Ocena efektywności biologicznego oczyszczania ścieków zawierających związki chromu za pomocą wskaźników tlenowych. Cz. II

The essay presents the research on the impact of chromium compounds on the effectiveness of biological treatment of effluents by activated sludge, the structure of activated sludge, the composition of microfauna and sedimentation characteristics of activated sludge. The determinations of the indexes of pollution of wastewater have been carried out according to Polish standards, with the exception of CODCr of biologically treated effluents containing hexivalent chromium. For such effluents a modified method for marking CODCr has been developed, eliminating the impact of hexivalent chromium added to effluents. In the research it has been established that oxygen indicators were not a reliable criterion for the assessment of the impact of chromium compounds on activated sludge. The microscopic structure research and microfauna composition examination of the activated sludge proved necessary.