N. Georgieva, Z. Yaneva, M. Todorova, R. Ivanova, N. Nizamov, P. Neicheva

Abstract. This study was designed to evaluate the ecological status and to define probable liquid/solid correlations of Zn distribution between dam waters and adjacent soils in Chirpan Municipality, as a part of a continuous water and soil assessment project of Stara Zagora Region. Zinc concentrations in the investigated water and soil samples were determined by atomic absorption spectrometry (AAS) on AAnalyst 800 Atomic Absorption Spectrometer, Perkin Elmer, over the period December 2009 – November 2010. The analysis of Zn temporal distribution in the dam waters revealed maximum heavy metal loading of the three surface water bodies during June 2010. The ecological assessment of the studied soil samples showed that Zn content in some of them surpassed the maximum permissible concentrations (MPC), according to Bulgarian state standards. Basic statistical parameters (standard deviation values), liquid-to-solid metal correlations, linear regression analyses and Principal component analyses (PCA) were used to rationalize and interpret the analytical data for both media. Relationships between Zn contents in dissolved (dam water samples) and particulate (soil samples) phases in Chirpan Municipality, ascertained a high degree of water/soil correlation during December 2009 (R2 0.9963) and July 2010 (R2 0.9033) in the three investigated compartments. Distribution coefficients (K ) of the trace metal between both phases presented as log K were in the range 1.98 – 3.26. The PCA confirmed the conclusions withdrawn on the bases of d d the chemical analyses and categorized the investigated sampling points into three classes – Class 1 (SP 216, SP 410A, SP 410-1A) with predominant Zn loading of the water bodies; Class 2 (SP 217, SP 418A, SP 418-1A) featured with excessive Zn soil contents; Class 3 (SP 215, SP 409A, SP 409-1A) with average levels of the heavy metal in both phases. The data of the present study provided a scientific basis for best-management practices of natural water and land use in the investigated municipality.