Influence of pyrolysis temperature on the characteristics and lead(II) adsorption capacity of phosphorus-engineered poplar sawdust biochar

Xu, Y. and Bai, T. and Li, Q. and Yang, H. and Yan, Y. and Sarkar, B. and Lam, S.S. and Bolan, N. (2021) Influence of pyrolysis temperature on the characteristics and lead(II) adsorption capacity of phosphorus-engineered poplar sawdust biochar. Journal of Analytical and Applied Pyrolysis, 154. ISSN 0165-2370

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Abstract

Phosphorus (P)–engineered biochars (BCP) were prepared via co-pyrolysis of poplar sawdust and monopotassium phosphate (KH2PO4) (10 %, w/w) at 300 ℃, 500 ℃ and 700 ℃ to evaluate their potential lead [Pb(II)] adsorption. Effects of pH, contact time, and initial Pb(II) concentration on the Pb(II) adsorption capacity of the biochars were investigated. The physico-chemical, morphological, porous structure, crystallinity and spectroscopic characteristics of pre- and post-Pb-adsorbed biochars were analyzed to unravel the Pb(II) adsorption mechanism. Results showed that KH2PO4 reacted with biomass carbon to form stable C–P and/or C–O–P groups in BCP, and increased carbon retention and aromaticity of BCP. However, the addition of KH2PO4 led to an adverse effect on porous structure, e.g. surface area of biochars produced at 300 ℃, 500 ℃ and 700 ℃ were decreased by 41.53 %, 80.32 %, and 59.74 %, respectively. Adsorption experiments displayed that BCP produced at 300 ℃ exhibited the highest Pb(II) adsorption capacity (qmax = 154.7 mg g−1), which was almost 6 times higher than the pristine biochar (qmax = 24.3 mg g−1). Potassium polymetaphosphate [(KPO3)n] particles were attached on the surface of BCP, which facilitated the precipitation of Pb(II) to form [Pb(PO3)2]n, Pb5(PO4)3OH and PbHPO4. This study thus demonstrated the effect of pyrolysis temperature on the enhancing removal capability of P-modified biochar for Pb(II) from aqueous solutions.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Analytical and Applied Pyrolysis
Additional Information:
This is the author’s version of a work that was accepted for publication in Journal of Analytical and Applied Pyrolysis. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Analytical and Applied Pyrolysis, 154, 2021 DOI: 10.1016/j.jaap.2020.105010
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1600
Subjects:
ID Code:
151372
Deposited By:
Deposited On:
03 Feb 2021 16:35
Refereed?:
Yes
Published?:
Published
Last Modified:
06 Oct 2021 08:00