Removal of lead from water using biochars prepared from hydrothermal liquefaction of biomass

J Hazard Mater. 2009 Aug 15;167(1-3):933-9. doi: 10.1016/j.jhazmat.2009.01.085. Epub 2009 Jan 30.

Abstract

Hydrothermal conversion of biomass into biofuel could produce a special type of biochar as byproduct. This biochar is quite different from biochar derived from high temperature pyrolysis. In the present study, two biochars, prepared from hydrothermal liquefaction of pinewood (P300) and rice husk (R300), were characterized and investigated for lead removal from aqueous solution. The results indicated that the biochars contained a large amount of oxygen-containing groups on the surface, which were quite effective for lead removal with capacities of 4.25 and 2.40 mg/g for P300 and R300, respectively. The adsorption equilibrium was achieved around 5h. Higher temperature favored the removal capacity implying that the adsorption was an endothermic process. The adsorption data at optimum solution pH 5 could be well described by Langmuir model and the adsorption process was well fitted by pseudo-second-order model. Moreover, it was found that the adsorption was mainly controlled by film diffusion. Thermodynamics analysis suggested that lead adsorption onto the biochars was physical endothermic process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Biomass*
  • Energy-Generating Resources
  • Hot Temperature
  • Lead / isolation & purification*
  • Oryza
  • Pinus
  • Thermodynamics
  • Water
  • Water Pollutants, Chemical / isolation & purification*
  • Water Purification / methods
  • Wood

Substances

  • Water Pollutants, Chemical
  • Water
  • Lead