COMPARISON of the DISTRIBUTION of ENVIRONMENTALLY HAZARDOUS ELEMENTS in COAL with KRIGING and IDW METHODS (TEKİRDAĞ-MALKARA COALFIELD)

Abstract

Coal is a fossil fuel that can have negative impacts on the environment and human health during extraction, transportation, and burning. In this study, samples were collected from eight boreholes in the Tekirdağ-Malkara coalfield and the major-trace element analysis was performed. Lithology data obtained from boreholes constitute well logs. Interpolation forms the basis of log correlation. The study aimed to determine the local areas that may pose a risk after selecting the interpolation method that provides the most accurate results directly in the study area. Among the elements, those that may cause environmental and human health problems were selected and divided into four groups according to their hazard class. The distributions in the whole field were estimated by Kriging and Inverse Distance Wighting (IDW) interpolation methods. These two interpolation methods were evaluated with a selected test probe and the Kriging method was determined to provide the most accurate results. With this method, the accuracy of results obtained with the elements in the hazard class were as follows: Hg and Cr 100%, Se 98.86%, Cd 75%, As 66.2%. After determining Kriging as the method to be applied, a re-classification analysis was carried out, and estimates made in the field were compared with coal from Turkey, the US, China, and the average upper continental crust. As a result of this comparison, the elements with the highest rate of distribution in all averages were determined as Be, Cu, V, and the elements with the lowest distribution rate were Mn, Mo, P, Sb