scholarly journals Adsorption Study of Some Sulphanilic Azo Dyes on Charcoal

2011 ◽  
Vol 8 (2) ◽  
pp. 739-747 ◽  
Author(s):  
H. J. Mohammed ◽  
B. J. Kadhim ◽  
Aseel Sh. Mohammed
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Process Variables ◽  
Equilibrium Isotherms ◽  
Freundlich Isotherms ◽  
Initial Ph ◽  
Equilibrium Data ◽  
Series Of Experiments ◽  
Adsorbent Dose

Studies on the removal of two dyes (sulphanilic azo antipyrine and sulphanilic azo imidazole) from aqueous solution by adsorption on charcoal as an adsorbent were carried out. A series of experiments were under taken in a batch adsorption technique to access the effect of the process variablesi.e. contact time, initial dye concentration, initial pH, adsorbent dose and temperature. Adsorbent dosage (0.1 g) higher value for both dyes. The equilibrium in the solution was observed within (35 min) of two sulphanilic dyes on charcoal. The equilibrium isotherms for both dyes were determined to describe the adsorption process. The results showed that the equilibrium data was fitted by of the Freundlich isotherms on charcoal surface. The result obtained shows that the adsorption isotherm for both dyes on charcoal was according to Giles classification. The thermodynamic factors such as ∆Η, ∆G and ∆S were calculated.

scholarly journals Removal of phenol from aqueous solution by adsorption onto seashells: equilibrium, kinetic and thermodynamic studies

2013 ◽  
Vol 3 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Papita Das Saha ◽  
Jaya Srivastava ◽  
Shamik Chowdhury
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Phenol Concentration ◽  
Phenol Removal ◽  
Solution Ph ◽  
Initial Ph ◽  
Equilibrium Data ◽  
Initial Phenol Concentration ◽  
Adsorption Equilibrium Data ◽  
Adsorbent Dose

The efficacy of seashells as a new adsorbent for removal of phenol from aqueous solutions was studied by performing batch equilibrium tests under different operating parameters such as solution pH, adsorbent dose, initial phenol concentration, and temperature. The phenol removal efficiency remained unaffected when the initial pH of the phenol solution was in the range of 3–8. The amount of phenol adsorbed increased with increasing initial phenol concentration while it decreased with increasing temperature. The adsorption equilibrium data showed excellent fit to the Langmuir isotherm model with maximum monolayer adsorption capacity of 175.27 mg g−1 at pH 4.0, initial phenol concentration = 50 mg L−1, adsorbent dose = 2 g and temperature = 293 K. Analysis of kinetic data showed that the adsorption process followed pseudo-second-order kinetics. Activation energy of the adsorption process, calculated using the Arrhenius equation, was found to be 51.38 kJ mol−1, suggesting that adsorption of phenol onto seashells involved chemical ion-exchange. The numerical value of the thermodynamic parameters (ΔG0, ΔH0 and ΔS0) indicated that adsorption of phenol onto seashells was feasible, spontaneous and endothermic under the examined conditions. The study shows that seashells can be used as an economic adsorbent for removal of phenol from aqueous solution.

scholarly journals Adsorption of Basic and Acidic Dyes onto Agricultural Wastes

2016 ◽  
Vol 70 ◽  
pp. 12-26 ◽  
Author(s):  
Nnaemeka John Okorocha ◽  
J. Josphine Okoji ◽  
Charles Osuji
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Thermodynamic Quantities ◽  
Order Kinetic ◽  
Dyes Adsorption ◽  
Adsorbent Dose

The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red (CR) dyes from aqueous solution was investigated. The adsorbent (ALP) was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of CV and CR dyes onto the adsorbent (ALP) was found to be: contact time (100mins), pH (10.0), temperature (343K) for an initial CV dye concentration of 50mg/L using adsorbent dose of 1.0g and contact time (100mins), pH (2.0), temperature (333K) for an initial CR dye concentration of 50mg/L using adsorbent dose 1.0g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for both CV and CR dyes adsorption. The maximum adsorption capacity of ALP was found to be 22.96mg/g and 7.77mg/g for the adsorption of CV and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0obtained for both dyes indicate the spontaneous nature of the adsorption process while the positive values of ΔH0and ΔS0obtained indicated the endothermic nature and increased randomness during the adsorption process respectively for the adsorption of CV and CR onto ALP. Based on the results obtained such as good adsorption capacity, rapid kinetics, and its low cost, ALP appears to be a promising adsorbent material for the removal of CV and CR dye stuff from aqueous media.

Application of Chitosan Film for the Removal of Triclosan from Aqueous Solutions by Adsorption

2016 ◽  
Vol 675-676 ◽  
pp. 455-458
Author(s):  
Peeyanan Noirod ◽  
Jittapat Lamangthong ◽  
Padarat Ninjiaranai
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Chitosan Film ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Acidic Ph ◽  
Adsorption Efficiency ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Equilibrium Data

The aim of this work was to study the adsorption efficiency of chitosan as an adsorbent for triclosan, commercially known as Irgasan, in aqueous solutions. The effects of contact time, pH and temperature were investigated using a batch adsorption technique. Langmuir and Freundlich isotherms were used to analyze the equilibrium data at different absorption conditions. The results showed that the maximum adsorption capacity for chitosan was found in the acidic pH 3 and at a temperature of 65 oC. These results suggested that chitosan can be used as an adsorbent for removal of triclosan from aqueous solutions.

scholarly journals Experimental and computational studies on activated Bambara groundnut (Vigna subterranean) hulls for the adsorptive removal of herbicides from aqueous solution

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Thomas Aondofa Nyijime ◽  
Abdullahi Muhammad Ayuba ◽  
Habibat Faith Chahul
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Quantum Chemical ◽  
Contact Time ◽  
Adsorption Process ◽  
Bambara Groundnut ◽  
Batch Adsorption ◽  
Computational Studies ◽  
Initial Concentration ◽  
Equilibrium Data

Abstract Background The excessive usage of herbicides to control herbs by farmers has become an issue of interest to the environmentalist due to the threat posed by such act to the ecosystem, and therefore, there is the need to curb such practices. The efficiency of Bambara groundnut shell for the removal of pendimethalin (PE) and paraquat dichloride (PQ) herbicides from aqueous solution was established in this work. The activated carbon was prepared via chemical activation method using trioxonitrate (v) acid by determining its void volume, moisture content, bulk density and Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) methods. Batch adsorption techniques were set to optimize the adsorption parameters such as solution pH, adsorbate concentration, contact time, adsorbent dosage and temperature in order to depict the best optimal conditions for the adsorption process. The adsorption process was examined in terms of its equilibrium data, kinetics, thermodynamics involved in the adsorption process as well as computational quantum chemical parameters evaluation. Results The batch adsorption experiments revealed that the amounts of PE and PQ adsorbed were found to vary with the contact time, adsorbent dosage, pH and initial concentration. The adsorption of PE and PQ decreased with increasing adsorbent dose but increases with increasing initial concentration of the PE and PQ solution. Isotherm studies revealed that the equilibrium data fitted to both Langmuir and Freundlich model with R-squared values of 0.976, 0.993 and 0.909, 0.978 for PE and PQ, respectively, which implied that Langmuir isotherm had a better fit. This was also found to be an indication that the uptake of PE and PQ by ACBGNS occurred through monolayer adsorption on identical homogenous sites. Also, kinetic modeling results obtained showed that the pseudo-second-order model explained the adsorption kinetics of PE and PQ by ACBGNS best, which meant that chemisorption was the slowest step and, thus, the rate determining step. The positive value of ΔH and the positive value of ΔG show the endothermic and spontaneous nature of adsorption of PE and PQ ACBGNS. Conclusion Batch adsorption experiment and characterization of the ACBGNS have indicated that Bambara ground nut shell can be used to produce activated carbon that can be applied effectively for adsorption of PE and PQ from an aqueous solution. Computational studies results obtained from quantum chemical analysis are consistent with the experimental results obtained from this study.

scholarly journals Experimental investigation of activated carbon prepared from apricot stones material (ASM) adsorbent for removal of malachite green (MG) from aqueous solution

2020 ◽  
Vol 38 (1-2) ◽  
pp. 24-45 ◽  
Author(s):  
Moussa Abbas
Keyword(s):  
Activated Carbon ◽  
Malachite Green ◽  
Contact Time ◽  
Batch Adsorption ◽  
Physical Parameters ◽  
Experimental Isotherm ◽  
Adsorption Capacities ◽  
Initial Ph ◽  
Equilibrium Data ◽  
Pseudo Second Order

The adsorption of malachite green onto activated carbon prepared from apricot stones material has been investigated at batch conditions. The effects of contact time (0–60 min), initial pH (3–11), agitation speed (100–700 r/min), temperature (298–343 K), adsorbent dose (1–10 g/L), and malachite green concentration (4.45–17.6 mg/L) on the malachite green adsorption by apricot stones material have been studied. Malachite green removal increases over the contact time until equilibrium. The batch adsorption experiments were carried out to optimize the physical parameters on the malachite green removal efficiency. It has been found that 23.80 mg/g at 25°C and 88.05 mg/g at 70°C were removed. The kinetic parameters, rate constants and equilibrium adsorption capacities, were calculated and discussed for each kinetic model. The adsorption of malachite green onto apricot stones material is well described by the pseudo second-order equation. The experimental isotherm data were analyzed by different models; the adsorption follows the Langmuir model, providing a better fit of the equilibrium data. The thermodynamics parameters such as the negative free energy Δ G° (−0.191 to −4.447 kJ/mol) and positive enthalpy Δ H° (50.86 kJ/mol) indicated the spontaneous and endothermic nature of the malachite green adsorption with a chemisorption process.

scholarly journals Utilization of Agro-Waste in the Elimination of Dyes from Aqueous Solution: Equilibrium, Kinetic and Thermodynamic Studies

2021 ◽  
Vol 86 ◽  
pp. 11-23
Author(s):  
Nnaemeka John Okorocha ◽  
Chijioke E. Omaliko ◽  
Collins C. Osuagwu ◽  
Maureen O. Chijioke-Okere ◽  
Conrad K. Enenebeaku
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Thermodynamic Quantities ◽  
Order Kinetic ◽  
Maize Cob ◽  
Adsorbent Dose

The prospective of maize cob powder (MCP) as an effective adsorbent for the removal of malachite green (MG) and congo red (CR) dyes from aqueous solution was investigated. The presence of functional groups and pores on maize cob powder were confirmed by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were examined to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of MG and CR onto the adsorbent (MCP) was found to be: contact time (60mins), pH (10.0) and temperature (303 K), adsorbent dose (1 g) for an initial MG dye concentration of 50 mg/L and contact time (80mins), pH (2.0) and temperature (343 K) for an initial CR dye concentration of 50 mg/L and adsorbent dose 1.0 g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for CR dye adsorption and Langmuir Isotherm for MG adsorption. The maximum adsorption capacity was found to be 13.02 mg/g and 9.41 mg/g for the adsorption of MG and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0, ΔH0 and ΔS0 obtained indicated the spontaneous and exothermic nature of the MG adsorption process while positive enthalpy (ΔH0) indicated an endothermic nature of CR adsorption process.

Utilisation of Biomass and Hybrid Biochar from Elephant Grass and Low Density Polyethylene for the Competitive Adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) from Aqueous Media

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Contact Time ◽  
Competitive Adsorption ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Elephant Grass

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.

scholarly journals Cadmium Removal by using Pumice Modified with Iron Nanoparticles from Aqueous Solutions

2016 ◽  
Vol 18 (2) ◽  
pp. 426-436 ◽  
Keyword(s):  
Contact Time ◽  
Iron Nanoparticles ◽  
Cadmium Concentration ◽  
Synthetic Wastewater ◽  
Isotherm Models ◽  
Cadmium Removal ◽  
Pumice Stone ◽  
Practical Applications ◽  
Equilibrium Data ◽  
Adsorbent Dose

<p>In this study, the removal of cadmium by using pumice coated with iron nanoparticles (INPs) from synthetic wastewater was investigated. The effects of parameters influencing adsorption: contact time (10-20 min), pH (3-9), initial cadmium concentration (25-125 mg l<sup>-1</sup>) and adsorbent dose (2-10 g l<sup>-1</sup>) were studied. The pumice stone used in this research was, first, crashed and then sieved with 20 mesh standard sieves (0.85 mm); finally, it was coated with INPs. An atomic absorption spectrophotometer was used to measure cadmium contents and isotherm models and adsorption kinetics were studied. The results showed the adsorption process of cadmium reached equilibrium at contact time of 80 min. With increasing pH solution, the efficiency enhanced which peaked at pH 7-8. Cadmium concentration increase resulted in a decrease in efficiency, whereas adsorbent dose increase improved it. Equilibrium data of adsorption followed isotherms models: Langmuir and Freundlich. The highest removal efficiency and adsorption capacity were, respectively, 83% and 17.27 mg g<sup>-1</sup>. Furthermore, absorption kinetics is better described by the pseudo second-order model. According to the results obtained, pumice coated with INPs is an effective adsorbent and can be introduced as a suitable option in practical applications</p>

scholarly journals Comparative Study on the Adsorption of [AuCl4]– onto Salicylic Acid and Gallic Acid Modified Magnetite Particles

2018 ◽  
Vol 16 (3) ◽  
pp. 329 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno Sutarno
Keyword(s):  
Salicylic Acid ◽  
Gallic Acid ◽  
Adsorption Process ◽  
Freundlich Isotherms ◽  
Precipitation Procedure ◽  
Initial Ph ◽  
Isotherm Adsorption ◽  
Pseudo Second Order ◽  
Magnetite Particles ◽  
Co Precipitation

Salicylic acid-modified magnetite (Mag-SA) and gallic acid-modified magnetite (Mag-GA) particles were prepared by co-precipitation procedure. Characterization results showed the interaction that occurs between the surface of magnetite with salicylic acid (Mag-SA) and gallic acid (Mag-GA) was through hydrogen bonding. Adsorption of [AuCl4]– onto Mag-SA and Mag-GA surfaces as a function of initial pH, contact time, and initial concentration of the [AuCl4]– solution were comparatively investigated. Result showed that the optimum adsorption of [AuCl4]– onto Mag-SA or Mag-GA was found at pH 3. The adsorption process were found to allow the pseudo-second order equation, both for Mag-SA and Mag-GA. The parameters in isotherm adsorption equations conformed to the Langmuir and Freundlich isotherms very well for Mag-GA, but for Mag-SA, only conformed to the Langmuir isotherm very well. The result of this study demonstrate that the ability Mag-GA to adsorb [AuCl4]– higher than Mag-SA.

scholarly journals Enhancing acidic dye adsorption by modified UiO-66

2020 ◽  
Vol 1 (2) ◽  
pp. 54-62
Author(s):  
Naser Al Amery ◽  
Hussein Rasool Abid ◽  
Shaobin Wang ◽  
Shaomin Liu
Keyword(s):  
Adsorption Process ◽  
Dye Adsorption ◽  
Batch Adsorption ◽  
First Order ◽  
Freundlich Isotherms ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
The Stability ◽  
Second Order Equations ◽  
Better Than

In this study, two improved versions of UiO-66 were successfully synthesised. Modified UiO-66 and UiO-66-Ce were characterised to confirm the integrity of the structure, the stability of functional groups on the surface and the thermal stability. Activated samples were used for removal harmful anionic dye (methyl orange) (MO) from wastewater. Batch adsorption process was relied to investigate the competition between those MOFs for removing MO from aqueous solution. Based on the results, at a higher initial concentration, the maximum MO uptake was achieved by UiO-66-Ce which was better than modified-UiO-66. They adsorbed 71.5 and 62.5 mg g-1 respectively. Langmuir and Freundlich isotherms were employed to simulate the experimental data. In addition, Pseudo first order and Pseudo second order equations were used to describe the dynamic behaviour of MO through the adsorption process. The high adsorption capacities on these adsorbents can make them promised adsorbents in industrial areas.

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