Effect Of Filtration Rate Research Articles

Start-up of biofilter for nitrification and effect of filtration rate on the ammonium removal efficiency in drinking water treatment on pilot plant

ABSTRACT Biological filtration is a process that can be used for ammonium removal from water. The removal of ammonium is based on the nitrification process. Nitrification depends on many factors, such as water quality and filtration process parameters. To investigate the influence of filtration rate on the nitrification efficiency, nitrifying biofilters were formed at the pilot plant in the industry for drinking water production from surface water. The new biological filters were started under optimal conditions for biofilm formation. After the biofilm formation, the influence of the filtration rate on nitrification was examined over 3 months (from November to January). The time required for the spontaneous growth of nitrifying bacteria on the new filters was around 70 days. The operating conditions at the start-up period were the continuous flow of water containing γ(NH4+) ≈ 1mg/L, dissolved oxygen in a concentration >9 mg/L, filtration rate <1 m/h, inlet water temperature >12 °C and pH from 7.8 to 8. After the complete formation of the nitrifying biofilm, the percentage of NH4+ removal was greater than 95% for all tested filtration rates, from 0.5 to 8.4 m/h, at γ(NH4+) from 1 to 2.5 mg/L and raw water temperature from 13 to 7°C.

Effect of filtration rate on coal-sand dual-media filter performances for microalgae removal

ABSTRACTThis study tested the efficiency of granular filtration using a bilayer sand filter for microalgae removal from culture dilutions ranging from 10,000 to 17,000 cells/mL. The objective is to evaluate the removal capacity of the filter without chemical coagulation. Two filter media, sand and anthracite, with mean grain sizes of 0.395 and 1.2 mm, respectively, were used in constant-flow-rate experiments (down-flow mode) with suspensions containing Heterocapsa triquetra microalga. The conventional rapid filtration which usually operates at a constant rate of approximately 5 m3/m2 h is compared to high-rate filtration. Two filtration velocities (5 and 10 m/h) were investigated with bed depth of 1100 mm. Average microalgal cell removal rates were 90% at 5 m/h and 68% at 10 m/h. Turbidity removal was more than 71% at 5 m/h but just 57% at 10 m/h. Head losses did not increase significantly, and values measured at process end were 32 mbar at 5 m/h and 78 mbar at 10 m/h. Retention probabilities were calculated from experimental data. A theoretical model was used to evaluate the contributions of the different drivers of microalgae removal. Hypotheses are developed on the understanding of change in the mechanisms of retention as a function of filtration velocity.

합성섬유 여재를 충진한 고속여과장치에 의한 탁수처리에 관한 연구

Abstract Laboratory study was undertaken to pursue the filter performance of a micro-filter module employing highly porous fiber media under a high filtration rate (over 1,500 m/day), faster than that of any conventional filter process. The effects of filtration rate, head loss, raw water turbidity, and filter aid chemicals on filter performance were analyzed. In spite of the extremely high filtration rate, the filter achieved an attractive efficiency, reducing the raw water turbidity by over 80%. As with other filter systems, the filter aid used (PAC in this study) greatly affected the performance of this particular fiber filter. Long term repetitive runs were additionally carried out to confirm the reproducibility of the filter performance. Finally, a comparison was carried out with other high rate filter systems which are either being tested for use in experimental studies, or are already commercially available. Key words : Fiber media, High filtration rate, Micro-filter, Turbid water

Effect of pore morphology on fluid flow and particle deposition on a track-etched polycarbonate membrane

Three-dimensional particles deposition on a filter pore of a track-etched polycarbonate membrane was studied numerically by analyzing forces acting on the depositing particles. The simulation was applied to examine how the morphology of the filter pore affects the deposition of particles on a membrane pore at the initial stage of filtration. The model of membrane structure is a 3D porous surface with circular holes of finite thickness. Both of the effects of constriction and expansion of inner pore geometries on fluid flow and particle deposition are taken into consideration in numerical calculation, and are compared with that of capillary pore. The disturbance of flow field and particle trajectory due to the presence of particles was taken into consideration during each simulation. Simulated results show that the effect of filtration rate, i.e., operating pressure, has a significant influence on the packing morphology of particles on a filter pore.

Filtrate turbidity improvement of existing mono-media filters based on a pilot plant study

With the advancement of knowledge in drinking water and health impacts related to it, requirements for drinking water have progressively become more stringent. Removal of particulate matter causing turbidity has also been found to be an effective means for removal of microbial contaminants such as Giardia. The conventional treatment process most effective at removal of small particulates is filtration. Presented is a two-phase pilot-scale study used to select new filter media for the Rossdale Water Treatment Plant in Edmonton, Alberta. The study was necessitated by more stringent turbidity guidelines which existing filters would have difficulty achieving. The design and planning of the study had to consider constraints posed by upgrading of an existing filter facility which dictated the media depth and the allowable bed expansion during backwashing. Phase I involved a screening test of four types of media. Based on the phase I results, a crushed quartz and a dual-media consisting of anthracite and sand were selected for more detailed study in the second phase involving investigation of the effects of filtration rate (3.5–12.5 m/h). Filter performance was analyzed using different statistical methods. Factorial experimental concepts were used to study significant effects. Results from both phases indicated that crushed quartz consistently provided the best effluent quality, while the dual-media provided longer filter runs. Key words: water treatment, constant rate filtration, turbidity standards, filter media, crushed quartz, statistical analysis.

Effect of Bentonitic Fluid Properties On Drilling Rate

Laboratory studies were conducted on kinematic viscosity, filtration rate, pressure gradient and permeability reduction beneath the bit, and the pressure gradient and permeability reduction beneath the bit, and the effects of solids concentration and of the formation's sensitivity to water. A major conclusion is that simply knowing one physical property of a fluid does not adequately account for the effect of that fluid on drilling rate. Introduction The question of which drilling fluid property controls drilling rate has often been asked, and conclusions have been derived from field and laboratory data. However, the conclusions are not all in agreement Young and Gray established a relationship between drilling rate and pressure gradient beneath the bit. They found that pressure gradients varied with the type of formation, the orientation of the bedding plane, the type of mud, and the difference between plane, the type of mud, and the difference between the mud-column pressure and the pressure within the core. Pressure gradients were greater in high-permeability rocks than in low-permeability rocks and were found to increase as the API fluid loss of the mud decreased. Several articles have been written concerning the effect of filtration rate on drilling rate. Eckel indicated that a viscosity relationship must also be considered in correlating drilling rate and filtration rate. Battelle Memorial Institute reported that low-fluid-loss muds decrease drilling rate because of the high viscosity of the muds and not because of fluid-loss properties. Homer et al. used microbit experiments properties. Homer et al. used microbit experiments to study filtration during drilling. No reliable correlation was established between dynamic filtration and rheological properties or API fluid loss. Cunningham and Goins have reported that drilling rates in shales were reduced as API fluid loss was reduced with the use of starch. The reduction in drilling rate appeared to be caused by the starch and not by the fluid-loss property. Young reported that in his microbit tests a property. Young reported that in his microbit tests a lowered API fluid loss reduced penetration rate in all rocks that were used at all borehole pressures and that these reductions were a result of higher pressure gradients for the low-fluid-loss mud. It is interesting to note that starch and lignosulfonate were used only in the low-fluid-loss mud. Myers and Gray reported that during bit-tooth impact tests, the lowering of API fluid loss from that of salt water to 3 cc for a mud significantly reduced the crater volume, and that if these laboratory results can be equated to results of field drilling, a similar reduction of drilling rate would be expected from lowering the fluid loss of the mud. Eckel reported that drilling rate in a given system with constant circulating rate and nozzle velocity is a function of the kinematic viscosity of the drilling fluid measured at near bit-nozzle shear rates, and that for the same kinematic viscosity, drilling rate is independent of solids content. Data available on the effect of solids on penetration rate are for weighted drilling fluids. Generally, an increase in density or solids in weighted systems results in a decrease in drilling rate. Lawhon et al. show that for best drilling rate results, type as well as concentration of clays or polymers should be considered. Their data also show that under certain laboratory conditions some types of clays or polymers can give drilling rates greater than those obtained with water. JPT P. 657

Effects of filtration rate and plasma sodium concentration on proximal sodium transport

ARTICLESEffects of filtration rate and plasma sodium concentration on proximal sodium transportJB Puschett, S Goldstein, S Godshall, BB Staum, and M GoldbergJB Puschett, S Goldstein, S Godshall, BB Staum, and M GoldbergPublished Online:01 Sep 1971https://doi.org/10.1152/ajplegacy.1971.221.3.788MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation More from this issue > Volume 221Issue 3September 1971Pages 788-794 Copyright & PermissionsCopyright © 1971 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1971.221.3.788PubMed5570335History Published online 1 September 1971 Published in print 1 September 1971 Metrics

Effect of Filtration Rate on Filtrate Quality

In the filtration of water through a granular medium, the effective utilization of the total depth of the medium is sought. Increased grain size and increased filtration rates are two current approaches for inducing deeper penetration of suspended solids into the bed. The purpose of this investigation was to examine, on a plant scale, the effects of filtration rate, influent water quality, and filter media sizes and porosity on filtrate quality. Both sand filters and anthracite filters were examined, and the differences in the performance of both media are attributable to differences in grain size and porosity of the two materials, rather than the materials themselves. The effects of filtration rate and influent turbidity on filtrate quality were also a function of media grain size and porosity. Another problem with the coarser medium was the poor effluent quality at all rates during the initial operating period after backwashing. The results of these experiments indicate that the conventional rate of 2 gpm/sq ft is not necessarily the correct rate.