Abstract: The soot obtained in the form of a soot-containing aqueous waste liquor in the course of synthesis gas manufacture is utilizable bya) mixing said liquor in a sewage sludge treatment plant with a sewage sludge to which organic flocculants are added as drainage aids with or without a further quantity of finely divided coal or ash,b) filtering this pretreated sludge mixture,c) incinerating the resulting filter cake andd) burying the ash in a sanitary landfill.

Abstract: Synthesis gases are prepared by partial autothermal oxidation of liquid fuels and/or solid fuels in the presence of oxygen or oxygen-containing gases with the addition of a temperature moderator, such as steam and/or CO.sub.2, in an empty reactor space without baffles, at from 1000.degree. to 1500.degree. C. under from 1 to 100 bar, the reactants fuel and oxygen-containing gas being fed separately to the reactor, by a process in which the steam or CO.sub.2 is fed in simultaneously with the feed of the fuel, and the steam is let down through one or more nozzles into the fuel steam directly before the orifice for the fuel, let-down being effected at from 30 to 250%, preferably from 80 to 140%, of the critical pressure ratio. An apparatus for carrying out the process is also described.

Abstract: Carbon black and ash containing wastewaters from high-temperature processes in which the carbon black is present in an extremely finely divided and partly colloidal state are cleaned and disposed of by treatment with organic flocculants, predewatering of the flocculated suspension by gravity filtration and post-dewatering of the carbon black sludge by pressure filtration within the range from 0.5 to 15 bar in a process comprising adding sufficient calcium hydroxide to the wastewaters that the pH of an aqueous extract of the filter cake obtained is more than 11.8, preferably more than 12.0.