Risk evaluation of biochars produced from Cd-contaminated rice straw and optimization of its production for Cd removal

Zhengtao Shen; Xiaoliang Fan; Deyi Hou; Fei Jin; David O'Connor; Daniel C.W. Tsang; Yong Sik Ok; Daniel S. Alessi

doi:10.1016/j.chemosphere.2019.05.238

Risk evaluation of biochars produced from Cd-contaminated rice straw and optimization of its production for Cd removal

Zhengtao Shen, Xiaoliang Fan, Deyi Hou, Fei Jin, David O'Connor, Daniel C.W. Tsang, Yong Sik Ok, Daniel S. Alessi

Research output: Contribution to journal › Article › peer-review

60 Citations (Scopus)

Abstract

Based on the “waste-treat-waste” concept, biochars were produced from cadmium (Cd)-contaminated rice straw (CRSBs) at 300, 500, and 700 °C (CRSB300, CRSB500, and CRSB700). The risks of the Cd remaining in CRSBs were evaluated and the optimal biochar pyrolysis temperature for Cd removal was investigated. It was observed that 41% of the total Cd in the raw rice straw was exchangeable, which may pose significant risks to crops and humans. Pyrolyzing at 300 °C did not significantly alter the Cd fractions, while the exchangeable fraction of Cd greatly dropped to 5.79% at 500 °C and further to 2.12% at 700 °C. Increasing the highest pyrolysis temperature resulted in CRSBs with higher pH values, greater surface area, and smaller pore sizes, thus providing more rapid and efficient removal of Cd from aqueous solutions. For Cd removal tests, increasing pyrolysis temperature (300–700 °C) increased the total (24.8–55.1 mg/g) and non-exchangeable (18.9–52.8 mg/g) Cd concentrations immobilized on the CRSBs and significantly decreased the exchangeable Cd fraction (23.7%–4.85%). It is suggested based on the study from aqueous solutions that CRSB700 was the most suitable for the remediation of Cd contaminated soil on site due to the lowest risks of remained Cd from feedstock, fastest and highest Cd removal, and most stable immobilization of Cd.

Original language	English
Pages (from-to)	149-156
Number of pages	8
Journal	Chemosphere
Volume	233
DOIs	https://doi.org/10.1016/j.chemosphere.2019.05.238
Publication status	Published - 2019 Oct

Bibliographical note

Funding Information:
This work was supported by China's National Water Pollution Control and Treatment Science and Technology Major Project (Grant No. 2018ZX07109-003 ), and the National Key Research and Development Program of China (Grant No. 2018YFC1801300 ). The first author would like to thank the Killam Trusts of Canada for kindly providing the Izaak Walton Killam Memorial Postdoctoral Fellowship.

Publisher Copyright:
© 2019 Elsevier Ltd

Keywords

Cadmium removal
Cadmium rice
Green/sustainable remediation
Pyrolysis temperature
Sustainable waste management
Waste valorization/recycling

ASJC Scopus subject areas

Public Health, Environmental and Occupational Health
Pollution
General Chemistry
Health, Toxicology and Mutagenesis
Environmental Engineering
Environmental Chemistry

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.chemosphere.2019.05.238

Cite this

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title = "Risk evaluation of biochars produced from Cd-contaminated rice straw and optimization of its production for Cd removal",

abstract = "Based on the “waste-treat-waste” concept, biochars were produced from cadmium (Cd)-contaminated rice straw (CRSBs) at 300, 500, and 700 °C (CRSB300, CRSB500, and CRSB700). The risks of the Cd remaining in CRSBs were evaluated and the optimal biochar pyrolysis temperature for Cd removal was investigated. It was observed that 41% of the total Cd in the raw rice straw was exchangeable, which may pose significant risks to crops and humans. Pyrolyzing at 300 °C did not significantly alter the Cd fractions, while the exchangeable fraction of Cd greatly dropped to 5.79% at 500 °C and further to 2.12% at 700 °C. Increasing the highest pyrolysis temperature resulted in CRSBs with higher pH values, greater surface area, and smaller pore sizes, thus providing more rapid and efficient removal of Cd from aqueous solutions. For Cd removal tests, increasing pyrolysis temperature (300–700 °C) increased the total (24.8–55.1 mg/g) and non-exchangeable (18.9–52.8 mg/g) Cd concentrations immobilized on the CRSBs and significantly decreased the exchangeable Cd fraction (23.7%–4.85%). It is suggested based on the study from aqueous solutions that CRSB700 was the most suitable for the remediation of Cd contaminated soil on site due to the lowest risks of remained Cd from feedstock, fastest and highest Cd removal, and most stable immobilization of Cd.",

keywords = "Cadmium removal, Cadmium rice, Green/sustainable remediation, Pyrolysis temperature, Sustainable waste management, Waste valorization/recycling",

author = "Zhengtao Shen and Xiaoliang Fan and Deyi Hou and Fei Jin and David O'Connor and Tsang, {Daniel C.W.} and Ok, {Yong Sik} and Alessi, {Daniel S.}",

note = "Funding Information: This work was supported by China's National Water Pollution Control and Treatment Science and Technology Major Project (Grant No. 2018ZX07109-003 ), and the National Key Research and Development Program of China (Grant No. 2018YFC1801300 ). The first author would like to thank the Killam Trusts of Canada for kindly providing the Izaak Walton Killam Memorial Postdoctoral Fellowship. Publisher Copyright: {\textcopyright} 2019 Elsevier Ltd",

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doi = "10.1016/j.chemosphere.2019.05.238",

language = "English",

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T1 - Risk evaluation of biochars produced from Cd-contaminated rice straw and optimization of its production for Cd removal

AU - Shen, Zhengtao

AU - Fan, Xiaoliang

AU - Hou, Deyi

AU - Jin, Fei

AU - O'Connor, David

AU - Tsang, Daniel C.W.

AU - Ok, Yong Sik

AU - Alessi, Daniel S.

N1 - Funding Information: This work was supported by China's National Water Pollution Control and Treatment Science and Technology Major Project (Grant No. 2018ZX07109-003 ), and the National Key Research and Development Program of China (Grant No. 2018YFC1801300 ). The first author would like to thank the Killam Trusts of Canada for kindly providing the Izaak Walton Killam Memorial Postdoctoral Fellowship. Publisher Copyright: © 2019 Elsevier Ltd

PY - 2019/10

Y1 - 2019/10

N2 - Based on the “waste-treat-waste” concept, biochars were produced from cadmium (Cd)-contaminated rice straw (CRSBs) at 300, 500, and 700 °C (CRSB300, CRSB500, and CRSB700). The risks of the Cd remaining in CRSBs were evaluated and the optimal biochar pyrolysis temperature for Cd removal was investigated. It was observed that 41% of the total Cd in the raw rice straw was exchangeable, which may pose significant risks to crops and humans. Pyrolyzing at 300 °C did not significantly alter the Cd fractions, while the exchangeable fraction of Cd greatly dropped to 5.79% at 500 °C and further to 2.12% at 700 °C. Increasing the highest pyrolysis temperature resulted in CRSBs with higher pH values, greater surface area, and smaller pore sizes, thus providing more rapid and efficient removal of Cd from aqueous solutions. For Cd removal tests, increasing pyrolysis temperature (300–700 °C) increased the total (24.8–55.1 mg/g) and non-exchangeable (18.9–52.8 mg/g) Cd concentrations immobilized on the CRSBs and significantly decreased the exchangeable Cd fraction (23.7%–4.85%). It is suggested based on the study from aqueous solutions that CRSB700 was the most suitable for the remediation of Cd contaminated soil on site due to the lowest risks of remained Cd from feedstock, fastest and highest Cd removal, and most stable immobilization of Cd.

AB - Based on the “waste-treat-waste” concept, biochars were produced from cadmium (Cd)-contaminated rice straw (CRSBs) at 300, 500, and 700 °C (CRSB300, CRSB500, and CRSB700). The risks of the Cd remaining in CRSBs were evaluated and the optimal biochar pyrolysis temperature for Cd removal was investigated. It was observed that 41% of the total Cd in the raw rice straw was exchangeable, which may pose significant risks to crops and humans. Pyrolyzing at 300 °C did not significantly alter the Cd fractions, while the exchangeable fraction of Cd greatly dropped to 5.79% at 500 °C and further to 2.12% at 700 °C. Increasing the highest pyrolysis temperature resulted in CRSBs with higher pH values, greater surface area, and smaller pore sizes, thus providing more rapid and efficient removal of Cd from aqueous solutions. For Cd removal tests, increasing pyrolysis temperature (300–700 °C) increased the total (24.8–55.1 mg/g) and non-exchangeable (18.9–52.8 mg/g) Cd concentrations immobilized on the CRSBs and significantly decreased the exchangeable Cd fraction (23.7%–4.85%). It is suggested based on the study from aqueous solutions that CRSB700 was the most suitable for the remediation of Cd contaminated soil on site due to the lowest risks of remained Cd from feedstock, fastest and highest Cd removal, and most stable immobilization of Cd.

KW - Cadmium removal

KW - Cadmium rice

KW - Green/sustainable remediation

KW - Pyrolysis temperature

KW - Sustainable waste management

KW - Waste valorization/recycling

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DO - 10.1016/j.chemosphere.2019.05.238

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AN - SCOPUS:85067052804

SN - 0045-6535

VL - 233

SP - 149

EP - 156

JO - Chemosphere

JF - Chemosphere

ER -

Risk evaluation of biochars produced from Cd-contaminated rice straw and optimization of its production for Cd removal

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

UN SDGs

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