PROJECT DESCRIPTION
BACKGROUND
Groundwater is the main source of drinking water for people living in rural areas in Mediterranean countries. However, because of pollution, severe drinking water shortages exist. Anthropogenic pollution by way of nitrate and pesticides is one of the main water quality problems in small and very small water supplies. Approximately 13% of groundwater monitoring stations across Europe exceed the 50 mg NO3/L limit established by Council Directive 91/676/EEC on protection against water pollution. However, in Mediterranean countries like Spain, this percentage rises to over 40%.
OBJECTIVES
The main objective of LIFE SPOT was to develop a new treatment process which removes nitrates and micropollutants from polluted groundwater and produces drinking water of good quality that meets the requirements of Council Directive 98/83/EC on drinking water quality. This method aimed to be replicated in rural areas with 50 inhabitants or <10 m3/day water consumption in the Mediterranean region. The project also sought to help in making rural areas more sustainable and resilient and in supporting the agriculture and tourism sectors.
The project aimed to build and operate 2 microalgae-cork (MA-cork) pilot treatment plants, the first treating 10 m3/day and the other 1 m3/day. Both MA-cork pilot plants used photobioreactors (bio-solar purification) and dissolved air flotation technology to enable microalgae separation and a filtration system based on granulated cork as a substrate.
LIFE SPOT supported the Council directives on drinking water quality (Directive 98/83/EC) and nitrates pollution (Directive 91/676/EEC).
RESULTS
The project has managed to achieve its main objective, demonstrating that the LIFE SPOT technology can decrease nitrate concentration below 50 mg/L and pesticides levels below 0.1 mg/L– the limits required to comply with the Drinking Water Directive – and to remove other contaminants (antibiotics/antibiotic resistance genes) present in the groundwater. To achieve this, the project designed, constructed and monitored 2 pilot plants for the treatment of polluted groundwater.
The groundwater treatment technology tested was based on a microalgae photobioreactor, a dissolved air flotation system and, a cork/wood biofilter. Although the performance of the pilots was lower than envisaged, up to 1 200 m3 of treated water have been produced and its quality tested on livestock (rabbits) with positive results. The project also managed to demonstrate at laboratory scale that microalgae sludge produced by the technology can be valorised and reused as phosphorous in the photobioreactor to produce biogas, and to produce algae-based fertilisers. Nonetheless, further research is needed to assess the real potential of the final products.
The LIFE SPOT technology resulted in demonstrating a feasible solution for isolated water consumers, rural households and small farms, especially during water scarcity periods. In this regard, replication and transfer projections have been defined for a 5-years horizon after the end of the project. This forecast includes replication in different locations for drinking water production and the replication of the LIFE SPOT methodology in 2 different scenarios (wastewater treatment plants and Reverse Osmosis brines treatment).
