Problem
A government installation with a 2.6 million gallon thermal storage system of loop water was in need of a cost effective microbiological control program. The system was known to have a slime layer in the storage tank. Actual biocide treatment history was unknown and undocumented.
Analysis
A cost effective microbiological control program can be a challenge in these systems. Further compounding the problem, degradation byproducts from traditional biocides leave organic residues that can ultimately provide a nutrient source for the bacterial population. Chlorine dioxide (ClO2) is not like traditional biocides. ClO2 is a dissolved gas in solution and is normally generated onsite from precursors. The resulting solution is fed to achieve a residual between 0.5 to 1.0 ppm as ClO2 and leaves no byproducts useful in biological assimilation.
Chem-Aqua Solution
Chem-Aqua supplied the chlorine dioxide generator, the chemistry, and the knowledge to bring a cost effective solution. The system is 3-precursor generator product engineered to use the system water as the motive water and directly injecting the product into the system. A quarterly treatment scheme was initiated. After the third application, a residual was achieved in the system, indicating that the associated chlorine dioxide demand from bacteria and other contaminants had been overcome. It has been more than a year since the last treatment, and ongoing microbiological tests do not indicate a need for additional treatment.
Results
Chem-Aqua’s recommendations helped resolve the microbiological issue and provide an immediate savings of over $85,000 as compared to traditional biocides. Additional savings of over $156,000 are available as a result of not having to treat the system quarterly with a traditional non-oxidizing biocide.
CS3-002