Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption

- SS liquefaction bio-chars were effective on MG and MB removal from aqueous.
- MG adsorption capacity depended strongly on carboxylic and phenolic groups.
- Metal release accounted for nearly 30% of the total MG adsorbed on bio-chars.
- Acetone and low temperature favor effective adsorbent production by liquefaction.