Environmental Geochemistry and Health

, Volume 39, Issue 2, pp 379–389

Metal immobilization by sludge-derived biochar: roles of mineral oxides and carbonized organic compartment

  • Weihua Zhang
  • Xinchen Huang
  • Yanming Jia
  • Frederic Rees
  • Daniel C. W. Tsang
  • Rongliang Qiu
  • Hong Wang
Original Paper

DOI: 10.1007/s10653-016-9851-z

Cite this article as:
Zhang, W., Huang, X., Jia, Y. et al. Environ Geochem Health (2017) 39: 379. doi:10.1007/s10653-016-9851-z

Abstract

Pyrolyzing sludge into biochar is a potentially promising recycling/disposal solution for municipal wastewater sludge, and the sludge-derived biochar (SDBC) presents an excellent sorbent for metal immobilization. As SDBC is composed of both mineral oxides and carbonized organic compartment, this study therefore compared the sorption behaviour of Pb and Zn on SDBC to those of individual and mixture of activated carbon (AC) and amorphous aluminium oxide (Al2O3). Batch experiments were conducted at 25 and 45 °C, and the metal-loaded sorbents were artificially aged in the atmosphere for 1–60 days followed by additional sorption experiments. The Pb sorption was generally higher than Zn sorption, and the co-presence of Pb reduced Zn sorption on each studied sorbent. Higher sorption capacities were observed at 45 °C than 25 °C for SDBC and AC, while the opposite was shown for Al2O3, indicating the significance of temperature-dependent diffusion processes in SDBC and AC. Nevertheless, metal sorption was more selective on Al2O3 that showed a greater affinity towards Pb over Zn under competition, correlating with the reducible fraction of sequential extraction. Furthermore, significant amounts of Pb and Zn were additionally sorbed on SDBC following 30-day ageing. The X-ray diffraction revealed the formation of metal-phosphate precipitates, while the X-ray photoelectron spectroscopy showed a larger quantity of metal–oxygen bonding after 30-day ageing of metal-loaded SDBC. The results may imply favourable long-term transformation and additional sorption capacity of SDBC. In conclusion, SDBC resembles the sorption characteristics of both organic and mineral sorbents in different aspects, presenting an appropriate material for metal immobilization during soil amendment.

Keywords

Metal sorption Sludge-derived biochar Mineral oxides Activated carbons 

Supplementary material

10653_2016_9851_MOESM1_ESM.docx (385 kb)
Supplementary material 1 (DOCX 384 kb)

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  • Weihua Zhang
    • 1
    • 2
  • Xinchen Huang
    • 1
  • Yanming Jia
    • 1
  • Frederic Rees
    • 3
    • 4
  • Daniel C. W. Tsang
    • 5
  • Rongliang Qiu
    • 1
    • 2
  • Hong Wang
    • 6
  1. 1.School of Environmental Science and EngineeringSun Yat-sen UniversityGuangzhouChina
  2. 2.Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation TechnologyGuangzhouChina
  3. 3.Laboratoire Sols et Environnement, UMR 1120Université de LorraineVandoeuvre-lès-Nancy cedexFrance
  4. 4.Laboratoire Sols et Environnement, UMR 1120INRAVandoeuvre-lès-Nancy cedexFrance
  5. 5.Department of Civil and Environmental EngineeringHong Kong Polytechnic UniversityHung Hom, KowloonChina
  6. 6.School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhenChina

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