1-STEP® filter

Waternet, the integrated water cycle company for Amsterdam and the surrounding area, has been using the 1-STEP® filter at its Horstermeer Sewage Treatment Plant (STP) since 2013 in order to upgrade the quality of treated effluent to industrial reuse standards.

This modular and compact fixed-bed activated carbon filter simultaneously and effectively reduces the concentrations of total suspended solids, phosphorus, nitrogen, heavy metals, and priority and emerging substances. Measured over a period of almost five years, the treated effluent at STP Horstermeer has an average total nitrogen concentration of 2.2 mg/l and a total phosphorus concentration of 0.18 mg/l. The effluent easily meets the stringent requirements defined in the European Water Framework Directive, and can be used for irrigation purposes as well as directly fed into membrane filtration processes used in the production of industrial process water.

The beneficial reuse of both municipal and industrial wastewater can be maximised by implementation of the 1-STEP® filter. Witteveen+Bos collaborated with Nijhuis Industries, Waternet, Cabot Norit Activated Carbon and Delft University of Technology on the development of this comprehensive tertiary treatment solution. The project partners are offering the 1-STEP® filter as a patented black box solution to municipalities and industries worldwide.