subsequent a higher fouling rate.

Correlation between membrane fouling and soluble/colloidal organic substances in membrane bioreactors for municipal wastewater treatment

2005 ◽  
Vol 51 (6-7) ◽  
pp. 1-8 ◽  
Author(s):  
B. Lesjean ◽  
S. Rosenberger ◽  
C. Laabs ◽  
M. Jekel ◽  
R. Gnirss ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Size Exclusion ◽  
Water Phase ◽  
Parallel Operation ◽  
Municipal Wastewater Treatment ◽  
Operational Conditions ◽  
The Difference

Two similar membrane bioreactors of 2 m3 each were operated in parallel over two years under the same operational conditions, fed with the same municipal wastewater. The only process and operational difference between both pilot plants was the position of the denitrification zone (pre-denitrification in pilot 1 and post-denitrification in pilot 2). Despite parallel operation, the two MBRs exhibited different fouling rates and decreases in permeability. These differences could not be accounted for by MLSS concentrations, loading rates, or filtration flux. In a one-year investigation, soluble and colloidal organic material in the activated sludge of both MBR was regularly analysed by spectrophotometric and Size Exclusion Chromatography (SEC) methods. The larger organic molecules present in the sludge water phase (i.e. polysaccharides, proteins and organic colloids) originating from microbial activity (extracellular polymeric substances) were found to impact on the fouling and to explain the difference in membrane performance between the two MBR units. In both pilot plants, a linear relationship could be clearly demonstrated between the fouling rate of the membrane and the concentration of polysaccharides in the sludge water phase during a 5 month operational period at an SRT of 8 days.

Pilot study of a submerged membrane bioreactor for water reclamation

2009 ◽  
Vol 60 (12) ◽  
pp. 3269-3274 ◽  
Author(s):  
Jian-Jun Qin ◽  
Maung Htun Oo ◽  
Guihe Tao ◽  
Kiran A. Kekre ◽  
Tomotaka Hashimoto
Keyword(s):  
Pilot Study ◽  
Municipal Wastewater ◽  
Hollow Fibre ◽  
Sodium Hypochlorite Solution ◽  
Water Reclamation ◽  
Membrane Unit ◽  
Membrane Area ◽  
Operational Conditions ◽  
Term Operation ◽  
Tropical Conditions

The objective of this pilot study was to investigate the operational conditions of newly developed MBR modules for water reclamation under tropical conditions. MUDC-620A MBR modules with hollow fibre PVDF membranes from Asahi-Kasei Chemicals were used in the study. The pilot plant with capacity of 50 m3/d was operated continuously (24-hour) over four months on site of Ulu Pandan Water Reclamation Plant (UPWRP) in Singapore. During the study, the MLSS in membrane tank was in the range of 6,840 ∼ 9,540 mg/L. Filtration operation mode of the membrane unit was 9 minutes on production and 1 minute backwash. The air scouring for the membranes was 0.18–0.30 Nm3/h per m2 membrane area all of the time. Trials on different membrane fluxes were conducted to obtain the sustainable flux. The analytical results showed that COD, TOC, T-N and NH4-N of the treated water were <30 mg/L, 5–7 mg/L, <13 mg/L and <0.1 mg/L, respectively, which met the requirement of Industrial Water for reuse. TMP was in the range of 12–40 kPa and could be recovered after cleaning with 2,000 mg/L sodium hypochlorite solution. Sludge clogging could be a challenge for long-term operation with the current module design. It was concluded that it was feasible for MUDC-620A MBR to operate at a net flux of 25–29 LMH (or 0.6–0.7 m/d) for treating the municipal wastewater at UPWRP.

The effect of drastic temperature changes on the performance of MBR treating municipal wastewater

2011 ◽  
Vol 64 (7) ◽  
pp. 1398-1405 ◽  
Author(s):  
Abdullah Al-Amri ◽  
Mohd Razman Salim ◽  
Azmi Aris
Keyword(s):  
Membrane Fouling ◽  
Temperature Increase ◽  
Municipal Wastewater ◽  
Hollow Fibre ◽  
Critical Conditions ◽  
Temperature Changes ◽  
Sludge Properties ◽  
Removal Efficiencies ◽  
Final Effluent ◽  
Biomass Reduction

A study has been carried out to define the effect of drastic temperature changes on the performance of lab-scale hollow-fibre MBR in treating municipal wastewater at a flux of 10 L m−2 h−1 (LMH). The objectives of the study were to estimate the activated sludge properties, the removal efficiencies of COD and NH3-N and the membrane fouling tendency under critical conditions of drastic temperature changes (23, 33, 42 & 33 °C) and MLSS concentration ranged between 6,382 and 8,680 mg/L. The study exhibited that the biomass reduction, the low sludge settleability and the supernatant turbidity were results of temperature increase. The temperature increase led to increase in SMP carbohydrate and protein, and to decrease in EPS carbohydrate and protein. The BRE of COD dropped from 80% at 23 °C to 47% at 42 °C, while the FRE was relatively constant at about 90%. Both removal efficiencies of NH3-N trended from about 100% at 33 °C to less than 50% at 42 °C. TMP and BWP ascended critically with temperature increase up to 336 and 304 mbar respectively by the end of the experiment. The values of suspended solids (SS) and the turbidity in the final effluent were negligible. The DO in the mixed liquor was varying with temperature change, while the pH was within the range of 6.7–8.3.

Factors Affecting Biological Removal of Phosphorus

1985 ◽  
Vol 17 (11-12) ◽  
pp. 187-198 ◽  
Author(s):  
T. Fukase ◽  
M. Shibata ◽  
Y. Miyaji
Keyword(s):  
Retention Time ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Factors Affecting ◽  
Operational Conditions ◽  
Biological Removal ◽  
Successful Removal ◽  
Anaerobic Zone ◽  
Aerobic Zone

A pilot plant study on biological removal of phosphorus was conducted over fifteen months to obtain optimum operational conditions and evaluate process performance. The pilot plant was composed of an anaerobic zone followed by an aerobic zone, and had a capacity of treating 100 m3 municipal wastewater per day. In the anaerobic zone, BOD loading rates and BOD to MLSS ratios were found to be important factors. In the aerobic zone, on the other hand, the hydraulic retention time had a significant influence on the phosphorus removal efficiency. For successful removal of phosphorus, a shorter hydraulic retention time in the aerobic zone along with appropriate parameters in the anaerobic zone (BOD loading rate ≦ 2 kg-BOD/kg-MLSS day, BOD to MLSS ratio ≦ 0.1 kg-BOD/kg-MLSS) are essential.

scholarly journals Analysis of Fouling Characteristics of Diatomite Ceramic Membrane Using Filtration Models

2021 ◽  
Vol 233 ◽  
pp. 01049
Author(s):  
YANG Yanqing ◽  
QIU Yan ◽  
LIU Yanhui ◽  
ZHAO Yan ◽  
LI jing ◽  
...  
Keyword(s):  
Humic Acid ◽  
Water Treatment ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Ceramic Membrane ◽  
Membrane Surface ◽  
Drinking Water Treatment ◽  
Polymeric Membrane ◽  
Membrane Pore ◽  
Fouling Characteristics

Ceramic membrane has made rapid progress in industrial/municipal wastewater treatment and drinking water treatment owing to its advantageous properties over conventional polymeric membrane. The ceramic membrane processes are a rapidly emerging technology for water treatment, yet virtually no information on the performance and fouling mechanisms diatomite ceramic membrane. In this study, filtration experiments were carried out using a mixture of humic acid and kaolin which simulated surface water under constant pressure to reveal fouling characteristics of the filtration of the diatomite ceramic membrane. The results showed that the removal rate of VU254 was 52%~70%, and turbidity was 90%~95% when treat mixed water of 5-10mg/L kaolin and humic acid. And membrane surface retention and membrane pore adsorption were the mainly removal routes. And the flux slowly decreases, rapidly decreases, gradually decreases and stabilizes were three processes of diatomite ceramic membrane fouling. And the first and third stages of membrane fouling mainly caused by complete blocking, and the second stage was mainly controlled by standard blocking. The study found that humic acid would cause both the pore blocking and the fouling of the membrane surface when turbidity was present, especially the membrane surface pollution, it was the major factor of diatomite ceramic membrane fouling.

The relationship between critical flux and fibre movement induced by bubbling in a submerged hollow fibre system

2005 ◽  
Vol 51 (6-7) ◽  
pp. 115-122 ◽  
Author(s):  
F. Wicaksana ◽  
A.G. Fan ◽  
V. Chen
Keyword(s):  
Membrane Fouling ◽  
Hollow Fibre ◽  
Transmembrane Pressure ◽  
Feed Concentration ◽  
Critical Flux ◽  
Improved Performance ◽  
Qualitative Relationship ◽  
The Relationship ◽  
Mechanical Movement ◽  
Fibre Characteristics

Bubbling has been used to enhance various processes. In this paper we deal with the effect of bubbling on submerged hollow fibre membranes, where bubbling is applied to prevent severe membrane fouling. Previous work with submerged hollow fibres has observed that significant fibre movement can be induced by bubbling and that there is a qualitative relationship between fibre movement and filtration performance. Therefore, the aim of the present research has been to analyse the link between bubbling, fibre movement and critical flux, identified as the flux at which the transmembrane pressure (TMP) starts to rise. Tests were performed on vertical isolated fibres with a model feed of yeast suspension. The fibres were subject to steady bubbling from below. The parameters of interest were the fibre characteristics, such as tightness, diameter and length, as well as feed concentration. The results confirmed that the critical fluxes are affected by the fibre characteristics and feed concentration. Higher critical flux values can be achieved by using loose fibres, smaller diameters and longer fibres. The enhancement is partially linked to fibre movement and this is confirmed by improved performance when fibres are subject to mechanical movement in the absence of bubbling.

A study about the use of chemicals in conventional tertiary treatment. Performances comparison of three municipal wastewater treatment plants and pilot plant experiences

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Wastewater Reclamation ◽  
Valencian Region ◽  
Municipal Wastewater Treatment Plants

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.

Removal of Residual Nutrients and Chemical Additives From Secondary Sewage by Reverse osmosis

1975 ◽  
Vol 10 (1) ◽  
pp. 101-109
Author(s):  
H. Kirk Johnston ◽  
H.S. Lim
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Pilot Plant ◽  
Waste Treatment ◽  
Iron Chloride ◽  
Treatment Technique ◽  
Chemical Additives ◽  
Cellulose Acetate Membranes ◽  
Municipal Wastewaters ◽  
Nutrient Solutions

Abstract The suitability of reverse osmosis as a renovation technique for the treatment of municipal wastewaters has been assessed. Cellulose acetate membranes capable of 70% and 90% NaCl rejections were employed in both laboratory and pilot plant studies to evaluate the efficiency of this technique in removing the residual precipitant chemicals generally employed in phosphorus removal programs (iron chloride, alum, and lime) and the nutrients (phosphates, nitrates and ammonia) characteristic of municipal wastewaters. Secondary sewage and raw sewage as well as prepared nutrient solutions were employed in the course of this program. Both laboratory and pilot plant studies indicated consistently outstanding removal efficiencies for the species examined, almost independent of the nature of the waste solutions being treated. Permeation of the purified effluent was subject to significant reductions due to membrane fouling. This characteristic was most pronounced for the more permeable (less selective) membranes. Routine chemical and physical cleanings enable satisfactory flux levels to be maintained, thereby suggesting that reverse osmosis may become a viable municipal waste treatment technique.

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