Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy • Author Copy Introduction Heavy metals are naturally present in soils but may be enhanced due to anthropogenic activities such as metal ore mining and smelting processes. Poland is one of the biggest copper producers, contributing 3.6% of the global copper market. More than 70 years of copper industry development in SW Poland has resulted in signifcant pollution of soils in the vicinity of mining and smelting sites. Initially high acidifcation of soils due to high emissions of sulfur dioxide from smelting and secondary mobilization of heavy metals such as lead (Pb), copper (Cu), cadmium (Cd), zinc (Zn) or arsenic (As) has led to serious chemical degradation of soils and the exclusion of large areas from agricultural use. Even if the scale of these activities is local, it may cause widespread environmental pollution and should be considered as sources of environmental and health risks associated with the transfer of heavy metals to the food chain and human exposure. To reduce the risk, the bioavailability of heavy metals can be modifed, leading to the decrease of their accumulation and toxicity in Pol. J. Environ. Stud. Vol. 29, No. 2 (2020), 1-9 Original Research Effect of Biochar Application on Heavy Metal Mobility in Soils Impacted by Copper Smelting Processes Agnieszka Medyńska-Juraszek*, Irmina Ćwieląg-Piasecka Institute of Soil Sciences and Environmental Protection, Wroclaw University of Environmental and Life Sciences, Wrocław, Poland Received: 27 February 2019 Accepted: 24 April 2019 Abstract Biochar seems to be a very promising material for remediation, reducing heavy metal mobility in contaminated sites. However, the effect of its application on soil depends on biochar origin, pyrolysis condition, soil type and properties like initial pH or cation exchange capacity, and also on metal form and interactions. This makes prediction about successful remediation with biochar more diffcult and a lot of attention should be paid to choose the proper material appropriate to soil conditions. The aim of our study was to evaluate wheat straw biochar application on multi-contaminated soil, to decrease their mobility and minimize the risk of heavy metal occurrence in the area impacted by copper smelting processes. The results of this study indicate that wheat straw biochar application can potentially reduce Cu, Pb, Zn or Cd mobility only in sandy or acidifed soils due to the liming effect. In alkaline soils the effect of biochar application on metal immobilization was imperceptible. The effect of wheat straw biochar on heavy metal immobilization in multi-contaminated soils is more complex and cannot be defned as all-purpose material in remediation procedures. Keywords: soil pollution, heavy metal, biochar, remediation *e-mail: agnieszka.medynska-juraszek@upwr.edu.pl DOI: 10.15244/pjoes/108928 ONLINE PUBLICATION DATE: