Experiences in integrity testing ultrafiltration membranes at a large potable water treatment works

2003 ◽  
Vol 3 (5-6) ◽  
pp. 1-7
Author(s):  
S. Oxtoby
Keyword(s):  
Water Treatment ◽  
Membrane Filtration ◽  
Membrane System ◽  
Primary System ◽  
Secondary System ◽  
Ultrafiltration Membranes ◽  
Integrity Testing ◽  
Particulate Loads ◽  
Integrity Tests ◽  
The Uk

The Clay Lane Water treatment works of Three Valleys Water, in the south east of England, is currently the world’s largest ultrafiltration works with a capacity of 160 Ml/d. It utilises ultrafiltration membranes constructed as hollow fibres with a number of membrane elements in a pressure housing. The plant has been operating since spring 2001. The decision to install the system was made in anticipation of the introduction of tighter regulations on Cryptosporidium in water supplies in the UK. Once a decision was made to proceed with a membrane system the ability to monitor the integrity of the system and to repair problems became a crucial design parameter that was a critical part of membrane selection. The need to include a system affected the design of the filtration units offered by manufacturers. The available systems for integrity testing are reviewed and the reasons for selecting the system adopted are discussed. These include particle counting and the dosing of test particulate loads. The different forms of air passage integrity tests are discussed and the displaced air flow system used is described. Once a failure has been detected it must be traced so that the fault can be repaired. This procedure is described together with the techniques of pin repair of damaged fibres. At Clay Lane and other membrane filtration sites the backwash water from membrane cleaning is recovered using a secondary membrane system. Currently the secondary system operates in the same integrity testing regime as the primary system and the secondary filtrate is returned ahead of the primary membrane system. The relative merits of this system, or the alternative of adding the recovered water to the filtrate are discussed.

scholarly journals Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Membrane System ◽  
Coagulation System ◽  
Fouling Control ◽  
Filtration System ◽  
Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

Monitoring and maintaining the integrity of immersed ultrafiltration membranes used for pathogen protection

2002 ◽  
Vol 2 (5-6) ◽  
pp. 307-311
Author(s):  
P. Côté ◽  
J. Cadera ◽  
N. Adams ◽  
G. Best
Keyword(s):  
Drinking Water ◽  
Membrane Filtration ◽  
Ultrafiltration Membranes ◽  
Vacuum Decay ◽  
Integrity Monitoring ◽  
Pressure Decay ◽  
Decay Test ◽  
Conventional Technology ◽  
Water Borne

Membrane filtration has become the preferred alternative to conventional technology to remove water-borne pathogens in the preparation of drinking water. This paper presents the integrity monitoring and maintenance options for the ZeeWeed® immersed membrane. Results from two versions of air-based tests, a pressure decay test and a vacuum decay test are presented and shown to be conservative when compared to challenge results from independent studies.

Biological sulfate removal in an acidogenic bioreactor with an ultrafiltration membrane system

1998 ◽  
Vol 38 (4-5) ◽  
pp. 513-520 ◽  
Author(s):  
O. Mizuno ◽  
H. Takagi ◽  
T. Noike
Keyword(s):  
Sulfate Reduction ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Volatile Fatty Acids ◽  
Membrane System ◽  
Organic Substrate ◽  
Ultrafiltration Membrane ◽  
Sulfate Concentration ◽  
Sulfate Removal ◽  
Chemostat Reactor

The biological sulfate removal in the acidogenic bioreactor with an ultrafiltration membrane system was investigated at 35°C. Sucrose was used as the sole organic substrate. The sulfate concentration in the substrate ranged from 0 to 600mgS·1−1. The chemostat reactor was operated to compare with the membrane bioreactor. The fouling phenomenon caused by FeS precipitate was observed at higher concentration of sulfate. However, it was possible to continuously operate the membrane bioreactor by cleaning the membrane. The efficiency of sulfate removal by sulfate reduction reached about 100% in the membrane bioreactor, and 55 to 87% of sulfide was removed from the permeate by the membrane filtration. The composition of the metabolite was remarkably changed by the change in sulfate concentration. When the sulfate concentration increased, acetate and 2-proponol significantly increased while n-butyrate and 3-pentanol decreased. The sulfate-reducing bacteria play the role as acetogenic bacteria consuming volatile fatty acids and alcohols as electron donors under sulfate-rich conditions. The results show that the acidogenesis and sulfate reduction simultaneously proceed in the membrane bioreactor.

Carbon–titanium dioxide (C/TiO2) nanofiber composites for chemical oxidation of emerging organic contaminants in reactive filtration applications

2021 ◽  
Vol 8 (3) ◽  
pp. 711-722
Author(s):  
Katherine E. Greenstein ◽  
Matthew R. Nagorzanski ◽  
Bailey Kelsay ◽  
Edgard M. Verdugo ◽  
Nosang V. Myung ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Water Treatment ◽  
Organic Contaminants ◽  
Membrane Filtration ◽  
Titanium Dioxide Nanoparticles ◽  
Chemical Oxidation ◽  
Tio2 Nanofiber ◽  
System P ◽  
Filtration System ◽  
Emerging Organic Contaminants

Electrospun carbon nanofibers with integrated titanium dioxide nanoparticles are used for water treatment in a photoactive membrane filtration system.

Treatment of highly-colored surface water by a hybrid microfiltration membrane system incorporating ion-exchange

2018 ◽  
Vol 19 (3) ◽  
pp. 855-863 ◽  
Author(s):  
T. Miyoshi ◽  
Y. Takahashi ◽  
T. Suzuki ◽  
R. Nitisoravut ◽  
C. Polprasert
Keyword(s):  
Surface Water ◽  
Hybrid System ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane System ◽  
Pilot Scale ◽  
Manganese Concentration ◽  
Moderate Increase ◽  
Coagulant Dosage ◽  
Filtration System

Abstract This study investigated the performance of a hybrid membrane filtration system to produce industrial water from highly-colored surface water. The system consists of a membrane filtration process with appropriate pretreatments, including coagulation, pre-chlorination, and anion exchange (IE) process. The results of the pilot-scale experiments revealed that the hybrid system can produce treated water with color of around 5 Pt-Co, dissolved manganese concentration of no more than 0.05 mg/L, and a silt density index (SDI) of no more than 5 when sufficient coagulant and sodium hypochlorite were dosed. Although the IE process effectively reduced the color of the water, a moderate increase in the color of the IE effluent was observed when there was a significant increase in the color of the raw water. This resulted in a severe membrane fouling, which was likely to be attributed to the excess production of inorganic sludge associated with the increased coagulant dosage required to achieve sufficient reduction of color. Such severe membrane fouling can be controlled by optimising the backwashing and relaxation frequencies during the membrane filtration. These results indicate that the hybrid system proposed is a suitable technology for treating highly-colored surface water.

Cryptosporidium removal during water treatment using dissolved air flotation

1995 ◽  
Vol 31 (3-4) ◽  
pp. 125-135 ◽  
Author(s):  
T. Hall ◽  
J. Pressdee ◽  
R. Gregory ◽  
K. Murray
Keyword(s):  
Water Treatment ◽  
Metal Ion ◽  
Ion Concentration ◽  
Sudden Increase ◽  
Water Turbidity ◽  
Dissolved Air Flotation ◽  
Treatment Processes ◽  
Air Flotation ◽  
The Uk ◽  
Dissolved Air

The occurrence of the protozoan parasite Cryptosporidium parvum in water supplies, and the resultant outbreaks of cryptosporidiosis in the UK and USA, have led to concern over the ability of conventional water treatment processes to remove Cryptosporidia from water sources. Large scale pilot plant trials of water treatment have been carried out in the UK to establish the degree of removal that can be achieved by a range of treatment processes, including dissolved air flotation, and to compare the performance of different treatment options. Results from part of these trials are presented in this paper. These results suggest that well operated chemical coagulation based treatment, using either dissolved air flotation or floc blanket clarification, should be capable of achieving removal of Cryptosporidium oocysts of over 99%. There was no evidence of differences in performance between the different types of filter media investigated. The risk of increased Cryptosporidium concentration in the filtered water will increase as filtrate turbidity increases. However, other factors such as high coagulant metal-ion concentration in the filtered water, or a sudden increase in clarified water turbidity, without any increase in filtered water turbidity, may also indicate treatment problems and associated risk from Cryptosporidia. Recycling of backwash waters may also increase the risk.

scholarly journals Fractionation of Glycomacropeptide from Whey Using Positively Charged Ultrafiltration Membranes

Foods ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 166 ◽  
Author(s):  
Abhiram Arunkumar ◽  
Mark Etzel
Keyword(s):  
Polymer Brushes ◽  
Cheese Whey ◽  
Fold Increase ◽  
Membrane System ◽  
Attractive Alternative ◽  
Salt Tolerant ◽  
Water Addition ◽  
Ultrafiltration Membranes ◽  
Charged Ultrafiltration Membranes ◽  
Positively Charged

Fractionation of the bovine glycomacropeptide (GMP) from the other proteins in cheese whey was examined using ultrafiltration membranes surface modified to contain positively charged polymer brushes made of polyhexamethylene biguanide. By placing a strong positive charge on a 1000 kDa ultrafiltration membrane and adjusting the pH of whey close to the isoelectric point of GMP, a 14-fold increase in selectivity was observed compared to unmodified membranes. A one stage membrane system gave 90% pure GMP and a three-stage rectification system gave 97% pure GMP. The charged membrane was salt-tolerant up to 40 mS cm−1 conductivity, allowing fractionation of GMP directly from cheese whey without first lowering the whey conductivity by water dilution. Thus, similarly sized proteins that differed somewhat in isoelectric points and were 50–100 fold smaller than the membrane molecular weight cut-off (MWCO), were cleanly fractionated using charged ultrafiltration membranes without water addition. This is the first study to report on the use of salt-tolerant charged ultrafiltration membranes to produce chromatographically pure protein fractions from whey, making ultrafiltration an attractive alternative to chromatography for dairy protein fractionation.

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