(2018) Science of the Total Environment_Characterization of bioenergy biochar and its utilization for metal/metalloid immobilization in contaminated soil

Yang X., Igalavithana A.D., Oh S.-E., Nam H., Zhang M., Wang C.-H., Kwon E.E., Tsang D.C.W., Ok Y.S.

(Elsevier B.V.) Science of the Total Environment ISSN: 489697 Vol.640-641 Issue. Article No. DOI: 10.1016/j.scitotenv.2018.05.298

This study is a comparison of the effect of biochar produced by bioenergy systems, via the pyrolysis and gasification processes, on the immobilization of metals/metalloids in soil. Because the processes for these two techniques vary, the feedstocks undergo different heating regimens and, as a result, their respective char products exhibit different physico-chemical properties. Therefore, this study focuses on (1) the characterization of derivative biochar from the bioenergy system to understand their features and (2) an exploration of various biochar impacts on the mobility of As and Pb in contaminated soil. The results showed bioenergy biochars (BBCs) performed well in mitigating Pb extractability (1 M ammonium acetate) with a Pb immobilization >80%, but unfavorably mobilized the bioavailable As, likely because of electrostatic repulsion and ion exchange competition. The BBC surface functional group would chemically bond with the As and remain stable against the pH change. An increment in aromatic carbon would effectively enhance cation-π interaction for Pb immobilization. Nevertheless, an amendment with richer condensed structure and higher inorganic minerals (Ca2+, K+, Mg2+, and Na+) can lead to better performance in retaining Pb. © 2018

This work was supported by the National Research Foundation of Korea ( NRF ) ( NRF-2015R1A2A2A11001432 ) and a Korea University Grant. This work was supported by the National Research Foundation of Korea (NRF) (NRF-2015R1A2A2A11001432) and a Korea University Grant.