INFLUENCE OF OPERATIONAL VARIABLES ON ENZYMATIC TESTS APPLIED TO MONITOR THE MICROBIAL BIOMASS ACTIVITY OF A BIOFILTER

Enzymatic assays were used to monitor the biomass of a biofilter worki ng under different operational conditions. In backwash waters used as biomass source, many hydrolytic enzymes as well as dehydrogenase expre ssed in volumetric units seem to correlate with volatile suspended sol ids (VSS) and with the volumetric feeding mass. However, only the spec ific concentration of beta-Glucuronidase correlates negatively with th is volumetric feeding mass. The influent temperature affects simultane ously the specific concentration of beta-Glucosidase, the headless beh aviour and the total sugars/VSS ratio. For the properties of the bioma ss, the sludge volume index (SVI) of the backwash waters correlates wi th Leu-aminopeptidase, suggesting that this enzyme could have been pro duced by filamentous organisms. (C) 1998 IAWQ. Published by Elsevier S cience Ltd.