FRAME: A Novel Framework to Assess and Manage Contaminants of Emerging Concern in Indirect Potable Reuse

Scarcity of freshwater resources in many regions of the world is one major obstacle for sustainable development. Potable water reuse strategies, both direct and indirect, are widely recognized as adequate measures to overcome this hindrance by reducing the need for freshwater resources. To ensure a high water quality in indirect potable reuse (INPR) systems, potential adverse effects of partially closed water cycles must be identified, assessed and managed. Contaminants of emerging concern (CECs), such as anthropogenic pollutants and pathogens, pose a potential threat to INPR systems. In the new research project FRAME, which started in January 2015, a cluster of seven European research institutions aims to develop an overall evaluation scheme to comprehensively assess and manage CECs and pathogens in INPR systems.

Within the project, the Chair of Urban Water Systems Engineering is responsible for the development of novel treatment combinations to be integrated in INPR schemes. Therefore, the research group Engineered Natural Treatment Systems conducts pilot-scale studies to evaluate reliable and cost efficient treatment strategies. Besides oxidation, adsorption and membrane processes, enhanced biofiltration is a promising technology for the mitigation of CECs in tertiary wastewater treatment plant effluents. The novel concept of sequential biofiltration combines high rate and low rate biofiltration to establish aerobic, carbon limited conditions in a sequential biofilter. Under such conditions, a highly diverse microorganism community, capable of degrading CECs, is established.

The experimental setup with four filtration trains allows for a large variety of filtration modes. Filter trains consist of two filters with different characteristics operated in series. Besides different filter materials (granular activated carbon (GAC), anthracite, sand) and hydraulic regimes, also hybrid processes (biofiltration + ozone/AOP) will be tested.

Project leader Dr.-Ing. Uwe Hübner
Researcher Dipl.-Ing. Johann Müller