Content of Heavy Metals in Various Biochar and Assessment Environmental Risk

Biochar is a product of biomass pyrolysis and has a number of environmentally beneficial uses, but it can also pose risks if not managed properly. These risks are mainly due to the chemical structure of biochar, the content of heavy metals. The aim of this study was to evaluate the mobility and environmental risk of heavy metals in biochar produced from plant biomass (BB), municipal solid waste (MSW), compost (C) and coal refuse (CR). Pollution indices were calculated: geo-accumulation index (GAI), ecological risk (Eri), the underlying ecological risk caused by the total pollution (PERI). The total heavy metal concentration is variable and depends on the type of biochar. The results indicate that there is a high risk of cadmium pollution in the environment. The underlying ecological risk caused by the total pollution values indicated that biochar from coal waste was the highest. The results obtained show the importance of mobility analysis in assessing the potential for natural use of biochar.