Data for filtration

It is known that the specific resistance for centrifuge cake, especially for compressible cake, is greater than that of the pressure or vacuum filter. Therefore, the specific resistance has to be measured from centrifuge tests for different cake thicknesses so as to scale up accurately for centrifuge performance. It cannot be extrapolated from pressure and vacuum filtration data. For cake thickness that is much smaller compared to the basket radius, Eq. (18-116 7) can be approximated by... 

Filtration Constants for Constant-Pressure Filtration. Data for constant- ... 

Filtration is employed when the suspended soUds concentration is less than 100 mg/L and high effluent clarity is required. Finely dispersed suspended soUds require the addition of a coagulant prior to filtration. Filters most commonly used in wastewater treatment are a dual media (anthrafUt and sand) or a moving bed or continuous-backwash sand filter. Performance data for the tertiary filtration of municipal and industrial wastewater are shown in Table 10. 

The correlations used are based partly on theoretical consideration and partly on empirical observations. The basic filtration data are correlated by application of the classic cake-filtration equation, aided by various simplifying assumptions which are sufficiently valid for many (but not all) situations. Washing and drying correlations are of a more empirical nature but with strong experimental justification. If steam or thermal diying is being examined, additional correlations are required beyond those summarized below for such applications, it is advisable to consult an eqmpment manufacturer or refer to pubhshed technical papers for guidance. 

FIGURE 2.4 Calibration curve of dextran on Sephacryi S-300 SF. Calibration curves were calculated from one chromatogram of a broad MWD reference sample using data for the molecular mass distribution as obtained by a calibrated gel filtration column ( , upper curve) and on-line MALLS ( ). The calibration curve was found useful for estimating the size of globular proteins. [Reproduced from Hagel et al. (1993), with permission.]... 

Unless otherwise indicated, all reactions were run under solid-liquid conditions in a nitrogen atmosphere and water was azeotropically removed during the course of the reaction. Initial product isolation was accomplished by rapid filtration of the reaction mixture through a silica gel column followed by concentration of the organic phase. Data for BTEAC liquid-liquid conditions and for TBAHS from ref 39. Benzyltrimethylammonium chloride,... 

Henry et al (23) have collected experimental data on cross-flow electro-filtration of Kaolin clay suspensions and oil-water emulsions. Since both the Kaolin particles and the oil droplets are negatively charged in aqueous suspensions, a direct electric field will always give higher filtration rates than cross-flow filtration alone. The level of improvement depends on the intensity of the fluid shear and the electric-field strength. Figures 47 and 48 present data for the Increase in flux with electric field strength for the oil-water emulsion and the clay suspension. 

Finally, radiochemical methods of analysis may be used to follow rates of detritiation. This method is particularly useful for very slow reactions (where it is impractical to collect data for any appreciable extent of reaction) as an initial rate approach may then be employed. Separation difficulties, at least for aqueous solutions, may be overcome by using the freeze-drying method or the more recent countercurrent dialysis and Sephadex gel filtration techniques. ... 

The inhibition of SuSy by the divalent cations (fCi 15 aM), Zn (fC 25 aM), and Ni (fti 37 aM) was exploited for further purification of SuSyl by immobilized metal affinity chromatography (IMAC). A subsequent gel filtration yielded homogeneous SuSyl suitable for crystallization experiments [24]. The protein chemical characterization revealed a homotetrameric organization of the 93 kDa subunit. Our kinetic data for the cleavage reaction and preliminary immunoblot analysis for phosphoserine suggested that SuSyl may be phosphorylated in the yeast expression system [28]. 

Fig. 20. Reduced viscosities for PS(OH)/PMMA in toluene as a function of the PS(OH)/PM-MA base ratio. The original concentrations of the individual polymers are 1.5 xlO" g/ml The dashed line shows the data for PS(OH)-24/PMMA, taken after filtrating the precipitation. The hydroxyl contents in PS(OH)-l, 3,5,8,10,18 and 24 are 1.0,2.8,4.4, 7.9,9.5,17.4 and 24.0, respectively [143]...

Kale, endive, carrots, lettuce, apples, potatoes, strawberries Extraction of crops with ethyl acetate and granular sodium sulfate, filtration, concentration with K-D. Sweep codistillation cleanup for GC. Florisil partition chromatography for polarographic confirmation. GC/KCI thermionic detector or GC/FPD polarographic confirmatory method No data for GC polarographic 0.2 ppm based on 1 g crop in 1 mL cell No data AOAC 1990... 

The following empirical dimensional equation [5], which is based on data for the UF of diluted blood plasma, can correlate the filtrate flux/p (cm min ) averaged over the hollow fiber of length/, (cm) ... 

GAC and Ozone-GAC. The Wilcoxon test was applied to compare results before and after GAC filtration. By using data for DCM or MeOH extracts, no interpretation of the variations observed and no statistical conclusions can be drawn. This situation is true for GAC treatment alone and for all combinations of dose, contact time, and GAC (Table III). 

Mutagenicity Patterns. Mutagenicity data for the GAC filtration and chlorination unit processes are summarized in Tables I and II, respectively. Removal of mutagenicity by GAC ranged from 71 to 92 for TA98 (avg = 83 ) and from 62 to 94 for TA100 (avg = 79 ) over the 6-week operational cycle. No temporal trend in mutagen removal... 

Data for some filter media are shown in Table 11.6. Although these porosities and permeabilities are of unused materials, the relative values may be useful for comparing behaviors under filtration conditions. Permeability Kp normally is the property... 

Literature data on the distribution of trace elements amongst the different size fractions in natural freshwaters are summarised in Table 8.1. There is a striking paucity of data for the environmentally important elements Cu, Pb and Cd. Elements which have a low affinity for complexing sites on NOM are present predominandy in the low molecular weight fraction, e.g. Cs, Sr, V while those which specifically coordinate to particular functional groups in NOM, e.g. Ag, Cd, tend to be present in the particulate and colloidal fractions. A major difficulty when trying to compare the literature data is that operational and variable size limits are used, and that filtration, which may lead to drastic artefacts, is still largely used for size fractionation. 

---