Risk management approach for monitoring UF membrane integrity and experimental validation using MS2-phages

2008 ◽  
Vol 8 (2) ◽  
pp. 239-244 ◽  
Author(s):  
Anne Brehant ◽  
Karl Glucina ◽  
Isabelle Lemoigne ◽  
Jean-Michel Laine
Keyword(s):  
Removal Efficiency ◽  
Membrane Filtration ◽  
Membrane Integrity ◽  
Drinking Water Treatment ◽  
Low Pressure ◽  
Full Scale ◽  
Microbial Pathogens ◽  
Management Approach ◽  
Pathogen Removal ◽  
Bench Scale

Low-pressure membrane filtration systems, such as microfiltration (MF) and ultrafiltration (UF), have received a great deal of attention in the past 15 years due to their ability to remove microbial pathogens, especially Cryptosporidium and Giardia. The major concern for the application of membrane technology is, however, how to ensure integrity of these barriers, since small defects in membranes could result in a significant reduction in pathogen removal efficiency. In order to ensure safe drinking water treatment, a number of environmental agencies request the membrane operators to conduct regular direct integrity tests to control the microbial log removal values (LRV) of the plants. Typically, test conditions must be selected to provide information on defects larger than 3 μm to ensure Cryptosporidium removal. In that context, the objective of this project was to develop and validate, both at bench-scale and full-scale, a model based on the equations proposed by USEPA and ASTM that uses the air flow rate throughout a defect during the air pressure test for predicting the microbial LRV. The project was conducted on a pressurised low-pressure membrane module. MS2-phages were used at bench-scale to validate the model and the selected assumptions with various calibrated defects carried out on the membrane fibres. The validity of the model was then evaluated at full-scale. A user-friendly tool using the Hagen Poiseuille Model proposed by the ASTM was developed to assist membrane operators in the integrity monitoring. The calibration of the model with full-scale tests resulted in adjusting some key-parameters representing air diffusion, flow regime and particles deposition. The numerical applications provide a very reliable result in predicting the pathogen removal efficiency and the equivalent number of broken fibres. This model could detect one complete broken fibre out of more than 700,000 fibres, which guaranteed more than 4 log of microorganism removal efficiency.

Assessing pathogen removal efficiency of microfiltration by monitoring membrane integrity

2001 ◽  
Vol 1 (4) ◽  
pp. 43-48 ◽  
Author(s):  
S.K. Hong ◽  
F.A. Miller ◽  
J.S. Taylor
Keyword(s):  
Removal Efficiency ◽  
Air Flow ◽  
Membrane Integrity ◽  
Operating Conditions ◽  
Pathogen Removal ◽  
Membrane Pore ◽  
Pressure Decay ◽  
Particle Counting ◽  
Integrity Tests ◽  
Microbial Challenge

This study was conducted to investigate the ability of various methods of monitoring membrane integrity to respond to changes in actual membrane integrity imposed by the compromised fibers within the microfiltration unit. In addition, the pilot-scale MF unit was challenged with high concentrations of coliform, Cryptosporidium, and spore, in order to assess the pathogen removal capability of microfiltration. A correlation between the integrity tests and microbial challenge data was also made. The integrity tests investigated in this study were pressure decay and diffusive air flow tests (direct integrity tests), and turbidity and particle counting (indirect integrity tests). Both pressure decay (PDT) and diffusive air flow (DAF) tests were sensitive enough to detect one damaged fiber out of 66,000. The extent of fouling did not affect the sensitivity of the PDT and DAF, showing that PDT and DAF tests are a simple, reliable means to monitor membrane integrity under field conditions. Indirect integrity monitoring using turbidity and particle counting, however, responded poorly to changes in membrane integrity. Microbial challenge study demonstrated that microfiltration was capable of removing various pathogens including Cryptosporidium, at the level required by drinking water regulations, under even adverse operating conditions. Finally, PDT and DAF tests showed a better correlation with actual microbial removal efficiency of microfiltration than turbidity and particle counting. The turbidity and particle counting grossly underestimated the removal of pathogen larger than MF membrane pore size due to poor sensitivity.

Performance of ultrafiltration membrane process combined with coagulation/sedimentation

2005 ◽  
Vol 51 (6-7) ◽  
pp. 209-219 ◽  
Author(s):  
N.-Y. Jang ◽  
Y. Watanabe ◽  
S. Minegishi
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Removal Efficiency ◽  
Membrane Fouling ◽  
Pilot Plant ◽  
Membrane Filtration ◽  
Operating Pressure ◽  
Membrane Process ◽  
Bench Scale ◽  
Jar Test

Effects of coagulation/sedimentation as a pre-treatment on the dead-end ultrafiltration (UF) membrane process were studied in terms of membrane fouling and removal efficiency of natural dissolved organic matter, using Chitose River water. Two types of experiment were carried out. One was a bench scale membrane filtration with jar-test and the other was membrane filtration pilot plant combined with the Jet Mixed Separator (JMS) as a pre-coagulation/sedimentation unit. In the bench scale experiment, the effects of coagulant dosage, pH and membrane operating pressure on the membrane fouling and removal efficiency of natural dissolved organic matter were investigated. In the pilot plant experiment, we also investigated the effect of pre-coagulation/sedimentation on the membrane fouling and the removal efficiency of natural dissolved organic matter. Coagulation/sedimentation prior to membrane filtration process controlled the membrane fouling and increased the removal efficiency of natural dissolved organic matter.

Reuse of filter backwash water by implementing ultrafiltration technology

2001 ◽  
Vol 1 (5-6) ◽  
pp. 207-214
Author(s):  
A. Brügger ◽  
K. Voßenkaul ◽  
T. Melin ◽  
R. Rautenbach ◽  
B. Golloing ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Pilot Study ◽  
Membrane Filtration ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Full Scale ◽  
Water Filters ◽  
Filter Backwash Water

Membrane filtration allows safe retention of microorganisms when treating filter backwash water from conventional drinking water filters. The permeate of the membrane plant can thus be reused to produce drinking water. The benefits are a higher yield of the drinking water treatment plant and a minimised wastewater production. This paper discusses the results of a pilot study, cost data and full-scale operation experiences concerning the application of ultrafiltration to treat filter backwash water. The effectiveness of ultrafiltration was assessed with regard to flux, cost and permeate quality.

Rural blackwater treatment by a full-scale Brazilian Biodigester Septic Tank: microbial indicators and pathogen removal efficiency

2021 ◽  
Author(s):  
Thaíssa Jucá Jardim Oliveira ◽  
Aníbal da Fonseca Santiago ◽  
Maria Célia da Silva Lanna ◽  
Gislaine Fongaro ◽  
Natália Ladeira Milagres ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Full Scale ◽  
Septic Tank ◽  
Pathogen Removal ◽  
Microbial Indicators

scholarly journals REMOVAL OF COMMERCIAL ANIONIC DETERGENT IN WATER USING CONTINUOUS PROCESS OF BIOLOGICAL REACTOR WITH ADDING OF PAC

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Nusa Idaman Said
Keyword(s):  
Activated Carbon ◽  
Removal Efficiency ◽  
Biological Treatment ◽  
Continuous Process ◽  
Drinking Water Treatment ◽  
Continuous Reactor ◽  
Aeration Tank ◽  
Bench Scale ◽  
Process System ◽  
Continuous Feeding

Synthetic detergents, mostly anionic detergents have been widely used in Indonesia  over past two decades, similar to its use in other developing countries, and residuals from such use have entered the country's riverine and estuarine systems. Detergent problems have become more serious especially in urban areas where the spread of sewerage systems are still low, even in drinking water treatment process. According to this reason, it is important to develop low-cost technology to solve this problem such as developing biological treatment for removing detergents.Effects OF continuous adding of powdeR activated carbon (PAC) on biological removal of anionic detergent in continuous reactor was assessed. Results of these experiments showed that introduction of PAC into biological treatment of anionic detergent (ABS or LAS), has indicated significant effect on removal efficiency. Conducting continuous feeding of PAC into bench scale of continuous process system for removal of detergent has resulted better stability of MBAS removal efficiency, even when MLSS concentration in aeration tank dropped or MBAS concentration in influent water rose rapidly. With continuous addition of PAC, the MBAS removal efficiency was relatively constant even when the water temperature dropped rapidly.  In other words, continuous feeding of PAC can improve the stability for shock loads or temperatures changes. At lower temperatures, micro organisms that were used for detergent removal in bench scale of continuous process system, need longer adaptation or acclimation periods compared with higher temperatures. Key Words: Commercial anionic detergent, biodegradation, biological reactor, powdered activated carbon (PAC).

Evaluation of a low-pressure membrane filtration for drinking water treatment: pretreatment by coagulation/sedimentation for the MF membrane

Desalination ◽  
2009 ◽  
Vol 247 (1-3) ◽  
pp. 271-284 ◽  
Author(s):  
Jihee Moon ◽  
Moon-Sun Kang ◽  
Jae-Lim Lim ◽  
Choong-Hwan Kim ◽  
Hee-Deung Park
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Membrane Filtration ◽  
Drinking Water Treatment ◽  
Low Pressure

scholarly journals Sorption Characteristics and Removal Efficiency of Organic Micropollutants in Drinking Water Using Granular Activated Carbon (GAC) in Pilot-Scale and Full-Scale Tests

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2053
Author(s):  
Oksana Golovko ◽  
Luana de Brito Anton ◽  
Claudia Cascone ◽  
Lutz Ahrens ◽  
Elin Lavonen ◽  
...  
Keyword(s):  
Drinking Water ◽  
Early Detection ◽  
Removal Efficiency ◽  
Solid Phase ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Full Scale ◽  
Organic Micropollutants ◽  
Full Scale Tests ◽  
The Impact

Granulated active carbon (GAC) is commonly used as a chemical barrier for the removal of organic micropollutants (OMPs) in drinking water treatment plants (DWTPs). However, little is known about the impact of dissolved organic carbon (DOC) and its long-term performance with regard to OMP removal efficiency. This study examined the performance of two GAC types (Norit 830W and Filtrasorb 400) in the removal of OMPs and DOC from natural lake water, in pilot-scale and full-scale tests run for almost one year. Potential early warning indicators of the exhaustion of GAC sorption capacity were also evaluated. The seven OMPs investigated (carbamazepine, lamotrigine, cetirizine, fexofenadine, oxazepam, fluconazole and N,N-diethyl-meta-toluamide (DEET)) all showed decreasing removal efficiencies after ~20,000 bed volumes (BV) in the pilot-scale Norit 830W and Filtrasorb 400 columns. However, columns with an 18-min empty bed contact time (EBCT) showed better performances than columns with 6-min EBCT. DEET was the OMP adsorbed most weakly. We found that DOC concentrations, methylene blue sorption kinetics, UV and fluorescence did not sufficiently explain the OMP breakthrough in the GAC columns. We concluded that carbamazepine, lamotrigine and fexofenadine can be used as indicators of decreasing GAC adsorption performance, due to their later breakthrough. Based on the results, UV and fluorescence removal could be used for the early detection of declining DOC removal, and online solid-phase extraction (SPE)–liquid chromatography–tandem mass spectrometry (SPE-LC-MS/MS) could be used for the early detection of OMPs in drinking water.

Low-pressure membrane integrity tests for drinking water treatment: A review

2010 ◽  
Vol 44 (1) ◽  
pp. 41-57 ◽  
Author(s):  
H. Guo ◽  
Y. Wyart ◽  
J. Perot ◽  
F. Nauleau ◽  
P. Moulin
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Membrane Integrity ◽  
Drinking Water Treatment ◽  
Low Pressure ◽  
Integrity Tests
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