农业环境科学学报
農業環境科學學報
농업배경과학학보
Journal of Agro-Environment Science
2010年
3期
476-480
,共5页
黑炭%菲%吸附%动力学
黑炭%菲%吸附%動力學
흑탄%비%흡부%동역학
charcoal%phenanthrene%sorption%kinetics
在300、500和700℃3种条件下加热木屑制备得到3种黑炭,并对其结构和组成进行了表征.通过吸附动力学实验和平衡吸附实验,研究了菲在这些黑炭样品上的吸附动力学和平衡吸附,分别应用拟一阶、拟二阶和叶洛维奇3种动力学模型及Freundlich吸附等温方程对实验数据进行了拟合.结果表明,菲在黑炭样品上的吸附可以分为极快吸附、快吸附和慢吸附3个阶段,拟一阶动力学和叶洛维奇动力学方程仅能对菲在黑炭上吸附动力学的某个阶段拟合较好,而拟二阶动力学模型可较好地拟合菲的整体吸附动力学过程.说明菲在黑炭上的吸附由多个过程控制,水膜扩散、吸附剂颗粒表面扩散和吸附剂内部微孔扩散等多个过程导致了其吸附动力学的复杂性.在快吸附阶段,菲在各个黑炭上吸附动力学的差异,主要受黑炭疏水性影响.Freundlich模型对吸附等温数据的拟合结果进一步证实,多环芳烃菲在黑炭样品上的吸附受多种机制影响.
在300、500和700℃3種條件下加熱木屑製備得到3種黑炭,併對其結構和組成進行瞭錶徵.通過吸附動力學實驗和平衡吸附實驗,研究瞭菲在這些黑炭樣品上的吸附動力學和平衡吸附,分彆應用擬一階、擬二階和葉洛維奇3種動力學模型及Freundlich吸附等溫方程對實驗數據進行瞭擬閤.結果錶明,菲在黑炭樣品上的吸附可以分為極快吸附、快吸附和慢吸附3箇階段,擬一階動力學和葉洛維奇動力學方程僅能對菲在黑炭上吸附動力學的某箇階段擬閤較好,而擬二階動力學模型可較好地擬閤菲的整體吸附動力學過程.說明菲在黑炭上的吸附由多箇過程控製,水膜擴散、吸附劑顆粒錶麵擴散和吸附劑內部微孔擴散等多箇過程導緻瞭其吸附動力學的複雜性.在快吸附階段,菲在各箇黑炭上吸附動力學的差異,主要受黑炭疏水性影響.Freundlich模型對吸附等溫數據的擬閤結果進一步證實,多環芳烴菲在黑炭樣品上的吸附受多種機製影響.
재300、500화700℃3충조건하가열목설제비득도3충흑탄,병대기결구화조성진행료표정.통과흡부동역학실험화평형흡부실험,연구료비재저사흑탄양품상적흡부동역학화평형흡부,분별응용의일계、의이계화협락유기3충동역학모형급Freundlich흡부등온방정대실험수거진행료의합.결과표명,비재흑탄양품상적흡부가이분위겁쾌흡부、쾌흡부화만흡부3개계단,의일계동역학화협락유기동역학방정부능대비재흑탄상흡부동역학적모개계단의합교호,이의이계동역학모형가교호지의합비적정체흡부동역학과정.설명비재흑탄상적흡부유다개과정공제,수막확산、흡부제과립표면확산화흡부제내부미공확산등다개과정도치료기흡부동역학적복잡성.재쾌흡부계단,비재각개흑탄상흡부동역학적차이,주요수흑탄소수성영향.Freundlich모형대흡부등온수거적의합결과진일보증실,다배방경비재흑탄양품상적흡부수다충궤제영향.
Three charcoals were obtained by heating sawdust at 300,500 and 700℃,respectively.The structures and compositions of the charcoals were characterized.Sorption kinetics and isotherms of phenanthrene onto these charcoals were determined.The data were fitted to the pseudo-first-order,the pseudo-second-order,the Elovich kinetic,and the Freundlich models,respectively.The sorption was divided into very fast,fast and slow stages.The pseudo-second-order model fitted the sorption kinetics data well orer the entire sorption duration:The pseudo-first-order and Elovich models did comparatively well for only selected sorption periods.These observations indicated that multi-processes controlled the sorption of phenanthrene on charcoals including diffusion into water film,diffusion on patticie surfaces of the char-coals,and diffusion in the internal micropores,which resulted in the observed complexity in the sorption kinetics.The differences in fast serpuon on charcoals were attributed to their varying hydrophobicities.The results from the Freundlich model analysis further suggested that the multiple processes controlled the sorption of phenanthrene onto charcoals.