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    Removal of heavy metals from aqueous solution using platinum nanopartcles/Zeolite-4A

    , Article Journal of Environmental Health Science and Engineering ; Vol. 12, issue. 1 , 2014 ; ISSN: 2052336X Mehdizadeh, S ; Sadjadi, S ; Ahmadi, S. J ; Outokesh, M ; Sharif University of Technology
    The effects of varying operating conditions on metals removal from aqueous solution using a novel platinum nanopartcles/Zeolite-4A adsorbent are reported in this paper. Characterization of the adsorbent showed successful production of platinum nanopartcles on Zeolite-4A using 3 Wt% platinum. The effects of operation conditions on metals removal using this adsorbent were investigated. The optimal metals adsorption was observed at pH 7, 0.1 g/10 mL dosage and 30 min contact time. Sorption data have been interpreted in terms of Langmuir and Freundlich isotherms  

    Use of response surface methodology for evaluation of effective parameters in codeposition of Cu-Sn alloys using non-cyanide electroplating solution

    , Article Transactions of the Institute of Metal Finishing ; Volume 90, Issue 1 , January , 2012 , Pages 38-43 ; 00202967 (ISSN) Asnavandi, M ; Ghorbani, M ; Sharif University of Technology
    A pyrophosphate based solution, as an acidic electrolyte, was developed for bronze electroplating. By using a statistical experimental design, response surface method, the effects of five factors [copper concentration (Cu), tin concentration (Sn), pyrophosphate concentration (P), current density j and pH] on the composition of the electroplated alloy as well as the process efficiency were evaluated. Statistical analysis indicated that all the parameters were significant and a second order polynomial model was successfully fitted to the data for both the alloy composition and the process efficiency. Based on the results obtained, a solution of Cu(II)8.04 g L -1, Sn(II)=26.36 g L -1, P=113.22... 

    Modeling of aqueous biomolecules using a new free-volume group contribution model

    , Article Industrial and Engineering Chemistry Research ; Volume 48, Issue 8 , 2009 , Pages 4109-4118 ; 08885885 (ISSN) Pazuki, G. R ; Taghikhani, V ; Vossoughi, M ; Sharif University of Technology
    In this article, a new group contribution model is suggested for obtaining the thermodynamic properties of biomolecules in aqueous solutions. Accordingly, a Freed-FV model has been applied for the combinatorial free-volume term. The activity coefficients, solubilities, densities, and vapor pressures of amino acids and simple peptides in aqueous solutions were correlated, using the proposed group contribution model. Group interaction parameters of the proposed model were obtained by use of experimental data from amino acids available in the literature. The results demonstrate that the group contribution model can accurately correlate activity coefficient, solubility, density, and vapor... 

    Removal of chromium from aqueous solution using polyaniline - Poly ethylene glycol composite

    , Article Journal of Hazardous Materials ; Volume 184, Issue 1-3 , December , 2010 , Pages 248-254 ; 03043894 (ISSN) Riahi Samani, M ; Borghei, S. M ; Olad, A ; Chaichi, M. J ; Sharif University of Technology
    The adsorption of chromium compounds from solutions by a composite of polyaniline/poly ethylene glycol (PANi/PEG) was investigated in this study. Experiments were conducted in batch mode under various operational conditions including agitation time, solution pH, PANi/PEG dose and initial concentration of chromium salts. Results showed that concentration of PEG at synthesizing stage has a significant effect on the capacity of produced composite for removal of chromium. Morphologically, PANi/PEG composite is closely dependent on the concentration of PEG. Maximum removal of hexavalent chromium was experienced when 2. g/L of PEG was used in synthesis of PANi/PEG. Removal of hexavalent chromium... 

    Degradation of humic acids through heterogeneous catalytic ozonation with bone charcoal

    , Article Reaction Kinetics, Mechanisms and Catalysis ; Volume 100, Issue 2 , 2010 , Pages 471-485 ; 18785190 (ISSN) Mortazavi, S. B ; Asgari, Gh ; Hashemian, S. J ; Moussavi, G ; Sharif University of Technology
    Catalytic ozonation has recently been used as a new means of contaminant removal from water and wastewater. In this study, bone charcoal (BC), a new catalyst prepared under laboratory conditions, was used to catalyze the ozonation of humic substances (HS) in aqueous solutions. The catalytic effect of bone charcoal and the relevant parameters of this ozonation process (solution pH, temperature, scavenger effect, humic acids concentration and BC dosage) were investigated. In the catalytic ozonation experiments, the degradation kinetics was investigated. The reaction rate and the rate constant were determined. The results showed that using a BC catalyst in the ozonation of HS produced a 1.43-...