Bactest

Wastewater Management

Fundamental to the process of dealing with sewage and wastewater is the generation of a stable Activated Sludge or biological Floc. Activated sludge is the actively growing biological material containing a mixed yet balanced population of microorganisms controlled within the process plant for the purification of raw sewage. Raw sewage enters the process and is combined with a quantity of established floc (from the end of the process) to seed the appropriate microorganisms and develop a new biological floc which over time reduces the organic content of the sewage. The process is continuous and kept in balance by adjusting flow rates of nutrient (sewage) and by maintaining the correct oxygen content within the floc to allow efficient microbial growth and purification.
Atmospheric air or pure oxygen is forced into raw sewage by large compressors to maintain the gaseous composition of the highly active floc.

Critically, large amounts of energy are used for the various pumping processes, forming the majority of the process cost and adding significantly to associated carbon emissions. Water utilities are major consumers of electricity.

Microbial monitoring systems employed in the water industry normally utilise Dissolved Oxygen technology based on submerged electrodes, with samples usually taken off-line and tested within a laboratory environment. Laboratory testing is generally located away from the process plant and the test results, process monitoring and control are slow and cumbersome.
Measurement of dissolved oxygen by current methods has issues of electrode fouling and unreliability, is only appropriate to larger installations, and limited in the metabolic processes that are monitored.

Inefficiency results in very high energy usage, process costs and associated carbon emissions.

Within current regimes there is little regard for operator safety despite the potential hazards of pathogenic microbial contaminants within the sample.