Aromatic organophosphate flame retardant(OPFR)pollutants and biochars are commonly present and continually released into soils due to their increasingly wide applications.In this study,for the first time,the sorption ...Aromatic organophosphate flame retardant(OPFR)pollutants and biochars are commonly present and continually released into soils due to their increasingly wide applications.In this study,for the first time,the sorption of OPFRs on biochars was investigated.Although triphenyl phosphate(TPhP)and triphenylphosphine oxide(TPPO)have similar molecular structures and sizes,TPhP exhibited much faster and higher sorption than TPPO due to its stronger hydrophobicity,suggesting the dominant role of hydrophobic interactions in TPhP sorption.Theπ-πelectron donor-acceptor(EDA)interactions also contributed to the sorption process,as suggested by the negative correlation between the sorption capacity of the aromatic OPFRs and the aromatic index(H/C atomic ratios)of biochar.Density functional theory calculations further showed that one benzene ring of aromatic OPFRs has no electrons,which may interact with biochar viaπ-πEDA interactions.The electrostatic attraction between the protonated P=O in OPFRs and the negatively charged biochar was found to occur at pH below 7.This work provides insights into the sorption behaviors and mechanisms of aromatic OPFRs by biochars.展开更多
基金This research was supported by the Beijing Natural Science Foundation(No.8182037)National Natural Science Foundation of China(Grant Nos.41703097 and 41977317)+1 种基金Fundamental Research Funds for the Central Universities(No.2018ZY16)National College Students'innovation and entrepreneurship training program(No.201810022077).
文摘Aromatic organophosphate flame retardant(OPFR)pollutants and biochars are commonly present and continually released into soils due to their increasingly wide applications.In this study,for the first time,the sorption of OPFRs on biochars was investigated.Although triphenyl phosphate(TPhP)and triphenylphosphine oxide(TPPO)have similar molecular structures and sizes,TPhP exhibited much faster and higher sorption than TPPO due to its stronger hydrophobicity,suggesting the dominant role of hydrophobic interactions in TPhP sorption.Theπ-πelectron donor-acceptor(EDA)interactions also contributed to the sorption process,as suggested by the negative correlation between the sorption capacity of the aromatic OPFRs and the aromatic index(H/C atomic ratios)of biochar.Density functional theory calculations further showed that one benzene ring of aromatic OPFRs has no electrons,which may interact with biochar viaπ-πEDA interactions.The electrostatic attraction between the protonated P=O in OPFRs and the negatively charged biochar was found to occur at pH below 7.This work provides insights into the sorption behaviors and mechanisms of aromatic OPFRs by biochars.
