Abstract: Described is a process for the dyeing of textile material by the exhaust method, whereby the dyeing is commenced at a pH value of between 6 and 12 and terminated at a pH value of between 3 and 7, which process is characterized in that during dyeing the pH value is lowered, by the addition of an inorganic acid, by at least 1 unit of pH value; and that subsequent to the dyeing the exhausted bath, after the addition of alkali, dye and, if required, further auxiliaries, is optionally used afresh for dyeing.Furthermore an apparatus for carrying out this process is described which consists of a dyeing aggregate having a liquor-circulating system which contains at least one pH-measuring point as well as at least one dosing device.

Abstract: There is described a process for dyeing paper or, in particular, cellulose containing fibre material with an aqueous dye liquor, which dye liquor contains at least one cationic or basic dye which(a) has available at least one system of delocalized .pi.-electrons, which system consists of at least 9 conjugated double bonds lying in one plane, and(b) possesses a planar molecular structure, the said material being treated, before or during dyeing, with at least one cationic or basic levelling agent; there is no necessity to add salt additionally to the dye bath, and there are obtained by this process level dyeings which exhibit a high degree of exhaustion of the dye, and which are characterized by good fastness properties, especially by good fastness to wet processing.

Abstract: A process for purifying industrial effluents, wherein said effluents are brought into contact with a polymer adsorption material which is in the form of a solvated, preferably hydrated, gel.

Abstract: Transiently water-soluble dyestuffs of the formula ##EQU1## WHEREIN F is a radical of a non-heterocyclic azo disperse dyestuff containing no groups which dissociate in water, n is 1 or 2, X is an electrophilic group, R.sub.1 is an optionally substituted ethylene group, and R.sub.2 and R.sub.3 are alkyl radicals which are different from each other and which carry altogether at least one water-solubilizing group and optionally still further substituents which do not impart solubility in water and R.sub.3 can furthermore be a hydrogen atom. The dyestuffs can be dissolved in aqueous dyeing baths and dye polyester fibers in yellow, red and blue shades of good fastness.