title: Optimization of the combined ultrasonic assisted/adsorption method for the removal of malachite green by gold nanoparticles loaded on activated carbon: experimental design.
abstract: The present study was aimed to experimental design optimization applied to removal of malachite green (MG) from aqueous solution by ultrasound-assisted removal onto the gold nanoparticles loaded on activated carbon (Au-NP-AC). This nanomaterial was characterized using different techniques such as FESEM, TEM, BET, and UV-vis measurements. The effects of variables such as pH, initial dye concentration, adsorbent dosage (g), temperature and sonication time on MG removal were studied using central composite design (CCD) and the optimum experimental conditions were found with desirability function (DF) combined response surface methodology (RSM). Fitting the experimental equilibrium data to various isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show the suitability and applicability of the Langmuir model. Kinetic models such as pseudo -first order, pseudo-second order, Elovich and intraparticle diffusion models applicability was tested for experimental data and the second-order equation and intraparticle diffusion models control the kinetic of the adsorption process. The small amount of proposed adsorbent (0.015 g) is applicable for successful removal of MG (RE>99%) in short time (4.4 min) with high adsorption capacity (140-172 mg g(-1)).
authors.affiliation: Chemistry Department, Yasouj University, Yasouj 75918-74831, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Roosta
authors.forename: M
authors.initials: M
authors.lastname: Ghaedi
authors.forename: N
authors.initials: N
authors.lastname: Shokri
authors.forename: A
authors.initials: A
authors.lastname: Daneshfar
authors.forename: R
authors.initials: R
authors.lastname: Sahraei
authors.forename: A
authors.initials: A
authors.lastname: Asghari
mesh_terms: D000327:Adsorption; D000704:Analysis of Variance; D002606:Charcoal / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008958:Models, Molecular; D016062:Porosity; D012394:Rosaniline Dyes / Q000737:chemistry / Q000302:isolation & purification*; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics; D013997:Time Factors; D014465:Ultrasonics / Q000379:methods*
chemical_list: D012394:Rosaniline Dyes; C005095:malachite green; D002606:Charcoal; D006046:Gold
keywords: Activated carbon; Adsorption; Experimental design; Gold nanoparticles; Malachite green; Removal of dyes