Potential Utilization of OECD 302 B Test in Biodegradability Assessment of Metalworking Fluids

摘要

The main aim of this study was to evaluate the ability of the activated sludge from sewage treatment plant to degrade a part of the 12 randomly selected metalworking fluids (MWFs) according to OECD 302B (with different addition of activated sludge AS - 0.25 g/l, 0.50 g/l and 1.00 g/l of suspended solids - SS). The degradability test showed that, after the first 3 hours of cultivating, adsorption grew with the increasing amount of inoculums. In the case of AS addition 1.00 g/l of SS were the adsorption rate lower than 20% in four samples, in the case of AS addition 0.50 g/l of SS in 9 samples and in the case of AS addition 0.25 g/l of SS in all 12 tested samples. In four samples were also observed the lag phase (adaptation of the bacteria's to the presented carbon source). If occur adsorption rate more than 20% it is probably impossible to distinguish biological degradation of organic matter from abiotic elimination from the suspension.