Possibilities of Determination of Risk Elements in Alluvial Agriculture Soils in the Mže and Otava River Basins by X-Ray Fluorescence Spectrometry

Abstract

Abstract The undesirable, hazardous, and risk elements are introduced into all environmental parts through human activities. They enter the soil and aquatic environment by atmospheric deposition, or by application of sewage sludge, pesticides, mineral and organic fertilisers, and by organic manures. Heavy metals (HMs) and risk elements can be determined in the soil by a wide range of analytical methods that differ in terms of time and financial costs, and the demands on service. One of the methods is the use of a portable XRF spectrometer under lab conditions, offering relatively fast determination of the concentration of chemical elements in the soil. In the presented study we evaluated the accuracy and the precision of the XRF device for analysis of the concentration of heavy metals (Pb, Zn, As, Mn, Cu, and Ni) in alluvial soils from the Mže and Otava river basins (Czech Republic), and validated and compared obtained results with the conventional lab method (ICP-OES). The soil samples (n = 502) were taken at 43 sampling sites at depths of 0 – 30, 30 – 60, and 60 – 90 cm, mainly in floodplains with Fluvisol soil type (N-year flow rates = Q100 m3/s). The multiple correlation coefficients R values ranged from 0.81 to 0.99. The R2 determination coefficients for individual HMs, measured by XRF, were determined as follows: Pb – 0.98, Zn – 0.97, Cu – 0.80, Mn – 0.79, As – 0.78, Ni – 0.66. According to our results, 66 – 98% points fit the designed models. The Pb and Zn have the best dependency (relationship tightness), and regression models are excellent. Cu, Mn, and As have a slightly worse dependency (tightness of the relationship), but the regression model is still very well suitable for agriculture practice, or for the purposes of environmental monitoring.