Abstract
A two-year soil incubation experiment was performed to investigate the long-term impacts of biochars (kenaf core and sewage sludge biochar (KBC and SBC) pyrolyzed at 350 °C and 550 °C) on metal(loid)s immobilization. Both KBC and SBC can immobilize Pb and Cu in contaminated soil, whereas they showed little effects on the immobilization of Zn, Cd and As. Interactions between the biochar and soil during two-year aging changed the metal species on both soil and biochar particles. KB350 formed more biochar-mineral complexes and O-containing functional groups than KB550 and thus transferred more residual metal(loid)s to their reducible species. More metal(loid)s sorbed on the KB350 than KB550 after two-year aging. However, SBC changed the acid-soluble species of metal(loid)s into the residual species during the aging process, probably due to the release of phosphate. Upon aging, SB550 exhibited a more significant increase in the residual metal amount and more sorption of metal(loid)s on the biochar particles than SB350 due to sorption of organic carbon and formation of meta-kaolinite. A key finding of our study was that different biochars have contrasting impacts on metal speciation and lability upon 2-year aging. This should be considered in assessing the actual risk of biochar-amended soils.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.