Prodn. wastewater was pretreated by coagulation with FeCl3 and flotation with dispersed air in the test plant with a capacity of 4 m(3)/h. The process course was followed by detn. COD, BOD5 and the concn. of anionic and nonionic surfactants in the wastewater at the inlet and outlet as well as the content of thy matter in the flotation sludge. The efficiency of COD, anionic and nonionic surfactants removal were 75.6%, 77.1% and 24.8%, resp. Moreover, the used method resulted in an increase of biodegrability of wastewater in (BOD5/COD ratio) from 0.14 to 0.40. Addnl., the math. models of the wastewater pretreatment were developed.