Four water technology projects honoured within PPP call for Agriculture, Water and Food

The water technology projects concern PFAS, climate adaptation in low-lying areas of the Netherlands, effluent reuse in greenhouse horticulture, and micronutrients in the circular loop. The results should provide answers to issues raised in the Agriculture, Water and Food knowledge and innovation agenda, concerning climate-proof rural and urban areas and the improvement of water quality.

PFAS

Per- and polyfluoroalkyl substances (PFAS) constitute a hazard for humans and the environment, and monitoring programmes have shown that these substances are present. But this only concerns a fraction of the more than 4,700 registered forms that make up the complex PFAS mix. We therefore do not know which ones are present in surface and drinking water, nor how they spread. A further complicating factor is that industry is constantly replacing regulated substances with more alternative PFAS. These are often not covered by the existing monitoring programmes.

This problem is tackled head-on in the project called ‘An integrated approach to the detection of undesirable perfluorinated substances in the water cycle’. By means of trend analyses, the presence and spread of both per- and polyfluoroalkyl substances will be determined, so that more locally-targeted (simpler and cost-efficient) measurement procedures can be set up to monitor water quality.

Climate- and water-robust low-lying areas of the Netherlands

Another water technology project in the series of approved PPP projects aims to develop guidelines for the climate-adaptive planning and land-use in low-lying areas of the Netherlands. Rural areas are encountering problems as a consequence of climate change and the intensive use of the natural system. Drought and an inadequate understanding of (changes in) water supply and demand, flooding, salinisation, land subsidence and unsatisfactory water quality are all issues that need to be addressed with a view to finding solutions.

The project called ‘Climate- and water-robust low-lying areas of the Netherlands from now to 2100’ involves collaboration with several stakeholders and users in rural areas – agriculture and nature, recreation, the agricultural complex and businesses – on a future-proof perspective for both the short and longer term (2050-2100). Using development and adaptation paths, these timelines can be interconnected by defining concrete steps and objectives. This will result in building blocks, measures, earnings models and adaptation paths, which are necessary for future-proof area planning and water management in low-lying areas of the Netherlands. Given its spatial and time scale, the project transcends the many initiatives that are already underway in this field.

Reuse of effluent

It has been demonstrated that the sharp improvement in the quality of municipal effluent means that it can be used by greenhouse horticulture in its crop production. A collaborative future plan called ‘Irrigation water supply for Greenport West-Holland greenhouse horticulture’ is thus now in the making, and includes an important option for effluent water from a collective’s WWTP and wastewater, or for wastewater from other industries or parties. But before the horticulturalists can make the transition to the reuse of effluent water, a blueprint assuring the irrigation water’s quality is needed.

The ‘Assuring WWTP effluent for the greenhouse horticulture sector’ project will meet this need. The idea is to continuously monitor signal substances. The water quality will be assured through the deployment of sensors, non-invasive monitoring techniques and decision-support systems (AI). And an acceptance strategy will have to get all stakeholders in the chain to collaborate with the risk management strategy based on an agreement on using the effluent, without risk to the crops or to public health.

Micronutrients in the circular loop

From the perspective of circularity, micronutrients in the agri-food-waste system deserve more attention than they now receive. As in the case of phosphates, micronutrients are extracted from geological reserves and used in the food chain in a linear fashion. Although consideration was given in the past to the reuse of organic residual streams, sludge streams and manure, it was not done with the functional value of micronutrients in mind. There is a strong desire to reshape this approach into a circular one.

The ‘Micronutrients in the circular loop’ project is directed at closing the loop of six to eight essential micronutrients in the Dutch food system within legal, environmental, economic and technological frameworks. The focus is on the direct (via the streams containing micronutrients) and indirect (following treatment of the stream) reuse of micronutrients. The project approach involves determining the nutrient stream loads and concentrations in residual streams, the plant availability of these micronutrients, and the development of value chains for recycled micronutrients.