Abstract
Whether the heavy metals in solid biomass is activated or sequestrated during hydrothermal process (HTP) is still debated. Herein, the speciation of light and heavy metals during HTP of swine manure (SM) was investigated to reveal the interactions among these metal species and specific particulates. With increasing temperature, most of exchangeable species and that bound to carbonates were released to liquid phase via ion exchange and acid dissolution. Dissociation of Fe-Mn oxides rarely happened in spite of anoxic atmosphere formed during HTP. Substantial decomposition of lignocelluloses hardly caused significant liberation of fraction bound to organics. Instead, a part of fraction in liquid phase was re-captured by new oxygen-containing functional groups on solid product surface to form fraction bound to organics. Donpeacorite, butschliite and iwakiite were formed as primary minerals, resulting in increase of residual fraction of all metals except for K and Mg at 250 °C. In summary, Cu, Zn and Pb species evolution was affected by speciation of K, Ca, Mg, Fe and Mn significantly. Cu, Zn, Pb, Fe, Mn and Ca were sequestrated whereas K and Mg were activated with enhancing temperature during HTP in terms of their mobility factors.
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.