Studies of degradation of non-ionic surfactants (NISA) in a model purification plant of an original design demonstrated an high rate and depth of degradation processes compared with periodic cultivation of free or immobilized degrading strains. A virtually complete primary degradation (99-99.5%), with destruction of the oxyethyl moiety of the molecule, was observed. In addition, NISA molecules were degraded to a greater extent, including considerable degradation of the hydrocarbon radical, partial degradation of aromatic structures in Neonol, and utilization of biologically "unyielding" fractions of commercial NISA preparations: polyethylene glycol (PEG) and long-chain fractions of polymer homologues.