Improving biochar properties by co-pyrolysis of pig manure with bio-invasive weed for use as the soil amendment

Jing Qiu, Marcella Fernandes de Souza, Ana A. Robles-Aguilar, Stef Ghysels, Yong Sik Ok, Frederik Ronsse, Erik Meers

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


Over recent years, pyrolysis has grown into a mature technology with added value for producing soil improvers. Further innovations of this technology lie in developing tailor-made products from specific feedstocks (or mixtures thereof) in combination with adjusted mixing ratio-temperature regimes. In this context, co-pyrolysis of pig manure (PM) and the invasive plant Japanese knotweed (JK) at different mixture ratios (w/w) of 3:1 (P3J1), 1:1 (P1J1), and 1:3 (P1J3) and varying temperatures (400–700 °C) was studied to address the low carbon properties and heavy metals (HMs) risks of manure-derive biochars and beneficially ameliorate the bio-invasion situation by creating value from the plant biomass. Co-pyrolysis of PM with JK increased by nearly 1.5 folds the fixed carbon contents in the combined feedstock biochars obtained at 600 °C compared with PM-derived biochar alone, and all combined feedstock biochars met the requirements for soil improvement and carbon sequestration. The total HMs in PM biochars were significantly reduced by adding JK. The combined feedstock biochar P1J1 generated at 600 °C was the most effective in transforming Cu and Zn into more stable forms, accordingly reducing the associated environmental risk of heavy metal leaching from the biochar. In addition, the accumulation of macronutrients can be an added benefit of the co-pyrolysis process, and P1J1-600 was also the biochar that retained the most nutrients (P, Ca, Mg, and K).

Original languageEnglish
Article number137229
Publication statusPublished - 2023 Jan

Bibliographical note

Funding Information:
This work was carried out with the support of the China Scholarship Council (CSC).

Publisher Copyright:
© 2022 Elsevier Ltd


  • Biochar aromaticity
  • Invasive plant
  • Metal speciation
  • Nutrients
  • Pig manure

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • General Chemistry
  • Pollution
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'Improving biochar properties by co-pyrolysis of pig manure with bio-invasive weed for use as the soil amendment'. Together they form a unique fingerprint.

Cite this