Sustainability assessment of wastewater reuse in a Portuguese military airbase

The current water-scarcity crisis that is being felt in Europe, namely in the southern region, has leveraged the development and implementation of national and regional water management plans. These policies aim to promote efficient wastewater reuse in industrial and urban sectors. Thus, stakeholders are now seeking strategies to enhance the sustainability of their wastewater treatment processes. The present work details the evaluation of the wastewater treatment methods used at an Air Force Base located in Portugal. In addition, this study also intended to determine how wastewater reuse can be implemented and add value to the environmental protection mission of the military airbase. Hence, an assessment of wastewater treatment practices was carried out, considering primary and secondary treatments. The chemical, physical, and biological indicators of samples collected over two consecutive years were analyzed to determine trends and fluctuations. The results revealed that the overall effectiveness of nutrient removal is low due to the oversized nature of the treatment plant, the age of the facility, and the composition of the wastewater. The effluent produced meets standards for non-potable reuse and could be used on base for aircraft maintenance and the cleaning of facilities. Nonetheless, the effectiveness of the plant could be improved by implementing a more advanced tertiary wastewater treatment to decrease the concentration of undesired compounds (e.g., total nitrogen), enabling the reuse of water in a broader range of activities.