Membrane fouling amelioration through pseudo dead-end filtration coupled with transmembrane pressure (TMP) set-point control in an anaerobic membrane bioreactor for municipal wastewater treatment

2021 ◽  
Author(s):  
K. M. Wang ◽  
L. J. Zhang ◽  
H. L. Zhang ◽  
J. L. Li ◽  
Y. C. Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Energy Demand ◽  
Municipal Wastewater ◽  
Sewage Treatment ◽  
Transmembrane Pressure ◽  
Municipal Wastewater Treatment ◽  
Set Point ◽  
Dead End ◽  
Point Control ◽  
Set Point Control

Sustainable membrane operation in an AnMBR achieved under pseudo dead-end filtration coupled with TMP set-point control with a low energy demand and operational cost, promoting energy neutral sewage treatment to be realized.

scholarly journals Impacts of the specific cake resistance on mbr fouling for wastewater treatment

2021 ◽  
Vol 72 (7) ◽  
pp. 841-849
Author(s):  
Guigui Christelle ◽  
Nga Vu Thi Thu
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Peak Height ◽  
Transmembrane Pressure ◽  
Strongly Correlated ◽  
Municipal Wastewater Treatment ◽  
Fouling Resistance ◽  
Sustainable Operation ◽  
Specific Cake Resistance

Membrane bioreactor (MBR) has been increasingly used for municipal wastewater treatment and reuse due to its good effluent quality. However, membrane fouling remains the major limitation of MBR. Understanding fouling is still a key issue for a more sustainable operation of MBRs. Thus, this research presents the influence of specific cake resistance (α) on the fouling propensity in the MBR. Correlation between α value with fouling resistance (Rf), fouling rate (dTMP/dt), especially of peak height 100-1000 kDa protein-like SMPs was investigated. The result reported that the α value was strongly correlated with the dTMP/dt in the MBR (R2 value of close to 1). In this study, however, there is an obvious discrepancy between the fouling resistance calculated from the resistance in the series model and the α value in the supernatant filtration. These observations demonstrated that the fouling propensities of the membrane could be monitored by the transmembrane pressure and the fouling characteristics, include fouling resistance and specific cake resistance in the filtration cell.

scholarly journals Comparison of fouling between aerobic and anaerobic MBR treating municipal wastewater

2018 ◽  
Vol 1 (2) ◽  
pp. 131-159 ◽  
Author(s):  
K. M. Wang ◽  
N. Martin Garcia ◽  
A. Soares ◽  
B. Jefferson ◽  
E. J. McAdam
Keyword(s):  
Wastewater Treatment ◽  
Knowledge Transfer ◽  
Membrane Fouling ◽  
Energy Demand ◽  
Municipal Wastewater ◽  
Primary Energy ◽  
Municipal Wastewater Treatment ◽  
Primary Energy Demand ◽  
Microbial Product ◽  
Aerobic And Anaerobic

Abstract The key driver for anaerobic membrane bioreactors (AnMBRs) for municipal wastewater treatment is enabling the transition to energy neutral wastewater treatment. However, municipal wastewater delivers a comparatively constrained methane yield, which means energy conservation must be prioritised to achieve the proposed energy neutral ambition. A critical focus on membrane fouling is therefore warranted, as membrane operation represents the primary energy demand in MBRs. This review seeks to quantify the characteristics of the prevailing AnMBR biological suspension and to ascertain whether knowledge transfer exists between fouling characteristics in aerobic and anaerobic MBRs for municipal applications. Analysis of literature data revealed that the level of extractable extracellular polymeric substrate is slightly higher in aerobic MBRs than in anaerobic MBRs. However, AnMBR comprises considerably higher soluble microbial product concentrations, which have been widely reported to increase fouling propensity in aerobic systems. More distinct is the difference in the colloidal and fine solids fraction (between 1 and 10–15 μm), which is likely to dominate fouling in anaerobic systems and limit knowledge transfer from aerobic MBRs. Literature data on energy production was compared to that employed for membrane operation, and evidences that despite the challenging character of the particle matrix, energy neutral operation is achievable for AnMBR applied to municipal wastewater treatment.

Treatment of Rural Domestic Sewage by Solar Ozonic Ecological Sewage Treatment Plant

2014 ◽  
Vol 955-959 ◽  
pp. 3393-3399 ◽  
Author(s):  
Wei Zheng ◽  
Yan Ming Yang ◽  
Yun Long Li ◽  
Jian Qiu Zheng
Keyword(s):  
Municipal Wastewater ◽  
Operating Cost ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Domestic Sewage ◽  
Design Parameters ◽  
Small Scale ◽  
Municipal Wastewater Treatment ◽  
Average Percentage

The process technique and design parameters of project of Solar Ozonic Ecological Sewage Treatment Plant (short for SOESTP) which consists of anaerobic reactor, horizontal subsurface flow (HSSF) constructed wetlands(CWs) and the combination of solar power and ozone disinfection are described, the paper further examines the removal efficiency for treating rural domestic sewage, running expense and recycling ability of product water. The results show that the average percentage removal values of CODcr，BOD5，SS，TN，NH3-N，TP range from 95.6% to 98.0%, 96.0% to 98.7%, 93.1% to 96.1%, 97.0% to 98.9%, 96.9% to 99.5%, 98.2% to 99.6%, respectively, the reduction of fecal coliform (FC) reaches 99.9%, the effluent quality meets the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant（GB18918-2002）. The running cost of SOESTP is 0.063yuan/ m3, saves much more than traditional sewage treatment, and the ozone water obtained from the reservoir will be an ideal choice for disinfection .The system has characteristics of easy manipulation, low operating cost, achieving advanced water, energy conservation and environment protection, is thought to be very suitable for use as the promotion of rural small - scale sewage treatment.

scholarly journals Telomere length set point regulation in human pluripotent stem cells critically depends on the shelterin protein TPP1

2020 ◽  
Vol 31 (23) ◽  
pp. 2583-2596
Author(s):  
John M. Boyle ◽  
Kelsey M. Hennick ◽  
Samuel G. Regalado ◽  
Jacob M. Vogan ◽  
Xiaozhu Zhang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Telomere Length ◽  
Pluripotent Stem Cells ◽  
Human Stem Cells ◽  
Set Point ◽  
Hypomorphic Allele ◽  
Point Control ◽  
Set Point Control ◽  
Stem Cell Lines

To better understand telomere length set point control in human stem cells, we generated knockout stem cell lines for TPP1 and contrasted their phenotypes with those of homozygous TPP1 L104A mutant stem cells. This comparison reveals that TPP1 L104A is not a hypomorphic allele but formally establishes TPP1 L104 as a dissociation of function mutant.

Enhanced Performance of Ultrafiltration Membrane with Powdered Zeolite Addition for Secondary Effluent Treatment

2013 ◽  
Vol 838-841 ◽  
pp. 2712-2716
Author(s):  
Yong Tu ◽  
Yong Gang Bai ◽  
Yong Chen ◽  
Wei Jing Liu ◽  
Jun Xu ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Fluorescence Spectra ◽  
Municipal Wastewater ◽  
Three Dimensional ◽  
Treatment Plant ◽  
Ultrafiltration Membrane ◽  
Effluent Treatment ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Sem Images

The research on ultrafiltration membrane assisted by powdered zeolite for the treatment of secondary effluent from a municipal wastewater treatment plant was studied. The results show that membrane fouling rate is reduced by pre-coating the ultrafiltration membrane with powdered zeolite, and the treatment performance of secondary effluent is enhanced. UV-vis, three-dimensional excitation emission matrix (3D-EEM) fluorescence spectra and scanning electron microscopy (SEM) images for ultrafiltration were also discussed.

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.

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.

Benchmarks for the energy demand of nutrient removal plants

2003 ◽  
Vol 47 (12) ◽  
pp. 125-132 ◽  
Author(s):  
O. Nowak
Keyword(s):  
Nutrient Removal ◽  
Energy Demand ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Electrical Energy ◽  
Anaerobic Sludge ◽  
Operational Experience ◽  
Municipal Wastewater Treatment ◽  
Sludge Digestion ◽  
Municipal Wastewater Treatment Plants

The energy demand of municipal wastewater treatment plants for nutrient removal equipped with primary clarifiers, activated sludge system, anaerobic sludge digestion, and CHP is evaluated theoretically, on the basis of COD balances. Operational experience from energy-efficient Austrian treatment plants confirms that the demand on external electrical energy can be kept as low as 5 to 10 kWh/(pe.a) depending on the N:COD ratio in the raw wastewater. A low N:COD ratio helps to keep not only the effluent nitrogen load low, but also the energy demand. Measures to minimise the energy demand at treatment plants and to reduce the nitrogen load are discussed.

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