This wastewater case study is a little more involved than most of the information we have. It involves the initial assessment of the use of F-TREAT in bioremediation of waste water. Specifically, the removal of Fats, Oils, and Grease (FOGs) and other organic wastes from the sewer lines in London, England and prepared for the Thames Water Utilities, LTD.
The bioremediation treatment on the Piccadilly Branch Sewer was the second such treatment by the Thames Water Utility using F-TREAT and was carried out as a result of successful tests achieved from a similar biotreatment on the sewer in the Parliament Street area.
The bioremediation strategy was planned after careful evaluation of all of the site conditions Dose rates were calculated on the length of the sewer to be treated and the extent of accumulation of fats and other solids.
The length of the sewer to be bioremediated covered approximately one kilometer and is estimated to have contained about 250 tons of FOGs and other organic solids. Sewage flow through this section of sewer was stopped for 6 of the 7.5 weeks of the F-TREAT treatment, a small input from local residences was inevitable.
The treatment of sewer by Custom Biologicals was carried out by the introduction of F-TREAT to the sewer line at three different entry points. Full dosing was carried out over 6 weeks followed by reduced dosing along with continued monitoring.
The tanks contained 200 Liters of concentrated F-TREAT which made a total of 2000 Liters when diluted for treatment purposes. The sewage line was monitored regularly throughout the treatment. Monitoring was conducted and a series of photographs and descriptive notes have been produced.
It is apparent from the notes and photographs made from physical inspection of the sewer lines by the Thames Water staff, that treatment using F-TREAT had a profound effect on the transformation on the fats in the sewage line. This transformation initially took the form of an overall softening of the solidified fat and later by the solubilizing of the fat, leaving the organic waste in a crumbly state.
It is important to note that the test was not designed to provide complete cleansing of the sewer line during the initial 7.5 week treatment period. This would not have been possible due to the extreme fat buildup and lack of constant water flow. Normal water flow was reestablished after the 9th week and a blockage did not occur. The previous test on Parliament street sewer line produced a more complete cleansing but followed a longer treatment period of 12 weeks, with the existence of a constant flow and less fat buildup.
The treatment of the Piccadilly Branch sewer line is continuing under conditions of constant flow. The existence of a constant flow of sewage through the sewer lines is an important factor in the success of the biotreatment. Such flow of sewerage not only provides an aqueous phase for bacterial proliferation but also a constant supply of nutrients and a means of flushing away solubilized fat products from microbial metabolism, not to mention the physical turbulence helping to break up the fat.
Bioremediation of city sewer lines is a complex. Contact Custom Biologicals on how the process of bioremediation of wastewater can help your sewage system.