Point-of-Use Re-Use (PU2R): a viable approach for sustainable decentralized reuse of water from single-household cesspits for agricultural irrigation

ABSTRACT Water reuse can contribute to climate-resilient water management because wastewater is available throughout the year. This can mitigate water stress and potential competition between drinking water supply, industry and agricultural irrigation. In rural areas, decentralized approaches may be advantageous compared with transporting wastewater to centralized treatment plants via diesel-powered trucks. The ‘Point-of-Use Re-Use’ (PU2R) approach proposes a mobile, small-scale wastewater treatment plant consisting of a membrane bioreactor (MBR) with UV disinfection for decentralized water reuse in agriculture. In this paper, the sustainability of the PU2R approach is evaluated, with focus on the following points: The capacity of flexible wastewater treatment from single-household cesspits in an MBR with activated carbon dosage and UV disinfection in combination with a H2O2-based advanced oxidation process is assessed.The fate of persistent and mobile organic micropollutants on the pathways from soil to plant and from soil to groundwater is analyzed. To support this, an open-source tool for a 50-year prognosis was developed.A cost assessment is carried out for the decentralized PU2R approach vs. the current wastewater disposal by truck transport and centralized treatment.A life cycle assessment of the potential environmental impact of the PU2R approach is examined for five impact categories.