Biochar is an emerging, cost-effective, and renewable carbonaceous material with abundant functional groups and tuneable mesoporous structure, showing a promising performance in fertility improvement, nutrient retention, microbial activity enhancement, and contaminant immobilization, etc. Dissolved organic matter (DOM) from biochar, which can be readily mobilized during soil application, is a key component for the soil matrix, microbial community, and the fate of contaminants. Comprehensive assessments of both positive and negative effects of biochar-derived DOM present critical environmental implications. This paper is the first of its kind to critically review the compositions and structures of biochar-derived DOM as well as its multiple roles in soil application. The effects of biochar-derived DOM on stabilization or migration/mobilization of contaminants/nutrients, as well as stimulation or inhibition of microbial activity and plant growth, depend on the nature of biochar-derived DOM, pollutant properties, soil characteristics, and environmental conditions including weather and hydrological conditions. The long-term stability of biochar-derived DOM is vital during soil application and involves various interactions such as physical disintegration, infiltration, sorption, and biotic/abiotic oxidation. Further studies of biochar-derived DOM are necessary for us to understand the fate of DOM and minimize the ecological and environmental risks (e.g., toxicity, competitive sorption, blockage effect, and solubilization) of biochar application.
Bibliographical noteFunding Information:
The authors appreciate the financial support from the Hong Kong Research Grants Council (PolyU 15222020) and PolyU Project of Strategic Importance.
© 2021 Elsevier B.V.
- Biomass waste management
- Dissolved organic matter
- Green and sustainable remediation
- Metal/metalloid immobilization
- Soil quality and health
ASJC Scopus subject areas
- Environmental Chemistry
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering