Hydrochemical transformations of river waters during the flow in the reception basin on the basis of Olechówka River in ŁódźTomasz Bagrowicz, Anna Fortuniak, Michał Górecki, Milena Lewandowska and Maciej ZiułkiewiczE3S Web Conf., 17 (2017) 00002DOI: https://doi.org/10.1051/e3sconf/20171700002