Filtrate quality

Existing statistical methods permit prediction of macroscopic results of the processes without complete description of the microscopic phenomena. They are helpful in establishing the hydrodynamic relations of liquid flow through porous bodies, the evaluation of filtration quality with pore clogging, description of particle distributions and in obtaining geometrical parameters of random layers of solid particles. 

Note that filter aid selection must be based on planned laboratory tests. Guidelines for selection may only be applied in the broadest sense, since there is almost an infinite number of combinations of filter media, filter aids, and suspensions that will produce varying degrees of separation. The hydrodynamics of any filtration process are highly complex filtration is essentially a multiphase system in which interaction takes place between solids from the suspension, filter aid, and filter medium, and a liquid phase. Experiments are mandatory in most operations not only in proper filter aid selection but in defining the method of application. Some general guidelines can be applied to such studies the filter aid must have the minimum hydraulic resistance and provide the desired rate of separation an insufficient amount of filter aid leads to a reduction in filtrate quality — excess amounts result in losses is filtration rate and it is necessary to account for the method of application and characteristics of filter aids. 

Changes in organoleptic and other filtrate qualities as a result of crossflow miciofiltration of two red wines using 0.2 pm alumina membranes... 

Effect of Sludge Chlorination on Slurry Filtrate Quality... 

The Standard Plant. The results presented in Figure 9 for the standard treatment plant indicate that effective removal (85% ) of suspended solids is produced by the flocculation-sedimentation process. Filter run length, as indicated by the time it takes to reach a head loss of 250 cm, is 28 hr. Filter ripening is rapid, and essentially complete removal of suspended solids is accomplished by the Alter throughout the run. The settling eflBciency, head loss development, and filtrate quality predicted by the model are consistent with typical water treatment plant performance. 

Plant performance in the absence of flocculation by fluid shear (G == 0 sec ) is examined in Figure 18. Some particle growth occurs by Brownian diffusion in the flocculator and by differential settling and Brownian diffusion in the settling tank. Removal efficiency by sedimentation is smaller than in the standard case (74% compared with 85% ), and filter runs are reduced from 28 to 16 hr. Filtrate quality is good throughout the run. 

Technique Typical face velocity Volume filtrate before regeneration per unit filter area at 0. Ig T sohds Relative running cost per unit mass removed Best filtrate quality achievable ... 

In several instances, in order to avoid membrane clogging and to guarantee filtrate quality, ubiafibration membranes are used for what would normally be regarded as a microfibration duty [Gutman and Knibbs, 1989]. 

The commissioning team should carefully note pressure drops, filtrate quality (clarity and hardness), and cycle times for future reference. 

The water-treating process can be improved by the introduction of a polyacrylamide. As the polyacrylamide content is increased, the ratio ajb drops off, i.e., the particle adhesion is reinforced and particle detachment by the water flow is diminished, thus improving the filtration quality. According to Mints, the parameter b is determined at the start of the filtration process, i.e., when the first contaminants adhere to the surface of the filter grains [302]. 

An insufficient amount of filter aid leads to a reduction in filtrate quality. Excess amounts result in losses in filtration rate. 

MF /UF filtrate quality is better, and, therefore, the colloidal fouling load to the RO is reduced with significantly lower SDI and turbidity. 

MF /UF filtrate quality remains much more constant since it is an absolute membrane barrier. 

This process continues until the precoat has been reduced to its minimum acceptable thickness, whereupon the process cycle is repeated. Drainage of filtrate is provided through grids and drainage mats, which allows for removal of filtrate from the entire compartment. The cake, of course, comes away with some precoat, and the process is only possible if this is acceptable - which it usually is, because it is mostly used for clarification. This process is distinctive on account of the high filtrate quality achieved. 

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