TY - JOUR
T1 - Rice husk-derived biochar can aggravate arsenic mobility in ferrous-rich groundwater during oxygenation
AU - Zhong, Delai
AU - Ren, Shupeng
AU - Dong, Xuelin
AU - Yang, Xiao
AU - Wang, Linling
AU - Chen, Jing
AU - Zhao, Zezhou
AU - Zhang, Yanrong
AU - Tsang, Daniel C.W.
AU - Crittenden, John C.
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (No. 22076053), National Key Research and Development Program of China (No. 2019YFC1805202), State Key Laboratory of Pollution Control and Resource Reuse Foundation (No. PCRRF18027), Key Research and Development Project of Hunan Province (No. 2016SK2057), and Program for HUST Academic Frontier Youth Team (No. 2018QYTD05). We would like to thank Ms. Dan Zhu at Hubei Geological Research Laboratory for the help with sample characterization. We appreciate the valuable suggestions and edits given by Prof. Yaoyu Zhou at Hunan Agricultural University and Dr. Zimo Lou at Zhejiang University of Technology. We also appreciate the support from the Brook Byers Institute for Sustainable Systems, Hightower Chair, and Georgia Research Alliance at the Georgia Institute of Technology. The views and ideas expressed herein are solely those of the authors and do not represent the ideas of the funding agencies in any form.
Funding Information:
This work was supported by the National Natural Science Foundation of China (No. 22076053), National Key Research and Development Program of China (No. 2019YFC1805202), State Key Laboratory of Pollution Control and Resource Reuse Foundation (No. PCRRF18027), Key Research and Development Project of Hunan Province (No. 2016SK2057), and Program for HUST Academic Frontier Youth Team (No. 2018QYTD05). We would like to thank Ms. Dan Zhu at Hubei Geological Research Laboratory for the help with sample characterization. We appreciate the valuable suggestions and edits given by Prof. Yaoyu Zhou at Hunan Agricultural University and Dr. Zimo Lou at Zhejiang University of Technology. We also appreciate the support from the Brook Byers Institute for Sustainable Systems, Hightower Chair, and Georgia Research Alliance at the Georgia Institute of Technology. The views and ideas expressed herein are solely those of the authors and do not represent the ideas of the funding agencies in any form.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/7/15
Y1 - 2021/7/15
N2 - Elevated As(III) and Fe(II) in shallow reducing groundwater can be frequently re-oxidized by introducing O2 due to natural/anthropogenic processes, thus leading to oxidative precipitation of As as well as Fe. Nevertheless, the geochemical process may be impacted by co-existing engineered black carbon due to its considerable applications, which remains poorly understood. Taking rice husk-derived biochar prepared at 500 °C as an example, we explored its impact on the process particularly for the As(III) oxidation and (im)mobilization during the oxygenation. The presence of the biochar had a negligible effect on the As(III) oxidation and immobilization extents within 1 d, while accelerating their rates. However, the immobilized As(III) was significantly liberated from the formed Fe(III) minerals afterward within 21 d, which was 2.2-fold higher than that in the absence of the biochar. The enhanced As(III) liberation was attributed to the presence of the surface silicon-carbon structure, consisting of the outer silicon and inner carbon layers, of the rice husk-derived biochar. The outer silicon components, particularly for the dissolved silicate primarily promoted the As(III) release via ligand exchange, while significantly impeding the transformation of ferrihydrite to lepidocrocite and goethite still resulted secondarily in the As(III) release. Our findings reveal the possible impact of biochar on the environmental behavior and fate of As(III) in the Fe(II)-rich groundwater during the oxygenation. This work highlights that biochar, particularly for its structural features should be a concern in re-mobilizing As in such scenarios when the oxygenation time reaches several days or weeks.
AB - Elevated As(III) and Fe(II) in shallow reducing groundwater can be frequently re-oxidized by introducing O2 due to natural/anthropogenic processes, thus leading to oxidative precipitation of As as well as Fe. Nevertheless, the geochemical process may be impacted by co-existing engineered black carbon due to its considerable applications, which remains poorly understood. Taking rice husk-derived biochar prepared at 500 °C as an example, we explored its impact on the process particularly for the As(III) oxidation and (im)mobilization during the oxygenation. The presence of the biochar had a negligible effect on the As(III) oxidation and immobilization extents within 1 d, while accelerating their rates. However, the immobilized As(III) was significantly liberated from the formed Fe(III) minerals afterward within 21 d, which was 2.2-fold higher than that in the absence of the biochar. The enhanced As(III) liberation was attributed to the presence of the surface silicon-carbon structure, consisting of the outer silicon and inner carbon layers, of the rice husk-derived biochar. The outer silicon components, particularly for the dissolved silicate primarily promoted the As(III) release via ligand exchange, while significantly impeding the transformation of ferrihydrite to lepidocrocite and goethite still resulted secondarily in the As(III) release. Our findings reveal the possible impact of biochar on the environmental behavior and fate of As(III) in the Fe(II)-rich groundwater during the oxygenation. This work highlights that biochar, particularly for its structural features should be a concern in re-mobilizing As in such scenarios when the oxygenation time reaches several days or weeks.
KW - Aging
KW - Arsenic remobilization
KW - Engineered black carbon
KW - Groundwater oxygenation
KW - Iron minerals transformation
UR - http://www.scopus.com/inward/record.url?scp=85107077902&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2021.117264
DO - 10.1016/j.watres.2021.117264
M3 - Journal article
AN - SCOPUS:85107077902
SN - 0043-1354
VL - 200
JO - Water Research
JF - Water Research
M1 - 117264
ER -