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resemble the parent substance in terms of structure or properties.
Desorption
Reverse of adsorption. The release of gases, liquids or solids from surfaces.
Desulfurization
The removal of sulfur or sulfur compounds from fuels (gas, coal, crude oil) prior to combustion or the removal of sulfurous combustion products i.e.
sulfur oxides from flue gases. In both cases, the objective is to lower sulfur dioxide emissions into the atmosphere. Desulfurization of gases and distillate
heating oils and diesel fuels is possible and is already performed today. Desulfurization of residual heating oils or solid fuels is theoretically conceivable,
e.g. by means of fuel gasification, but still requires a great deal of research. Several methods of desulfurizing waste gas at efficiencies in excess of 80%
are available and in use.
Detergents
In Germany, this term was originally used for surface-active substances in general, which today are referred to as Tensides. In other countries, the word
detergents was always understood to mean finished washing agents, a meaning which has also become widespread in Germany.
Deutsches Institut for Normung e.V. (German Standards Institution)
See: DIN.
De-dusting system
Technical systems such as fabric filters, electrostatic filters, wet filters and other Separator for reducing emissions.
Dialysis
The separation of dissolved particles according to their particle size as a result of Diffusion through semipermeable membranes. Gentle means of
purification of macromolecules (e.g. proteins) in chemistry and technology.
Diffusion
The distribution of molecules of one substance into another, resulting from thermal motion, dependent on concentration gradient, temperature and
molecular weight. The diffusion constant indicates the rate at which a diffusing quantity of substance spreads through a unit area per unit of time.
Dilute acid
Diluted (20%) used sulfuric acid. Accrued in large quantities in the chemical industry, e.g. in the preparation of titanium dioxide. Dilute acid is
regenerated.
DIN
Abbreviation for the German Standards Institution, which publishes standards in the form of standards sheets with the designation DIN. All DIN
standards together make up the German Collection of Standards. This includes around 20,000 DIN standards, i.e. definitions, dimensions, testing
procedures, variable determinations etc. for technical areas, sciences, medicine, agriculture and numerous other areas of human activity. Accounting for
approximately 2/ 3 of all standards, the field of engineering and technology is by far the largest.
Dioxins
Synonym for chlorinated dibenzo-p-dioxins. Highly toxic compound of chlorine and hydrocarbon causing serious health damage and developmental
disorders.
Dirt
Substances that undesirably stick to other materials or are distributed throughout other materials. Subjective perception determines whether or not this is
dirt. See: Impurities.
Disperse system
Chemistry: System of two or more phases, in which one phase (the dispersed substance or dispersed phase) is finely distributed in another (disperser or
dispersing medium). Depending on the degree of dispersion (degree of distribution) of the disperse phase, a distinction is made between:
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coarsely dispersed: particle size larger than 100 millimeters and
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molecularly disperse: particle size less than 1 millimeter.