In the field of sustainable water management, reclaimed water holds great promise: supplying irrigation in water-scarce regions, reducing the need for fresh water and synthetic fertilizers, and closing the loop in nutrient and water cycles. But such reuse must be safe — both agronomically and microbiologically — if it is to be feasible and accepted. At the heart of our PRIMA‑SAFE laboratory work lies exactly this: turning reclaimed water into actionable data that enables safe, practical reuse. In this latest work-package of the NEWater initiative, we analyse irrigation waters and treatment-plant effluents to track organic micropollutants, antibiotic-resistance markers, salinity and nutrient levels — all with the aim of ensuring fit-for-purpose reuse in Mediterranean and semi-arid agricultural systems.
Why analyze reclaimed water?
In Mediterranean agriculture, using treated wastewater can boost soil fertility, reduce fertilizer inputs and improve water-use efficiency. However, such waters can also carry potential hazards, including organic micropollutants (for example pharmaceuticals), pathogens or antibiotic-resistance genes (ARGs), pesticides and elevated salinity.
In the NEWater project, our goal is to apply nature-based, low-energy solutions — so we need data that identifies where standard treatments suffice, and where additional polishing or constructed-wetland or soil-filter interventions become essential.
What we test (and why it matters)
- We focus on three main categories of parameters:
- Pharmaceuticals & other chemicals of emerging concern (CECs), chosen because they are often found in treated wastewater and can migrate from water → soil → crops.
- Antibiotic resistance genes (ARGs) — because classical indicators (e.g., coliform counts) do not cover the microbiological risk dimension from resistance spread.
- Agronomic/chemical basics such as salinity, major nutrients, to safeguard soil health, microbial biodiversity and crop productivity
How the workflow works
Step 1 – From field to lab: Teams across our pilot sites sample influent, effluent and irrigation-line waters, following uniform protocols for sample handling and storage so that inter-site and seasonal comparisons are robust.
Step 2 – Prioritising what to measure: Rather than measuring every possible contaminant, PRIMA-SAFE used a screening of 148 pharmaceuticals, applying an occurrence-persistence-bioaccumulation-toxicity (OPBT) scoring framework. This enabled a curated list of 47 priority compounds for monitoring.
Step 3 – Bench-scale polishing tests: Beyond measuring, we test interventions too. For example, volcanic-ash derived soil was shown to adsorb the antibiotic trimethoprim (77.6 % removal under optimised conditions). These bench-scale data inform low-energy polishing choices for the field.
Step 4 – Nature-based pilots + genetic safety signals: In constructed wetlands, bio-augmentation (e.g., with Trichoderma asperellum) improved removal of compounds (diclofenac, benzotriazole) by >10 %, while ARG monitoring enabled tracking of microbiological risk trends. Polar compounds remain challenging — thus pointing to hybrid solutions (nature-based + polishing) within NEWater.
From data to decisions
All of this analytical and experimental work feeds into our overarching aim: safe, practical water reuse tailor-made for local conditions and farmers’ real needs. It links lab analytics, treatment optimisation, agronomic trials — bridging science and practice. In NEWater, we are particularly focused on low-energy, natural-based technologies (wetlands, soil-filters, adsorption media) that make reuse feasible in water-scarce Mediterranean regions.
What’s next?
In the coming months we will scale up the prototype polishing systems, integrate them with the agronomic monitoring of soil-crop systems, and refine a risk-informed decision-framework for reuse that can be transferred to other similar regions. Stay tuned for upcoming deliverables and pilot-site visits.