Patent ID: 7943047

Claim:
A process for the treatment of alkaline wastewater from an aldolization process which is contaminated with water-soluble and/or dispersed organic impurities by means of single-stage or multistage extraction with an organic liquid of the aldolization process wastewater from the preparation of 2-ethylhexenal or 2-propylheptenal which has been acidified to a pH of from 0 to 6, wherein an organic liquid obtained by stripping volatile organic impurities from the acidified aldolization process wastewater or of the acidified and extracted aldolization process wastewater, condensation of the stripped compounds and phase separation of the condensate is used as extractant for the extraction of organic impurities from the acidified aldolization process wastewater, and wastewater having a lower content of organic impurities than the aldolization process wastewater fed to the extraction is taken off from the stripping apparatus.