2,298
Views
46
CrossRef citations to date
0
Altmetric
Articles

Surface and colloid properties of biochar and implications for transport in porous media

ORCID Icon, , & ORCID Icon
Pages 2484-2522 | Published online: 13 Dec 2019
 

Abstract

Biochar contains a large amount of colloidal particles. Biochar colloids are generated (1) during pyrolysis of the feedstock, where some of the biochar formed is in the colloidal size fraction, and (2) by the breakdown of larger biochar particles. Here, we review the surface and colloid properties of biochar and the implications for transport of biochar colloids in porous media. We discuss the origin of biochar colloids and their physical and chemical properties relation to feedstock and pyrolysis temperature. We then review the transport of colloidal biochar in sand columns and soils and relate the transport behavior to surface characteristics. We finally examine the effects of aging, i.e., natural and simulated environmental weathering, on the surface properties of biochar colloids. Biochar colloids tend to have lower zeta potential and lower aromaticity than the bulk biochar. Due to their smaller size, biochar colloids are more stable in aquatic environments and more mobile in the subsurface than the parent biochar particles. Like the parent biochar material, pristine biochar colloids contain a variety of hydrophobic functional groups (e.g., alkyl, aromatic), and become more hydrophilic as the biochar ages. At environmentally relevant pH, biochar colloids are negatively charged.

Graphical Abstract

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (Project 41771255), the NIFA Hatch Project (1014527), the National Key Research and Development Program (Project 2017YFD0801503), the Program of “1000-Talents Plan” for young researchers, and the China Scholarship Council (201806350121).

Log in via your institution

Log in to Taylor & Francis Online

PDF download + Online access

  • 48 hours access to article PDF & online version
  • Article PDF can be downloaded
  • Article PDF can be printed
USD 61.00 Add to cart

Issue Purchase

  • 30 days online access to complete issue
  • Article PDFs can be downloaded
  • Article PDFs can be printed
USD 652.00 Add to cart

* Local tax will be added as applicable

Related Research

People also read lists articles that other readers of this article have read.

Recommended articles lists articles that we recommend and is powered by our AI driven recommendation engine.

Cited by lists all citing articles based on Crossref citations.
Articles with the Crossref icon will open in a new tab.