title: Adsorption of anionic dyes from aqueous solutions using chemically modified straw.
abstract: The effective disposal of redundant straw is a significant work for environmental protection and full utilization of resource. In this work, the wheat straw has been modified by etherification to prepare a kind of quaternary ammonium straw adsorbents. The adsorption behaviors of the modified straw for methyl orange (MO) and acid green 25(AG25) were studied in both batch and column systems. The adsorption capacity of the straw for both dyes improved evidently after modification. The maximal MO and AG25 uptakes were more than 300 and 950 mg g(-1), respectively. Furthermore, the adsorption equilibrium, kinetics and column studies all indicated that the adsorption behavior was a monolayer chemical adsorption with an ion-exchange process. In addition, after adsorption of anionic dyes, the used adsorbents were successfully applied to adsorb a cationic dye directly at suitable conditions in the secondary adsorption. This was due to the altered surface structures of the used adsorbents.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Wenxuan
authors.initials: W
authors.lastname: Zhang
authors.forename: Haijiang
authors.initials: H
authors.lastname: Li
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Kan
authors.forename: Lei
authors.initials: L
authors.lastname: Dong
authors.forename: Han
authors.initials: H
authors.lastname: Yan
authors.forename: Ziwen
authors.initials: Z
authors.lastname: Jiang
authors.forename: Hu
authors.initials: H
authors.lastname: Yang
authors.forename: Aimin
authors.initials: A
authors.lastname: Li
authors.forename: Rongshi
authors.initials: R
authors.lastname: Cheng
mesh_terms: D000327:Adsorption; D000838:Anions; D001391:Azo Compounds / Q000302:isolation & purification; D004396:Coloring Agents / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008086:Lissamine Green Dyes / Q000302:isolation & purification; D008751:Methylene Blue / Q000302:isolation & purification; D008956:Models, Chemical; D020005:Propanols / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012996:Solutions; D055672:Static Electricity; D013696:Temperature; D014908:Triticum / Q000737:chemistry*; D014866:Waste Products / Q000032:analysis*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D000838:Anions; D001391:Azo Compounds; D004396:Coloring Agents; D008086:Lissamine Green Dyes; D020005:Propanols; D000644:Quaternary Ammonium Compounds; D012996:Solutions; D014866:Waste Products; D014874:Water Pollutants, Chemical; D014867:Water; C100258:methyl orange; C496948:(3-chloro-2-hydroxypropyl)trimethylammonium chloride; D008751:Methylene Blue