Research Progress on the Transformation of Heavy Metals in Hydrothermal Carbonization of Excess Sludge
The ecological risk of heavy metals is a major obstacle to sludge hydrothermal biochar resource utilization.How to effectively stabilize and immobilize heavy metals in sludge biochar to prevent their release has been a difficult problem for the harmless treatment and resource utilization of sludge.The review analyzed the transformation patterns of heavy metal content and chemical speciation during the sludge hydrothermal carbonization process,and summarized the effects of reaction time,hydrothermal temperature,pH,chemical additives and biomass on the heavy metal content and speciation of sludge hydrothermal biochar.Finally,an outlook on the future research direction was proposed to provide a reference for the immobilization of heavy metals in sludge hydrothermal biochar.
hydrothermal carbonizationexcess sludgeheavy metal