title: Removal enhancement of 1-naphthol and 1-naphthylamine in single and binary aqueous phase by acid-basic interactions with polymer adsorbents.
abstract: In the present study removal performance of 1-naphthol and 1-naphthylamine from wastewater by single and binary adsorption was compared. Synergistic effects were investigated in single-solute, binary-solute, and the preloading adsorption systems at 293 K. Two commercial polystyrene adsorbents Amberlite XAD-4, a macroporous adsorbent, and NDA-100, a hyper-cross-linked adsorbent, were employed here for their frequent use in organic pollutants removal from contaminated waters. All the adsorption isotherms of 1-naphthol and 1-naphthylamine on both adsorbents were found to be well represented by the Langmuir equation. Adsorption capacity of the primary solute was enhanced in the presence of the co-solute, arising presumably from the synergistic effect caused by the laterally acid-base interaction between the adsorbed 1-naphthol and 1-naphthylamine molecules. Due to the stronger adsorption affinity of 1-naphthylamine to nonpolar adsorbents, adsorption enhancement of 1-naphthylamine in the presence of 1-naphthol is greater than that of 1-naphthol in the presence of 1-naphthylamine. The greater synergistic effect of 1-naphthol/1-naphthylamine equimolar mixtures on XAD-4 than that on NDA-100 partly results from the larger average pore size of the former adsorbent. A modified extended Langmuir model is proved to well describe the synergistic adsorption of 1-naphthol/1-naphthylamine equimolar mixtures in the binary-solute system. The synergistic coefficient of one adsorbate is linearly correlated with the amount of the other adsorbed on the adsorbent.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, and School of the Environment, Nanjing University, Nanjing 210093, People's Republic of China. wmzhang@nju.edu.cn
authors.forename: Weiming
authors.initials: W
authors.lastname: Zhang
authors.forename: Changhong
authors.initials: C
authors.lastname: Hong
authors.forename: Bingcai
authors.initials: B
authors.lastname: Pan
authors.forename: Zhengwen
authors.initials: Z
authors.lastname: Xu
authors.forename: Qingjian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Lu
authors.initials: L
authors.lastname: Lv
mesh_terms: D015057:1-Naphthylamine / Q000737:chemistry / Q000302:isolation & purification*; D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D009284:Naphthols / Q000737:chemistry / Q000302:isolation & purification*; D013816:Thermodynamics
chemical_list: D009284:Naphthols; C029350:1-naphthol; D015057:1-Naphthylamine