scholarly journals Equilibrium and Kinetic Study of Anionic and Cationic Pollutants Remediation by Limestone–Chitosan–Alginate Nanocomposite from Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2586
Author(s):  
Inas A. Ahmed ◽  
Ahmed H. Ragab ◽  
Mohamed A. Habila ◽  
Taghrid S. Alomar ◽  
Enas H. Aljuhani
Keyword(s):  
Physical Adsorption ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Sem Images ◽  
Bet Analysis ◽  
Adsorption Processes ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Multilayer Formation

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.

Biosorption of Cu2+ from Aqueous Solutions Using NaOH-Modified Fir Sawdust

2013 ◽  
Vol 726-731 ◽  
pp. 1827-1832
Author(s):  
Hong Mei Deng ◽  
Yong Heng Chen ◽  
Cui Qin Wu ◽  
Xue Xia Huang ◽  
Tao Liu
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Process ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Factors Affecting ◽  
Langmuir Adsorption ◽  
Adsorption Processes ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Agricultural Material

Fir sawdust, a low-cost residual agricultural material, was used as adsorbent for the removal of Cu2+from aqueous solutions. Factors affecting the adsorption behavior of Cu2+, such as pH, initial metal concentration, contact time and temperature, have been carried out. The Cu2+removal was pH-dependent, reaching a maximum at pH 5. The adsorption capacity of the fir sawdust from Langmuir adsorption isotherm was 38.6 mg/g at 25°C. The adsorption process followed pseudo-second-order kinetics. The equilibrium data fitted very well to the Freundlich isotherm. The negative ΔGovalues at various temperatures confirm that the adsorption processes are spontaneous.

scholarly journals Equilibrium, Kinetics, and Thermodynamics of the Removal of Nickel(II) from Aqueous Solution Using Cow Hooves

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
I. Osasona ◽  
O. O. Ajayi ◽  
A. O. Adebayo
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Room Temperature ◽  
Physical Adsorption ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Equilibrium Studies ◽  
Equilibrium Data

The feasibility of using powdered cow hooves (CH) for removing Ni2+ from aqueous solution was investigated through batch studies. The study was conducted to determine the effect of pH, adsorbent dosage, contact time, adsorbent particle size, and temperature on the adsorption capacity of CH. Equilibrium studies were conducted using initial concentration of Ni2+ ranging from 15 to 100 mgL−1 at 208, 308, and 318 K, respectively. The results of our investigation at room temperature indicated that maximum adsorption of Ni2+ occurred at pH 7 and contact time of 20 minutes. The thermodynamics of the adsorption of Ni2+ onto CH showed that the process was spontaneous and endothermic. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were used to quantitatively analysed the equilibrium data. The equilibrium data were best fitted by Freundlich isotherm model, while the adsorption kinetics was well described by pseudo-second-order kinetic equation. The mean adsorption energy obtained from the D-R isotherm revealed that the adsorption process was dominated by physical adsorption. Powdered cow hooves could be utilized as a low-cost adsorbent at room temperature under the conditions of pH 7 and a contact time of 20 minutes for the removal of Ni(II) from aqueous solution.

Removal of Rhodamine B from Wastewater by Rectorite and Sepiolite-Kinetic Study and Equilibrium Isotherm Analyses

2011 ◽  
Vol 183-185 ◽  
pp. 362-366 ◽  
Author(s):  
Jun Li ◽  
Ming Zhen Hu
Keyword(s):  
Rhodamine B ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Isotherm Equation ◽  
Adsorption Removal ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Adsorption removal of a cationic dye, rhodamine B (RhB) from water onto rectorite and sepiolite was investigated. The rectorite and sepiolite were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Attempts were made to fit the isothermal data using Langmuir and Freundlich equations. The experimental results have demonstrated that the equilibrium data are fitted well by a Freundlich isotherm equation. Pseudo-first-order and pseudo-second-order models were considered to evaluate the rate parameters. The experimental data were well described by the pseudo-second-order kinetic model. The results indicate that the rectorite exhibited higher adsorption capacity for the removal of RhB than sepiolite and could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.

scholarly journals Kush - A Potential Biosorbent in the removal of Cd (II) and Zn (II) from aqueous solution

2012 ◽  
Vol 27 ◽  
pp. 107-114
Author(s):  
Jagjit Kour ◽  
P. L. Homagai ◽  
M. R. Pokherel ◽  
K. N. Ghimire
Keyword(s):  
Low Cost ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Waste Streams ◽  
Adsorption Capacities ◽  
Optimum Ph ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The industrial discharge of heavy metals into waters' course is one of the major pollution problems affecting water quality. Therefore, they must be removed prior to their discharge into waste streams. An efficient and low-cost bioadsorbent has been investigated from Desmostachya bipinnata (Kush) by charring with concentrated sulphuric acid and functionalized with dimethylamine.It was characterised by SEM, FTIR and elemental analysis. The effect of pH, initial concentration and contact time of the metal solution was monitered by batch method. The maximum adsorption capacities were determined for Cd and Zn at their optimum pH 6. The equilibrium data were analysed using Langmuir and Freundlich isotherm models. Langmuir isotherm model fitted well and the rate of adsorption followed the pseudo second order kinetic equation.DOI: http://dx.doi.org/10.3126/jncs.v27i1.6669 J. Nepal Chem. Soc., Vol. 27, 2011 107-114  

scholarly journals Adsorption of Chromium (VI) by Cu (I)-MOF in Water: Optimization, Kinetics, and Thermodynamics

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hongxue Qi ◽  
Xianjun Niu ◽  
Haipeng Wu ◽  
Xiuping Liu ◽  
Yongqiang Chen
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Entropy Change ◽  
Maximum Adsorption Capacity ◽  
Sem Images ◽  
First Order ◽  
Chromium Vi ◽  
Function Change ◽  
Pseudo Second Order ◽  
Pseudo First Order

To investigate the adsorption behavior of Cu (I)-MOF material for chromium (VI) in water, the parameters of influencing adsorption were optimized and found as follows: the optimal pH was 6 for the adsorption of Cr (VI) by the Cu (I)-MOF, the optimal amount of adsorbent was 0.45 g·L−1, and the adsorption saturation time was within 180 min. Subsequently, the kinetics results were fitted by four models such as pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. Among them, the adsorption of chromium (VI) was more inclined to the pseudo-first-order model (Radj2 = 0.9230). Then, the isotherm data were fitted by Langmuir and Freundlich models. The results indicated that Langmuir isotherm was the excellent match model (Radj2 = 0.9827). It belongs to a monolayer adsorption, and the maximum adsorption capacity was 95.92 mg·g−1. Subsequently, the thermodynamic parameters of the adsorption were calculated as follows: enthalpy change (ΔHθ) was −8.583 kJ·mol−1, entropy change (ΔSθ) was −8.243 J·mol−1 K−1, and the Gibbs function change (ΔGθ) was less than zero in the temperature range of 288–328 K, indicating that the reaction was spontaneous. Finally, both the spectra of infrared and XPS supported the adsorption mechanism that belonged the ion exchange. The spectra of XRD and SEM images shown that the structure of Cu (I)-MOF remained stable for at least 3 cycles. In conclusion, Cu (I)-MOF material has a high adsorption capacity, good water stability, low cost, and easy to prepare in large quantities in practical application. It will be a promising adsorbent for the removal of Cr (VI) from water.

Adsorption of Cu(II) onto HNO3-Modified Cedar Sawdust (Cedrus deodara): FTIR Analysis, Kinetics and Adsorption Isotherms Modeling

2011 ◽  
Vol 396-398 ◽  
pp. 2388-2393 ◽  
Author(s):  
Hong Mei Deng ◽  
Yong Heng Cheng ◽  
Xiang Yang Chang ◽  
Jian Gong ◽  
Cui Qin Wu ◽  
...  
Keyword(s):  
Freundlich Isotherm ◽  
Attenuated Total Reflectance ◽  
Ionic Exchange ◽  
Ftir Analysis ◽  
Cedrus Deodara ◽  
Adsorbate Concentration ◽  
Before And After ◽  
Adsorption Processes ◽  
Equilibrium Data ◽  
Pseudo Second Order

Cedar sawdust (Cedrus deodara), an agricultural by-product abundant in China, was used as an adsorbent for the removal of Cu(II) from aqueous solutions. The extent of adsorption was investigated as a function of pH, contact time, adsorbate concentration and reaction temperature. The Cu(II) removal was pH-dependent, reaching a maximum at pH 5. The adsorption process followed pseudo-second-order kinetics and equilibrium was reached at 60 min. The rate constantly increased with the increase of temperature, indicating the endothermic nature of adsorption. The equilibrium adsorption capacity of Cu(II) determined from the Langmuir equation was 64.52 mg/g at 25°C. The equilibrium data fitted very well to the Freundlich isotherm model as compared to the Langmuir isotherm. The negative ΔGo values at various temperatures confirm that the adsorption processes are spontaneous. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) analysis of cedar sawdust, before and after adsorption of Cu(II), suggested that the main mechanisms involved in the removal of Cu(II) might be the ionic exchange and complexation.

scholarly journals Biochars derived from bamboo and rice straw for sorption of basic red dyes

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254637
Author(s):  
Ebenezer Ampofo Sackey ◽  
Yali Song ◽  
Ya Yu ◽  
Haifeng Zhuang
Keyword(s):  
Adsorption Capacity ◽  
Rice Straw ◽  
Low Cost ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Acceptor Interaction ◽  
Equilibrium Data ◽  
Pseudo Second Order

The primary purpose of this study is to eliminate Basic Red 46 dye from aqueous solutions utilizing batch experiments by adsorption on biochars prepared from bamboo and rice straw biomass. Biochars prepared from bamboo (B), and rice straw (R) was pyrolyzed at 500°C (B500 and R500). Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD), and surface area and porosity analyzers were used to characterize the B500 and R500 samples. The characterization results indicated that the biochars possessed an amorphous porous structure with many functional groups consisting primarily of silicates. The adsorption rate of BR46 was evaluated using two kinetic models (pseudo-first-order and pseudo-second-order), and the results indicated that the pseudo-second-order model fitted to the experimental data well (R2>0.99). Nearly 24 h was sufficient to achieve equilibrium with the dye adsorption for the two biochars. R500 had a greater adsorption efficiency than B500. As pH levels increased, the dye’s adsorption capability increased as well. The Langmuir and Freundlich isotherm models were used to investigate the equilibrium behavior of BR46 adsorption, and the equilibrium data fitted well with the Langmuir model (R2>0.99) compared to the Freundlich model (R2>0.89). The maximum adsorption capacities of BR46 are 9.06 mg/g for B500 and 22.12 mg/g for R500, respectively. Additionally, adsorption capacity increased as temperature increased, indicating that adsorption is favored at higher temperatures. The electrostatic interaction is shown to be the dominant mechanism of BR46 adsorption, and BR46 acts as an electron-acceptor, contributing to n-π EDA (Electron Donor-Acceptor) interaction. Thermodynamic parameters for the dye-adsorbent system revealed that the adsorption process is spontaneous and feasible. The values of the adsorption coefficient (Kd) were on the order of 102−103. Kd of R500 was greater than that of B500, indicating that R500 had a greater adsorption capacity. The results showed that R500 could be used as a low-cost alternative adsorbent for removing BR46 from effluents.

scholarly journals ADSORPTION STUDIES ON THE REMOVAL OF NAPHTOL-AS DYE USING IRON FILINGS AS ADSORBENT

2021 ◽  
Vol 46 (2) ◽  
Author(s):  
C. M. Ngwu ◽  
O. K. Amadi ◽  
M. O. Mac-Kalunta ◽  
J. Onyeuwaoma
Keyword(s):  
Experimental Data ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Second Order ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Controlled Adsorption

This study investigated the potential of iron filings as low cost and environmentally friendly adsorbent for removing Naphthol AS dye from aqueous solutions. The batch-adsorption experiments were performed as a function of pH, temperature, concentration, contact time as well as dynamics of the process. The Langmuir, Freundlich and Dubinin-Raduskevich isotherm models for the adsorption processes were tested but Freundlich isotherm provided the best description for adsorption of the dye solution onto the iron filings, suggesting a physisorption controlled adsorption. The adsorption process was highly pH-dependent and the result indicates that the optimum pH for adsorption of Naphthol AS onto the adsorbent occurred at 4.0 having a maximum removal efficiency of 88 % respectively. Pseudo first-order and second-order as well as the intra-particle diffusivity kinetic models were applied to the experimental data and results showed that the pseudo second-order provided best fit for the experimental data. Kinetic studies also showed that the adsorption transport mechanism was particle-diffusion controlled.

scholarly journals Adsorptive removal of ciprofloxacin and isoniazid from aqueous solution

2018 ◽  
Vol 17 (1) ◽  
pp. 16-28 ◽  
Author(s):  
Cyril Dube ◽  
Roman Tandlich ◽  
Brendan Wilhelmi
Keyword(s):  
Electrostatic Interactions ◽  
Physical Adsorption ◽  
Coal Fly Ash ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Solid Liquid ◽  
Best Fit ◽  
Regression Correlation

Abstract This paper describes study of ciprofloxacin and isoniazid removal from aqueous solutions using coal fly ash (FA), kaolinite, perlite, talc and vermiculite. The adsorptive features of the adsorbents were evaluated for ciprofloxacin and isoniazid with regards to the effects of contact time, pH, the solid/liquid ratio and antibiotic concentration. All adsorbents were sterilised by dry heat before use to avoid the proliferation of antimicrobial resistance by the bacteria present on the adsorbents during experiments. The regression correlation coefficients indicate that the Langmuir model gives the best fit for the sorption of both antibiotics onto FA and talc, ciprofloxacin onto kaolinite, and isoniazid onto perlite and vermiculite with R2 values ranging from 0.908 – 0.999. The Freundlich isotherm best describes the sorption of ciprofloxacin onto vermiculite and isoniazid onto kaolinite with R2 values of 0.999 for both. The Tempkin model best describes the sorption of ciprofloxacin onto perlite with an R2 = 0.997. The values of the Freundlich exponent, 1/n, range from 0.221 – 0.998, indicating a favourable adsorption of ciprofloxacin and isoniazid onto the adsorbents. The heat of sorption, B, calculated from the Temkin plots has values ranging from 0.018 – 10.460 J/mol, indicating a physical adsorption process (physisorption). Adsorption equilibrium was achieved after 30 min for both antibiotics and the kinetic data obtained conforms best to the pseudo-second order equation with R2 values ranging from 0.998 – 0.999. The removal of ciprofloxacin and isoniazid by all adsorbents except FA was strongly influenced by the pH suggesting that electrostatic interactions play a major role in the adsorption processes.

scholarly journals Natural Clay as a Low-Cost Adsorbent for Crystal Violet Dye Removal and Antimicrobial Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2789
Author(s):  
Ali Q. Alorabi ◽  
Mallick Shamshi Hassan ◽  
Mohammad Mahboob Alam ◽  
Sami A. Zabin ◽  
Nawaf I. Alsenani ◽  
...  
Keyword(s):  
Crystal Violet ◽  
Chemical Interaction ◽  
Low Cost ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Aqueous Environment ◽  
Physico Chemical ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Isotherm And Kinetic Models

This investigation aimed at evaluating the efficiency of micro and nanoclays as a low-cost material for the removal of crystal violet (CV) dye from an aqueous solution. The impacts of various factors (contact time, pH, adsorbent dosage, temperature, initial dye concentration) on the adsorption process have been taken into consideration. Six micro and nanoclay samples were obtained by treating clay materials collected from different locations in the Albaha region, Saudi Arabia. Out of the six tested micro and nanoclays materials, two (NCQ1 and NCQ3) were selected based on the highest adsorption efficiency for complete experimentation. The morphology and structure of the selected micro and nanoclay adsorbents were characterized by various techniques: SEM-EDX, FTIR, XRF, XRD, and ICP-MS. The XRF showed that the main oxides of both nanoclays were SiO2, Al2O3, Fe2O3, K2O, CaO, and MgO, and the rest were impurities. All the parameters affecting the adsorption of CV dye were optimized in a batch system, and the optimized working conditions were an equilibrium time of 120 min, a dose of 30 mg, a temperature of 25 °C, and an initial CV concentration of 400 mg/L. The equilibrium data were tested using nonlinear isotherm and kinetic models, which showed that the Freundlich isotherm and pseudo-second-order kinetics gave the best fit with the experimental data, indicating a physico-chemical interaction occurred between the CV dye and both selected micro and nanoclay surfaces. The maximum adsorption capacities of NCQ1 and NCQ3 adsorbents were 206.73 and 203.66 mg/g, respectively, at 25 °C. The thermodynamic factors revealed that the CV dye adsorption of both micro and nanoclays was spontaneous and showed an exothermic process. Therefore, the examined natural micro and nanoclays adsorbents are promising effective adsorbents for the elimination of CV dye from an aqueous environment.

Sign in / Sign up

Export Citation Format

Share Document