Abstract: The microbial decontamination of soils contaminated with hydrocarbons, in particular with mineral oils, by microbial oxidation is improved by a process in which in addition to supplying the oxygen necessary for degradation, by aeration, soluble nutrients, water and soluble or dispersed biosurfactants as such or mixed with chemical surfactants are metered into the contaminated soils directly or into the removed contaminated soil layers, in one or more batches at time intervals, in an amount such that the formation of toxic intermediates which slow down or block microbial degradation in prevented, the accessibility of mineral oils and their products for the microorganisms is simultaneously increased and, as a result, accelerated, virtually complete mineralization by respiration to CO.sub.2 and H.sub.2 O is effected.

Abstract: Solid particles of various sizes are separated from viscous liquids, for example biomass from liquids of biotechnological processes, by pressure filtration by subjecting the inhomogeneous or homogenized suspension, without or after only a little dilution, to a pressure filtration whereby the solid particles of various sizes are retained according to size in a plurality of, in particular in from 1 to 3, superposed or juxtaposed filter stages on filter layers of various depths and on filter surfaces and are separated from the viscous liquid.

Abstract: Solid wastes, and wastes to be compacted, are pretreated for introduction into underground salt cavities or salt caverns via a downpipe under the force of gravity by a process in which solid, uncomminuted or comminuted or finely divided to very finely divided wastes are mixed with waste sludges in a ratio such that a material results from which moldings are produced, with or without the addition of a binder, in the form of granules, agglomerates or pellets by a granulation method, or in the form of flakes by a pressing method, the flakes being comminuted to give small moldings, and, if appropriate, the moldings are surface-dried or dried completely, the moldings which are free-flowing under the force of gravity are then trickled into the salt cavity or into the salt cavern and form a pile therein until the said cavity or cavern is substantially full, and, if required, the salt cavity or the salt cavern is closed.