Application of Box–Behnken design for modeling of lead adsorption onto unmodified and NaCl-modified zeolite NaA obtained from biosilica

2016 ◽  
Vol 75 (2) ◽  
pp. 358-365 ◽  
Author(s):  
Pinar Terzioğlu ◽  
Sevil Yücel ◽  
Mehmet Öztürk
Keyword(s):  
Optimum Process ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Lead Adsorption ◽  
Box Behnken Design ◽  
Lack Of Fit ◽  
Adsorption Capacities ◽  
Zeolite Naa ◽  
Wheat Husk

The main objective of the present study was to optimize lead adsorption onto zeolite NaA. For this purpose, to synthesize zeolite NaA under hydrothermal conditions, local wheat husk was precleaned with chemical treatment using hydrochloric acid solution. The unmodified (ZU) and NaCl-modified (ZN) zeolites were characterized by Brunauer–Emmett–Teller, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray diffraction. The optimization of adsorption process was examined using Box–Behnken Experimental Design in response surface methodology by Design Expert Version 7.0.0 (Stat-Ease, USA). The effects of initial lead (II) concentration, temperature, and time were selected as independent variables. Lack of fit test indicates that the quadratic regression model was significant with the high coefficients of determination values for both adsorbents. Optimum process conditions for lead (II) adsorption onto ZU and ZN were found to be 64.40°C and 64.80°C, respectively, and 90.80 min, and 350 mg L−1 initial lead(II) concentration for both adsorbents. Under these conditions, maximum adsorption capacities of ZU and ZN for lead (II) were 293.38 mg g−1 and 321.85 mg g−1, respectively.

Characterization of Fe2O3-CaO-SiO2 Glass Ceramics Prepared by Sol-Gel

2014 ◽  
Vol 624 ◽  
pp. 114-118 ◽  
Author(s):  
Yao Yao Wang ◽  
Bin Li ◽  
Yong Ya Wang
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Optimum Process ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Crystallization Activation Energy ◽  
Treatment Technology ◽  
X Ray ◽  
Heat Treatment Technology

Ferromagnetic glass ceramics with magnetism and biological activity could be used for magnetic induction hyperthermia. In this study Fe2O3-CaO-SiO2glass-ceramics were prepared by sol-gel method. The sample was characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). The results showed that the major phases of the sample are wollastonite and magnetite and the crystallization activation energy of sample is 189.3KJ/mol, which would provide a theoretical basis for the establishment of the optimum process conditions of heat treatment technology.

scholarly journals Cleaner Production of Chromium Oxide from Low Fe(II)-Chromite

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 460 ◽  
Author(s):  
Qing Zhao ◽  
Chengjun Liu ◽  
Peiyang Shi ◽  
Lifeng Sun ◽  
Maofa Jiang ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Processing Parameters ◽  
Dissolution Behavior ◽  
Optimum Process ◽  
Process Conditions ◽  
Box Behnken Design ◽  
Functional Relationships ◽  
Leaching Process

Sulfuric acid-based leaching is a promising cleaner method to produce chromium salts, but its feasibility for treating low Fe(II)-chromite still remains to be proven. A Box–Behnken design (BBD)-based set of experiments for sulfuric acid leaching of low Fe(II)-chromite was utilized in this work for generating an experimental dataset for revealing the functional relationships between the processing parameters and the extraction yields of Cr and Fe. The dependent variables were found to exhibit strong intercorrelations and the models developed on the basis of statistical criteria showed excellent prediction accuracy. The optimum process conditions of leaching treatment were found to be a temperature of 176 °C, a dichromic acid/chromite mass ratio of 0.12, and a sulfuric acid concentration of 81%. Furthermore, the dissolution behavior of chromite in the leaching process and the effect of dichromic acid were experimentally investigated. It was found that the decomposition efficiency was highly dependent on the Fe(II) content of chromite, and that the dichromic acid acted both as an oxidant and a catalyst in the leaching process. On the basis of the results of this study, a novel process for treating low-Fe(II) chromite was proposed.

Preparation and Properties of Electroless Ni-P-β-SiC Composition Coating

2014 ◽  
Vol 809-810 ◽  
pp. 621-626
Author(s):  
Xiao Meng Zhang ◽  
Li Bin Niu ◽  
Xiao Cui Wei ◽  
Xiao Gang Wang ◽  
Xiao Hu Hua
Keyword(s):  
Composite Coating ◽  
Deposition Rate ◽  
Optimum Process ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Coating Deposition ◽  
Chemical Plating ◽  
Plating Method ◽  
Electroless Ni ◽  
Sic Particle

Through orthogonal test of Ni-P chemical plating process optimization to determine the optimum process recipe, the Ni-P-β-SiC composite coating were prepared by chemical plating method. The deposition rate, microhardness, composition and organization of Ni-P-β-SiC composite coating are observed and analyzed by scanning electron microscopy (SEM), vivtorinox microhardness tester, X ray diffraction (XRD) and energy spectrum analysis (EDS). The influences of β-SiC particle concentration in bath on the solution of composite coating deposition rate and microhardness. The results show that the influence of composite coating deposition rate and microhardness are NiSO4•6H2O, NaH2PO2•H2O, C3H6O3, and PH. The optimum process conditions: NiSO4•6H2O 25 g/L, NaH2PO2•H2O 27 g/L, C3H6O327 ml/L, PH 5.2. It was found that the Ni-P-β-SiC composite coating with 5g/Lβ-SiC particles exhibited a maximum deposition rate and microhardness, the deposition rate of composite coating is 12.32μm/h, microhardness is 567.93HV0.05.

Chemically-Induced Graft Copolymerization of Diethylenetriamine onto Bagasse Celluloses

2011 ◽  
Vol 295-297 ◽  
pp. 1494-1498
Author(s):  
Nan Nan Xia ◽  
Hong Xiang Zhu ◽  
Shuang Fei Wang ◽  
Ying Xiao Mu ◽  
Chao Bing Deng ◽  
...  
Keyword(s):  
Reaction Time ◽  
Aqueous Medium ◽  
Reaction Temperature ◽  
Graft Copolymerization ◽  
Optimum Process ◽  
Process Conditions ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Chemically Induced ◽  
Ft Ir

Graft copolymerization of diethylenetriamine onto bagasse celluloses was investigated with ammonium ceric nitrate as initiator in an aqueous medium. The condition of the graft copolymerization initiator concentration, the mass ratio of monomer/cellulose, reaction temperature, reaction time based on the experiment is optimized according to the zeta potential. The results showed the relative optimum process conditions were: the concentration of initiator at 36.98mmol/L, the mass ratio of the monomer and cellulose at 1:1, the reaction temperature at 70°C, and the reaction time by 3h. In addition, the graft copolymers were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction analysis (XRD). The results showed that bagasse celluloses could be grafted with diethylenetriamine in aqueous medium.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

A 2-D Zn(II) coordination polymer based on 4,5-imidazoledicarboxylate and bis(benzimidazole) ligands: synthesis, crystal structure and fluorescence properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xinzhao Xia ◽  
Lixian Xia ◽  
Geng Zhang ◽  
Yuxuan Jiang ◽  
Fugang Sun ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Zigzag Chain ◽  
Supramolecular Framework ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Hydrogen Bond Interaction ◽  
X Ray ◽  
New Type ◽  
Solid State Fluorescence

Abstract In this work, a new type of zinc(II) coordination polymer {[Zn(HIDC)(BBM)0.5]·H2O} n (Zn-CP) was synthesized using 4,5-imidazoledicarboxylic acid (H3IDC) and 2,2-(1,4-butanediyl)bis-1,3-benzimidazole (BBM) under hydrothermal conditions. Its structure has been characterized by infrared spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. The Zn(II) ion is linked by the HIDC2− ligand to form a zigzag chain by chelating and bridging, and then linked by BBM to form a layered network structure. Adjacent layers are further connected by hydrogen bond interaction to form a 3-D supramolecular framework. The solid-state fluorescence performance of Zn-CP shows that compared with free H3IDC ligand, its fluorescence intensity is significantly enhanced.

Analyzing the Effect of Fiber, Yarn and Fabric Variables on Bagging Behavior of Single Jersey Weft Knitted Fabrics

2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800 ◽  
Author(s):  
Mitra Karimian ◽  
Hossein Hasani ◽  
Saeed Ajeli
Keyword(s):  
Optimum Process ◽  
Process Conditions ◽  
Knitted Fabrics ◽  
Yarn Twist ◽  
Fabric Density ◽  
Fabric Structure ◽  
Controllable Factors ◽  
Yarn Count ◽  
The Individual ◽  
Single Jersey

This research investigates the effect of fiber, yarn and fabric variables on the bagging behavior of single jersey weft knitted fabrics interpreted in terms of bagging fatigue percentage. In order to estimate the optimum process conditions and to examine the individual effects of each controllable factor on a particular response, Taguchi's experimental design was used. The controllable factors considered in this research are blending ratio, yarn twist and count, fabric structure and fabric density. The findings show that fabric structure has the largest effect on the fabric bagging. Factor yarn twist is second and is followed by fabric density, blend ratio and yarn count. The optimum conditions to achieve the least bagging fatigue ratio were determined.

A Method for Evaluating Intensity of Water Cavitation Peening Processing

2011 ◽  
Vol 675-677 ◽  
pp. 747-750
Author(s):  
B. Han ◽  
Dong Ying Ju ◽  
Xiao Guang Yu
Keyword(s):  
Residual Stress ◽  
Process Capability ◽  
Diffraction Method ◽  
Spring Steel ◽  
Bubble Collapse ◽  
Plastic Layer ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Near Surface ◽  
The Impact

Water cavitation peening (WCP) with aeration, namely, a new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration a standard N-type almen strips of spring steel SAE 1070 was treated byWCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by means of the Almen-scale and X-ray diffraction method, respectively. The optimal fluxes of aeration and the optimal standoff distances were achieved. The maximum of arc height value reach around 150μm. The depth of plastic layer observed from the results of residual stresses is up to 150μm. The results verify the existence of macro-plastic strain in WCP processing. The distributions of residual stress in near-surface under different peening intensity can provide a reference for engineers to decide the optimal process conditions of WCP processing.

Adsorption of the harmful hormone ethinyl estradiol inside hydrophobic cavities of CTA+ intercalated montmorillonite

2016 ◽  
Vol 74 (3) ◽  
pp. 663-671 ◽  
Author(s):  
A. E. Burgos ◽  
Tatiana A. Ribeiro-Santos ◽  
Rochel M. Lago
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
High Efficiency ◽  
Interlayer Space ◽  
Ethinyl Estradiol ◽  
Significant Loss ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrophobic Cavity ◽  
Adsorption Capacities ◽  
Derivative Thermogravimetry

Hydrophobic cavities produced by cetyltrimethylammonium cation (CTA+) exchanged and trapped in the interlayer space of montmorillonite were used to remove the harmful hormone contaminant ethinyl estradiol (EE2) from water. X-ray diffraction, thermogravimetry/derivative thermogravimetry, elemental analysis (carbon, hydrogen, nitrogen), Fourier transform infrared, scanning electron microscopy/energy dispersive spectroscopy, Brunauer–Emmett–Teller and contact angle analyses showed that the intercalation of 9, 16 and 34 wt% CTA+ in the montmorillonite resulted in the d001 expansion from 1.37 to 1.58, 2.09 and 2.18 nm, respectively. EE2 adsorption experiments showed that the original clay montmorillonite does not remove EE2 from water whereas the intercalated composites showed high efficiency with adsorption capacities of 4.3, 8.8 and 7.3 mg g−1 for M9CTA+, M16CTA+ and M34CTA+, respectively. Moreover, experiments with montmorillonite simply impregnated with cetyltrimethylammonium bromide showed that the intercalation of CTA+ to form the hydrophobic cavity is very important for the adsorption properties. Simple solvent extraction can be used to remove the adsorbed EE2 without significant loss of CTA+, which allows the recovery and reuse of the adsorbent for at least five times.

Cetyltrimethylammonium bromide- and ethylene glycol-assisted preparation of mono-dispersed indium oxide nanoparticles using hydrothermal method

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Selvakumar Dhanasingh ◽  
Dharmaraj Nallasamy ◽  
Saravanan Padmanapan ◽  
Vinod Padaki
Keyword(s):  
Ethylene Glycol ◽  
Hydrothermal Method ◽  
Indium Oxide ◽  
Cetyltrimethylammonium Bromide ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractThe influence of cetyltrimethylammonium bromide and ethylene glycol on the size and dispersion of indium oxide nanoparticles prepared under hydrothermal conditions was investigated. The precursor compound, indium hydroxide, obtained by the hydrothermal method in the absence as well as the presence of cetyltrimethylammonium bromide, was converted to indium oxide by sintering at 400°C. The formation of nanoscale indium oxide upon sintering was ascertained by the characteristic infrared adsorption bands and X-ray diffraction patterns of indium oxide. Transmission electron microscopy and band gap values confirmed that the cetyltrimethylammonium bromide facilitated the formation of indium oxide nanoparticles smaller in size and narrower in distribution than those prepared without the assistance of cetyltrimethylammonium bromide.

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