The effect of biochar on migration of selected heavy metals to soil, waters and plant biomass and physical and chemical properties of soil

In general, biochar used to improve soils has a positive effect on their physical, chemical, and microbiological properties. Most often, it improves yielding and processing quality of biomass. However, due to the risk of introducing a number of xenobiotics into the soil with biochar, such as heavy metals, polycyclic aromatic hydrocarbons, or phenols, the quality and properties of this product should be monitored on regular basis. The main aim of the study was to analyze the effect of the use of biochar to enrich soils on their sorption properties. Three types of sandy soils were used for biochar fertilization. Biochar from burning of Sida hermaphrodita was added to the soils with the amounts of 1% and 2%. pH (active acidity), hydrolytic acidity (potential acidity), nitrogen and phosphorus content, organic matter, total carbon, and heavy metals were studied. Migration of heavy metals to soil waters and S. hermaphrodita biomass from soils fertilized with biochar were also studied. The use of 1% and 2% biochar for fertilization of sandy soils did not significantly reduce the mobility of heavy metals in soils and the accumulation of these elements in the examined plants. The content of heavy metals in the infiltrating water from most of the research objects ranged from Class 2 (good quality water) to Class 3 (satisfactory quality water) for groundwater.