Lipids are important and burdensome organic constituents of most wastewater. The amount of lipids in municipal wastewater is approximately 30-40% of the total organic matter, measured as chemical oxygen demand (COD). Lipids can form oil films on the surface of activated sludge flocks, preventing the diffusion of oxygen and causing problems in the pumping and aeration systems with development of filamentous microorganisms. The current practice to improve the biodegradation of lipids is bioaugmentation, with the addition of microorganisms or enzyme preparations for wastewater treatment. Influence of substrate on fluctuation of lipolytic activity and parameters of activated sludge were studied. The activated sludge was bred from biological uses to bioaugmentation process. Enzymatic activities of activated sludge formed the schema: first, the maximum of lipolytic activity with respirometric activity were observed, next, the highest was dehydrogenases activity. It could be caused by a change of the metabolic path in Pseudomonas fluorescens cells, which includes replacement of TCA cycle by glyoxylate cycle. This replacement requires higher metabolic energy, so high lipolytic activity was connected with respirometric activity. The influence of pH on enzymatic activity of activated sludge was studied. The most effective method to remain stable pH in the chamber of reactor (6,5 ? 7,0) was buffered inflow with KH2PO4/NaOH.
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Anna Wiechetek, Katedra Biotechnologii Srodowiskowej, Wydzial Inzynierii Srodowiska, Politechnika Slaska, ul. Akademicka 2, 44-100 Gliwice, Poland