Role of biochar surface characteristics in the adsorption of aromatic compounds: Pore structure and functional groups

• Published in: Chinese chemical letters Vol. 32; no. 10; pp. 2939 - 2946
• Main Authors: Tan, Xue-Fei, Zhu, Shi-Shu, Wang, Ru-Peng, Chen, Yi-Di, Show, Pau-Loke, Zhang, Feng-Fa, Ho, Shih-Hsin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2021; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology,Sun Yat-sen University,Guangzhou 510275,China%State Key Laboratory of Urban Water Resource and Environment,School of Environment,Harbin Institute of Technology,Harbin 150090,China%State Key Laboratory of Urban Water Resource and Environment,School of Environment,Harbin Institute of Technology,Harbin 150090,China; State Key Laboratory of Urban Water Resource and Environment,School of Civil and Environmental Engineering,Harbin Institute of Technology(Shenzhen),Shenzhen 518055,China%Department of Chemical and Environmental Engineering,Faculty of Science and Engineering,University of Nottingham Malaysia,43500 Semenyih,Selangor,Malaysia%College of Materials and Chemical Engineering,Heilongjiang Institute of Technology,Harbin 150050,China; State Key Laboratory of Urban Water Resource and Environment,School of Environment,Harbin Institute of Technology,Harbin 150090,China%School of Environmental Science and Engineering,Sun Yat-sen University,Guangzhou 510275,China; College of Materials and Chemical Engineering,Heilongjiang Institute of Technology,Harbin 150050,China
• Subjects: Adsorption; Aromatics; Biochar; Surface characteristics; Surface functional groups; Aromatics; Adsorption; Biochar; Surface characteristics; Surface functional groups
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2021.04.059

Biochar (BC) are widely used as highly efficient adsorbents to alleviate aromatics-based contaminants due to their ease of preparation, wide availability, and high sustainability. The surface properties of BCs usually vary greatly due to their complex chemical constituents and different preparation processes and are reflected in the values of parameters such as the specific surface area (SSA), pore volume/size, and surface functional groups (SFGs). The effects of SSA and pore volume/size on the adsorption of aromatics have been widely reported. However, the corresponding mechanisms of BC SFGs towards aromatics adsorption remains unclear as the compositions of the SFGs are usually complex and hard to determine. To address in this gap in the literature, this review introduces a new perspective on the adsorption mechanisms of aromatics. Through collecting previously-reported results, the parameters logP (logarithm of the Kow), polar surface area, and the positive/negative charges were carefully calculated using ChemDraw 3D, which allowed the hydrophobicity/hydrophilicity properties, electron donor-acceptor interactions, H-bonding, and electrostatic interactions between SFGs and aromatics-based contaminates to be inferred intuitively. These predictions were consistent with the reported results and showed that tailor-made BCs can be designed according to the molecular weights, chemical structures, and polarities of the target aromatics. Overall, this review provides new insight into predicting the physicochemical properties of BCs through revealing the relationship between SFGs and adsorbates, which may provide useful guidance for the preparing of highly-efficient, functional BCs for the adsorption of aromatics. The underlying mechanisms of the interactions between aromatics and surface adsorption sites are summarized, which suggests that the hydrophobic effect, H-bonding, and EDA interactions, as well as coulombic forces, correspond to the surface functional groups and pore size or volume. [Display omitted]