Recovery concentration factor

Continuous Operation This mode of operation is typical of paint recovery, whey processing, and wastewater processing where high solids and low fluxes require multiple passes, and continuous operation is allowed by the manufacturing process. For a feed concentration Cp, a volumetric concentration factor X (= retentate flow/feed flow), and retention R, the outlet retentate concentration is... 

Keywords Additional discharge streams Antisealants Chemical treatment Coagulation/flocculation Concentration factor Dechlorination Filtration High recovery Membrane cleaning Pretreatment Recovery rate... 

For example, a plant operating at a recovery ratio of 90% will have a concentration factor of 10 (i.e., the components in the feed solution are concentrated 10 times). 

Fig. 2.1 Increase in concentration factor and decrease in concentrate volume with increasing recovery rate. The shaded regions represent typical recovery ranges for typical seawater reverse osmosis (SWRO) and brackish water reverse osmosis (BWRO) processes...

The more water that is extracted, the smaller the volume of concentrate, but the greater the salinity of the brine. This trade off between concentration factor and recovery rate is shown in Fig. 2.1. As recovery approaches 100%, there is a sharp increase in the concentration factor, however the volume of the concentrate relative to the volume of feed, Qc/Qr is shown to decrease linearly. Figure 2.1 provides a useful comparison between the degree of concentration that may be achieved, and the volume of concentrate that must be managed. Higher recoveries are generally more desirable, as more water is recovered and less feed water is required to produce the same amount of water. 

Table 2.3 shows the calculated ion concentrations with a concentration factor of 3.33, and compares them with actual plant values. Note that there are significant differences between the calculated and actual ion concentrations for most species, however this is likely to be a result of the plant operating below the stated recovery rate of 70%. The differences in the concentration factors from the actual plant data (ranging from 0.79 for nitrate to 3.03 for sodium) are largely a result of the different precipitation points for each of the species in the water. 

Scale is caused by precipitation of dissolved metal salts in the feed water on the membrane surface. As salt-free water is removed in the permeate, the concentration of ions in the feed increases until at some point the solubility limit is exceeded. The salt then precipitates on the membrane surface as scale. The proclivity of a particular feed water to produce scale can be determined by performing an analysis of the feed water and calculating the expected concentration factor in the brine. The ratio of the product water flow rate to feed water flow rate is called the recovery rate, which is equivalent to the term stage-cut used in gas separation. 

The relationship between brine solution concentration factor and water recovery rate is shown in Figure 5.20. With plants that operate below a concentration factor of 2, that is, 50 % recovery rate, scaling is not normally a problem. However, many brackish water reverse osmosis plants operate at recovery rates of 80 or 90 %. Salt concentrations on the brine side of the membrane may then be far above the solubility limit. In order of importance, the salts that most commonly form scale are ... 

Figure 5.20 The effect of water recovery rate on the brine solution concentration factor...

Based on mass-transfer data for MBSE and MBSS of Phe in a HF contactor with a surface area of 1.4 m2 published in ref. [86] a simulation of the pilot plant for recovery of Phe was done [127]. Number of contactors needed for recovery of Phe was estimated for the unit with a feed flowrate of 100Lh 1, Phe concentration of 50 mol m 3 in the filtered broth, yield of Phe in MBSE 70%, Resell = 2.0, approach to the equilibrium at the raffinate end of contactor of 60%, and concentration factor of 10 were supposed. The estimated number of contactors of Liqui-Cel type 4" x 28" (Membrana, with an effective length of fibers of 0.6 m and surface area of fibers 19.2 m2) in series was 6 in MBSE and 5 in stripping. From simulations it followed that the number of contactors (length of fibers) in M B S E and M B S S is very sensitive to the... 

Higher recovery results in the need to dispose of less reject water. However, higher recovery also results in lower-purity permeate. Consider the example shown in Figure 3.1. At the influent end of the membrane, the influent concentration is 100 ppm, while the recovery is 0%, and the membrane passes 2% total dissolved solids (TDS) (see Chapter 3.3). The permeate right at this spot would be about 2 ppm. As the influent water passes across more and more membrane area, more water is recovered. At 50% recovery, the concentration factor is 2, so the influent water now has a concentration of about 200 ppm. The permeate water at this point would now have a concentration of 4 ppm. At 75% recovery, the concentration factor is 4, so the influent water now has a concentration of about 400 ppm. The permeate water at this point would have a concentration of 8 ppm. Hence, higher recovery results in lower product purity. 

In laboratory tests using simulated HLW solution spiked with fission product tracers, Am and Cm, the denitration step proved to be a sensitive process, but Am/Cm recoveries of ca. 90% in the aqueous supernate could be realized under optimized conditions. Decontamination factors (DF) > 1000 for Zr, Nb, Mo, and 100 for Ru and Fe were obtained in the precipitation step. The solvent extraction cycle gave > 98% recovery of Am/Cm and DF > 10 for rare earths, Sr and Cs. Appreciable decontamination was also obtained for Zr/Nb (DF = 20), Ru (50), U (650), Pu (250), Np (800) and Fe (420). The ion exchange cycle served mainly for Am-Cm concentration and for removal of DTPA and lactic acid based on tests with europium as a stand-in for trivalent actinides, concentration factors of about 50 could be expected under optimized conditions. 

DNA binding of transcription factors is present for concentrations of test chemicals that elicit mild and moderate scores of ocular irritancy via the Draize. The binding is greatly reduced or absent for concentrations producing a severe ocular irritancy score by the Draize. The lack of binding indicates loss of viability and poor recovery. Concentration of test chemical used may be varied to reach a non-binding outcome to reveal stages of stress and recovery or lack there of. 

After the completion of the procedure above described, the concentration factor was 200-fold, and alkali and alkaline earth elements, which often provide spectral interferences in furnace AAS, could be removed. The overall recoveries were examined by using seawater samples spiked with nsmCd, 64Cu and 65 Zn, and were 98.9 0.7% (n = 10) for Cd, 97.9 1.2% (n = 3) for Cu and 99.0 0.8% (n = 5) for Zn. The experimental results obtained by Bruland and Franks are shown in Figs. 1 and 4 and Table 3. 

Alternatively, calculate the mean calibration gradient from the standard solutions and divide this into the mean peak-hei t ratio of the sample. The mean apparent drug concentration should be multipUed by die appropriate recovery correction factor in order to take account of the incomplete recovery of the individual drugs from plasma. These correction factors are, for chlormethiazole 1.04, for ethchlorvynol 1.05, and for trichloroethanol 1.33. 

The achievement of an economically viable process for the extraction of uranium fix>m seawater, however, could be achieved only through use of a sorbent with uranium concentrating factors greater than those provided by titanium oxides [181]. Polyacrylamidoxime sorbents, characterized by D value > 10 ( 10 ) (see Table 5) made an appearance at the end of the 1970s to remove this impediment to the economic recovery of uranium fix>m seawater. Their appearance reoriented research in the field of uranium recovery toward highly selective organic resins [188, 189]. 

Baggiani et al. [21] in frontal LC (entry L in Tables 15.1 and 15.2). The material was then used as sorbent for the SPE and a preliminary procedure for the enrichment of the analyte from water samples was tested. Good recoveries (91-96 %) and concentration factors of 3.2 15.2 were found. 

The percent recovery of DOM by membrane processes is strongly dependent on both the value of R and on the water concentration factor (the ratio of total volume of feed water to final volume of retentate solution). Uetting W be the water concentration factor, it can be shown that the percent recovery of a solute is predicted to be... 

With the objective of increasing calcium and lactose content of MF retentate in addition to micellar casein whUe maximizing whey protein depletion. Nelson and Barbano [114] developed a multistage MF process that removed -95% of whey protein from skim milk. They reported that the MF retentate produced from this process contained soluble minerals, NPN, and lactose similar to the original milk. This was accomplished by using the permeate from the UF of the MF permeate to diafilter the MF retentate after achieving a concentration factor of 3 in the MF. Aside from the recovery of native micellar caseins, they showed that the process enabled the production of whey protein stream (UF retentate) with protein content similar to that of commercial WPC. 

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