Enzyme Activities as a Tool for Biological Control in Dairy Wastewater Treatment

Sofia University “St. Kliment Ohridski”, Department of General and Applied Hydrobiology, Faculty of Biology, BG – 1164 Sofia, Bulgaria


Schneider, I. and Y. Topalova, 2013. Enzyme activities as a tool for biological control in dairy wastewater treatment. Bulg. J. Agric. Sci., Supplement 2, 19: 132–134


The increased application of biofilm processes in the wastewater treatment requires development of new indicators for fixed biomass activity characterization. The evaluation of opportunity for application of enzyme activities of the total dehydrogenase, nitrate reductase, ß-galactosidase and phosphatase as biological indicators of well functioning biofilms in dairy wastewater treatment is the aim of this article. The lab scale wastewater treatment process was simulated in anaerobic biofilters in semi-continuous regime. The activity of biofilm and suspended biomass was studied in parallel. The enzyme activities were discussed with removal effectiveness for chemical oxygen demand, proteins and lactose at the 216th day, corresponding to the phase of stabilization of sequencing batch process. The obtained data showed two important tendencies for biofilm activity assessment: i/ the total dehydrogenase activity was appropriate indicator for assessment of total organic matter mineralization and ii/ the phosphatase and nitrate reductase activity were related to protein biotransformation. The ß-galactosidase activity of suspended biomass was more appropriate indicator for assessment of lactose biodegradation. The investigated enzyme activities can be used for quick, accuracy and easy applicable tool for control and management of dairy wastewater treatment.

Key words: anaerobic biofilm, ß-galactosidase activity, nitrate reductase activity, phosphatase activity index, total dehydrogenase activity
Abbreviations: AS – activated sludge; ASBB – anaerobic sequencing batch biofilm; COD – chemical oxygen demand; DHA – total dehydrogenase activity; GAL – ß-galactosidase activity; NRA – nitrate reductase activity; PAI – phosphatase activity index

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