Wastewater Reuse: An Economic Perspective to Identify Suitable Areas for Poplar Vegetation Filter Systems for Energy Production

The increasing interest towards climate change, water and energy saving, and soil protection has led the research community to consider non-conventional water as a sustainable source for irrigation of energy crops. Vegetation filter systems are considered a reliable technique for sustainable biomass cultivation, enabling the use of reclaimed wastewater as water and nutrients sources during irrigation periods. In this study, a geographic information system (GIS)-based spatial model was developed to identify areas potentially suitable for creating vegetation filter systems with poplars to size the plants of energy production. An economic assessment allowed us to identify the cost-effectiveness areas for biomass production that can be fertigated by reclaimed wastewater. Considering the Basilicata region as the test region, a surface area of 258,512 ha was investigated, identifying 73,331 ha of SRF soils sited downstream of 45 wastewater treatment plants (WWTPs). However, considering only areas that have positive net present value and are economically attractive, results indicate 1606 ha of SRF falling within the areas of influence of 39 WWTPs. The results show that the sector of dedicated crops, adjacent and linked with WWTPs, expresses a total capacity of 50.56 MW for thermal, 8.25 MW for electricity, and 31 MW for cogeneration (25.07 MWt and 5.94 MWe) plants.