scholarly journals The adsorption and Fenton behavior of iron rich Terra Rosa soil for removal of aqueous anthraquinone dye solutions: kinetic and thermodynamic studies

2017 ◽  
Vol 76 (11) ◽  
pp. 3114-3125 ◽  
Author(s):  
Doga Aktas ◽  
Nadir Dizge ◽  
H. Cengiz Yatmaz ◽  
Yasemin Caliskan ◽  
Yasin Ozay ◽  
...  

Abstract Adsorption and advanced oxidation processes are being extensively used for treatment of wastewater containing dye chemicals. In this study, the adsorption and Fenton behavior of iron rich Terra Rosa soil was investigated for the treatment of aqueous anthraquinone dye (Reactive Blue 19 (RB19)) solutions. The impact of pH, initial dye concentration, soil loading rate, contact time and temperature was systematically investigated for adsorption process. A maximum removal efficiency of dye (86.6%) was obtained at pH 2, soil loading of 10 g/L, initial dye concentration of 25 mg/L, and contact time of 120 min. Pseudo-first-order, pseudo-second-order, Elovich, and Weber–Morris kinetic models were applied to describe the adsorption mechanism and sorption kinetic followed a pseudo-second-order kinetic model. Moreover, Langmuir, Freundlich and Temkin isotherm models were used to investigate the isothermal mechanism and equilibrium data were well represented by the Langmuir equation. The maximum adsorption capacity of soil was found as 4.11 mg/g using Langmuir adsorption isotherm. The effect of soil loading and hydrogen peroxide (H2O2) dosage was solely tested for Fenton oxidation process. The highest removal efficiency of dye (89.4%) was obtained at pH 2, H2O2 dosage of 10 mM, soil loading of 5 g/L, initial dye concentration of 50 mg/L, and contact time of 60 min. Thermodynamic studies showed that when the adsorption dosage of dye was 25 mg/L at 293–313 K, adsorption enthalpy (ΔH) and entropy (ΔS) were negative and adsorption free energy (ΔG) was positive. This result indicated that the adsorption was exothermic. Morphological characteristics of the soil were evaluated by X-ray fluorescence (XRF), scanning electron microscopy (SEM), and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy before and after the adsorption and oxidation process.

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2295 ◽  
Author(s):  
Souad Rakass ◽  
Hicham Oudghiri Hassani ◽  
Mostafa Abboudi ◽  
Fethi Kooli ◽  
Ahmed Mohmoud ◽  
...  

Nano Molybdenum trioxide (α-MoO3) was synthesized in an easy and efficient approach. The removal of methylene blue (MB) in aqueous solutions was studied using this material. The effects of various experimental parameters, for example contact time, pH, temperature and initial MB concentration on removal capacity were explored. The removal of MB was significantly affected by pH and temperature and higher values resulted in increase of removal capacity of MB. The removal efficiency of Methylene blue was 100% at pH = 11 for initial dye concentrations lower than 150 ppm, with a maximum removal capacity of 152 mg/g of MB as gathered from Langmuir model. By comparing the kinetic models (pseudo first-order, pseudo second-order and intraparticle diffusion model) at various conditions, it has been found that the pseudo second-order kinetic model correlates with the experimental data well. The thermodynamic study indicated that the removal was endothermic, spontaneous and favorable. The thermal regeneration studies indicated that the removal efficiency (99%) was maintained after four cycles of use. Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of the MB dye on the α-MoO3 nanoparticles after adsorption and regeneration. The α-MoO3 nanosorbent showed excellent removal efficiency before and after regeneration, suggesting that it can be used as a promising adsorbent for removing Methylene blue dye from wastewater.


2020 ◽  
Vol 24 (2) ◽  
pp. 329-333
Author(s):  
D.O. Jalija ◽  
A . Uzairu

The objective of this study was to investigate the biosorption of Cu (II) and Ni (II) ions from aqueous solution by calcium alginate beads. The effects of solution pH, contact time and initial metal ion concentration were evaluated. The results showed that maximum Cu (II) removal (93.10%) occurred at pH of 9.0, contact time of 120 minutes and initial ion concentration of 10 mg/L while that of Ni (II) was 94.6%, which was achieved at pH of 8.0, contact time of 120 minutes and initial ion concentration of 10 mg/L. The equilibrium data fitted well to the Langmuir Isotherm indicating that the process is a monolayer adsorption. The coefficients of determination, R2, values for the Langmuir Isotherm were 0.9799 and 0.9822 respectively for Cu (II) and Ni (II) ions. The values of the maximum biosorption capacity, Qo, were 10.79 and 6.25 mgg-1 respectively. The kinetic data also revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots for Cu (II) and Ni (II) were 0.9988 and 0.9969 respectively. These values were higher than those for the pseudo – first order plots. The values of the biosorption capacity qe obtained from the pseudo – second order plots were very close to the experimental values of qe indicating that the biosorption process follows the second order kinetics. This study has therefore shown that calcium alginate beads can be used for the removal of Cu (II) and Ni (II) ions from wastewaters. Keywords: Keywords: Adsorption, Calcium alginate, Isotherm, Langmuir, Pseudo- first order, Pseudo-second order


Author(s):  
P. H. Kumaraiah

Recently, low-cost adsorbents from sustainable sources are required for the remediation of textile wastewater. Carbonized Orange Peels (COPs) was utilized in remediating colour, Zinc and Copper from textile wastewater. The initial and final pH, colour and trace metals’ composition of the wastewater used were determined for the adsorption processes. Batch adsorption experiment was carried out on COPs and textile wastewater’s mixture to find effects of COP’s dosage, agitation, pH and contact time on the colour, Zinc and Copper’s removal from the wastewater. The adsorption isotherms and kinetic studies were conducted using Langmuir, Freundlich, Pseudo-first-order and Pseudo-second-order models. Findings established that the optimum removal of colour, Zinc and Copper respectively occurred at an adsorbent dosage of 2.5, 0.5 and 3.0 g/100ml, pH of 10, 4 and 2, rotating speed of 100, 250 and 250 rpm, contact time of 40, 60, and 40 mins. The adsorption isotherms revealed only copper adsorption as optimum and well fitted Langmuir isotherm. Pseudo-second-order kinetic model best suited adsorption data of the colour and metal ions with high correlation coefficient (R2) exceeding 0.95. Conclusively, COPs is effective in remediating the colour, copper and zinc from the wastewater, thus, recommended as suitable adsorbent for treatment of textile wastewater


2020 ◽  
Author(s):  
Eman Alabbad

Abstract Background Water contamination has increasingly become a significant problem affecting the welfare of living organisms perceived to be aquatic beneficiaries. The nature and origin of the contaminant always determines the purification techniques. The most common contaminants in wastewater include organic compounds such as dyes that must be eliminated to enhance water purity and safety.Result The results indicate that the removal of DY50 by the modified chitosan was affected by the solution pH, sorbent dosage, initial DY50 concentration, contact time, and temperature. The experimental data were fitted to the Langmuir, Freundlich, and Temkin isotherms, and Langmuir isotherm showed the best fit. The kinetic data were fitted to the pseudo-first-order and pseudo-second-order rate equations. The removal rate was 97.9% by chemisorption components after the three hours at about 0.05 g of sorbent dose and 100 ppm of the Direct Yellow 50 dye initial concentration. The adsorption behavior of the modified chitosan for the removal of DY50 was well-described using the pseudo-second-order kinetic model, Intraparticle diffusion analysis was also conducted. The thermodynamic properties such as free energy (∆G), enthalpy (∆H), and entropy (∆S), in addition to the intra-particle diffusion rate were similarly defined.Conclusion The pH, initial DY50 concentration, sorbent dosage, adsorption temperature, and contact time had a significant effect on the adsorption of DY50 by chitosan-iso-vanillin.


Author(s):  
Farhad Salimi ◽  
Keivan Tahmasobi ◽  
Changiz Karami ◽  
Alireza Jahangiri

Modified nano-silica with Bismuth and Iron adsorbent was synthesized to be used as an effective adsorbent material for methylene blue (MB) removal from water solution. The prepared samples were characterized using SEM, FTIR, XRD and TEM. The effect of experimental parameters such as pH, contact time and initial concentration on adsorption treatment were studied. Results indicated that the optimum conditions for maximum <strong>adsorption</strong> of 20 mg/L MB <strong>were:</strong> contact time of 20 minutes, pH= 5-6 and 8 gr/L adsorbent, the remaining MB in solution was 1.75%. Langmuir and Freundlich isotherms were employed to model the experimental results and the Freundlich isotherm was the best-fitting models for the experiment results. The kinetic data were also analyzed through pseudo-first-order and pseudo-second-order models. The pseudo-second-order kinetic model well depicted the kinetics of dyes adsorption on adsorbent.


2019 ◽  
Vol 9 (1) ◽  
pp. 1-11
Author(s):  
Samia Glissi ◽  
Meriem Tarbaoui ◽  
Laila Makouki ◽  
Khadija Legrouri ◽  
Hassan Hannache ◽  
...  

In this work, some adsorbent materials were prepared from residual biomass, which constitutes a real hazard for the environment and human health. So, in order to valorize this vegetal resource, a process of transformation was studied. The residual biomass was turned into adsorbent materials under the effect of chemical activation with phosphoric acid which allows the development of a large pore in the activated materials. The optimization of the conditions for the elaboration of our adsorbents was realized by experimental design by evaluating some parameters (percentage of phosphoric acid, temperature and time of activation) and their effects on the responses (capacity of adsorption of methylene blue, adsorbent yield), these parameters were selected after a screening study. The activation of our residual biomass was effected with 60% of phosphoric acid in 225°C while 115 min. The studied biomass was characterized by different physic-chemical methods (Differential Thermal Analysis /Thermogravimetric Analysis (DTA/TGA), Scanning Electron Microscopy (SEM), Raman and X-Ray Diffraction (XRD)); the results of characterization show the presence of the excellent textural and structural properties. The application of the best adsorbent in the removal of textile dyes (methylene blue) from aqueous solutions was studied. The impact of various parameters such as contact time, pH and concentration on the removal was evaluated by batch method. The adsorption isotherms were studied using Langmuir and Freundlich isotherm models. Langmuir isotherm provided the best fit to the equilibrium data with a correlation coefficient equal to 0.998. This result shows the presence of monolayer adsorption. The experiments demonstrated that the removal of methylene blue followed the pseudo-second-order kinetic model. The correlation coefficient is consistent and equal to unity, and the experimental qe value (44.17) was agreed with the calculated qe value (45.45) of pseudo-second-order then the value of pseudo-first-order which confirm a chemisorption process. The obtained results revealed that the elaborated material is an effective adsorbent for the removal of methylene blue.


Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 852
Author(s):  
Sicong Yao ◽  
Massimiliano Fabbricino ◽  
Marco Race ◽  
Alberto Ferraro ◽  
Ludovico Pontoni ◽  
...  

Digestate, as an urban solid waste, was considered as an innovative adsorbent for colorant polluted wastewater. Batch adsorption experiments were carried out using digestate as an adsorbent material to remove various dyes belonging to different categories. The removal rate and adsorption capacity of dyes were evaluated and the dose of digestate, contact time, and initial dye concentration were studied. The maximum removal rate was approximately 96% for Methylene Blue. The equilibrium time for the Methylene Blue was 4 h, while for other dyes, a longer contact time was required to reach the equilibrium. The suspicion of colloidal matter release into the solution from solid fraction of the digestate led to the investigation of the consequence of a washing step of the digestate adsorbent upstream the adsorption experiment. Washed and not washed adsorbents were tested and the differences between them in terms of dye removal were compared. Moreover, experimental data were fitted by pseudo-first order, pseudo-second order, and intra-partial diffusion kinetic models as well as Langmuir, Freundlich, and Sips isotherm models. The results from fitted models showed that the adsorption of various dyes onto the digestate was mostly well fitted by the Langmuir isotherm and pseudo-second-order kinetic model.


2011 ◽  
Vol 236-238 ◽  
pp. 155-158
Author(s):  
Li Fang Zhang ◽  
Shu Juan Dai ◽  
Ying Ying Chen

In this study, Biosorption of hexavalent chromium ions from aqueous solution by using biomass ofAspergillus nigerwas investigated. Different parameters such as initial pH, biosorbent amount, contact time and temperature were explored. The biosorption of Cr (VI) ions was highly pH dependent and the optimum pH for biosorption of Cr (VI) ions was found to be 2.0. Biosorption capacity of Cr (VI) ions decreased with increased biosorbent dosage. The biosorption equilibrium was established in about 120min of contact time. Equilibrium uptake of Cr (VI) ions onto biomass increased from 12.57 mg/g at 20°C to 19.48 mg/g at 40 °C for 20mg/L Cr (VI) ions concentration. The biosorption process followed the pseudo-second order kinetic model and the correlation coefficients from the pseudo-second order model were all higher than 0.997 in all studied temperatures. These results suggest that the biomass ofAspergillus nigeris a promising biosorbent for removal of chromium (VI) ions from the wastewater.


2020 ◽  
Vol 7 (1) ◽  
pp. 16-25
Author(s):  
Eman A. Alabbad

Introduction: Water pollution is a serious issue in several countries. In addition, because of limited water resources, the recycling of wastewater is crucial. Consequently, new and effective sorbents are required to reduce the cost of wastewater treatment as well as to mitigate the health problems caused by water pollution. Methods: In this study, the removal of Methyl Orange (MO) dye from wastewater using a chitosan-iso-vanillin polymer was evaluated. The removal of MO from an aqueous solution was studied in a batch system, using the modified chitosan polymer. Results: The results indicate that the removal of MO by the modified chitosan was affected by the solution pH, sorbent dosage, initial MO concentration, contact time, and temperature. The experimental data were fitted to the Langmuir, Freundlich, and Temkin isotherms, and Freundlich isotherm showed the best fit. The kinetic data were fitted to the pseudo-first-order and pseudo-second-order rate equations. Thus, the removal of MO was controlled via chemisorption, and the removal rate was 97.9% after 3 h at an initial MO concentration of 100 ppm and a sorbent dose of 0.05 g. The adsorption behavior of the modified chitosan for the removal of MO was well-described using the pseudo-second-order kinetic model. Intraparticle diffusion analysis was also conducted, and the thermodynamic properties, including entropy (∆S), enthalpy (∆H), and free energy (∆G), were determined. Conclusion: The pH, initial MO concentration, sorbent dosage, adsorption temperature, and contact time had a significant effect on the adsorption of MO by chitosan-iso-vanillin.


Author(s):  
E. S. Isagba ◽  
S. Kadiri ◽  
I. R. Ilaboya

This paper investigated the use of yam peel as a natural adsorbent for the removal of Copper (Cu) and Manganese (Mn) from waste water. The yam peels were thoroughly washed with distilled water, dried, pulverized and carbonized. The carbonized yam peel was then characterized for its particle sizes, moisture content, ash content, volatile matter, Methylene Blue number, Iodine number. The raw yam peels were prepared using the same procedure, but was not carbonized. The adsorption of Mn(II) and Cu(II) ions were investigated using adsorption experiment at room temperature. The effect of contact time, metal ion concentration and dosage were evaluated. The residual concentrations of the metal ions were determined by Atomic Absorption Spectrophotometer (AAS). Experimental data obtained were analyzed using Kinetic models and Isotherms such as Pseudo- First order kinetic models, Pseudo-second order kinetic models, Langmuir isotherms and Freundlich isotherm. The analysis showed that the pseudo-second order kinetic model best described the adsorption of the metal ions; ( Cu; r2 = 0.991 for RYP and r2 = 0.834 for AYP) and (Mn; r2 = 0.958 for RYP and r2 = 0.896 for AYP) and the experimental data best fit the Freundlich model; (Cu; r2 = 0.564 for RYP and r2 = 0.871 for AYP) and (Mn; r2 = 0.685 for RYP and r2 = 0.736 for AYP). Finally, optimum removal efficiencies of 30.54% for Mn(II) and 39.62% for Cu(II) were obtained for AYP at concentrations of 50mg/l and mass dosage of 1.0g, 120 minutes contact time and a pH of 6.8.


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