title: Removal and recovery of copper and nickel ions from aqueous solution by poly(methacrylamide-co-acrylic acid)/montmorillonite nanocomposites.
abstract: Nanocomposite hydrogels based on poly(methacrylamide-co-acrylic acid) and nano-sized montmorillonite were prepared by aqueous dispersion and in situ radical polymerization. Optimum sorption conditions were determined as a function of montmorillonite content, contact time, pH, and temperature. The equilibrium data of Cu(2+) and Ni(2+) conformed to the Freundlich and Langmuir isotherms in terms of relatively high regression values. The maximum monolayer adsorption capacity of the nanocomposite hydrogel (with 3 wt% montmorillonite content), as obtained from the Langmuir adsorption isotherm, was found to be 49.26 and 46.94 mg g(-1) for Cu(2+) and Ni(2+), respectively, at contact time = 60 min, pH = 6.8, adsorbent dose = 100 mg/ml, and temperature = 318 K. Kinetic studies of single system indicated that the pseudo-second order is the best fit with a high correlation coefficient (R (2) = 0.97-0.99). The result of five times sequential adsorption-desorption cycle shows a good degree of desorption and a high adsorption efficiency.
authors.affiliation: Chemical Engineering Department, Faculty of Engineering, Arak University, Arak, 38156-8-8349, Iran. a-barati@araku.ac.ir
authors.forename: Aboulfazl
authors.initials: A
authors.lastname: Barati
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Asgari
authors.forename: Taghi
authors.initials: T
authors.lastname: Miri
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Eskandari
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053761:Nanocomposites; D009532:Nickel / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry*
chemical_list: D000179:Acrylates; D011109:Polymethacrylic Acids; C583639:poly(methacrylamide-co-acrylic acid); D014867:Water; D001546:Bentonite; D003300:Copper; D009532:Nickel