Biologisch-chemisches Verfahren zur Prüfung des Abbau- und Eliminierungsverhaltens organischer Abwasserinhaltsstoffe

After the checking for the toxic inhibition of degradation, the testing of the degradation behaviour at concentrations below the toxicological threshold value should be performed. For this, activated sludge with 1.5 … 2 g/l organic dry weight in special reaction vessels with a stirring and aeration equipment as well as electrochemical oxygen measurement is used. The possibly necessary adaptation is effected by a repeated change of the aqueous phase with the test substance as the single carbon source. Measurements are carried out in three vessels: control, experimental vessel and another experimental vessel for the makeup of volume at sampling. The increase of biomass and the consumption of substrate are determined from samples. Determinations of totals as COD and/or C_organic are recommended, since the determination of the pure substrate allows only statements on the persistence, but not on the full degradation. The technique, represented with the schematic diagram and examples of application, can be automated easily.