Turbidity diameter

Equation (li ) can be used to calculate uncorrected diameter averages. For the number, surface, volume, specific surface, weight and turbidity diameter averages (their definitions have been stated elsewhere (11,12), the following relations can be derived ... 

In this context it is the separation of solids from water by forcing the water through a porous filter media. The objective is typically to reduce the level of TDS in the water and often to reduce both the size of the particle remaining and the turbidity of the water. Filtration efficiency and quality is a function of many variable factors, although filtration is usually carried out at relatively low velocities, where velocity and pressure drop are directly related to each other. Typically a sand filter will remove a high percentage of particles above a diameter of 20 to 30 pm, whereas dual or multimedia filtration is required to remove particles down to a diameter of 10 to 20... 

Particle separation can be characterized by the separation factor, Rp, which is the ratio of eluant to particle elution volumes, or, by the difference in elution voliame, AV, between particle and eluant marker turbidity peaks. For polystyrene monodisperse standards, a linear relationship occ irs between the log of the particle diameter and AV, with a series of parallel lines resulting for different concentration of either salt or surfactant below its critical micelle concentration (IT>18,19) The separation factor has also been shown to be independent of eluant... 

Almost all fiber and partial titanium dioxide can be recovered from white water by DAF under full flow pressurization mode43 with chemical addition. On June 10, 1982, at Mead Corporation, pulp was prepared with 40% cotton fiber and 60% wood fiber. The loading of titanium dioxide was about 50% (i.e., 273 kg Ti02 per 600 kg total pulp). The white water from No. 2 machine was fed to a DAF cell (diameter = 3 m) at 15.8 L/s (250gal/min) under full flow pressurization mode. Turkey red oil (TRO) was dosed as a flotation aid at 80mL/min. The influent white water (before TRO addition), DAF effluent, and floated scum were sampled for analysis. The DAF influent had 98 mg/L of TSS, and 650 NTU of turbidity at pH 9.27. The DAF effluent had 15 mg/L TSS and 550 NTU of turbidity at pH 9.25. Although TSS (fiber and titanium dioxide) recovery rate was 85%, the ash content (titanium dioxide) of the recovered TSS was very low. Therefore, using a DAF clarifier under full flow pressurization mode and TREO, the majority of fibers in white water but only about half of titanium dioxide can be recovered. 

Fig. 6.7 Change in turbidity of hydrogels after 1 cycle and 12 cycles ofthe alternate soaking process. Round-shaped hydrogels were used (diameter 10 mm, thickness 1 mm).

Hence c(g/ml) is the concentration of colloidal suspension G90 is the reading on the LS photometer at 6 = 90°, 2 is the path length, which equals the cell diameter when using a cylindrical cell t is the turbidity obtained from measurements of optical density. Table 4 gives the results of calibrating a Sofica instrument with colloidal... 

In cases where water is turbid, samples are generally filtered through glass fiber Alters (GEE) prior to percolation through sorbents. This step recovers waterborne particulates and microorganisms with average diameters >0.7 pm, which are analyzed separately. However, chemicals associated with colloid-sized particulates and DOC are not removed by GFFs. 

The fractions coilected are each run dropwise into 100 ml of stirred methanol to which two drops of concentrated hydrochloric acid have been added.Turbidity or precipitation will be observed from about the 6th fraction to about the 20th fraction.The precipitated fractions are filtered off, washed with methanol and dried to constant weight in vacuum at 20 °C. For each fraction the viscosity is measured in water at 25 °C using a capillary viscometer (capillary diameter 0.35 mm) and at as high a concentration as possible (10 g/l) in order to minimize errors.The limiting viscosity number, and hence the molecular weight, is estimated (see Sect. 2.3.3.3.1). Adjacent fractions for which there may be insufficient material for a viscosity measurement,can be combined where necessary. 

Sulphates. — Dissolve 3 gm. of sodium hydroxide in 50 cc. of water, acidulate with 15 cc. of hydrochloric acid, heat to boiling, and add barium chloride solution. The liquid should not have more than a slight turbidity and it should still be transparent when observed in a test-tube of 2 cm. diameter. 

Examination is made of a drop of the deposit obtained when the wine is either allowed to stand or centrifuged or, with very turbid wine, a drop of the latter itself may be examined. A magnification of 500 diameters is first used, but detection of the smallest bacteria requires about 1000 diameters. 

Microemulsions are emulsions with droplet diameters in the range of about 0.01 to 0.1 fim. They are, consequently, of low turbidity. 

Figure 4. Expansion curve of carboxylic Latex 42BRD47 as determined by the sedimentation method. The estimate of particle diameter by turbidity was 0.43 pm.

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