title: Simultaneous ultrasound-assisted ternary adsorption of dyes onto copper-doped zinc sulfide nanoparticles loaded on activated carbon: optimization by response surface methodology.
abstract: The simultaneous and competitive ultrasound-assisted removal of Auramine-O (AO), Erythrosine (Er) and Methylene Blue (MB) from aqueous solutions were rapidly performed onto copper-doped zinc sulfide nanoparticles loaded on activated carbon (ZnS:Cu-NP-AC). ZnS:Cu nanoparticles were studied by FESEM, XRD and TEM. First, the effect of pH was optimized in a one-at-a-time procedure. Then the dependency of dyes removal percentage in their ternary solution on the level and magnitude of variables such as sonication time, initial dyes concentrations and adsorbent dosage was fully investigated and optimized by central composite design (CCD) under response surface methodology (RSM) as well as by regarding desirability function (DF) as a good and general criterion. The good agreement found between experimental and predicted values supports and confirms the suitability of the present model to predict adsorption state. The applied ultrasound strongly enhanced mass transfer process and subsequently performance. Hence, a small amount of the adsorbent (0.04 g) was capable to remove high percentage of dyes, i.e. 100%, 99.6% and 100% for MB, AO and Er, respectively, in very short time (2.5 min). The experimental equilibrium data fitting to Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models showed that the Langmuir model applies well for the evaluation and description of the actual behavior of adsorption. The small amount of proposed adsorbent (0.015 g) was applicable for successful removal of dyes (RE>99.0%) in short time (2.5 min) with high adsorption capacity in single component system (123.5 mg g(-1) for MB, 123 mg g(-1) for AO and 84.5 mg g(-1) for Er). Kinetics evaluation of experiments at various time intervals reveals that adsorption processes can be well predicated and fitted by pseudo-second-order and Elovich models.
authors.affiliation: Chemistry Department, Yasouj University, Yasouj 75918-74831, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Asfaram
authors.affiliation: Chemistry Department, Yasouj University, Yasouj 75918-74831, Iran. Electronic address: m_ghaedi@mail.yu.ac.ir.
authors.forename: Mehrorang
authors.initials: M
authors.lastname: Ghaedi
authors.affiliation: Department of Physics, Yasouj University, Yasouj 75918-74831, Iran.
authors.forename: Shaaker
authors.initials: S
authors.lastname: Hajati
authors.affiliation: Department of Polymer Engineering, Golestan University, Gorgan 49188-88369, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Goudarzi
authors.affiliation: Chemistry Department, Yasouj University, Yasouj 75918-74831, Iran.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Bazrafshan
mesh_terms: D000327:Adsorption; D000704:Analysis of Variance; D001576:Benzophenoneidum / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004923:Erythrosine / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D013440:Sulfides / Q000737:chemistry*; D013696:Temperature; D014465:Ultrasonics / Q000379:methods*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D013440:Sulfides; D017967:Zinc Compounds; D002606:Charcoal; D001576:Benzophenoneidum; D003300:Copper; C031238:zinc sulfide; D004923:Erythrosine; D008751:Methylene Blue
keywords: Auramine-O; Erythrosine; Methylene Blue; Nanoparticle-loaded activated carbon; Response surface methodology; Ultrasound-assisted dye removal