A cyclohexanone process waste fraction contg. ε-hydroxycaproic acid up to 40, adipic, glutaric and succinic acids up to 20, unidentified compds. up to 35, and water 10-15%, was dehydrated and esterified with n-octanol (20 h, 450 K). The product was sulfonated with a 30% oleum, neutralized, and purified with MeOH and petr. ether to yield surfactants (78% on purified dicarboxylic acid fraction basis). IR spectra of the surfactants revealed ester, sulfonic, sulfate, al-kyl's -CH2-, and alcohol's OH groups. The HLB-value was 49.08 as compared with the 49.55 found for Na salt of di-n-octylsulfosuccinate. The surfactants were hydrophiles sol. in water, and good solubilizers. They had the highest foam formability and stability, the lowest d., the highest surface tension, and a similar critical micelle concentration as compared with the reference surfactants prepd. from succinic acid and maleic anhydride. Primary and total biodegradation tests showed the surfactants to be environment-friendly.