Principles of an enhanced MBR-process with mechanical cleaning

2011 ◽  
Vol 64 (10) ◽  
pp. 1951-1958 ◽  
Author(s):  
S. Rosenberger ◽  
F. P. Helmus ◽  
S. Krause ◽  
A. Bareth ◽  
U. Meyer-Blumenroth
Keyword(s):  
Membrane Fouling ◽  
Pilot Plant ◽  
Membrane Bioreactors ◽  
Fluidised Bed ◽  
Chemical Cleaning ◽  
Retention System ◽  
Reactor Geometry ◽  
Membrane Modules ◽  
Physical And Chemical ◽  
Mechanical Cleaning

Up to date, different physical and chemical cleaning protocols are necessary to limit membrane fouling in membrane bioreactors. This paper deals with a mechanical cleaning process, which aims at the avoidance of hypochlorite and other critical chemicals in MBR with submerged flat sheet modules. The process basically consists of the addition of plastic particles into the loop circulation within submerged membrane modules. Investigations of two pilot plants are presented: Pilot plant 1 is equipped with a 10 m2 membrane module and operated with a translucent model suspension; pilot plant 2 is equipped with four 50 m2 membrane modules and operated with pretreated sewage. Results of pilot plant 1 show that the establishment of a fluidised bed with regular particle distribution is possible for a variety of particles. Particles with maximum densities of 1.05 g/cm3 and between 3 and 5 mm diameter form a stable fluidised bed almost regardless of activated sludge concentration, viscosity and reactor geometry. Particles with densities between 1.05 g/cm3 and 1.2 g/cm3 form a stable fluidised bed, if the velocity at the reactor bottom is sufficiently high. Activities within pilot plant 2 focused on plant optimisation and the development of an adequate particle retention system.

Studies on Fouling and its Prevention in MBRs

2010 ◽  
Vol 5 (2) ◽  
Author(s):  
B. Siembida ◽  
P. Cornel ◽  
S. Krause ◽  
B. Zimmermann
Keyword(s):  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
High Flux ◽  
Chemical Cleaning ◽  
Sustainable Operation ◽  
The One ◽  
The Impact ◽  
Very High ◽  
Mechanical Cleaning

Investigations of fouling alleviation and permeability decline in membrane bioreactors (MBR) were carried out at two pilot plants. On the one hand, the minimization of membrane fouling via adding abrasive granulates into activated sludge (submerged operated membrane) was tested. On the other hand, the impact of truly soluble compounds released into the liquid phase of activated sludge on fouling behavior was investigated. The first research into the impact of mechanical cleaning via adding granulates showed the unwanted formation of fouling layers was reduced as a result of abrasion processes. With this method continuous sustainable operation was achieved, without chemical cleaning and, at the same time, reaching very high flux levels up to 40 L/(m2·h) over more than 500 days (>16 months). The investigation of the effect of truly soluble compounds on membrane fouling showed that the permeability decline during 145 days of operation resulted predominantly from wastewater or activated sludge matter larger than 0.04 μm.

Membrane bioreactors for wastewater treatment: A review of mechanical cleaning by scouring agents to control membrane fouling

2017 ◽  
Vol 307 ◽  
pp. 897-913 ◽  
Author(s):  
Muhammad Aslam ◽  
Amine Charfi ◽  
Geoffroy Lesage ◽  
Marc Heran ◽  
Jeonghwan Kim
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Mechanical Cleaning

A study on membrane fouling due to algal deposition

2000 ◽  
Vol 41 (10-11) ◽  
pp. 327-335 ◽  
Author(s):  
S. Babel ◽  
S. Takizawa
Keyword(s):  
Organic Matter ◽  
Membrane Fouling ◽  
Cell Lysis ◽  
Chemical Cleaning ◽  
Membrane Cleaning ◽  
Treatment Techniques ◽  
Ozone Pretreatment ◽  
Extensive Cell ◽  
Pre Treatment ◽  
Physical And Chemical

Batch filtration experiments in dead-end mode were carried out to investigate the membrane fouling phenomenon due to Chlorella deposition and to analyse the effectiveness of pretreatment techniques to control membrane fouling. Experiments were also conducted to identify efficient and effective physical and chemical methods for cleaning the membrane. For both cellulose acetate and PVDF membranes, the effect of algal concentration was found similar. Initially when the deposition was less, the flux was high and the resistance was very low or negligible. As the deposition increased, the resistance increased exponentially. With further increase in deposition, the resistance increases linearly at a constant rate. Among the three pre-treatment techniques studied, coagulation with alum and ozonation were effective in controlling the fouling of membrane. Chlorine pretreatment was not effective in reducing the algal cake resistance because it brought about an extensive cell lysis. Photographs taken by Scanning Electron Microscope (SEM) showed damage to the cell surface architecture and release of organic matter to the medium after chlorination. Ozone pretreatment was more effective than chlorine in disintegrating only the extracelluar organic matter (EOM) without causing cell lysis, thus bringing down the algal cake resistance. Cleaning experiments after algal filtration without pre-treatment showed that physical cleaning was less effective than chemical cleaning. All four chemicals tested for membrane cleaning could reduce the cake resistance by more than 99%.

Control Of Surface Fouling Of Membrane Modules In Membrane Bioreactors

2019 ◽  
pp. 88-92
Keyword(s):  
Membrane Fouling ◽  
Biomass Accumulation ◽  
Membrane Bioreactors ◽  
Membrane Module ◽  
Factors Affecting ◽  
Fouling Control ◽  
A Value ◽  
Aeration System ◽  
Membrane Modules ◽  
Positive Effect

The article considers the approaches in the field of membrane fouling control in membrane bioreactors used for wastewater treatment. It is highlighted that a significant number of research world-wide is devoted to the study of membrane fouling, which makes it possible to point out and identify the main factors affecting membrane fouling. Generally, such factors are the parameters of operation of the biological treatment reactor with a submerged membrane module, the properties of the biomass of activated sludge, as well as the characteristics of the membranes themselves, while the process of fouling is a three-stage mechanism. This article considers two approaches to control the process of the surface fouling of membrane modules: by improving the functioning of the aeration system and using floating biomass carriers. For aeration systems the concept of the minimum allowable aeration intensity is defined as a value which positively affects the reduction of fouling. The use of biomass carriers in addition to the function of biomass accumulation makes it possible to create additional shear forces on the surface of the membrane module, which contribute to more intensive removal of contaminants from the surface. It is established that the combination of several ways to control fouling is particularly effective, which has a positive effect on the operation of the treatment systems.

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.

Membrane thickening of water works sludge

2001 ◽  
Vol 1 (5-6) ◽  
pp. 215-220
Author(s):  
A. Gillighan ◽  
S.J. Judd ◽  
R. Eyres
Keyword(s):  
Hydraulic Resistance ◽  
Reasonable Agreement ◽  
Chemical Cleaning ◽  
Solids Concentration ◽  
Significant Difference ◽  
Layer Resistance ◽  
Tubular Membranes ◽  
Resistance Data ◽  
Mechanical Cleaning ◽  
Dynamic Layer

The efficacy of ultrafiltration (UF) and microfiltration (MF) membranes was assessed for the concentration of actual waterworks sludges using crossflow tubular membranes operated at constant trans-membrane pressure. The MF membrane gave higher initial fluxes than the UF membrane but after 10 min of filtration the flux value and its decline tended to be very similar for both membranes operating under the same conditions. All membranes gave permeate product water of <0.2 NTU and <100ppb coagulant at all times. For both membranes mechanical cleaning, with sponge balls, was at least as effective as acid chemical cleaning, indicating that no significant permanent internal fouling occurred for these membrane materials. Hydraulic resistance data indicated a significant difference in the dynamic layer resistance between the two membranes. Whilst the UF membrane had a hydraulic resistance 3.7 times that of the MF membrane, the dynamic layer formed on the UF membrane during operation displayed a maximum hydraulic resistance almost nine times lower than that of the MF membrane operating under the same conditions. Correlation of cake resistance R versus feed solids concentration C for all the data generated for t>0 demonstrated reasonable agreement with the expression R∝ca where a=0.37 in the current study. This trend has been recorded in previous reported studies, a varying between 0.33 and 0.62 depending on sludge dewaterability.

scholarly journals Correction: Membrane fouling characteristics of membrane bioreactors (MBRs) under salinity shock: extracellular polymeric substances (EPSs) and the optimization of operating parameters

2021 ◽  
Author(s):  
Ling Luo ◽  
Hui Zhong ◽  
Ye Yuan ◽  
Wenwang Zhou ◽  
Changming Zhong
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Operating Parameters ◽  
Salinity Shock ◽  
Fouling Characteristics

Correction for ‘Membrane fouling characteristics of membrane bioreactors (MBRs) under salinity shock: extracellular polymeric substances (EPSs) and the optimization of operating parameters’ by Changming Zhong et al., Environ. Sci.: Water Res. Technol., 2021, DOI: .

Fate and abatement of mercury and other trace elements in a coal fluidised bed oxy combustion pilot plant

Fuel ◽  
2012 ◽  
Vol 95 ◽  
pp. 272-281 ◽  
Author(s):  
O. Font ◽  
P. Córdoba ◽  
C. Leiva ◽  
L.M. Romeo ◽  
I. Bolea ◽  
...  
Keyword(s):  
Trace Elements ◽  
Pilot Plant ◽  
Fluidised Bed

The importance of measuring the sludge filterability at an MBR – introduction of a new method

2012 ◽  
Vol 66 (1) ◽  
pp. 9-14 ◽  
Author(s):  
C. Thiemig
Keyword(s):  
Membrane Fouling ◽  
Reliable Method ◽  
Membrane Bioreactors ◽  
New Method ◽  
Strong Impact ◽  
Laboratory Equipment ◽  
Filtration Performance ◽  
Sludge Properties ◽  
Operational Aspects ◽  
General Method

Sludge properties have a strong impact on the operational aspects of membrane bioreactors (MBRs). Poor sludge properties cause stronger membrane fouling and reduce the filtration performance of MBRs. Up to now there is no general method used to measure the fouling or filtration relevant sludge properties in MBRs. The aim of this work was to develop a simple but reliable method to supply operators a tool to monitor the important sludge properties for their application and to compare this method with existing techniques. Through extensive research a new method called the sludge filtration index (SFI) has been developed to indicate the appropriate sludge parameters for MBR systems in a cheap and easy manner. The SFI can be measured with simple laboratory equipment and offers operators a powerful tool to monitor the conditions of their sludge, independent of the membrane conditions.

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