UV rays

More UV, Better Disinfection: Ambiorix vs Conventional Iron Chelates

UV disinfection is often used in horticulture to safeguard the hygienic quality of nutrient solutions. Its effectiveness depends heavily on UV transmission, which is the solution's ability to let through the UV rays needed to inactivate microorganisms. One of the factors that can influence this transmission is the presence of iron.
10 December 2025

CDDM Prepares Trial Setup

The Departmental Committee for Market Gardening Development (CDDM) in Nantes organised a trial to test Ambiorix against two competitors. The trial aimed to compare the effect of three iron sources (Ambiorix, Competitor 1 and Competitor 2) on UV transmittance, and determine the extent to which these differences could influence the performance of UV disinfection systems.

For each of the three fertilisers, a stock solution was prepared by diluting 1g of product in 500 mL of raw water. Based on these solutions, the required amounts were calculated to achieve each target concentration, applying the same approach across all products and concentrations.

Ambiorix chart
Results transmittance analysis

Measurement of the UV-transmittance

A transmittance analysis was carried out using a UV‑T meter (UV transmittance meter), this was performed thrice to ensure the reliability of the data.

Results

The trials were conducted at five concentrations (10–50 µmol/L), with average transmittance measured. The graph (Figure 1) shows three distinct behaviour patterns:

  • Ambiorix: high transmittance with only a slight decline despite increasing iron concentration.
  • Competitors 1 & 2: lower transmittance and a rapid decline associated with increasing iron concentration.

The loss of transmittance was roughly half as high with Ambiorix compared to the competitors.

Conclusion

The results show that Ambiorix behaves differently from conventional chelates, which show a steeper decline in UV transmittance as iron concentration increases. At higher concentrations, Ambiorix allows up to 30% more UV to pass through, delivering a higher UV dose and improving disinfection efficiency.

Consequently, Ambiorix is less likely to limit the effectiveness of UV disinfection , while also significantly lowering iron‑related decline in UV performance. With conventional chelates, monitoring UV transmittance at higher iron levels may be necessary.

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