Biochar (Sep 2024)

Novel utilization exploration for the dephosphorization waste of Ca–modified biochar: enhanced removal of heavy metal ions from water

  • Weilin Fu,
  • Mengmeng Li,
  • Hongan Chen,
  • Jianhua Qu,
  • Lisheng Zhang,
  • Shangkai Qiu,
  • Menghan Feng,
  • Mingyao Yuan,
  • Changbin Guo,
  • Jien Zhou,
  • Zhaolin Du,
  • Feng Wang

DOI
https://doi.org/10.1007/s42773-024-00373-8
Journal volume & issue
Vol. 6, no. 1
pp. 1 – 16

Abstract

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Abstract Phosphorus-modified biochar has been proven to enhance the precipitation and complexation of heavy metal ions from wastewater. However, the current modification methods require large amounts of exogenous P and have high energy consumption. Hence, this study proposes and analyzes a strategy integrating biochar production, phosphorus wastewater treatment, dephosphorization waste recovery, and heavy metal removal. “BC-Ca-P” was derived from Ca-modified biochar after phosphorus wastewater treatment. The adsorption of Pb(II) by BC-Ca-P followed the Langmuir isotherm and pseudo–second–order kinetic models. The maximum adsorption capability of 361.20 mg·g−1 at pH 5.0 for 2 h was markedly greater than that of external phosphorous-modified biochar. The adsorption mechanisms were dominated by chemical precipitation and complexation. Furthermore, density functional theory calculations indicated that oxygen-containing functional groups (P-O and C-O) contributed the most to the efficient adsorption of Pb(II) onto BC-Ca-P. To explore its practical feasibility, the adsorption performance of BC-Ca-P recovered from an actual environment was evaluated. The continuous-flow adsorption behavior was investigated and well-fitted utilizing the Thomas and Yoon–Nelson models. There was a negligible P leakage risk of BC-Ca-P during heavy metal treatment. This study describes a novel and sustainable method to utilize dephosphorization waste for heavy metal removal. Graphical Abstract

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