![]() ![]() Ion- sorption pumps with an electrostatic field Future research needs for field application of biochar include competitive sorption mechanisms of co-existing metals, biochar reuse, and cost reduction of biochar production. Besides sorption mechanisms, recent advance in modifying biochar by loading with minerals, reductants, organic functional groups, and nanoparticles, and activation with alkali solution to enhance metal sorption capacity is discussed. Different mechanisms dominate sorption of As (complexation and electrostatic interactions), Cr ( electrostatic interactions, reduction, and complexation), Cd and Pb (complexation, cation exchange, and precipitation), and Hg (complexation and reduction). Biochar properties vary considerably with feedstock material and pyrolysis temperature, with high temperature producing biochars with higher surface area, porosity, pH, and mineral contents, but less functional groups. This review summarizes the characteristics of biochar (e.g., surface area, porosity, pH, surface charge, functional groups, and mineral components) and main mechanisms governing sorption of As, Cr, Cd, Pb, and Hg by biochar. However, there is a lack of information on the roles of different sorption mechanisms for different metals and recent development of biochar modification to enhance metal sorption capacity, which is critical for biochar field application. Li, Hongbo Dong, Xiaoling da Silva, Evandro B de Oliveira, Letuzia M Chen, Yanshan Ma, Lena Qīiochar produced by thermal decomposition of biomass under oxygen-limited conditions has received increasing attention as a cost-effective sorbent to treat metal-contaminated waters. Mechanisms of metal sorption by biochars: Biochar characteristics and modifications. ![]() Hydrophobic interaction dominated the sorption of perfluorinated compounds on carbon nanotubes, while electrostatic repulsion suppressed their sorption. â–º Electrostatic repulsion suppresses the sorption of PFCs on CNTs. â–º Hydrophobic interaction is principally involved in the sorption of PFCs on CNTs. Highlights: â–º Sorption capacities of PFOA on different CNTs are less than that on activated carbon and resins. The hydrophobic C-F chains can be closely adsorbed on the CNTs surface in parallel to the axis or along the curvature, making it impossible to form micelles on the CNT surface, leading to the lower sorption than other adsorbents. Hydrogen bonding interaction was negligible. Electrostatic repulsion suppressed the sorption of PFCs on the CNTs, resulting in the lower sorption with increasing pH. In this study, the sorption of six PFCs on CNTs increased with increasing C-F chain length when they had a same functional group, and the CNTs with hydroxyl and carboxyl groups had much lower adsorbed amount than the pristine CNTs, indicating that hydrophobic interaction dominated the sorption of PFCs on the CNTs. Sorption of perfluorinated compounds (PFCs) on carbon nanotubes (CNTs) is critical for understanding their subsequent transport and fate in aqueous environments, but the sorption mechanisms remain largely unknown. ![]() ![]() International Nuclear Information System (INIS)ĭeng Shubo Zhang Qiaoying Nie Yao Wei Haoran Wang Bin Huang Jun Yu Gang Xing Baoshan Sorption mechanisms of perfluorinated compounds on carbon nanotubes ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |