Sludge particle

Incineration can be accompHshed ia multiple-hearth furnaces, ia which the sludge passes vertically through a series of hearths. In a fluidized-bed sludge, particles are fed iato a bed of sand fluidized by upwardly moving air. 

Activated sludge Sludge particles produced in raw or settled wastewater (primary effluent) by the growth of organisms (including zoogleal bacteria) in aeration tanks in the presence of dissolved oxygen. The term "activated" comes from the fact that... 

Pin Floe Excessive solids carryover. May occur from time to time as small suspended sludge particles in the supernatant. There are two kinds grey -ashlike, inert, has low BOD - indicates old sludge and brown, but a portion neither settles nor rises, has high BOD - indicates young sludge. 

To improve the efficiency of collection, several units can be installed in series. The plate type unit is the most common design for dry dust removal, while pipe design is mainly for removal of liquid or sludge particles and volatilized fumes. The plates/pipes are the collecting electrodes, with the discharge electrodes suspended between the plates or suspended in the pipes [41,53,57],... 

Prevention of agglomeration of insoluble oxidation products and sludge particles generated by the combustion of diesel fuels as discussed in Chapter 2, (see also Fig. 1.3). 

The formation of gas bubbles in a porous medium affects, e.g., the performance of anaerobic granular sludge particles containing entrapped gas (waste-water treatment), or the performance of electrochemical reactors where a gas (hydrogen, oxygen, chlorine) evolves inside a porous electrode. A related problem is that of bubble nucleation on structure surfaces, which can be as varied as specially designed surfaces for enhanced nucleate boiling heat transfer, or the... 

Lime, alum, and various ferric salts have been used to condition sludge prior to dewatering. Lime reacts to form calcium carbonate crystals, which act as a solid matrix to hold the sludge particles apart and allow the water to escape during dewatering. Alum and iron salts... 

Because of the substantial scatter of the degree of elimination it is advisable in critical cases to determine P-values experimentally in simulated systems or from field measurements. In an ETAD-project [11] P-values have been determined by Zahn-Wellens measurements but such values have to be considered as worst-case situations because test conditions require relatively high soluble dye concentrations in relation to the amount of suspended sludge [11], Furthermore, P-values are pH-dependent and can be determined from adsoiption isotherms. In the case of wool and polyamide dyeing, P-values can be estimated from the data on fixation (F), due to the similarity of the surface functional groups of sludge particles to those of the textile substrate. 

The baffle at the bottom has an apparently neutral effect on agitation it does, however, allow particle separation. It was observed that particles with a mean weight of 0.01 g are incorporated into the flow described previously. At the same time, particles with a mean weight of 0.06 g settled. This section of the bioreactor should be adjusted to allow the separation of a specific particle size to satisfy specific needs, such as large sludge particles that could lose efficiency. 

Gravitational free water, which is in the cavities between sludge particles, is present in the highest amounts. This water can be removed very easily (for example, by several hours of sedimentation in so-called thickeners). 

When solid particles of sludge agglomerate, capillaries are formed between the sludge particles, and water present in them is bonded by capillary forces. To remove this water, it would be necessary to exert a force on the water-sludge mixture equal to the force binding this water. 

Highly loaded activation — this employs the fact that the smaller the sludge particles the better dispersion of microorganisms and the better their degradation capability. The volume loading can be increased up to... 

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

Second, the majority of digested sludge particles are less than 53 /xm in diameter, and thus are slow to settle and difficult to remove by sedimentation processes. The particulate specific surface area (ssa), which increases as the particle diameter decreases (ssa oc 1/d), should be high. These smaller particles should include bacterial cell bodies, fine cellulose, clay material, and mineral precipitates, such as metal sulfides, Fc304, etc. 

An attempt has been made to use Millipore cellulose ester membranes to size sewage and sludge particles (see Chen et al. (15)). However, previous work on marine particle filtration (see Sheldon (16), Sheldon and Sutcliff (17), and Cranston and Buckley (18)) clearly shows that cellulose ester membranes are unsuited for such separation. Sheldon and Sutcliffe (17) point out that one manufacturer of such membranes, Millipore, actually recommends that their product not be used in such applications. 

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