Dewatering efficiency

Mineral separations, 15 442 Minerals industry, size of, 16 598 Mineral sludge dewatering efficiency, poly(ethylene oxide) in, 10 688 Mineral solids, hybrid materials based on, 13 541... 

Figure 19. Comparison of electroacoustic analysis and dewatering efficiency of the mixed demulsifier as a function of the apparent spreading rate.

There is a great deal of confusion surrounding the dewatering efficiency in terms of the significance of the measured electric current and the related problem of liters per ampere-hour (or liters per watt-hour at constant voltage). It has been remarked that experimental efficiencies translate to high and obviously untenable amounts of water per ion. 22The nature of the current and the flux in terms of its various components has been recently elucidated,as follows. 

Dewatering Efficiency in Terms of Liters per Ampere-Hour (or Liters per Watt-Hour at Constant Voltage)... 

How Cationic Polymer Structure Relates to Dewatering Efficiency of Waste-Activated Sludges... 

The 10% cake times of the same copolymer series were compared for dewatering efficiency of raw primary sludge. The 10% cake time denotes the amount of time, in seconds, required to produce a sludge cake containing 90% moisture, or 10% solids. Figure 9 illustrates that all of the polymers produce nearly the same filtration time. Because of its fibrous nature, this sludge forms a noncompressible cake and is dewatered easily. Polymer structure has a minimal effect for this type of sludge. 

These considerations point to the inportance of a residual filter cake liquor in its influence on the cake disdharge mechanism It follows that the cake discharge process is mateiialh affected by flie cake drainage or dewatering effici cy. Industrial reports... 

After the electroacoustic measurements were finished, the sample was placed into a centrifuge tube and spun at 1500 rpm in a table top centrifuge (International Model HN). The amount of released water was recorded to confirm the relative dewatering efficiency of the demulsifiers. 

Interfacial tensiometry is technique which is sensitive to the adsorption of surface-active solutes. The time-dependent interfacial tension measurements served to reveal the physico-chemical changes at oil/aqueous interface during mass transfer of demulsifiers and demulsifier mixtures to the interface. The apparent spreading rate which was determined from the time-dependent tensions provided a measure for the ease of deformation of the interface and the speed of adsorption to the interface. The apparent spreading rate parameter correlated very well with the coalescence behavior and dewatering efficiency of the emulsion. 

Danquah, M. K. Gladman, B. Moheimani, N. Forde, G. M. Microalgal growth characteristics and subsequent influence on dewatering efficiency. Chem. Eng. J. 2009, 151, 73-78. 

The procedure was validated by comparison with the dewatering efficiency measured by Karl-Fischer titration. The dewatering efficiency was calculated as shown in Equation 12.2, where 1 and 2 denote the water content before and after the application of the electric field ... 

Figure 12.4 shows the comparison between viscosity ratio and dewatering efficiency for the case of water-in-crude oil A emulsions with the addition of very hydrophobic particles (Aerosil 972). The two variables follow the same trend. Therefore, it is possible to relate the viscosity changes due to the application of a shear stress and an electric field to the emulsions stability and the emulsion stability can be described in terms of the viscosity ratio. 

Aw% dewatering efficiency, defined by Equation 12.2 w%,i water content in the emulsion before electric field application %) water content in the emulsion after electric field application (%)... 

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