Sludge physical properties

Aggslides SM, Londra PA (2000) Effects of compost produced from town wastes and sewage sludge on the physical properties of a loamy and a clay soil. Bioresour Technol 71 253-259... 

Depending upon the physical properties of a surfactant (component), removal from the mixed liquor is further possible through precipitation of insoluble salts and adsorption onto solids or bacterial floes, which, in turn, are subsequently withdrawn with the excess sludge [53]. In particular, intact or partly degraded low water-soluble surfactants are eliminated by this route. 

With foams, sludge, and slimes often encountered in biotechnology, we are confronted with the problem of not being able to list the physical properties because they are still unknown and therefore cannot be quantified. This situation often leads to the opinion that dimensional analysis would fail in such cases. 

When must model experiments be carried out exclusively with the original material system Where the material model system is unavailable (e.g., in the case of non-Newtonian fluids) or where the relevant physical properties are unknown (e.g., foams, sludges, slimes), the model experiments must be carried out with the original material system. In this case measurements must be performed in models of various sizes (cf. Example 4). 

The nature and sizing of equipment depends on the economic values and proportions of the phases as well as certain physical properties that influence relative movements of liquids and particles. Pressure often is the main operating variable so its effect on physical properties should be known. Table 11.1 is a broad classification of mechanical processes of solid-liquid separation. Clarification is the removal of small contents of worthless solids from a valuable liquid. Filtration is applied to the recovery of valuable solids from slurries. Expression is the removal of relatively small contents of liquids from compressible sludges by mechanical means. 

Occasionally, one could have read about the failures of the Theory of Similarity or of its limits. However, this criticism has arisen when, due to some physical reasons, a complete similarity could not be achieved (see e.g. remarks of Damkohler [113] on p. 183) or the scale-up criterion could not have been worked out with certainty because the measuring conditions did not allow it (false model scale, wanted sensitivity of the target quantity, non-availability of the model material system, ignorance about relevant physical properties, such as in foams and sludges, etc.). 

Material Ordinary Portland cement was used in the experiment. Chemical composition and physical properties of the cement are given in Table 1 and Table 2 respectively. Aggregates used in the experiment was standard sand satisfying Korean Standard L 5100. Ash from incineration of paper sludge was investigated in this study especially. Chemical composition of the ash is given in Table 3. From the composition of the ash, it can be... 

Table 3.68. Physical properties of sludge in dependence on the amount of water [11]...

Some physical properties of several digested sludges were measured to better characterize the sludge particle system. 

The degree to which FGD scrubber material is treated influences its physical properties. Basic physical properties include solids content, moisture content, specific gravity, and wet and dry density [67]. When dewatered, the calcium sulfite FGD sludges become a soft filter cake with a solids content typically in the 40-65% range. Calcium sulfate FGD sludges can be dewatered much more easily and may achieve solid contents as high as 70-75% after dewatering [67]. 

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