Bao, X, Li, M, Niu, R et al. (4 more authors) (2021) Hygroscopic Water Retention and Physio-Chemical Properties of Three In-House Produced Biochars from Different Feedstock Types: Implications on Substrate Amendment in Green Infrastructure. Water, 13 (19). 2613. ISSN 2073-4441
Abstract
Recent studies have proposed usage of biochar as a substrate amendment in green infrastructure, such as green roofs and bio-filtration units. However, understanding of the variation in physio-chemical properties of biochar due to the production process and feedstock is still lacking. The present study investigated the effects of pyrolysis temperature and feedstocks on the hygroscopic water content and physio-chemical properties of biochar. Biochars were produced from three feedstock types, invasive vegetation (i.e., water hyacinth), non-invasive vegetation (i.e., wood) and one animal waste (i.e., chicken manure). Biochar was produced at two different pyrolysis temperatures (i.e., 300 °C and 600 °C). Scanning electron microscopy + energy dispersive spectrometry (SEM + EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) were performed on all samples to analyze the surface morphology, pore size, element content, functional groups, and chemical bonds. Relative humidity was adjusted to reflect the biochar’s hygroscopic property by measuring the maximum moisture content at the sample equilibrium state. The characterization reveals that the lowest carbon content (42.78%) was found at 300 °C for water hyacinth biochar (WHB). The highest carbon content (92.14%) was found at 600 °C for wood biochar (WB). As the pyrolysis temperature increased, the mean pore volume (from 0.03 to 0.18 cm3/g) and diameter (from 8.40 to 10.33 nm) of the WHB increased. However, the pore diameter of chicken manure (CB) decreased (from 9.23 nm to 7.53 nm) under an increase in pyrolysis temperature. For a given pyrolysis temperature, the hygroscopicity of WHB was highest among all biochars. With an increase in pyrolysis temperature, the hygroscopicity of biochars changed differently. The hygroscopicity of WHB decreased from 82.41% to 44.33% with an increase of pyrolysis temperature. However, the hygroscopicity of CMB and WB remained unchanged. This study suggests that production process of biochars need to be considered for appropriate selection as substrate material in green infrastructure. Further, it promotes the establishment of commercial production of biochar for usage in green infrastructure.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 by the authors. This is an open access article under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0) (https://creativecommons.org/licenses/by/4.0/) |
Keywords: | biochar; pyrolysis; agricultural waste management; surface characteristic; green infrastructure; soil amendments |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Civil Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 26 Nov 2021 14:14 |
Last Modified: | 26 Nov 2021 14:14 |
Status: | Published |
Publisher: | MDPI AG |
Identification Number: | 10.3390/w13192613 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:180558 |