József Zsolt PLÁSZTÁN¹, Mihály JÁNÓSZKY², Richard William MCINTOSH³ & Csaba Albert TÓTH^4
1Department of Physical Geography and Geoinformatics, University of Debrecen, 4032 Debrecen, Egyetem tér 1., Hungary, e-mail: plasztanj@gmail.com
²Agricultural Instrumentation Centre, University of Debrecen, 4032 Debrecen, Börszörményi út 138., Hungary, e-mail: mihaly.janoszky@gmail.com
³Department of Mineralogy and Geology, University of Debrecen, 4032 Debrecen, Egyetem tér 1., Hungary, e-mail: mcintosh.richard@science.unideb.hu
⁴Department of Physical Geography and Geoinformatics, University of Debrecen, 4032 Debrecen, Egyetem tér 1., Hungary, e-mail: toth.csaba@science.unideb.hu

STUDYING ENVIRONMENTAL LOAD IN THE RIVER BED SEDIMENTS OF BERETTYÓ RIVER AT BERETTYÓÚJFALU, EAST HUNGARY

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Signs of anthropogenic environmental load are detected in the river bed sediments of Berettyó River in the section at Berettyóújfalu. The geology of the river bed exposed by boreholes is described and sediment conditions and micro-element compositions determined at every 5cm in the river bed sediments are compared. Results of element analysis were classified based on geoaccumulation index (Igeo) and an environmental protection evaluation was performed using the limit values given in the KvVM-EüM-FVM decree 6/2009 (IV.14.). Sediment bodies observed in the river bed are currently formed by erosion and accumulation. Although their morphology and formation mechanism were identified the time of the start of their formation and the rate of accumulation were not possible to determine. Bed sediments are composed of silty, clayey small grained sand of fossil deposition, recent deposited sediment dominated by coarse – medium grained sand and reworked sediment of recent deposition showing recent and fossil characteristics as well. No significant difference between the median of humus content of the three groups was found, however, greatest standard deviation was found in the humus content values of fossil sediments within the groups. Element concentrations measured in every stratum and their changes are in close correlation with grain-size distribution. Element concentration co-change with the change of particle-size can be detected in the case of several elements. Based on geoaccumulation categorization and comparison with limits of the decree, all elements can be classified into contamination free categories (Igeo) not exceeding the limit of decree 6/2009 apart from arsenic and silver.