1-STEP® filter: the Magic bullet for phosphorus and nutrient removal
Kramer, F.1, Menkveld, W.2, Gray, J.3 and Bechger, M.4, 1Witteveen+Bos Consulting Engineers, the Netherlands, 2Nijhuis Water Technology, The Netherlands, 3Nijhuis Industries UK & Ireland, 4Waternet, The Netherlands
(free)
Abstract
To ensure a cleaner and protected environment and human health conditions for the future, both UK and EU environmental legislation require further improvement of surface water quality by advanced wastewater treatment. Ultra-low phosphorous standards (< 0.25 mg P/L) combined with low nitrogen and total suspended solids standards are on the way in the upcoming asset management plans. As a consequence, additional treatment and extension of wastewater treatment plants (WWTPs) by tertiary treatment becomes necessary.
The 1-STEP® filter is the most cost-effective total tertiary treatment solution available to improve the effluent quality of municipal sewage treatment plants. This compact, efficient and effective total tertiary treatment solution has been developed and successfully implemented in the Netherlands over the last decade. This paper presents the results of full operation over six years (2012-2018) of the 1-STEP® filter at WWTP Horstermeer of Waternet, Amsterdam. The 1-STEP® filter is a modular and compact fixed-bed activated carbon filter, combining four processes in a single treatment unit. In addition to the removal of suspended solids by filtration, nitrogen is simultaneously removed via biological denitrification (using a selective carbon source), chemical phosphate and heavy metals are removed by coagulation and flocculation (with a low dose of metal salt), and, if required, organic micro-pollutants and medical residues can be removed by adsorption onto the activated carbon.
