title: Adsorption of p-nitroaniline from aqueous solutions onto activated carbon fiber prepared from cotton stalk.
abstract: Activated carbon fiber prepared from cotton stalk was used as an adsorbent for the removal of p-nitroaniline (PNA) from aqueous solutions. Liquid phase adsorption experiments were conducted and the maximum adsorptive capacity was determined. The effect of experimental parameters such as pH, salinity and temperature on the adsorption was studied. The obtained experimental data were then fitted with the Langmuir, Freundlich and Redlich-Peterson models to describe the equilibrium isotherms. The kinetics rates were modeled by using the pseudo-first-order and pseudo-second-order equations. The results indicated that cotton stalk activated carbon fiber (CS-ACF) is an effective adsorbent for the removal of PNA from aqueous solutions. The maximum adsorption capacity of 406 mg g(-1) was achieved at the initial PNA concentration of 200 mg L(-1). The optimum pH for the removal of PNA was found to be 7.6. The presence of ammonium chloride proved to be favorable for the process of adsorption. The adsorption amount decreased with increasing temperature. The Redlich-Peterson model was found to best represent the equilibrium data. The kinetic data followed closely the pseudo-second-order equation. Thermodynamic study showed the adsorption was a spontaneous exothermic physical process.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China.
authors.forename: Kunquan
authors.initials: K
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zheng
authors.forename: Jingwei
authors.initials: J
authors.lastname: Feng
authors.forename: Jibiao
authors.initials: J
authors.lastname: Zhang
authors.forename: Xingzhang
authors.initials: X
authors.lastname: Luo
authors.forename: Guohua
authors.initials: G
authors.lastname: Zhao
authors.forename: Xingfa
authors.initials: X
authors.lastname: Huang
mesh_terms: D000327:Adsorption; D000814:Aniline Compounds / Q000302:isolation & purification*; D002606:Charcoal / Q000737:chemistry*; D003368:Gossypium / Q000737:chemistry*; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods
chemical_list: D000814:Aniline Compounds; D012996:Solutions; D014874:Water Pollutants, Chemical; D002606:Charcoal; C019498:4-nitroaniline