title: Evaluation of ammonium removal using a chitosan-g-poly (acrylic acid)/rectorite hydrogel composite.
abstract: This paper concerns the removal of ammonium ions (NH(4)(+)) from aqueous solution using a hydrogel composite chitosan grafted poly (acrylic acid)/rectorite prepared from in situ copolymerization. The effects of rectorite content, contact time, pH, NH(4)(+) concentration and temperature on the adsorption capacity were discussed. Langmuir, Freundlich, Tempkin and Redlich-Peterson isotherms were used to describe the experimental data. The results indicate that the adsorption equilibrium can be achieved within 3-5 min and, the hydrogel composite has a higher adsorption capacity for NH(4)(+) in a wide pH levels ranged from 4.0 to 9.0. No significant changes in the adsorption capacity are found over the temperature range studied. The adsorption mechanism of NH(4)(+) onto hydrogel composite was proposed, and the reusable ability of this hydrogel adsorbent was evaluated.
authors: Center for Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors: Yian
authors: Y
authors: Zheng
authors: Aiqin
authors: A
authors: Wang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D000077215:Clay; D005068:Eutrophication; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008422:Materials Testing; D008903:Minerals / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000302:isolation & purification*; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D020100:Hydrogels; D007477:Ions; D008903:Minerals; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; C546376:rectorite; C006903:carbopol 940; D048271:Chitosan; D000077215:Clay