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RAPID BIOMASS ASSESSMENT KIT
Phone: (985) 674-0660
Fax: (985) 674-3483
www.ebsbiowizard.com
Technical Background and Example Applications
BUSINESS SPECIALISTS, LLCCopyright © 2015, Environmental Business Specialists, LLC
Rapid Biomass Assessment Kit TechnicalBackground and Example Applications
INTRODUCTIONBiological wastewater treatment is an important and necessary component of water treatment due to the microorganisms’ abilities to breakdown and consume harmful organic compounds before treated wastewater is discharged into the environment. Historically, operators and engineers have employed indirect techniques, such as mixed liquor volatile suspended solids (MLVSS) or oxygen uptake rates (OUR), to assess and control the bacterial population of the system. While these are useful tools, they have some inherent limitations, primarily the inability to distinguish between live/dead, active/inactive/viable populations (MLVSS) and lack of direct correlation to bacterial activity or concentration (OUR). THE BETTER WAYThere are methods for better determining the overall health and abundance of the bacterial population. However, current methods for biological monitoring are either cost prohibitive, time consuming and/or lack sufficient accuracy to be useful for day-to-day monitoring and control. These limitations have been addressed with the introduction of the EBS Rapid Biomass Assessment (RBA) Kit (Figure 1). The RBA Kit allows operators to quickly, simply, affordably, and accurately determine the overall bacterial concentration and activity of the system’s biological population or biomass. The techniques are applicable to virtually any biological wastewater system, including activated sludge, aerated stabilization basins (ASBs), and sequencing batch reactors (SBRs). Because every plant’s microbiology and operating conditions are different, there are no single number answers or strict control ranges for the data generated by the RBA Kit. Therefore, with every kit sold, EBS will provide three months of in-depth technical support by one of our Environmental Specialists. They will analyze the RBA data along with other critical plant data provided to us to develop trends, correlations, and operating targets.
TECHNICAL BASIS AND DETAILSAdenosine Triphosphate (ATP) measurements are used to assess the health of the biomass within both activated sludge (AS) and aerated stabilization basin (ASB) wastewater systems from industrial plants using the EBS RBA kit. ATP is the energy currency of cells because it is the primary molecule for reserving and transmitting energy within cells. It can be measured easily with the firefly luciferase assay, which is an oxidative enzyme used in bioluminescence. ATP measurements have proven to be a rapid and accurate monitoring tool to assess the health of the living biomass within biological wastewater treatment systems. Traditionally, mixed liquor volatile suspended Solids (MLVSS) has been the primary tool for quantifying how much bacteria are in a system, however measuring ATP provides us with additional information on how the bacteria are performing on the cellular and biochemical level. Measuring the total, free, and microbial ATP throughout a system gives operators and engineers an opportunity to identify areas of improvement, such as optimization of food to microorganism ratios, load balancing, supplemental feed rates of bacteria and nutrients, and respirometry (or treatability) studies. Total ATP measures the ATP contained in living cells and particulate matter, as well as the ATP dissolved in water. Free ATP measures only the dissolved ATP. The difference between the two represents the contribution from living organisms or the biomass, referred to as microbial ATP.
Effective wastewater treatment requires a viable and abundant bacterial population. Various plate count methods are often used methods for enumerating viable bacteria with results reported as colony forming units per milliliter (cfu/ml). Conventional plate count method can require up to 48 hours for results. In addition, media preparations, plate inoculation as well as an onsite incubator are necessary. Bacterial abundance and viability are evaluated using the Total Viable Counts (TVC) feature of the RBA Kit. TVC results are interpreted in conjunction with other parameters (MLVSS, OUR, ATP, etc.) to reflect the overall health of the WWTS and assist plant personnel in making a variety of process decisions regarding sludge wasting, influent loading, aeration levels, etc.). The TVC test for the RBA Kit requires a simple one-sample calibration performed by the EBS Microbiology Laboratory in Mandeville, LA, which will provide the client with their specific calibration factor. Future samples can be tested on-site with the EnSure device and generate a CFU value by multiplying the correction factor. EBS will provide quarterly calibration checks at no charge.
BUSINESS SPECIALISTS, LLC
EXAMPLE 1:Weekly data was collected from a paper and pulp mill with an aerated stabilization basin (ASB) wastewater treatment system. Figure 2 shows Influent BOD combined with ATP values from the first basin of this WWTP. Data shows there are trends in food source entering the system and the amount of free and microbial ATP values. Drops in ATP values appear to be related to the loading entering the system. Note that the ATP values recover after the decreases, suggesting the bacteria are acclimating to the food source (incoming BOD).
EXAMPLE 2: ATP measurements were utilized for a treatability study in which a pulp and paper mill with an activated sludge WWTS wanted to use a new biocide in their production process. They were concerned about adverse effects on the activated sludge microorganisms, so a simple experiment was designed to evaluate free and microbial ATP levels at three different exposure times for the test biocide. Influent was mixed with specific concentrations of the biocide and ATP levels were measured at three different intervals. The results showed that there was a slight shift in the distribution of the ATP from microbial (cellular) ATP to free (exocellular) ATP, which would indicate an increase in the number of lysed cells over time (Figure 3). However, the magnitude of this increase was relatively small, indicating that the biocide dosage tested would not have a significantly adverse impact on the activated sludge system.
EXAMPLE 3: In order to demonstrate the applicability of the Total Viable Count component of the RBA Kit, samples from two pulp and paper activated sludge systems were analyzed using both the RBA Kit test with a 7-hour incubation and traditional plate counts incubated for 48 hours. Figure 4 shows the excellent relationship between the two methods for both sets of samples.
At EBS, we are committed to assisting our client in reducing the risk of wastewater non-compliance with the goal of minimizing or preventing the impact of upset conditions, loading events, or seasonal variations. The EBS RBA Kit is just another of the EBS products and services designed to help our clients reach these goals. For more information on the EBS Rapid Biomass Assessment Kit, please contact us at [email protected] or at 985-674-0660.
EXAMPLESThe ATP measurements are being used to monitor AS and ASB wastewater treatment plants from industrial processes. Determining the ATP levels of wastewater microorganisms enhances the operators ability to predict and troubleshoot problems, such as presence of inhibitory or toxic compounds, poor BOD removal and/or high loading events.
A relative light unit (RLU) is the standard
unit of measurement in bioluminescence, and is used
here to measure levels of adenosine tri-phosphate. As ATP in a sample mixes with ingredients in the test kit, it produces bioluminescence. Luminometers measure and
quantify this bioluminescence. It is a very simple correlation, the greater the RLU value, the
more ATP in the sample.
Figure 2. Influent BOD and ATP
Figure 3. Activated Sludge - Biocide Addition
Figure 4. Comparison of Viable Bacteria Counts for Two Pulp and Paper Mill Activated Sludge Systems
