Simultaneous scavenging of Cd(II) and Pb(II) from water by sulfide-modified magnetic pinecone-derived hydrochar

Sulfide-modified magnetic hydrochar described as MHC-S4 was synthesized by simultaneously supporting Fe3O4 nanoparticles and grafting sulfide-containing groups onto pinecone-derived hydrochar. The MHC-S4 could effectively adsorb Cd(II)/Pb(II) over a wide pH range, and could achieve fast uptake equilibrium within 25 min. Moreover, the MHC-S(4 )possessed excellent adsorption properties in single system with maximum monolayer uptake of 62.49 and 149.33 mg/g for Cd(II) and Pb(II). While the binding rate and uptake of metal ions by MHCS4 in binary system were inferior to that of single system, and Pb(II) exhibited conspicuous inhibition to Cd(II) adsorption onto MHC-S4. Furthermore, the MHC-S-4 was demonstrated to achieve excellent Cd(II)/Pb(II) binding primarily through electrostatic interaction, ion exchange and complexation. These results suggested the sulfide modified magnetic hydrochar as a high-performance adsorbent for heavy metals removal.

Automated summary

Sulfide-modified magnetic hydrochar (MHC-S4) was synthesized and found to effectively adsorb Cd(II)/Pb(II) over a wide pH range and achieve fast uptake equilibrium. In single system, MHC-S4 showed excellent adsorption properties with maximum monolayer uptake of 62.49 and 149.33 mg/g for Cd(II) and Pb(II), respectively. However, the binding rate and uptake of metal ions in the binary system were inferior, and Pb(II) exhibited significant inhibition to Cd(II) adsorption onto MHC-S4. The results suggested that sulfide-modified magnetic hydrochar is a high-performance adsorbent for heavy metals removal.