Leaching of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge-derived biochar

Xiaoyang Chen, Lisitai Yang, Satish C.B. Myneni, Yang Deng

Research output: Contribution to journalArticle

Abstract

Polycyclic aromatic hydrocarbons (PAHs), a family of persistent organic pollutants with various negative health effects, are inherently formed during biochar pyrolysis. However, the knowledge regarding the leaching potentials and mechanisms of PAHs remains limited for biochar implementation to soil. In this study we evaluated the leaching behaviors of PAHs from sewage sludge-derived biochar pyrolyzed at different temperatures (300–700 °C) using the protocol of Synthetic Precipitation Leaching Procedure (SPLP) with deionized water. Leachate concentrations of sixteen U.S. Environmental Protection Agency PAHs increased with the increasing pyrolysis temperature, exhibiting an opposite pyrolytic temperature dependence with their concentrations in biochar. The total leachate PAH concentration peaked at 700 °C with 11.75 μg/L, corresponding to 15.9% of total PAHs present in biochar. PAH leaching was associated with the release of hydrophobic organic compounds (HOCs) that created a mobile phase to facilitate the mobilization of PAHs into water. The enhanced release of calcium, aluminum, and barium from the biochars with pyrolysis temperature could also favor the leaching of biochar PAHs, due to the destruction of HOCs-(metal ions)-mineral linkages, which improved the release of HOCs and HOCs-bound PAHs; and because the extent of metal cross-linking in biochar is reduced, enabling better diffusion of PAHs through the inner matrix and thus accelerating their desorption.

Original languageEnglish
Pages (from-to)840-845
Number of pages6
JournalChemical Engineering Journal
Volume373
DOIs
StatePublished - 1 Oct 2019

Fingerprint

Polycyclic Aromatic Hydrocarbons
Sewage sludge
Polycyclic aromatic hydrocarbons
Leaching
PAH
leaching
Organic compounds
organic compound
pyrolysis
Pyrolysis
leachate
biochar
sewage sludge
temperature
Temperature
Organic pollutants
Deionized water
metal
Environmental Protection Agency
barium

Keywords

  • Biochar
  • Leaching
  • Polycyclic aromatic hydrocarbons (PAHs)
  • Pyrolysis temperature
  • Sewage sludge

Cite this

Chen, Xiaoyang ; Yang, Lisitai ; Myneni, Satish C.B. ; Deng, Yang. / Leaching of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge-derived biochar. In: Chemical Engineering Journal. 2019 ; Vol. 373. pp. 840-845.
@article{4735742e833d441eaf98940269a68b39,
title = "Leaching of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge-derived biochar",
abstract = "Polycyclic aromatic hydrocarbons (PAHs), a family of persistent organic pollutants with various negative health effects, are inherently formed during biochar pyrolysis. However, the knowledge regarding the leaching potentials and mechanisms of PAHs remains limited for biochar implementation to soil. In this study we evaluated the leaching behaviors of PAHs from sewage sludge-derived biochar pyrolyzed at different temperatures (300–700 °C) using the protocol of Synthetic Precipitation Leaching Procedure (SPLP) with deionized water. Leachate concentrations of sixteen U.S. Environmental Protection Agency PAHs increased with the increasing pyrolysis temperature, exhibiting an opposite pyrolytic temperature dependence with their concentrations in biochar. The total leachate PAH concentration peaked at 700 °C with 11.75 μg/L, corresponding to 15.9{\%} of total PAHs present in biochar. PAH leaching was associated with the release of hydrophobic organic compounds (HOCs) that created a mobile phase to facilitate the mobilization of PAHs into water. The enhanced release of calcium, aluminum, and barium from the biochars with pyrolysis temperature could also favor the leaching of biochar PAHs, due to the destruction of HOCs-(metal ions)-mineral linkages, which improved the release of HOCs and HOCs-bound PAHs; and because the extent of metal cross-linking in biochar is reduced, enabling better diffusion of PAHs through the inner matrix and thus accelerating their desorption.",
keywords = "Biochar, Leaching, Polycyclic aromatic hydrocarbons (PAHs), Pyrolysis temperature, Sewage sludge",
author = "Xiaoyang Chen and Lisitai Yang and Myneni, {Satish C.B.} and Yang Deng",
year = "2019",
month = "10",
day = "1",
doi = "10.1016/j.cej.2019.05.059",
language = "English",
volume = "373",
pages = "840--845",
journal = "Chemical Engineering Journal",
issn = "1385-8947",
publisher = "Elsevier",

}

Leaching of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge-derived biochar. / Chen, Xiaoyang; Yang, Lisitai; Myneni, Satish C.B.; Deng, Yang.

In: Chemical Engineering Journal, Vol. 373, 01.10.2019, p. 840-845.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Leaching of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge-derived biochar

AU - Chen, Xiaoyang

AU - Yang, Lisitai

AU - Myneni, Satish C.B.

AU - Deng, Yang

PY - 2019/10/1

Y1 - 2019/10/1

N2 - Polycyclic aromatic hydrocarbons (PAHs), a family of persistent organic pollutants with various negative health effects, are inherently formed during biochar pyrolysis. However, the knowledge regarding the leaching potentials and mechanisms of PAHs remains limited for biochar implementation to soil. In this study we evaluated the leaching behaviors of PAHs from sewage sludge-derived biochar pyrolyzed at different temperatures (300–700 °C) using the protocol of Synthetic Precipitation Leaching Procedure (SPLP) with deionized water. Leachate concentrations of sixteen U.S. Environmental Protection Agency PAHs increased with the increasing pyrolysis temperature, exhibiting an opposite pyrolytic temperature dependence with their concentrations in biochar. The total leachate PAH concentration peaked at 700 °C with 11.75 μg/L, corresponding to 15.9% of total PAHs present in biochar. PAH leaching was associated with the release of hydrophobic organic compounds (HOCs) that created a mobile phase to facilitate the mobilization of PAHs into water. The enhanced release of calcium, aluminum, and barium from the biochars with pyrolysis temperature could also favor the leaching of biochar PAHs, due to the destruction of HOCs-(metal ions)-mineral linkages, which improved the release of HOCs and HOCs-bound PAHs; and because the extent of metal cross-linking in biochar is reduced, enabling better diffusion of PAHs through the inner matrix and thus accelerating their desorption.

AB - Polycyclic aromatic hydrocarbons (PAHs), a family of persistent organic pollutants with various negative health effects, are inherently formed during biochar pyrolysis. However, the knowledge regarding the leaching potentials and mechanisms of PAHs remains limited for biochar implementation to soil. In this study we evaluated the leaching behaviors of PAHs from sewage sludge-derived biochar pyrolyzed at different temperatures (300–700 °C) using the protocol of Synthetic Precipitation Leaching Procedure (SPLP) with deionized water. Leachate concentrations of sixteen U.S. Environmental Protection Agency PAHs increased with the increasing pyrolysis temperature, exhibiting an opposite pyrolytic temperature dependence with their concentrations in biochar. The total leachate PAH concentration peaked at 700 °C with 11.75 μg/L, corresponding to 15.9% of total PAHs present in biochar. PAH leaching was associated with the release of hydrophobic organic compounds (HOCs) that created a mobile phase to facilitate the mobilization of PAHs into water. The enhanced release of calcium, aluminum, and barium from the biochars with pyrolysis temperature could also favor the leaching of biochar PAHs, due to the destruction of HOCs-(metal ions)-mineral linkages, which improved the release of HOCs and HOCs-bound PAHs; and because the extent of metal cross-linking in biochar is reduced, enabling better diffusion of PAHs through the inner matrix and thus accelerating their desorption.

KW - Biochar

KW - Leaching

KW - Polycyclic aromatic hydrocarbons (PAHs)

KW - Pyrolysis temperature

KW - Sewage sludge

UR - http://www.scopus.com/inward/record.url?scp=85065891200&partnerID=8YFLogxK

U2 - 10.1016/j.cej.2019.05.059

DO - 10.1016/j.cej.2019.05.059

M3 - Article

AN - SCOPUS:85065891200

VL - 373

SP - 840

EP - 845

JO - Chemical Engineering Journal

JF - Chemical Engineering Journal

SN - 1385-8947

ER -