title: Modified chitosan for the collection of reactive blue 4, arsenic and mercury from aqueous media.
abstract: In the present investigation a series of modified chitosan as adsorbents were synthesized free radically at 70 °C using acryloylated chitosan (AC-chitosan) as macromer, 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS), 2-(diethylamino) ethylmethacrylate (DAEMA) as co-monomers and N,N'-methylene bisacrylamide (N-MBA) as a crosslinker for using as adsorbents in effluent remediation. Their structures ((1)H and (13)C NMR), thermal stability (TG/DTG), surface morphology (SEM), reactive blue 4 (RB4), toxic metals such as arsenic (AsO(2-)) and mercury (Hg(2+)) uptake, swellability and reusability were evaluated. The adsorption of RB4 (701 mg/g), and the uptake of AsO(2-) (551 mg/g) and Hg(2+) (455 mg/g) showed Langmuir isotherm behavior with pseudo-first-order kinetics. The diffusion of water, RB4, AsO(2-) and Hg(2+) into the matrix followed non-Fickian mechanism. The evaluated changes in Gibbs free energy (ΔG°), entropy (ΔS°) and enthalpy (ΔH°) for adsorption indicated that the process was exothermic.
authors.affiliation: Department of Physical Sciences, Bannari Amman Institute of Technology, Erode Dt, Sathyamangalam 638 401, Tamil Nadu, India.
authors.forename: V
authors.initials: V
authors.lastname: Dhanapal
authors.affiliation: Department of Biotechnology, Bannari Amman Institute of Technology, Erode Dt, Sathyamangalam 638 401, Tamil Nadu, India. Electronic address: drksubramanian@rediffmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Subramanian
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000327:Adsorption; D000476:Alkanesulfonates / Q000737:chemistry; D001151:Arsenic / Q000737:chemistry / Q000302:isolation & purification; D048271:Chitosan / Q000737:chemistry*; D004058:Diffusion; D004785:Environmental Pollutants / Q000737:chemistry* / Q000302:isolation & purification*; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008628:Mercury / Q000737:chemistry / Q000302:isolation & purification; D008689:Methacrylates / Q000737:chemistry; D058105:Polymerization; D013816:Thermodynamics; D014227:Triazines / Q000737:chemistry / Q000302:isolation & purification; D014867:Water / Q000737:chemistry*
chemical_list: D000178:Acrylamides; D000476:Alkanesulfonates; D004785:Environmental Pollutants; D008689:Methacrylates; D014227:Triazines; D014867:Water; C036598:procion blue MX-R; C056288:2-acrylamido-2-methylpropanesulfonate; D048271:Chitosan; C021221:N,N'-methylenebisacrylamide; D008628:Mercury; C519537:diethylaminoethyl methacrylate; D001151:Arsenic
keywords: Adsorption thermodynamics; Dyes; NMR; Remediation; Toxic metals