Ingredient-Wise Study of Flux Characteristics in the Ceramic Membrane Filtration of Uncontaminated Synthetic Metalworking Fluids, Part 1: Experimental Investigation of Flux Decline

1999 ◽  
Vol 122 (4) ◽  
pp. 739-745 ◽  
Author(s):  
Steven J. Skerlos ◽  
N. Rajagopalan ◽  
Richard E. DeVor ◽  
Shiv G. Kapoor ◽  
V. Don Angspatt

Membrane Filtration (MF) technology can remove microbes, particulates, and tramp oils that contaminate metalworking fluids (MWFs). Consequently MF has the potential to reduce health risks and extend MWF life in the machine tool industry. This research assesses the productivity of ceramic membrane filters during filtration of synthetic MWFs and examines the contribution of MWF chemical ingredients to productivity decline. The majority of the chemistry comprising typical synthetic MWFs has negligible impact on MF productivity. However, specialty additives such as lubricants, defoamers, and biocides can significantly reduce MF productivity. Results show that slight variations in formulation can dominate the productivity of the process. Specialty additives can also impart residual effects on the membrane that adversely impact productivity in subsequent applications of the ceramic membrane. [S1087-1357(00)01103-5]

1999 ◽  
Vol 122 (4) ◽  
pp. 746-752 ◽  
Author(s):  
Steven J. Skerlos ◽  
N. Rajagopalan ◽  
Richard E. DeVor ◽  
Shiv G. Kapoor ◽  
V. Don Angspatt

Part 2 of this paper reveals the predominant mechanism of flux decline during microfiltration of the synthetic MWF described in Part 1 of this paper. An analysis of flux data obtained during the experimental investigation suggests that adsorptive interactions occur at the membrane surface. Field Emission Environmental Scanning Electron Microscopy (FE-ESEM) images of aluminum oxide membranes after MWF microfiltration illustrate that adsorption leads to a reduction in pore diameter that serves to reduce flux. The majority of the adsorption is accounted for by a single lubricant additive in the MWF formulation. FE-ESEM images also reveal that the mechanism of flux decline for the defoamer varies depending on the presence of lubricant additive in solution. In the absence of lubricant additive, the defoamer forms a cake layer at the membrane surface. In the presence of the lubricant additive, the defoamer adsorbs to the surface of the membrane with the lubricant additive to constrict pores. In contrast to the lubricant additive and defoamer, base fluid flux decline observed after specialty additive exposure cannot be accounted for by adsorption leading to pore constriction. [S1087-1357(00)01203-X]


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 460
Author(s):  
Bastiaan Blankert ◽  
Bart Van der Bruggen ◽  
Amy E. Childress ◽  
Noreddine Ghaffour ◽  
Johannes S. Vrouwenvelder

The manner in which membrane-fouling experiments are conducted and how fouling performance data are represented have a strong impact on both how the data are interpreted and on the conclusions that may be drawn. We provide a couple of examples to prove that it is possible to obtain misleading conclusions from commonly used representations of fouling data. Although the illustrative example revolves around dead-end ultrafiltration, the underlying principles are applicable to a wider range of membrane processes. When choosing the experimental conditions and how to represent fouling data, there are three main factors that should be considered: (I) the foulant mass is principally related to the filtered volume; (II) the filtration flux can exacerbate fouling effects (e.g., concentration polarization and cake compression); and (III) the practice of normalization, as in dividing by an initial value, disregards the difference in driving force and divides the fouling effect by different numbers. Thus, a bias may occur that favors the experimental condition with the lower filtration flux and the less-permeable membrane. It is recommended to: (I) avoid relative fouling performance indicators, such as relative flux decline (J/J0); (II) use resistance vs. specific volume; and (III) use flux-controlled experiments for fouling performance evaluation.


Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  

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.


2001 ◽  
Vol 43 (10) ◽  
pp. 225-232 ◽  
Author(s):  
C. Jarusutthirak ◽  
G. Amy

The reuse of treated wastewater to augment natural drinking water supplies is receiving serious consideration. Treatment of secondary and tertiary effluent by membrane filtration was investigated by assessing nanofiltration (NF) membrane and ultrafiltration (UF) membranes in bench-scale experiments. It was found that secondary and tertiary effluent contained high concentration of effluent organic matter (EfOM), contributing EfOM-related fouling. Flux decline and EfOM rejection tests were evaluated, using a dead-end stirred cell filtration unit. Surface charge and molecular weight cut-off (MWCO) of membranes were significant factors in membrane performance including permeability and EfOM-rejection.


2005 ◽  
Vol 51 (6-7) ◽  
pp. 181-192 ◽  
Author(s):  
Z. Lewandowski ◽  
H. Beyenal

The goal of this presentation is to identify biofouling mechanisms that cause undesirable effects to the membrane separation processes of flux decline and pressure drop. The underlying assumption of this presentation is that biofouling is unavoidable and that the operator cannot eliminate it entirely. This premise justifies research efforts toward understanding the mechanisms by which biofouling affects the membrane processes, rather than expecting that technology can entirely eliminate membrane biofouling in the near future. An improved understanding of biofouling mechanisms may lead to better membrane design, better membrane modules, and better membrane cleaning procedures.


1985 ◽  
Vol 31 (8) ◽  
pp. 686-692 ◽  
Author(s):  
A. H. Havelaar ◽  
M. During ◽  
E. H. M. Delfgou-Van Asch

The recovery of Pseudomonas aeruginosa on several selective culture media was tested using raw sewage and secondary sewage effluent samples as well as spiked chlorinated imitation swimming water and samples from whirlpools. mPA-medium B gave good recovery of both vital and chlorine-injured P. aeruginosa and selectivity was greater than 90% when analysing whirlpool samples. It is therefore the medium recommended for examination of chlorinated swimming pools. When analysing sewage polluted water with the mPA-B medium, reduced selectivity was noted from low verification rates and from overgrowth by competitive flora. A modified medium (mPA-D; addition of cetrimide, omission of sulphapyridine and actidione) was more selective and sufficiently recovered noninjured cells. Chlorine-injured cells were completely inhibited, however. C-390 (9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan) was confirmed to be highly selective for P. aeruginosa when used in spread plates at a concentration of 30 μg/mL; P. aeruginosa was slightly inhibited. However, the medium could not be used with conventional membrane filtration techniques, because cellulose ester filters interfered with the selective action of C-390. Selectivity could be improved by using Gelman Tuffryn (polysulphone) filters and increasing the C-390 concentration to 120 μg/mL. At this concentration, however, the medium was strongly inhibitory to P. aeruginosa; resuscitation only partially improved recovery. Two other membrane filtration media were tested. Both cetrimide – nalidixic acid agar and Drake's medium No. 19 were inhibitory to chlorine-injured cells. Several types of membrane filters were tested and there was little difference between them. In the most-probable-number technique, recovery of P. aeruginosa was shown to be excellent when using asparagine broth. Malachite green broth was strongly inhibitory to chlorine-injured P. aeruginosa.


2007 ◽  
Vol 7 (5-6) ◽  
pp. 43-51 ◽  
Author(s):  
Y. Matsui ◽  
T. Aizawa ◽  
M. Suzuki ◽  
Y. Kawase

The musty-earthy taste and odour caused by the presence of geosmin and other compounds in tap water are major causes of consumer complaints. Although ozonation and granular activated carbon (GAC) adsorption have been practiced in water-treatment plants to remove these compounds effectively, two major problems associated with the application of these processes – formation of stringently regulated bromate ions by ozonation and unhygienic invertebrate colonisation of GAC filters – are still to be resolved. This research advanced the process of adsorption by powdered activated carbon (PAC) by reducing its particle size to the submicrometre range for microfiltration pretreatment. Adsorption pretreatment by using this super (S)-PAC removed the geosmin with vastly greater efficiency than by normal PAC. Removal was attained in a much shorter contact time and at a much lower dosage. The S-PAC was also beneficial in attenuating the transmembrane pressure rises that occurred between both physical backwashings and chemical cleanings.


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