MONITORING PERFORMANCE IN ACTIVATED SLUDGE PLANTS

    The BioTech HMB Biological Tester is used to monitor aerobic biological activity. Features of the HMB include simplicity of operation, and the fact that it gives its answers in 15 minutes.

The HMB is in use in thousands of facilities worldwide, wherever real-time information about the level of biological activity is important. It is used in two key areas in waste water treatment facilities.

Current compliance requirements include BOD testing, the results of which are not available for 5 days. The HMB readings on these samples are typically low when in compliance, and show a decided jump when the BOD is elevated. Daily monitoring with the HMB allows the operator to have immediate predictive information and, when indicated by the test results, to divert or reduce effluent flow until confirming data is available.

In normal circumstances, the HMB and O.U.R. give similar information. In starved situations however, filamentous organisms tend to prosper at the expense of other organisms whose presence enhance flocculation. This imbalance diminishes the efficiency of settling, and may result in foaming problems, both of which negatively affect the performance of the plant. Filamentous organisms use oxygen but tend to be poor in reducing enzymes. For this reason, the HMB readings drop precipitously in a reduced nutrient environment, while the O.U.R. results do not necessarily show this effect until after the plant’s performance is affected. Thus, HMB readings offer routine monitoring capabilities and may detect changes in biomass that would be missed by other methods.