scholarly journals Biosorption of six basic and acidic dyes on brown alga Sargassum ilicifolium: optimization, kinetic and isotherm studies

2017 ◽  
Vol 75 (11) ◽  
pp. 2631-2638 ◽  
Author(s):  
Reza Tabaraki ◽  
Negar Sadeghinejad

Biosorption of Methyl Blue (MB), Fuchsin Acid (FA), Rhodamine B (RB), Methylene Blue (MEB), Bromocresol purple (BC) and Methyl Orange (MO) onto Sargassum ilicifolium was studied in a batch system. Effect of dye structure on biosorption by Sargassum ilicifolium was studied to define the correlation between chemical structure and biosorption capacity. Different dye groups such as triarylmethane (MB, FA and BC), monoazo (MO), thiazine (MEB) and xanthene (RB) were studied. At optimum experimental conditions for each dye, biosorption capacity was determined and compared. The results indicate that the chemical structure (triarylmethane, monoazo, thiazine, xanthene), number of sulfonic groups, basicity (element of chromophore group: S, N, O) and molecular weight of dye molecules influence their biosorption capacity. Experimental parameters such as biosorbent dose, pH, contact time, and initial dye concentration were optimized for each dye. The biosorption kinetic data were successfully described by the pseudo second-order model. The biosorption results were also analyzed by the Langmuir and Freundlich isotherms. Finally, biosorption capacities obtained using Sargassum ilicifolium were compared with the ones presented in the literature.

Author(s):  
C. B. Lopes ◽  
M. Otero ◽  
Z. Lin ◽  
E. Pereira ◽  
C. M. Silva ◽  
...  

Mercury is one of the most toxic heavy metals present in the environment and therefore is extremely important develop new, simple and reliable techniques for its removal from aqueous solutions. A recent line of research within this context is the application of microporous materials. The use of these materials for removing heavy metals from solutions may become a potential clean-up technology in the field of wastewater treatment. In this work it is reported the application of microporous titanosilicate ETS-4 as ion exchanger to remove Hg2+ from aqueous solution. Under batch conditions, we studied the effect of contact time, titanosilicate mass and initial Hg2+ concentration. Only 5 mg of ETS-4 are required to purify 2 litres of water with 50 μg L−1 of metal. Under the experimental conditions, the initial Hg2+ concentration and ETS-4 mass have strong influence on the sorption process, and it is proved that 24 h are almost always sufficient to attain ion exchange equilibrium. Langmuir and Freundlich isotherms were used to fit equilibrium experimental results. The kinetics of mercury removal was reliably described by a pseudo second-order model. On the whole, ETS-4 shows considerable potential to remove Hg2+ from wastewaters.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
C. R. Girish ◽  
V. Ramachandra Murty

The present work investigates the potential of Lantana camara, a forest waste, as an adsorbent for the phenol reduction in wastewater. Batch studies were conducted with adsorbent treated with HCl and KOH to determine the influence of various experimental parameters such as pH, contact time, adsorbent dosage, and phenol concentration. The experimental conditions were optimized for the removal of phenol from wastewater. Equilibrium isotherms for the adsorption of phenol were analyzed by Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich isotherm models. Thermodynamic parameters like the Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were also determined and they showed that the adsorption process was feasible, spontaneous, and exothermic in the temperature range of 298–328 K. The kinetic data were fitted with pseudo-second-order model. The equilibrium data that followed Langmuir model with the monolayer adsorption capacity was found to be 112.5 mg/g and 91.07 mg/g for adsorbent treated with HCl and KOH, respectively, for the concentration of phenol ranging from 25 to 250 mg/L. This indicates that the Lantana camara was a promising adsorbent for the removal of phenol from aqueous solutions.


2015 ◽  
Vol 18 (1) ◽  
pp. 25-37 ◽  

<div> <p>Biosorption is an emerging technique for water treatment utilizing abundantly available biomaterials.The potential feasibility of magnetic peanut hulls particle for removal of cationic dye (methylene blue) from aqueous solution was investigated. The effects of various experimental parameters were examined and optimal experimental conditions were decided. Characterization of biosorbent was carried out by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analyzer. FT-IR analysis showedthe presence of hydroxyl, carbonyl and carboxyl groups which can involve in the biosorption process. The results in this study indicated that peanut hull was an attractive candidate for removing cationic dyes from dye wastewater. Different kinetic and equilibrium models were applied to the experimental data. Tempkin model was the most fitted isotherm as R<sup>2</sup>= 0.963. While the resulting data for the different parameters studied was suitable to be pseudo second order.&nbsp;</p> </div> <p>&nbsp;</p>


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2518
Author(s):  
Dorota Kołodyńska ◽  
Yongming Ju ◽  
Małgorzata Franus ◽  
Wojciech Franus

The possibility of application of chitosan-modified zeolite as sorbent for Cu(II), Zn(II), Mn(II), and Fe(III) ions and their mixtures in the presence of N-(1,2-dicarboxyethyl)-D,L-aspartic acid, IDHA) under different experimental conditions were investigated. Chitosan-modified zeolite belongs to the group of biodegradable complexing agents used in fertilizer production. NaP1CS as a carrier forms a barrier to the spontaneous release of the fertilizer into soil. The obtained materials were characterized by Fourier transform infrared spectroscopy (FTIR); surface area determination (ASAP); scanning electron microscopy (SEM-EDS); X-ray fluorescence (XRF); X-ray diffraction (XRD); and carbon, hydrogen, and nitrogen (CHN), as well as thermogravimetric (TGA) methods. The concentrations of Cu(II), Zn(II), Mn(II), and Fe(III) complexes with IDHA varied from 5–20 mg/dm3 for Cu(II), 10–40 mg/dm3 for Fe(III), 20–80 mg/dm3 for Mn(II), and 10–40 mg/dm3 for Zn(II), respectively; pH value (3–6), time (1–120 min), and temperature (293–333 K) on the sorption efficiency were tested. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin adsorption models were applied to describe experimental data. The pH 5 proved to be appropriate for adsorption. The pseudo-second order and Langmuir models were consistent with the experimental data. The thermodynamic parameters indicate that adsorption is spontaneous and endothermic. The highest desorption percentage was achieved using the HCl solution, therefore, proving that method can be used to design slow-release fertilizers.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Klaiani B. Fontana ◽  
Giane Gonçalves Lenzi ◽  
Erica R. L. R. Watanabe ◽  
Ervin Kaminski Lenzi ◽  
Juliana A. M. T. Pietrobelli ◽  
...  

The removal of Pb(II) from water by biosorption processes onto malt bagasse was investigated and the kinetic and thermodynamic parameters were obtained; additionally a diffusion modeling was proposed. The characterization of malt bagasse was performed by FTIR and SEM/EDS. The experiments were conducted in batch system and an experimental design based response surface methodology was applied for agitation speed and pH optimization. The kinetics of biosorption followed pseudo-second-order model and the temperature of the process affected the biosorption capacity. Isotherm models of Langmuir, Freundlich, and Elovich were applied and the Langmuir model showed better fit and the estimated biosorption capacity was 29.1 mg g−1. The negative values obtained for ΔG° and positive values of ΔH° confirm, respectively, the spontaneous and endothermic nature of the process. The diffusion modeling was performed based on experiments in the absence of agitation to investigate the influence of the biosorbent on the sorption process of Pb(II) ions.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3209
Author(s):  
Aphiwe Siyasanga Gugushe ◽  
Anele Mpupa ◽  
Tshimangadzo Saddam Munonde ◽  
Luthando Nyaba ◽  
Philiswa Nosizo Nomngongo

In this study, Fe3O4-ZrO2 functionalized with 3-aminopropyltriethoxysilane (Fe3O4-ZrO2@APS) nanocomposite was investigated as a nanoadsorbent for the removal of Cd(II), Cu(II), Mn (II) and Ni(II) ions from aqueous solution and real samples in batch mode systems. The prepared magnetic nanomaterials were characterized using X-ray powder diffraction (XRD), scanning electron microscopy/energy dispersion x-ray (SEM/EDX) Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). Factors (such as adsorbent dose and sample pH) affecting the adsorption behavior of the removal process were studied using the response surface methodology. Under optimized condition, equilibrium data obtained were fitted into the Langmuir and Freundlich isotherms and the data fitted well with Langmuir isotherms. Langmuir adsorption capacities (mg/g) were found to be 113, 111, 128, and 123 mg/g for Cd, Cu, Ni and Mn, respectively. In addition, the adsorption kinetics was analyzed using five kinetic models, pseudo-first order, pseudo-second order, intraparticle diffusion and Boyd models. The adsorbent was successfully applied for removal of Cd(II), Cu(II), Mn (II) and Ni(II) ions in wastewater samples.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 855
Author(s):  
Ahmed Amine Azzaz ◽  
Salah Jellali ◽  
Nasser Ben Harharah Hamed ◽  
Atef El Jery ◽  
Lotfi Khezami ◽  
...  

In the present study, methylene blue (MB) removal from aqueous solutions via the photocatalytic process using TiO2 as a catalyst in the presence of external ultra-violet light (UV) was investigated. The results of adsorption in the absence of UV radiation showed that adsorption reached an equilibrium state at 60 min. The experimental kinetic data were found to be well fitted by the pseudo-second-order model. Furthermore, the isotherm study suggested that dye uptake by TiO2 is a chemisorption process with a maximum retention capacity of 34.0 mg/g. The photodegradation of MB was then assessed under various experimental conditions. The related data showed that dye mineralization decreased when dye concentrations were increased and was favored at high pH values and low salt concentrations. The simultaneous presence of organic and inorganic pollution (Zinc) was also evaluated. The effect of the molar ratio Zn2+/MB+ in the solution at different pH values and NaCl concentrations was also monitored. The corresponding experimental results showed that at low values of Zn2+ in the solution (30 mg/L), the kinetic of the MB removal became faster until reaching an optimum at Zn2+/MB+ concentrations of 60/60 mg/L; it then slowed down for higher concentrations. The solutions’ carbon contents were measured during the degradation process and showed total mineralization after about 5 h for the optimal Zn2+/MB+ condition.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
An Zheng ◽  
Michael Lamkin ◽  
Yutong Qiu ◽  
Kevin Ren ◽  
Alon Goren ◽  
...  

Abstract Background A major challenge in evaluating quantitative ChIP-seq analyses, such as peak calling and differential binding, is a lack of reliable ground truth data. Accurate simulation of ChIP-seq data can mitigate this challenge, but existing frameworks are either too cumbersome to apply genome-wide or unable to model a number of important experimental conditions in ChIP-seq. Results We present ChIPs, a toolkit for rapidly simulating ChIP-seq data using statistical models of key experimental steps. We demonstrate how ChIPs can be used for a range of applications, including benchmarking analysis tools and evaluating the impact of various experimental parameters. ChIPs is implemented as a standalone command-line program written in C++ and is available from https://github.com/gymreklab/chips. Conclusions ChIPs is an efficient ChIP-seq simulation framework that generates realistic datasets over a flexible range of experimental conditions. It can serve as an important component in various ChIP-seq analyses where ground truth data are needed.


2017 ◽  
Vol 75 (6) ◽  
pp. 1500-1511 ◽  
Author(s):  
Shengjiong Yang ◽  
Pengkang Jin ◽  
Xiaochang C. Wang ◽  
Qionghua Zhang ◽  
Xiaotian Chen

In this study, a granular material (GM) developed from building waste was used for phosphate removal from phosphorus-containing wastewater. Batch experiments were executed to investigate the phosphate removal capacity of this material. The mechanism of removal proved to be a chemical precipitation process. The characteristics of the material and resulting precipitates, the kinetics of the precipitation and Ca2+ liberation processes, and the effects of dosage and pH were investigated. The phosphate precipitation and Ca2+ liberation processes were both well described by a pseudo-second-order kinetic model. A maximum precipitation capacity of 0.51 ± 0.06 mg g−1 and a liberation capacity of 6.79 ± 0.77 mg g−1 were measured under the experimental conditions. The processes reached equilibrium in 60 min. The initial solution pH strongly affected phosphate removal under extreme conditions (pH &lt;4 and pH &gt;10). The precipitates comprised hydroxyapatite and brushite. This novel GM can be considered a promising material for phosphate removal from wastewater.


2013 ◽  
Vol 67 (11) ◽  
pp. 2560-2567 ◽  
Author(s):  
Fan Yang ◽  
Xiaojie Song ◽  
Lifeng Yan

Cationic paper was prepared by reaction of paper with 2,3-epoxypropyltrimethylammonium chloride in aqueous suspension, and tested as low-cost adsorbent for wastewater treatment. The experimental results revealed that anionic dyes (Acid Orange 7, Acid Red 18, and Acid Blue 92) were adsorbed on the cationic paper nicely. The maximum amount of dye Acid Orange 7 adsorbed on cationic paper was 337.2 mg/g in experimental conditions. The effects of initial dye concentration, temperature, and initial pH of dye solution on adsorption capacity of cationic paper were studied. The pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data. The Freundlich and Langmuir adsorption models were used to describe adsorption equilibrium. The thermodynamic data indicated that the adsorption process of dye on cationic paper occurred spontaneously.


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