Problem: Thames Water’s Sewage Treatment Works in Beckton, East London needed a system that would prevent the wash-water nozzles from blocking and disrupting the screenings separation process. The treatment process features eight large screens that can operate continually to remove screenings from the sewage. Following primary and secondary treatment, washwater is fed into the screens via a series of nozzles to wash the sludge off and clean the screens and brushes.

Solution: A Bollfilter automatic filtration system has been installed comprising two Boll 6.19 automatic self-cleaning filters and CCD pumps mounted on one skid. The filters which operate under low pressure conditions are fitted to the wash-water inlet feed prior to the pumps, protecting these from possible particulate damage. A small amount of the pressurised washwater is fed back into the filters for efficient cleaning without the need for separate backflush pumps, creating a low energy, space efficient solution.