Environmental Science and Pollution Research

, Volume 25, Issue 26, pp 25648–25658 | Cite as

Quantitative characterization of pore structure of several biochars with 3D imaging

  • Jari Hyväluoma
  • Sampo Kulju
  • Markus Hannula
  • Hanne Wikberg
  • Anssi Källi
  • Kimmo Rasa
Environmental functions of biochar


Pore space characteristics of biochars may vary depending on the used raw material and processing technology. Pore structure has significant effects on the water retention properties of biochar amended soils. In this work, several biochars were characterized with three-dimensional imaging and image analysis. X-ray computed microtomography was used to image biochars at resolution of 1.14 μm and the obtained images were analysed for porosity, pore size distribution, specific surface area and structural anisotropy. In addition, random walk simulations were used to relate structural anisotropy to diffusive transport. Image analysis showed that considerable part of the biochar volume consist of pores in size range relevant to hydrological processes and storage of plant available water. Porosity and pore size distribution were found to depend on the biochar type and the structural anisotopy analysis showed that used raw material considerably affects the pore characteristics at micrometre scale. Therefore, attention should be paid to raw material selection and quality in applications requiring optimized pore structure.


Biochar Soil amendment Pore structure Water retention X-ray tomography Image analysis 



This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 637020 – MOBILE FLIP.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  1. 1.Natural Resources Institute Finland (Luke)JokioinenFinland
  2. 2.BioMediTech Institute and Faculty of Biomedical Sciences and EngineeringTampere University of TechnologyTampereFinland
  3. 3.VTT Technical Research Centre of Finland Ltd.EspooFinland

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