Using Turbidity control to Reduce Sand Trickle Filter. More info below.
Partech recently worked with a UK water company on a Sewage Treatment Works with disproportionately high electricity costs caused by running Sand Trickle Filters continuously. Their effluent was constantly being sent through final Sand Trickle Filters for tertiary treatment, even when it was well within the discharge consent levels.
The works served a population equivalent of 6500 and pumped final effluent from settling tanks into the Sand Filters for tertiary treatment via four pumps prior to discharge into the nearby river. The issue with the system was that the effluent was constantly being pumped into the Sand Filters, regardless of whether it needed to be, incurring high pumping costs, pump run times and unnecessary maintenance on the Sand filters. Being able to reduce the amount of time the pumps were running would save electricity and mean less wear and tear on the pumps and cut down on servicing.
Partech installed a turbidity sensor in the effluent chamber to use turbidity as a measure of when the effluent required tertiary treatment. Turbidity was selected as the control parameter, as it closely matched the visual observations of the site operators who were confident that the sand filter did not need to operate all the time.
By using the Turbidity control the water company reduced the pump run times from over 18 hours per day to around 4 hours, even on this mid sized work the savings equated to 62KWH per day per pump, with the additional reduction in maintenance that 24/7 operation causes.
Our self-cleaning TurbiTechw² LS sensor operates for extended periods of time and therefore does not create any additional maintenance work, with only a quick check being required when other maintenance is being carried out on the sand filters.