Aluminum-impregnated biochar for adsorption of arsenic(V) in urban stormwater runoff

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Abstract

Biochar has recently emerged for the alleviation of various pollutants in urban runoff. However, the adsorption of arsenate (a frequently identified pollutant in urban runoff) with biochar is typically poor. In this study, an aluminum-impregnated biochar was investigated for adsorption of arsenate. Results with synthetic arsenic-polluted urban runoff show that As(V) was bound to amorphous aluminum hydroxide on biochar surface through irreversible inner-surface complexation. At pH 7.6, the adsorption kinetic data followed pseudo-second-order reaction models (R2≥0.96), and the Langmuir and Frendulich models both fit well adsorption isotherm data (R2≥0.99). The adsorption was little influenced by pH (4.5-8.5) and ionic strength (0-100 mM NaCl) in this study. Although phosphate and dissolved organic matter (DOM) have a potential to suppress As(V) adsorption, their inhibiting effects were insignificant under the study conditions [0-200 μg/L P, 0-40 mg/L dissolved organic carbon, and 500 μg/L As(V)]. However, it is likely that the suppression of phosphate or DOM on the As(V) adsorption becomes more significant with the increasing molar ratio of P or DOM to As in urban runoff during the realistic stormwater treatment. Besides As(V), the aluminum-impregnated biochar could effectively remove many other runoff pollutants (i.e., Pb, Zn, Cu, and PO43) in a polluted real urban runoff. Exhausted aluminum-impregnated biochar passed the toxicity characteristic leaching procedure (TCLP) screening, suggesting that the spent adsorbent can be safely disposed of in municipal landfills. This study demonstrates that surface modification with aluminum enriches active surface sites of biochar for arsenate and expands biochar applications in stormwater treatment.

Original languageEnglish
Article number04019008
JournalJournal of Environmental Engineering (United States)
Volume145
Issue number4
DOIs
StatePublished - 1 Apr 2019

Fingerprint

Arsenic
Aluminum
Runoff
stormwater
arsenic
aluminum
runoff
adsorption
Adsorption
Biological materials
arsenate
dissolved organic matter
Phosphates
pollutant
Hydrated alumina
phosphate
Organic carbon
Land fill
Ionic strength
Complexation

Keywords

  • Adsorption
  • Aluminum-impregnated Biochar
  • Arsenic
  • Surface modification
  • Urban stormwater runoff

Cite this

@article{b2cd26ddcddc4a6d842e3a2094bf5f62,
title = "Aluminum-impregnated biochar for adsorption of arsenic(V) in urban stormwater runoff",
abstract = "Biochar has recently emerged for the alleviation of various pollutants in urban runoff. However, the adsorption of arsenate (a frequently identified pollutant in urban runoff) with biochar is typically poor. In this study, an aluminum-impregnated biochar was investigated for adsorption of arsenate. Results with synthetic arsenic-polluted urban runoff show that As(V) was bound to amorphous aluminum hydroxide on biochar surface through irreversible inner-surface complexation. At pH 7.6, the adsorption kinetic data followed pseudo-second-order reaction models (R2≥0.96), and the Langmuir and Frendulich models both fit well adsorption isotherm data (R2≥0.99). The adsorption was little influenced by pH (4.5-8.5) and ionic strength (0-100 mM NaCl) in this study. Although phosphate and dissolved organic matter (DOM) have a potential to suppress As(V) adsorption, their inhibiting effects were insignificant under the study conditions [0-200 μg/L P, 0-40 mg/L dissolved organic carbon, and 500 μg/L As(V)]. However, it is likely that the suppression of phosphate or DOM on the As(V) adsorption becomes more significant with the increasing molar ratio of P or DOM to As in urban runoff during the realistic stormwater treatment. Besides As(V), the aluminum-impregnated biochar could effectively remove many other runoff pollutants (i.e., Pb, Zn, Cu, and PO43) in a polluted real urban runoff. Exhausted aluminum-impregnated biochar passed the toxicity characteristic leaching procedure (TCLP) screening, suggesting that the spent adsorbent can be safely disposed of in municipal landfills. This study demonstrates that surface modification with aluminum enriches active surface sites of biochar for arsenate and expands biochar applications in stormwater treatment.",
keywords = "Adsorption, Aluminum-impregnated Biochar, Arsenic, Surface modification, Urban stormwater runoff",
author = "Qingsong Liu and Laying Wu and Matthew Gorring and Yang Deng",
year = "2019",
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day = "1",
doi = "10.1061/(ASCE)EE.1943-7870.0001503",
language = "English",
volume = "145",
journal = "Journal of Environmental Engineering (United States)",
issn = "0733-9372",
publisher = "American Society of Civil Engineers (ASCE)",
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TY - JOUR

T1 - Aluminum-impregnated biochar for adsorption of arsenic(V) in urban stormwater runoff

AU - Liu, Qingsong

AU - Wu, Laying

AU - Gorring, Matthew

AU - Deng, Yang

PY - 2019/4/1

Y1 - 2019/4/1

N2 - Biochar has recently emerged for the alleviation of various pollutants in urban runoff. However, the adsorption of arsenate (a frequently identified pollutant in urban runoff) with biochar is typically poor. In this study, an aluminum-impregnated biochar was investigated for adsorption of arsenate. Results with synthetic arsenic-polluted urban runoff show that As(V) was bound to amorphous aluminum hydroxide on biochar surface through irreversible inner-surface complexation. At pH 7.6, the adsorption kinetic data followed pseudo-second-order reaction models (R2≥0.96), and the Langmuir and Frendulich models both fit well adsorption isotherm data (R2≥0.99). The adsorption was little influenced by pH (4.5-8.5) and ionic strength (0-100 mM NaCl) in this study. Although phosphate and dissolved organic matter (DOM) have a potential to suppress As(V) adsorption, their inhibiting effects were insignificant under the study conditions [0-200 μg/L P, 0-40 mg/L dissolved organic carbon, and 500 μg/L As(V)]. However, it is likely that the suppression of phosphate or DOM on the As(V) adsorption becomes more significant with the increasing molar ratio of P or DOM to As in urban runoff during the realistic stormwater treatment. Besides As(V), the aluminum-impregnated biochar could effectively remove many other runoff pollutants (i.e., Pb, Zn, Cu, and PO43) in a polluted real urban runoff. Exhausted aluminum-impregnated biochar passed the toxicity characteristic leaching procedure (TCLP) screening, suggesting that the spent adsorbent can be safely disposed of in municipal landfills. This study demonstrates that surface modification with aluminum enriches active surface sites of biochar for arsenate and expands biochar applications in stormwater treatment.

AB - Biochar has recently emerged for the alleviation of various pollutants in urban runoff. However, the adsorption of arsenate (a frequently identified pollutant in urban runoff) with biochar is typically poor. In this study, an aluminum-impregnated biochar was investigated for adsorption of arsenate. Results with synthetic arsenic-polluted urban runoff show that As(V) was bound to amorphous aluminum hydroxide on biochar surface through irreversible inner-surface complexation. At pH 7.6, the adsorption kinetic data followed pseudo-second-order reaction models (R2≥0.96), and the Langmuir and Frendulich models both fit well adsorption isotherm data (R2≥0.99). The adsorption was little influenced by pH (4.5-8.5) and ionic strength (0-100 mM NaCl) in this study. Although phosphate and dissolved organic matter (DOM) have a potential to suppress As(V) adsorption, their inhibiting effects were insignificant under the study conditions [0-200 μg/L P, 0-40 mg/L dissolved organic carbon, and 500 μg/L As(V)]. However, it is likely that the suppression of phosphate or DOM on the As(V) adsorption becomes more significant with the increasing molar ratio of P or DOM to As in urban runoff during the realistic stormwater treatment. Besides As(V), the aluminum-impregnated biochar could effectively remove many other runoff pollutants (i.e., Pb, Zn, Cu, and PO43) in a polluted real urban runoff. Exhausted aluminum-impregnated biochar passed the toxicity characteristic leaching procedure (TCLP) screening, suggesting that the spent adsorbent can be safely disposed of in municipal landfills. This study demonstrates that surface modification with aluminum enriches active surface sites of biochar for arsenate and expands biochar applications in stormwater treatment.

KW - Adsorption

KW - Aluminum-impregnated Biochar

KW - Arsenic

KW - Surface modification

KW - Urban stormwater runoff

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U2 - 10.1061/(ASCE)EE.1943-7870.0001503

DO - 10.1061/(ASCE)EE.1943-7870.0001503

M3 - Article

AN - SCOPUS:85061918581

VL - 145

JO - Journal of Environmental Engineering (United States)

JF - Journal of Environmental Engineering (United States)

SN - 0733-9372

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