title: [Sorption Characteristics of Phenanthrene and 1, 1-Dichloroethene onto Reed Straw Biochar in Aquatic Solutions].
abstract: The purpose of this study was to investigate the sorption characteristics of phenanthrene (PHE) and 1, 1-dichloroethene (1, 1-DCE) onto reed straw biochar at 500 degrees C in aquatic solutions. The sorption mechanisms and effects of solution pH and biochar mass on sorption intensity were discussed. The results showed that the time required to reach sorption equilibrium was 60 min and 480 min for PHE and 1, 1-DCE, respectively, with maximum removal rates of 81, 87% and 90.18%. The sorption kinetics of both PHE and 1, 1-DCE fitted the pseudo-second-order model well, but the pseudo-second-order reaction rate of PHE was higher than that of 1, 1-DCE. Furthermore, the sorption processes were controlled by both membrane diffusion and intra-particle diffusion, and the latter was found to be the rate-controlling step. Sorption isotherms of the two organic pollutants fitted well with the Freundlich equation, and the sorption affinity of 1, 1-DCE onto biochar was greater than that of PHE. The total sorption mechanism of biochar was the combination of partition and adsorption, and dominated by adsorption. The adsorption capacity of 1, 1-DCE was greater than that of PHE, but its partition capacity was much smaller, indicating that pollutants' molecular volume and relative polarity would mainly affect the total sorption. Analysis of Fourier transform infrared spectroscopy (FTIR) demonstrated that oxygen- and hydrogen-containing functional groups and pi--pi interaction were important for PHE and 1, 1-DCE sorption onto biochar. The solution pH value had no significant effect on the sorption intensity of PHE and 1, 1-DCE, however, with biochar mass increasing from 5 mg to 50 mg, the equilibrium sorption amount of PHE and 1, 1-DCE decreased by 6.78 times and 2.18 times, and the removal rate increased by 20.21% and 15.78%, respectively.
authors.forename: Qing-wen
authors.initials: QW
authors.lastname: Wu
authors.forename: Liang
authors.initials: L
authors.lastname: Meng
authors.forename: Zhi-hao
authors.initials: ZH
authors.lastname: Zhang
authors.forename: Qi-shi
authors.initials: QS
authors.lastname: Luo
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D002606:Charcoal; D004000:Dichloroethylenes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010616:Phenanthrenes / Q000737:chemistry*; D012996:Solutions
chemical_list: D004000:Dichloroethylenes; D010616:Phenanthrenes; D012996:Solutions; C540010:biochar; D002606:Charcoal; C029297:vinylidene chloride