Co-liquefaction of municipal sewage sludge (MSS) and heavy metal (HM) contaminated lignocellulosic biomass (rice straw or wood sawdust) was conducted at 300 °C with ethanol as the solvent to study the transformation behavior of HMs (e.g., Cu, Cd, Pb, Cr, Zn, and Ni). The results indicate that HMs in rice straw or wood sawdust transferred heavily to bio-oils (up to 10–25% of the total Cu, Cd, and Zn) when they were liquefied individually, compared with MSS with only ∼5% distributed to bio-oil. The bio-available fraction of HMs in bio-chars and bio-oils produced from liquefaction of individual biomass were assessed to show medium to high risk to the environment. Co-liquefaction promoted the distribution of HMs to solid bio-char. Moreover, co-liquefaction benefited the immobilization of HMs in bio-chars and bio-oils. Synergistic effects were found for HMs immobilization during co-liquefaction.
Bibliographical noteFunding Information:
The study was supported by the National Natural Science Foundation of China (Nos. 51668044, 51768043, and 21276069), the Key Research Development Program of the Jiangxi Province of China (Nos. 20161BBH80029 and 20171BBG70036), the Talent Program for Distinguished Young Scholars of Jiangxi Province of China (No. 20171BCB23015), the Science Foundation for Youths of Jiangxi Province, China (No. 20171BAB216037), and the Key Science and Technology Research Program of Department of Education of the Jiangxi Province of China (No. 150029).
© 2018 Elsevier Ltd
- Distribution behavior
- Heavy metal
- Lignocellulosic biomass
- Sewage sludge