TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The water from the sump of the distillation processing of the aqueous fraction is subjected to a flash evaporation, and the resulting purified water is led in the process for the preparation of isophorone. The reaction is carried out in a liquid phase, where the acetone is converted to isophorone by catalytic reaction at 100-250 degrees C, preferably 180-250 degrees C and a pressure of 5-50 bar, preferably 20-50 bar and the specified values are combined with each other. The reaction is carried out in a gas phase, where the acetone is converted to isophorone by catalytic reaction at 100-400 degrees C, preferably 200-400 degrees C. The reaction is carried out in a critical area, where the acetone is converted to isophorone by catalytic reaction at 250-350 degrees C and a pressure of 50-200 bar. The method uses a homogeneous or a heterogeneous catalyst, preferably a homogeneous catalyst. The reaction is carried out in the liquid phase with the homogeneous catalyst. The reaction is carried out in a reactor comprising a tubular reactor (preferred), a mixing vessel, a stirred-tank reactor, a fixed bed reactor, a reactive distillation column, a microstructured reactor and/or a loop reactor. The reaction mixture is processed after carrying out the reaction and is separated into individual components, where the separation is carried out completely or partially. The separation of the individual fractions is carried out by separation methods e.g. distillation, flash evaporation, crystallization, extraction, sorption, permeation and/or phase separation continuously or batchwise, in single or multiple steps, preferably by distillation in single or many devices. The distillation is carried out spatially separated from the isophorone synthesis or takes place in a reaction apparatus, preferably by reactive distillation, preferably in a reactive distillation column with a side stream removal. The separation is carried out into three fractions comprising (a) a fraction of unreacted acetone, water and low boilers, which condense and are fed back to the reaction in the reactor, (b) a faction enriched with the coloring substances, where the fraction is further purified and the valuable substances are fed back into the process, and (c) a fraction from isophorone, highly condensed products, water and catalyst, known as recycling flow, where this fraction is then subjected to hydrolysis. The fraction (a) is removed as a vapor stream comprising acetone, water and low boilers, condensed in diacetone alcohol and mesityl oxide, and the reactor is added back with the starting materials of acetone, water and catalyst. The fraction (b) is removed as a side stream of the distillation column, preferably the reactive distillation column. The purification of the fraction (b) is carried out by combination of neutralization or extraction and subsequent distillation in the reactive distillation column. The refined phase fraction of (b) is led with the valuable products from isophorone, high boiling compounds and optionally the catalyst in the hydrolysis. The additional obtained phase of the fraction (b) of valuable product comprising acetone, diacetone alcohol and mesityl oxide, is recycled to the reaction. The fraction (c) is subjected to hydrolysis, where the by-products are converted partially or completely into isophorone, acetone and other valuable products. The hydrolysis is carried out in the reactive distillation column, where the resulting low boilers comprising acetone, diacetone alcohol and mesityl oxide is directly removed from the hydrolysis zone and is fed back into the reaction. The hydrolysis of the fraction (c) is carried out in an apparatus by the reactive distillation, preferably in the reactive distillation column, where simultaneously the separation of the reaction mixture takes place into the fractions (a)-(c), so that the resulting products are separated simultaneously and the fraction (c) is hydrolyzed. The hydrolysis of the fraction (c) is at a water concentration in the hydrolysis of 0.1-99.9 wt.%, preferably 30-90 wt.%, preferably 0,001-10 wt.%, preferably 0.05-1 wt.%. The hydrolysis of the fraction (c) is carried out at a pressure in the hydrolysis of 1-200 bar, preferably 20-60 bar, where this pressure is provided in isophorone synthesis step. The hydrolysis of the fraction (c) is carried out at a temperature of 100-300 degrees C, preferably 210-260 degrees C. The hydrolysis of the fraction (c) is carried out in the reactive distillation column, where a temperature or a temperature profile is adjusted, which corresponds to the boiling temperature in the sump and to the individual separating- and reaction steps. The refined fraction (c) is subjected to phase separation to obtain organic fraction (d) and aqueous fraction (e). The purification of the organic fraction (d) is carried out by distillation, preferably a combination of neutralization or extraction and subsequent distillation. The aqueous fraction (e) is supplied to waste water purification, where the wastewater purification is carried out preferably in at least one distillation column. The pressure during the wastewater purification in the wastewater column is 1-200 bar, preferably 20-60 bar. The system pressure is carried out in the wastewater column, which occurs in the overall system hydrolysis/wastewater column, preferably when the vapors of the column wastewater are discharged directly into the hydrolysis part of the reactive distillation column. The pressure in the flash evaporation is below the pressure in the wastewater column. The vapors (g) of the flash evaporation stage comprising pure water is condensed, and recycled as water in the reaction. Preferred Components: The alkali (less than 1 wt.%, preferably of less than 0.2 wt.%,), preferably sodium hydroxide (0.015-0.05 wt.%) is used as the catalyst. EXAMPLE - No suitable example given.