applying nature to wastewater
Where Biosol is being dosed or has been dosed to a sewer system for odour and
corrosion control, improvements in sewage process have been noted, in particular
reductions in nutrients, (N & P) TSS, BOD5/COD. The reductions vary but are generally
greater than 20% to 30%.
However they may be as high as an order of magnitude as seen in the Western Water’s
Sunbury treatment plant results where you will note that a 10 fold reduction in
phosphorus was achieved and approx. 50% reduction in Nitrogen
Laboratory and University research have given an understanding of how and why such
results occur. The explanation is relatively simple:
• There is increased readily available carbon at the treatment plant to aid N & P
removal
• Bacteria arriving at the treatment plant are NOT inhibited by toxins and metabolic
products
• Sulphide production is inhibited in the sewer catchment and sulphides do not inhibit
process
Increased readily available carbon at the treatment plant.
Biosol products send bacteria from the feeding biofilm / floc form to a single cell planktonic
form (survival form) in the sewer catchment. This reduces both the bacteria’s metabolic
(feeding) and reproduction rate by greater than 99%. This means that less carbon is
consumed in the sewer catchment and more carbon is available at the treatment plant for
improved process and nutrient removal. There is clear evidence of this change of state in
the KBR sponsored research from Victoria University supervised by Professor Stephen
Gray. The Griffith sewer pipe also shows this change of state in the bacteria in the sewer
pipe.
Metabolic product inhibition.
Bacteria in a floc or biofilm form have a poor ability to excrete wastes. These wastes
(toxins) build up within the exopolysaccharide matrix of the floc or biofilm and inhibit both
the metabolic and reproduction rate of the bacteria, which slows sewage process. This
reduction in the reproduction and metabolic rate can be seen the heterotrophic (standard)
plate counts for the controls in both the aerobic and anaerobic plate counts.
Bacteria freed of these metabolic products that have reformed into flocs or biofilms have a
much higher metabolic and reproduction rate as can be seen in the plate counts. Simply
more bacteria competing for the same food source will improve sewage process.
applying nature to wastewater
Increased bacteria with increased readily available carbon = Improved process and
nutrient removal. This is not rocket science.
Biosol manipulates bacteria.
Biosol sends the bacteria from floc or biofilm form to the single cell planktonic form and
floc / biofilm disintegrates releasing the excretory products into the wastewater stream.
About 8 to 12 hours later the flocs reform and are uninhibited by the metabolic toxins,
which enables a massive acceleration of the metabolic and reproduction rate of the
bacteria, leading to faster, better sewage process.
Sulphides
Dosing back in the sewage catchment to minimise sulphide production helps sewage
process. It is well known that sulphides inhibit microbial activity and sewage process.
Sending bacteria from the floc / bioflm form to the single cell planktonic form stops the
formation of sulphides. Sewage arriving at the inlet at the treatment has low sulphides
which means faster and more complete process.
Every sulphide molecule requires 4 atoms of oxygen to form sulphate. High levels of
sulphides arriving at the treatment plant not only cause extensive infrastructure corrosion,
but inhibit process as mentioned. The provision of oxygen to convert sulphides to
sulphates costs is expensive.
Odour & Corrosion Control
Recently I had the opportunity to survey part of a sewer system in South East Queensland.
The survey revealed extensive infrastructure corrosion with the surface pH of the
infrastructure as low as pH1. At pH 2, 50cm of concrete will be corroded in just 8 years
according to the Los Angeles Sanitary District Research. If the surface of the same 50 cm
of concrete is raised to pH 5, it will last 200 years. Dosing to control sewage odour,
minimises infrastructure corrosion and saves money.
Biosols Scientific Approach.
Biosol require the use of OdaLogs to measure sewer odour levels in sewer catchments
before and after dosing. Biosol also require the use of Universal Indicator Paper to ensure
that the surface pH of sewer infrastructure is increased so as to minimise corrosion rates.
Biosol also use Dr Richard Pomeroy’s (US EPA) model to predict the reduction in
infrastructure corrosion rates and measure the predictions against the actual rates using
universal indicator paper. This allows the use of a Biosol model that can predict the NPV
(Net Present Value) savings that can be made by deferring the replacement / relining of
sewer assets from say 1 years to 5 years or even 5 years to 20 years or more. This can
allow the most appropriate use of scarce capital.
In summary Biosol have the field results and the research to demonstrate that we can
assist in your EPA compliance issues. In the process Biosol has demonstrated the ability
to save millions of dollars in reduced infrastructure corrosion while reducing sewage
process costs.
www.biosol.net
E: sales@biosol.net
T: +61 (0)3 9515 5660
M: +61 (0)400 372 000