TY - JOUR
T1 - Experiment and multiscale molecular simulations on the Cu absorption by biochar-modified asphalt
T2 - An insight into removal capability and mechanism of heavy metals from stormwater runoff
AU - Yaphary, Yohannes L.
AU - He, Mingjing
AU - Lu, Guoyang
AU - Zou, Fuliao
AU - Liu, Pengfei
AU - Tsang, Daniel C.W.
AU - Leng, Zhen
N1 - Funding Information:
We would like to acknowledge this research work was supported by a grant from the Germany/Hong Kong Joint Research Scheme sponsored by the Research Grants Council of Hong Kong (Ref. no. G-505/21), General Research Fund from Research Grants Concil of Hong Kong (Ref. no. 15221921), and the German Academic Exchange Service of Germany (Grant no. 57601840), and high performance computing facilities of The Hong Kong Polytechnic University and National University of Singapore.
Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/4/15
Y1 - 2023/4/15
N2 - Asphalt has been the primary material for pavements and other building components such as roof shingles and waterproofing systems, which can be the path for stormwater runoff pollutants such as heavy metals (HMs). In this study, the capability and mechanism of asphalt and biochar-modified asphalt (BMA) to remove Cu as the typical HM found in the road dust and surface runoff were fundamentally explored for the first time. Experiment and multiscale molecular simulations were performed. Molecular dynamics (MD) simulations showed the Cu absorption into the asphalts. Monte Carlo (MC) and density functional theory (DFT) revealed the detailed mechanism of Cu absorption. Biochar (BC) presence modified the spatial distribution of maltene and asphaltene fractions in asphalt and enhanced the absorption. Maltenes were absorbed into the porous structure of BC, leaving more asphaltenes in the asphalt part of BMA. Asphaltenes were the Cu adsorbing preference sites ascribed to the cation-π interaction between Cu and the aromatic plane. The DFT simulations also suggested favourable adsorption of other commonly found metals (e.g., Cr, Pb, Ni, Cd, and Zn) onto asphaltenes. The present study found the capability and mechanism of BMA and asphalt to remove HMs at the molecular scales, providing a path for designing asphalts with value-added functionality in minimizing environmental pollution.
AB - Asphalt has been the primary material for pavements and other building components such as roof shingles and waterproofing systems, which can be the path for stormwater runoff pollutants such as heavy metals (HMs). In this study, the capability and mechanism of asphalt and biochar-modified asphalt (BMA) to remove Cu as the typical HM found in the road dust and surface runoff were fundamentally explored for the first time. Experiment and multiscale molecular simulations were performed. Molecular dynamics (MD) simulations showed the Cu absorption into the asphalts. Monte Carlo (MC) and density functional theory (DFT) revealed the detailed mechanism of Cu absorption. Biochar (BC) presence modified the spatial distribution of maltene and asphaltene fractions in asphalt and enhanced the absorption. Maltenes were absorbed into the porous structure of BC, leaving more asphaltenes in the asphalt part of BMA. Asphaltenes were the Cu adsorbing preference sites ascribed to the cation-π interaction between Cu and the aromatic plane. The DFT simulations also suggested favourable adsorption of other commonly found metals (e.g., Cr, Pb, Ni, Cd, and Zn) onto asphaltenes. The present study found the capability and mechanism of BMA and asphalt to remove HMs at the molecular scales, providing a path for designing asphalts with value-added functionality in minimizing environmental pollution.
KW - Asphalt
KW - Biochar
KW - Metal removal/absorption
KW - Runoff pollution
KW - Stormwater quality
KW - Surface water treatment
UR - http://www.scopus.com/inward/record.url?scp=85149818769&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2023.142205
DO - 10.1016/j.cej.2023.142205
M3 - Journal article
AN - SCOPUS:85149818769
SN - 1385-8947
VL - 462
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 142205
ER -