Filtration Apparatus Research Articles

An Efficient and Inexpensive Apparatus for Hot Filtration

An efficient apparatus for hot filtration is described. It is constructed from recycled glass laboratory material (Erlenrneyer flask and funnel), modified by simple glass blowing techniques.

Gene structure and alternative splicing of murine podocalyxin: a member of the CD34 sialomucin family.

Podocalyxin is a sialoglycoprotein of the glomerular podocytes, vascular endothelial cells, platelets, and hemopoietic stem cells. The function of podocalyxin is unknown, but it contains most of the protein bound sialic acid in the glomerulus and is considered vital in the structure and function of the glomerular filtration apparatus. The murine podocalyxin full-length cDNA has been determined and is 5,318 base pairs. The gene localizes to chromosome 6B1 by FISH analysis and contains eight major exons with one additional alternatively spliced exon. The alternatively spliced isoform of podocalyxin codes for a truncated intracellular domain and is expressed in a tissue specific pattern in parallel with full-length podocalyxin. The organization of the gene structure of murine podocalyxin is similar to the murine CD34 gene and suggests a distant evolutionary relationship to CD34.

Mini-Scale Solid-Phase Collection and Concentration of Ultra-Trace Elements in Natural Waters for the Simultaneous Multielement Determination by Air-Flow Injection/ ICP-Mass Spectrometry

Abstract A mini-scale solid-phase collection and concentration method for the multielement determination of ultra-trace rare earth elements (REEs) in natural water samples was developed by using a newly designed small-scale filtration apparatus. A small-size chelating resin disk (iminodiacetate type: IDA; 10 µm pore size; 5 mm diameter; 0.5 mm thickness) was used for high-enrichment preconcentration of REEs and for elimination of alkali and alkaline earth metals in sample solutions. At pH 5.5, REEs in artificial river waters were quantitatively collected on the chelating resin disk, and most of alkali and alkaline earth metals were removed. The REEs on the chelating resin disk were completely recovered by ultrasonication of the disk with 1 cm3 or less of 0.1 mol dm−3 nitric acid. A small amount (25 µL) of the concentrated sample solution was automatically injected and measured by inductively coupled plasma – mass spectrometry (ICP–MS) coupled with an air flow injection (AFI) system.

醤油火入れ澱のクロスフロー膜ろ過濃縮における懸濁物質濃度増加の透過流束に及ぼす影響

Cross-flow ultrafiltration and microfiltration have been used to recover soy sauce products from the brewing soy sauce lees for 20 years. To select appropriate membrane module and operating condition for the filtration of soy sauce lees, it is important to analyze the relation between permeate flux decline at varying operating conditions and fouling formation in the batch-concentration-filtration quantitatively. The cross-flow filtration apparatus with 0.006 m2 polysulfone flat-sheet membrane (pore size, 0.2μm) module was used at a constant transmembrane pressure and different cross-flow velocity in both permeate-recycle-and batch-concentration-filtration. Flux decline in the batch-concentration-filtration showed good agreement with the cake-filtration-model proposed in the present study by the Runge-Kutta-Gill method in which the lift velocity at initial concentration was defined as a steady-state flux in the permeate-recycle-filtration and the lift velocity in the batch-concentration-filtration decreased with VRF (volume reduction factor) to the 0.9th power. The lift velocity of soy sauce lees which contain particles of wide range particle size distribution had larger dependence on the particle concentration than that of the suspensions containing latex or yeast shown in the literatures. The cake filtration model applied in the batch-concentration-filtration of soy sauce lees with cross-flow microfiltration membrane was useful to design the process of soy sauce recovery from soy sauce less.

Using mechatronics technology to assess pressure filtration

This paper describes some recent (initial) developments in laboratory scale cake filtration technology which may ultimately lead to the production of standard equipment for assessing filtration performance. The principles of mechatronics, which integrates electronics, computers, process control and mechanical systems, have been used to provide a state-of-the-art pressure filtration apparatus capable of performing repeatable experiments over a range of pressure/flow regimes commonly encountered in industrial filtrations. Data obtained at constant pressure and proportionally controlled variable pressure are presented to illustrate the scope of the apparatus and the benefits of removing operator interference and damaging pumping operations from filtration experiments. It is shown how scale-up parameters (obtained for aqueous mineral suspensions) can be used to successfully predict constant pressure filtration performance and the problems which can arise when predictions of more compressible variable pressure filtrations are made using data obtained at constant pressure.

Electroosmotically Enhanced Sludge Pressure Filtration

Wastewater sludge is routinely dewatered to lower the cost of transportation and disposal. Dewatering is achieved via vacuum filtration, centrifugation, sand beds, and belt filter presses. Electroosmosis, the movement of water in the influence of a direct‐current (dc) electric field, has been used since the 1930s to dewater soil for construction purposes. This study examines dewatering anaerobically and aerobically digested municipal wastewater solids with applied direct pressure and constant voltage direct current. A pressure filtration apparatus, consisting of a piston and drain plate made of conductive material encased in a body of nonconductive material, was used to apply constant pressure and constant voltage (variable current) during the experiments. Three experimental series were conducted evaluating the effect of polymer dosage and voltage on the final cake total solids; the relationship among pressure, voltage, time, and final cake total solids; and the relationship among initial feed solids and final cake total solids after electroosmotic filtration. Results show that final cake solids were increased to as much as 50% with 60 V dc applied. Final cake solids may be enhanced by increasing pressure, voltage, or time, and additional water may be removed from a conventionally dewatered cake by further application of dc voltage.

Surface sterilisation of phylloxera eggs for investigating grapevine-phylloxera interactions in tissue culture

A simple method has been developed for sterilising eggs of grape phylloxera (Daktulosphaira vitifoliae Fitch) to use in controlled experiments involving in vitro cocultivation of phylloxera with grapevine (Vitis spp.). Eggs are collected and washed with 70% ethanol followed by a sterile water rinse using a Millipore filtration apparatus. Such a filter provides a rapid means of transferring a known number of eggs into tissue culture, and subsequently determining percentage hatched.

Development and laboratory evaluation of a polymerase chain reaction for monitoring Schistosoma mansoni infestation of water.

A sensitive and specific detection of cercariae of human schistosomes is required for better definition of risk of infection. In the present study, we have developed a polymerase chain reaction (PCR) assay for the detection of cercariae of Schistosoma mansoni in water. A simple DNA preparation was adapted for this purpose, and PCR primers were designed based on the 121-basepair highly repeated sequence we previously identified in the genome of S. mansoni. The PCR assay detected as little as 10(-6) ng of S. mansoni DNA, and the high sensitivity enabled the detection of a single cercaria. For trapping of cercariae we adapted a filtration apparatus previously used for separating schistosome eggs from turbid enzymatic digests of tissues. A single cercaria could be detected in repeated tests of water filtrates. Since the target DNA is tandemly arranged, a ladder pattern of the PCR products was demonstrated. A direct relationship was demonstrated between the number of ladder bands of the amplification products, and DNA concentration or number of cercariae. The feasibility of semiquantitation of schistosome larvae in natural water was thus suggested. The potential of the procedures described here for epidemiologic studies is discussed.

98/01620 Filtration apparatus for removing residual ozone from treated wastewaters: Motohashi, H. and Yoshimoto, S. Jpn. Kokai Tokkyo Koho JP 08,173,957 [96,173,957] (Cl. C02F1/28), 9 Jul 1996, Appl. 94/334,659, 20 Dec 1994, 5 pp. (in Japanese)

98/01620 Filtration apparatus for removing residual ozone from treated wastewaters: Motohashi, H. and Yoshimoto, S. Jpn. Kokai Tokkyo Koho JP 08,173,957 [96,173,957] (Cl. C02F1/28), 9 Jul 1996, Appl. 94/334,659, 20 Dec 1994, 5 pp. (in Japanese)

INVESTIGATION OF ASPHALTENE PRECIPITATION AT ELEVATED TEMPERATURE

ABSTRACT In order to obtain quantitative data on the asphaltene precipitation induced by the addition of n-alkane (heptane) at temperatures above the normal boiling point of the precipitant, a high temperature/ high pressure filtration apparatus has been constructed. Oil and alkane are mixed at the appropriate temperature and the pressure in closed vessels keeping the mixture at the liquid state. The filtration is performed with a small differential pressure over the filter so as to avoid flashing the mixture. The technique requires a low dead volume in the system to minimize the content of maltenes in the extracted fraction, hence there is no room for stirring. The equipment as well as solutions to some of the problems are presented along with precipitation data from 40 to 200° C The asphaltenes separated are analyzed using FT-ir. The filtrate containing the maltenes was cooled to room temperature and the asphaltenes separating upon cooling was collected and analyzed. The oil and selected maltene fractions and extraction/ cleaning solvents were analyzed using GC

A new approach to variable pressure cake filtration

The widespread reliance on heuristics for the design and specification of particle/fluid separation devices has prompted a new, mechatronic based approach to dead-end pressure filtration. A computer driven experimental apparatus was used to facilitate proportionally controlled filtrations over a range of pressure/flow regimes whilst maintaining inherent suspension properties. Preliminary results from constant flow experiments using distilled water and aqueous suspensions of calcite are presented where the air pressure within the filter is controlled through a combination of flow and pressure transducers and an electronically adjusted pressure regulator. The effects of controller type, controller gain, sampling time and set point flow on system response are shown to illustrate what can be achieved using mechatronics. Predictions of constant flow filtration experiments are made using data from constant pressure tests and reasonably good agreement is achieved. A simulation, based on classical filtration and control theories, is also presented and shown to compare well with the filtrate flow responses observed from the filtration apparatus.

Morphogenesis of the glomerular filter: the synchronous assembly and maturation of two distinct extracellular matrices.

The morphogenesis of the glomerular filtration apparatus during pre- and postnatal development in the rodent involves the coordinated assembly of two closely apposed but morphologically different extracellular matrices, the glomerular capillary basement membrane and the mesangial matrix. The cellular origin of these matrices is known to be distinct and complex; however, the mechanisms by which these matrices are assembled during morphogenesis are not entirely understood. It has been shown that in the earliest stages of glomerular morphogenesis the nascent glomerular basement membrane exists as a four-layered structure, the product of both the visceral epithelium and capillary endothelium. During the latter stages of glomerular development, the quadrilaminar structure becomes a trilaminar basement membrane, the event thought to occur by fusion of closely apposed basement membrane layers. In subsequent stages of maturation and throughout the life of the animal, the visceral epithelial cells, which line the periphery of the glomerular capillary, are the primary source of newly synthesized basement membrane material. The mesangial matrix, which lacks the specific organization of a basement membrane, first occurs in the developing glomerulus as a diffuse matrix central to the developing glomerular capillaries. During glomerular maturation the mesangial matrix undergoes a compaction/arborization coincident with the ramification of the vascular histoarchitecture of the glomerular tuft. Recent advances in the cell biology of basement membrane now demonstrate that there is a divergence in isoforms of the molecules that comprise the glomerular capillary basement membrane and mesangial matrices during development, possibly coincidental with functional specialization during the process of glomerular maturation.

97/03372 Sintered metal filtration apparatus for treatment of high-temperature waste gases

97/03372 Sintered metal filtration apparatus for treatment of high-temperature waste gases

DIRECT ENUMERATION OF BACTERIA FROM MACROALGAE BY EPIFLUORESCENCE MICROSCOPY AS APPLIED TO THE FLESHY RED ALGAE KAPPAPHYCUS ALVAREZII AND GRACILARIA SPP. (RHODOPHYTA)1

ABSTRACTThis report describes a simplified method for direct counting of total bacteria associated with the fleshy red algae Kappaphycus alvarezii (Doty) Doty and Gracilaria spp. A Nuclepore® polycarbonate membrane (0.2–μm pore size) fitted to a vacuum filtration apparatus was used to filter algal tissue homogenate after serial dilution and staining with the fluorochrome 4′,6‐diamidino‐2‐phenylindole. Using epifluorescence microscopy, it is possible to count bacteria without preseparating them from the algae. The technique requires homogenized algal tissue diluted with 0.2‐μm‐filtered, autoclaved seawater to a level appropriate for counting. Dilution reduces the amount of autofluorescent algal debris, which may interfere with Counting. The membrane filtration method yielded a bacterial count two orders of magnitude higher than that of the conventional agarspread plate technique. This method offers a more accurate approach to counting the total number of bacteria on macroalgae.

Direct extraction of catalytic proteins from natural microbial communities

A method was developed for rapid investigation of enzymes in natural microbial communities without isolation or cultivation of individual species. Conservative extraction of total proteins present in cells concentrated from up to 1 l of freshwater or wastewater sludge samples was performed by sonication and centrifugation. The protein extracts were immobilized on 0.2 μm pore size nitrocellulose membranes using a vacuum-driven compartmentalized filtration apparatus. Reaction-dependent colorimetric staining of the membranes allowed the detection of enzymatic activities attributable to acid phosphatase, catechol oxidase, cellulase, nitrate reductase, peroxidase, and xanthine dehydrogenase in protein extracts from the wastewater sludge samples. Only catechol oxidase, nitrate reductase, peroxidase, and xanthine dehydrogenase activities were detected in protein extracts from the freshwater samples. Control experiments with Pseudomonas putida indicated a detection limit of enzyme activity of 10 3 cells or 3.3 ng of total protein. The method described precludes the detection of allozyme or isozyme multiplicity, but it facilitates rapid screening of several different enzymes and could be adapted for quantitative assessment of spatial and temporal distribution of enzymes in many heterogenous aquatic microbial communities.

Assessment of melt cleanliness in A356.2 aluminium casting alloy using the porous disc filtration apparatus technique: Part I Inclusion measurements

The present work was undertaken to study the role of the major operating parameters commonly applied in aluminium foundries, as well as the effect of minor alloying elements on inclusion formation in one of the most widely used Al–Si alloys, i.e., A356.2 primary alloy, using the porous disc filtration apparatus (PoDFA) technique. A set of 23 experiments was conducted (each using a melt of 25 kg of fresh alloy material). In each case, four to six successive PoDFA trials were executed. PoDFA samples containing the unfiltered part of the metal (about 5 mm in thickness) in contact with the PoDFA filter were polished for metallographic examination. Inclusion classification and counting were done using the grid method. The present work summarizes the types and concentrations of non-metallic inclusions as well as aluminium oxide films that can occur in this alloy prior to casting.

Novel Protonephridial Filtration Apparatus in Cylindrostoma fingalianum, Allostoma sp. and Pseudostomum quadrioculatum (Platyhelminthes: Prolecithophora)

The diverse types of protonephridial filtration apparatus in the Platyhelminthes provide valuable characters for phylogenetic resolution, yet only one species from the order Prolecithophora has previously been studied. We examined three further species, two belonging to the family Cylindrostomidae and one from the Pseudostomidae, and found a novel arrangement consisting of scattered, short filtration slits in the cytoplasmic cylinder of the terminal cell surrounding the flame of cilia. In these species there are no regular, longitudinal ‘ribs’, such as are found in many other platyhelminth taxa, nor bundles of supporting microtubules in the cylinder wall, and cilia arise at various levels throughout the long terminal cell column rather than in a group at the base of the flame, as is found in most other taxa. The perikaryon lies adjacent to the flame, the wall surrounding the lumen is strengthened by long, cross-striated ciliary rootlets, and the terminal cell is joined to the proximal canal by a septate junction. This simple type of filtration structure bears some resemblance to that found in Tricladida, but is distinctly different from that described in another prolecithophoran, Archimonotresis limophila (Protomonotresidae). This suggests that there may be a fundamental division within the Prolecithophora with regard to protonephridial filtration structures.

Extracellular nucleotides as signalling molecules for renal mesangial cells.

1. Glomerular diseases frequently cause chronic renal failure which ultimately requires dialysis and kidney transplantation. The events leading to destruction of the glomerular filtration apparatus include injury of glomerular cells, aggregation of thrombocytes and infiltration of immune cells into the glomerulus. 2. Nucleotides (e.g. ATP and UTP) are present in all glomerular cell types as well as in thrombocytes. The release of nucleotides into the extracellular space occurs after damage of glomerular cells and aggregation of thrombocytes. Several in vitro and in vivo findings indicate that extracellular nucleotides may play a role as pro-inflammatory mediators in glomerulonephritis. 3. A hallmark finding in kidney biopsies from patients with glomerulonephritis is proliferation of glomerular mesangial cells. Cell culture studies demonstrated that extracellular ATP (10-300 microM) stimulated growth of mesangial cells. The mitogenic effect of ATP was potentiated in the presence of multiple growth factors. 4. Nucleotide-induced signalling in mesangial cells included an increase of intracellular calcium, activation of phosphatidylinositol-specific phospholipase C and phospholipase D, inhibition of adenylylcyclase, stimulation of mitogen-activated protein kinase and increased expression of the immediate early genes, c-fos, c-jun and Egr-1. 5. In previous studies of experimental mesangioproliferative glomerulonephritis, exogenously given ADP beta S and ATP gamma S have been shown to aggravate the course of the disease, while 2-chloroadenosine had beneficial effects. 6. Taken together, these findings support the concept that nucleotides may function as proinflammatory mediators in glomerulonephritis while adenosine may have antiinflammatory effects.

Effects of colloidal stability on clarification and dewatering of activated sludge

The effect of colloidal stability upon activated sludge properties for clarification and dewatering by filtration was investigated through controlled chemical manipulations of sludge in laboratory scale. The manipulations resulted in changes of the surface charge density and the shear sensitivity, the latter indicating a weakening of the sludge floc structure. The shear sensitivity was found to correlate with the residual turbidity after settling as well as with sludge filterability characteristics. The data strongly suggest the importance of blinding to increase with increasing shear sensitivity. The amount of fine particles present in the sludge was found to increase when sludge was exposed to a shear of similar magnitude to the shear in the employed filtration apparatus, indicating erosion of flocs during filtration to be important for blinding. Qualitatively similar results were obtained in full scale investigations of sludge from a treatment plant with varying inlet wastewater composition, indicating the possible importance of colloidal stability for solid/liquid separation processes in full scale wastewater treatment.

5421846 Air filtration apparatus for the control of industrial air pollution: Klimczak William J Charlotte, NC, United States Assigned to Dustex Corporation

5421846 Air filtration apparatus for the control of industrial air pollution: Klimczak William J Charlotte, NC, United States Assigned to Dustex Corporation