Frequently Asked Questions

• Suspended solids have suddenly started weiring over from the secondary clarifier. Why?

This could be caused be several different process problems, all of which are linked to the microbiology of your process. It may be filamentous bulking, slime bulking, sludge burnout, dispersed bacterial growth, or denitrification in the clarifier. Analysis of your biomass by The Wastewater Specialists can help you identify the cause of the problem, and identify appropriate remedial actions. 

• We haven’t undertaken microbiological analysis of our biomass before, so why should we start now?

Microbiological analysis can provide a valuable proactive process monitoring tool. The biomass in a healthy, stable treatment process will be predictable. Once the normal biomass for your plant is understood, this can be used as a benchmark to identify adverse changes such as overloading, toxic shock, or adverse environmental conditions. These microbiological changes can be used to help formulate an appropriate response.

• We undertake our own microbiological analysis on site, so why should we use your service?

Three key reasons:
1) It is always good to get a second opinion from an experienced professional who can look objectively at the results.
2) Analysis by a third party provides calibration of your own evaluation.
3) The Wastewater Specialists are equipped to undertake a variety of staining techniques which can be used to identify types of filamentous bacteria. Where filamentous bulking occurs, identification of the filament type is critical to formulating an appropriate response.

• We undertake other process monitoring (such as MLSS, settleability, DO, ammonia, nitrate, phosphorous, etc), so why would we be interested in microbiological analysis?

Chemical analysis is important for proactive monitoring WwTP’s, however in many situations changes in chemical parameters can occur relatively slowly, and by the time the changes are identified serious process failure can occur. Microbiological analysis can be used as part of a proactive process monitoring programme as changes in microbiology are often evident before resulting chemical changes occur.

• How often should we undertake microbiological analysis?

Ideally, at least once per sludge age. For example, if you are running at a sludge age of 14 days, analysis should be undertaken fortnightly. However, it is understood that in some situations (short sludge age processes, small treatment plants) this may be cost prohibitive. To get value from the microbiological analysis, it should be undertaken frequently enough to allow the “normal” biomass to be understood for a particular treatment plant, so changes from the norm can be identified.

• Where in the treatment process should samples be taken for microbiological analysis?

Samples should be collected from the aeration basin at a location with good mixing just prior to the secondary clarifier (or from the membrane tank in MBR processes, or the decant end of SBR processes). Samples should be collected from below the surface. If surface foam is of concern, take a separate sample of the foam. 

• What is the best way to send biomass samples to you for microbiological analysis?

You should send your biomass sample in a small, unpreserved sample jar, filled approximately 1/3 with sample. The air in the top of the sample jar will help maintain aerobic conditions. The sample jar must be clearly marked with the name of your wastewater treatment plant and the date the sample was collected. The lid should be screwed on tight, and the sample jar placed inside a sealed ziplock bag inside an addressed, sealed courier bag.

• How much does the microbiological analysis cost?

$330 + GST.