Influence of particle size and surface charge on critical flux of crossflow microfiltration

1998 ◽  
Vol 38 (4-5) ◽  
pp. 481-488 ◽  
Author(s):  
D. Y. Kwon ◽  
S. Vigneswaran
Keyword(s):  
Particle Size ◽  
Ionic Strength ◽  
Membrane Surface ◽  
Transmembrane Pressure ◽  
Dense Layer ◽  
Critical Flux ◽  
Large Particles ◽  
Effect Of Particle Size ◽  
Definition Of ◽  
Crossflow Microfiltration

The effect of particle size and ionic strength of the feed suspension on critical flux was studied. The critical flux was defined in two different ways (strong and mild definition). The fouling, the increase of resistance (which is the basis of the mild definition of the critical flux) was relatively sensitive to the deposition of particles of 0.46 μm on the membrane of 0.2 μm mean pore. On the other hand, the deposition of large particles of 3.2 μm to a certain value on the membrane surface of 0.2 μm mean pore did not lead to the increase in resistance. In case of 11.9 μm particles, the transmembrane pressure did not increase even with significant amount of deposition of particles. The ionic strength of suspension had significant effect on the critical flux. For an ionic strength less than 1×10−1.5 M, there was a decrease in the critical flux. This could be due to the dense layer of deposit which is the result of less diffuse layer thickness of particles. Above this ionic strength, a significant increase in critical flux was noticed which may be due to the aggregation of particles.

Influence of particle size and operating parameters on virus ultrafiltration efficiency

2011 ◽  
Vol 11 (1) ◽  
pp. 31-38
Author(s):  
Angayar K. Pavanasam ◽  
Ali Abbas ◽  
Vicki Chen
Keyword(s):  
Particle Size ◽  
Filtration Efficiency ◽  
Transmembrane Pressure ◽  
Operating Parameters ◽  
Particle Removal ◽  
Major Step ◽  
Virus Removal ◽  
Virus Particles ◽  
Key Factor ◽  
Effect Of Particle Size

In water treatment, virus removal using ultrafiltration is a major step towards better water quality. In this paper, we study virus filtration efficiency using surrogate virus particles and via statistical surface-response approach. We focus on the effect of particle size (20–100 nm range) as a key factor along with the effects of transmembrane pressure (20–60 kPa range) and feed flowrate (0.3–1.0 L/F;min range) on the filtration virus removal efficiency (LRV). The particle size is shown to impart a great deal of influence on surrogate particle removal. The effect of particle-to-pore-size ratio is reported for comparison of membrane molecular weight cut off (MWCO) performance. It was shown experimentally and through the developed empirical regression model that transmembrane pressure plays a major role in controlling the filtration efficiency along with flowrate. In the studied experimental range, higher LRV values are obtained at lower transmembrane pressure (20 kPa) and at higher feed flowrate (1 L/F;min). Further the effect on LRV of the interaction between transmembrane pressure and particle size seems to be more significant than that of the interaction of flowrate with particle size.

Improvement of microfiltration performance in water treatment: is critical flux a viable solution?

2000 ◽  
Vol 41 (10-11) ◽  
pp. 309-315 ◽  
Author(s):  
S. Vigneswaran ◽  
D.Y. Kwon ◽  
H.H. Ngo ◽  
J.Y. Hu
Keyword(s):  
Membrane Fouling ◽  
Particle Deposition ◽  
Material Balance ◽  
Transmembrane Pressure ◽  
Operational Mode ◽  
Permeate Flux ◽  
Critical Flux ◽  
Viable Solution ◽  
Crossflow Microfiltration

In this study, three definitions for critical flux were introduced based on the crossflow microfiltration (CFMF) experiments conducted under an operational mode of constant permeate flux. The critical flux based on material balance was calculated from the rate of particles deposition. The highest permeate flux results in no particle deposition being taken at the critical flux. The second definition was based on the increase in transmembrane pressure (TMP). The critical flux based on the TMP increase is the flux below which the membrane fouling does not occur. The third definition was based on the direct observation of particles deposition through microscope. Detailed experiments were conducted with synthetic suspension of different sizes of latex particles. Long term experiments conducted with polydispersed kaolin clay suspension indicated that the critical flux based on material balance concept is more realistic in field conditions.

APPARENT FEED PARTICLE SIZE PREFERENCE BY BROILERS

1988 ◽  
Vol 68 (3) ◽  
pp. 923-930 ◽  
Author(s):  
F. J. PORTELLA ◽  
L. J. CASTON ◽  
S. LEESON
Keyword(s):  
Particle Size ◽  
Chemical Analysis ◽  
Key Words ◽  
Feed Intake ◽  
Feed Consumption ◽  
Broiler Chicks ◽  
Disappearance Rate ◽  
Large Particles ◽  
Effect Of Particle Size ◽  
Size Preference

Broiler chicks of different ages were used to study particle size disappearance and the effect of particle size on feed intake. The disappearance of particles larger than 1.18 mm was obvious at all ages. However, it was noticed that at 8 and 16 d disappearance of particles between > 1.18 mm and < 2.36 mm was most pronounced. As birds became older, disappearance rate was greatest for particles > 2.36 mm. Throughout a 24-h period, particle breakdown was noted. Birds did eat these smaller particles at the end of a 24-h period, especially when the concentration of large particles was reduced. Chemical analysis revealed that birds selected material on the basis of particle size, since nutrient composition of the diet and of different diet fractions did not change throughout the day. Changing particle size abruptly from crumbles to pellets did not adversely affect overall feed consumption (P > 0.05) or bird performance. Key words: Broiler, particle size preference, crumbles, pellets

The effect of particle size of superphosphate on the availability of its phosphorus and sulphur to pasture plants

1969 ◽  
Vol 20 (2) ◽  
pp. 265 ◽  
Author(s):  
CH Williams ◽  
J Lipsett
Keyword(s):  
Particle Size ◽  
Spatial Distribution ◽  
High Capacity ◽  
Subterranean Clover ◽  
Plant Response ◽  
Affected Plant ◽  
Large Particles ◽  
Effect Of Particle Size ◽  
Pasture Plants

In glasshouse experiments, the responses of plants to the phosphorus and sulphur in top-dressed superphosphate were affected by its particle size. On four soils, yields of subterranean clover differed by 12–25% owing to differences in particle size of applied superphosphate. Both rate of solution and spatial distribution of the fertilizer affected plant response. Under non-leaching conditions, the sulphur in large particles of superphosphate was always less available than that in fine. The phosphorus in large particles was slightly less available when superphosphate was applied to soils of low, or moderate, capacities to sorb phosphate but more available when applied to a soil of high capacity to sorb phosphate.Pastures would probably respond better to granulated superphosphate than to normal on sulphur-deficient soils subject to strong leaching, or on soils of high capacity to sorb phosphate. On many soils, however, no difference would be expected, and on some sulphur-deficient soils the granulated product may even be inferior in some seasons.

Inkjet printable silver dispersions: Effect of bimodal particle-size distribution on film formation and electrical conductivity

2010 ◽  
Vol 25 (5) ◽  
pp. 821-827 ◽  
Author(s):  
Krishna Balantrapu ◽  
Meaghan McMurran ◽  
Dan V. Goia
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Size Distribution ◽  
Film Formation ◽  
Small Particles ◽  
Silver Films ◽  
On Demand ◽  
Drop On Demand ◽  
Large Particles ◽  
Effect Of Particle Size

Inks containing silver nanoparticles of 12 nm, 80 nm, and a 15%/85% mixture of the two sizes were used to evaluate the effect of particle size and size distribution on the electrical properties of sintered films. The silver layers deposited with a “drop-on-demand” inkjet printer were heated at temperatures ranging from 125 to 200 °C. The small particles formed less resistive films at 125 °C, while the larger ones provided better electrical conductivity above 150 °C. The inks containing mixed small and large particles yielded the most conductive silver films over the entire investigated temperature range. A mechanism explaining these results is proposed based on the evolution of film microstructure with temperature.

Effect of Recycled Particle Size to Micro-Hardness Properties of Styrene Acrylonitrile

2016 ◽  
Vol 368 ◽  
pp. 154-157 ◽  
Author(s):  
Vojtech Šenkeřík ◽  
Michal Stanek ◽  
David Manas ◽  
Miroslav Maňas ◽  
Adam Škrobák ◽  
...  
Keyword(s):  
Particle Size ◽  
Ambient Temperature ◽  
Research Paper ◽  
Dust Particles ◽  
Original Material ◽  
Micro Hardness ◽  
Large Particles ◽  
Effect Of Particle Size ◽  
Styrene Acrylonitrile ◽  
Recycled Material

The aim of this research paper is to study the effect of particle size of recycled material on the micro harness. Valuation of recycled material effect takes place in several mixtures of materials. These mixtures differ in particle size, which are made during grinding of plastic waste, from large particles similar to the original material to dust particles. The recycled material is always the same as is the original material. Tested material is styrene acrylonitrile SAN. Testing is performed at ambient temperature of 23°C. After the first recycling there is a change of hardness; which decrease mostly in mixture with the smallest particles.

Effects of particle size distribution on the cake formation in crossflow microfiltration

2002 ◽  
Vol 2 (2) ◽  
pp. 305-311 ◽  
Author(s):  
S. Kim ◽  
S.-H. Cho ◽  
H. Park
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Particle Deposition ◽  
Membrane Surface ◽  
Particle Diameter ◽  
Feed Concentration ◽  
Cake Formation ◽  
Effective Particle ◽  
Monodisperse Suspensions ◽  
Crossflow Microfiltration

In crossflow microfiltration, the tendency of particle deposition of polydisperse suspensions has been established experimentally and compared with that of monodisperse suspensions. The mass transfers of particles are different according to size in polydisperse suspensions. The most particles, which deposit to membrane surface without clogging pore in microfiltration, are much larger than 0.1 μm. Among these particles, smaller particles are easier to deposit than larger particles because of shear-induced diffusion and particle deposition depends on the size distribution of small particles. Effective particle diameter is introduced as a representative particle size which can reflect the diffusivity of each particle according to size and it describes the tendency of particle deposition very well in polydisperse suspensions. The effect of effective particle diameter is larger than that of feed concentration. The most important factor affecting particle deposition of polydisperse suspensions is effective particle diameter. The results of our research suggest that the effective particle diameter can be an important factor which can represent the potential for cake formation.

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