Wastewater from a village in southern Portugal is affecting the water quality of the local receiving water. A hydroponic system strengthens local strawberry production while reducing nutrient concentrations in the wastewater. A feasibility study certified the economic viability of the implementation concept.

The wastewater from the approximately 800 inhabitants of the Portuguese village of Albernoa near Évora is collected and flows through a settling pond before being discharged into a stream. This falls almost dry in summer, negatively impacting the aquatic environment with high nitrogen concentrations that are barely reduced in the settling ponds.

The HypoWave concept offers a solution to this wastewater problem by using the dissolved nutrients of the treated irrigation water in a hydroponic system for the cultivation of strawberries after further treatment. On the one hand, this reduces the nutrient concentrations in the wastewater. In addition, some of the irrigation needs in local agriculture can be met from the hydroponic effluent.

An implementation concept was developed in a feasibility study. Activated carbon filters and UV irradiation remove micropollutants as well as pathogens and disinfect the nutrient-laden irrigation water. The strawberry plants, which are arranged in hydroponic systems in a greenhouse of almost 1 ha, are provided with optimal nutrient conditions and clean the wastewater as a result of their growth. The economic viability of the project is given on the one hand by the sales of the strawberries and on the other hand by the savings of an alternative wastewater treatment, savings due to a reduced need for irrigation as well as the improved water quality of the natural flowing water. In addition, jobs will be created to operate the plant in a rural area.