²¹⁰Po and major ions in drainage water from soil treated with various types of fertilizers

Abstract

The levels of ²¹⁰Po, nutrients (NH₄ ⁺, NO₃ ⁻, PO₄ ^{3 −}) and major ions (Na⁺, K⁺, Mg^{2 +}, Ca^{2 +}, F⁻, NO^{2 −}, Br⁻, Cl⁻, SO₄ ^{2 −}) were determined, by means of lysimeter experiences, in drainage waters for agricultural soils untreated and treated with different types of fertilizers (animal manure, sewage sludge and NPK synthetic fertilizer) applied at several rates. Analytical determinations were performed by using α -spectrometry in the case of ²¹⁰Po, or Ion Exchange liquid chromatography for the other ionic species. Statistical uni and multivariate analysis of the results shown significant differences among lixiviates according to the different fertilizer treatments. Sewage sludge and manure applications resulted in similar compositions of lixiviates with low ²¹⁰Po levels, whereas synthetic fertilizers produced higher ²¹⁰Po concentrations and different concentration patterns of ionic species when applied at or above the recommended rates. All ²¹⁰Po levels were well below the limits proposed by the 2001/928/ Euratom Recommendation. The concentrations of the rest of the ionic species, exception made from NH₄ ⁺ and NO₃ ⁻, were also below the limits proposed by Spanish regulations.

Keywords:

• Organic fertilizer
• NPK fertilizer
• sewage sludge
• leaching
• 210-Polonium

Acknowledgments

We are grateful to Laboratorio de Técnicas Instrumentales (LTI) of the Universidad de Valladolid for technical support. Authors wish to acknowledge to Agencia de Desarrollo Económico (ADE) of the Junta de Castilla y León for financial support.