scholarly journals Use of cerium oxide (CeO2) nanoparticles for the adsorption of dissolved cadmium (II), lead (II) and chromium (VI) at two different pHs in single and multi-component systems

2015 ◽  
Vol 17 (3) ◽  
pp. 536-543 ◽  
Keyword(s):  
Heavy Metals ◽  
Experimental Design ◽  
Aqueous Solutions ◽  
Cerium Oxide ◽  
Polynomial Function ◽  
Ceo2 Nanoparticles ◽  
Factorial Experimental Design ◽  
Chromium Vi ◽  
Component Systems ◽  
Sorbent Materials

<p>&nbsp; Cerium oxide (CeO<sub>2</sub>) nanoparticles (NPs) were used for the removal of cadmium (II), lead (II) and chromium (VI) ions in single aqueous solutions and in solutions with mixtures of the three metals. The adsorption studies were carried out at pH 5 and 7 using a systematic factorial experimental design that considered the metal concentration from 1 mg l<sup>-1</sup> to 10 mg l<sup>-1</sup> and NP concentration from 0.064 g l<sup>-1</sup> to 0.640 g l<sup>-1</sup>. The highest adsorption capacity was obtained in the removal of lead (II) (128.1 mg g<sup>-1</sup>), followed by cadmium (II) (93.4</p> <div> <p>mg g<sup>-1</sup>) and finally chromium (VI) (34.4 mg g<sup>-1</sup>). Data were fitted to a polynomial function obtaining the best reduced models. The type of system (single, multi-component) did not affect sorption capacity, whilst pH affected the sorption of Cd and Cr, but not that of lead. CeO<sub>2</sub> nanoparticles proved to be effective adsorbents in removing all three heavy metals in multi-component systems, which opens a new window for their use as sorbent materials in complex waters contaminated with mixtures of heavy metals.&nbsp;</p> </div> <p>&nbsp;</p>

Experimental design and batch experiments for optimization of Cr(VI) removal from aqueous solutions by hydrous cerium oxide nanoparticles

2014 ◽  
Vol 92 (7) ◽  
pp. 1354-1362 ◽  
Author(s):  
Ahmad B. Albadarin ◽  
Zheyu Yang ◽  
Chirangano Mangwandi ◽  
Yoann Glocheux ◽  
Gavin Walker ◽  
...  
Keyword(s):  
Experimental Design ◽  
Aqueous Solutions ◽  
Cerium Oxide ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Batch Experiments

scholarly journals Effective Factor Analysis for Chromium(VI) Removal from Aqueous Solutions and Its Application to Tunçbilek Lignite Using Design of Experiments

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Âli Yurdun Orbak ◽  
İlkün Orbak
Keyword(s):  
Heavy Metals ◽  
Activated Carbon ◽  
Design Of Experiments ◽  
Aqueous Solutions ◽  
Textile Industry ◽  
Chemical Engineering ◽  
Chemical Precipitation ◽  
Physical Activation ◽  
Factors Affecting ◽  
Chromium Vi

Poisonous heavy metals in air, water, and soil produce global environmental problems that are considerable threats to humankind. To meet the local and international guidelines for heavy metal release, companies often use different approaches, such as chemical precipitation, chelating agents, or activated carbon produced by adsorption. One of these heavy and toxic metals is chromium(VI). Chromium(VI) is commonly used in many applications, such as dye fixation in the textile industry or as an anticorrosive agent in paints. The aim of this paper is to explore the factors affecting the removal of one of these deadly heavy metals, chromium(VI), from aqueous solutions. For this purpose, activated carbon from Turkish Tunçbilek lignite is prepared with both chemical and physical activation methods to investigate the adsorption behavior of chromium(VI). The effects of initial chromium(VI) concentration, adsorption temperature, and pH on adsorption are studied using a design of experiments method with a full 24 factorial design with center points. The Freundlich and Langmuir adsorption isotherms that are commonly used in chemical engineering are also applied both for predicting the amount of chromium(VI) adsorbed and confirming the validity and advantages of the obtained regression model. The results indicate that the design of experiments and regression can explain and support the design of new materials by using linear and physically meaningful equations instead of local nonlinear and empirical models that are usually insufficient. Additionally, three experiments were carried out in the liquid phase to test the activated carbon samples: chromium, chromium and sucrose, and chromium-sucrose-ion. A change in adsorption capacities of the activated carbon samples was observed. Sucrose was chosen for the experiments because it contains six carbon atoms in a slightly soluble structure. The results indicated that Tunçbilek lignite exhibits good adsorption capability.

Biosorption of chromium(VI), nickel(II) and Remazol Blue by Rhodotorula muciloginosa biomass

2012 ◽  
Vol 65 (3) ◽  
pp. 471-477 ◽  
Author(s):  
Nalan Oya San ◽  
Gönül Dönmez
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Aqueous Solutions ◽  
Metal Concentration ◽  
Metal Ion ◽  
Heavy Metal Concentration ◽  
Reactive Dye ◽  
Ion Concentration ◽  
Chromium Vi

The passive removal of commonly used reactive dye and two heavy metals, from aqueous solutions by inexpensive biomaterial, yeast Rhodotorula muciloginosa biomass, termed biosorption, was studied with respect to pH, initial dye concentration and initial metal ion concentration. The biomass exhibited maximum dye and chromium(VI) uptake at pH 5 and pH 6 for nickel(II) in media containing 50 mg/L heavy metal and 50 mg/L remazol blue. It was found that the highest chromium(VI) removal yields measured were 31.3% for 49.0 mg/l initial chromium(VI) concentrations. The nickel(II) removal yield was 32.5% for 22.3 mg/L. Higher R. Blue removal yields were obtained, such as 77.1% for 117.5 mg/L. The maximum dye biosorption yield was investigated in medium with a constant dye (∼50 mg/L) and increasing heavy metal concentration. In the medium with 48.8, 103.8 and 151.8 mg/L chromium(VI) and constant dye concentration, the maximum chromium(VI) biosorption was 7.4, 9.3 and 17.1%, whereas the maximum dye biosorption was 61.6, 56.6 and 55.9%. The maximum nickel(II) biosorptions in the medium with dye were 38.1, 22.1 and 8.8% at 23.7, 37.7 and 60.1 mg/L nickel(II) concentrations. In these media, dye biosorptions were 93.9, 86.4 and 93.3%, respectively.

Identifying suboptimalities with factorial model comparison

2018 ◽  
Vol 41 ◽  
Author(s):  
Wei Ji Ma
Keyword(s):  
Experimental Design ◽  
Model Comparison ◽  
Process Models ◽  
Multiple Forms ◽  
Factorial Experimental Design ◽  
Factorial Model ◽  
Multiple Components ◽  
The Many

AbstractGiven the many types of suboptimality in perception, I ask how one should test for multiple forms of suboptimality at the same time – or, more generally, how one should compare process models that can differ in any or all of the multiple components. In analogy to factorial experimental design, I advocate for factorial model comparison.

Oxidized eucalyptus charcoal: a renewable biosorbent for removing heavy metals from aqueous solutions

2021 ◽  
Author(s):  
Elias Costa de Souza ◽  
Alexandre Santos Pimenta ◽  
Alfredo José Ferreira da Silva ◽  
Paula Fabiane Pinheiro do Nascimento ◽  
Joshua O. Ighalo
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions
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