scholarly journals Husk of Agarwood Fruit-Based Hydrogel Beads for Adsorption of Cationic and Anionic Dyes in Aqueous Solutions

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1437
Author(s):  
Chih Ming Ma ◽  
Bo-Yuan Yang ◽  
Gui-Bing Hong
Keyword(s):  
Aqueous Solutions ◽  
Selective Adsorption ◽  
Order Model ◽  
Anionic Dyes ◽  
Adsorption Selectivity ◽  
Hydrogel Beads ◽  
Batch System ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.

scholarly journals Fish (Labeo rohita) scales as a new biosorbent for removal of textile dyes from aqueous solutions

2012 ◽  
Vol 2 (3) ◽  
pp. 175-184 ◽  
Author(s):  
Sagnik Chakraborty ◽  
Shamik Chowdhury ◽  
Papita Das Saha
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Assessment ◽  
Arrhenius Equation ◽  
Textile Dyes ◽  
Fish Scale ◽  
Fish Scales ◽  
Solution Ph ◽  
Batch System ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The feasibility of utilizing fish scales as a new biosorbent for removal of textile dyes, namely crystal violet (CV) and methylene blue (MB), from their aqueous solutions was investigated in a batch system. Experiments were conducted as a function of initial solution pH (2–10), contact time (0–180 min), biosorbent dose (0.5–5 g) and temperature (293–313 K). The Langmuir isotherm model showed excellent fit to the equilibrium biosorption data of both CV and MB. The maximum dye biosorption capacity of fish scale was calculated as 74.39 and 58.67 mg g−1 for CV and MB, respectively, at 313 K. Biosorption phenomena of CV and MB by fish scales followed pseudo-second-order kinetics. Activation energy calculated by using the Arrhenius equation suggested the chemisorption nature of the biosorption processes. A thermodynamic assessment indicated the spontaneous and endothermic nature of biosorption of the textile dyes. It could be concluded that fish scales may be used as an inexpensive and effective biosorbent for removal of dyes from aqueous solutions.

Cysteine-modified orange peel for removal of Cu(II) from aqueous solutions

2013 ◽  
Vol 67 (11) ◽  
pp. 2444-2450 ◽  
Author(s):  
Mingdeng Liu ◽  
Qunhui Yuan ◽  
Hanzhong Jia ◽  
Shouzhu Li ◽  
Xiaohuan Wang ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Orange Peel ◽  
Aqueous System ◽  
Order Equation ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Influential Parameters ◽  
Better Than

In the present work, cysteine-modified orange peel (COP) for the removal of Cu(II) from aqueous solutions has been developed and comparatively studied with diethylenetriamine-modified orange peel (DOP). Both COP and DOP were systematically evaluated via their capabilities for adsorbing Cu(II), including the key influential parameters such as initial pH, contact time and initial Cu(II) concentration. Further studies suggest that the sorption of Cu(II) onto both COP and DOP fits well with the pseudo-second-order equation, and the corresponding sorption isotherm can be classified to a Langmuir isotherm model. COP appears more advantageous over DOP and far better than that of unmodified OP in removal of Cu(II) from aqueous system. The maximum capacities of COP and DOP for adsorbing Cu(II) are 95.23 and 83.68 mg/g, respectively, about three times higher than that of unmodified OP. The sorption efficiency of COP drops by merely about 3% after five cycles, implying a promising usage in the removal of Cu(II) from wastewater in practice.

Optimization of uranyl ions removal from aqueous solution by natural and modified kaolinites

2017 ◽  
Vol 105 (8) ◽  
Author(s):  
O. A. Elhefnawy ◽  
A. A. Elabd
Keyword(s):  
Aqueous Solutions ◽  
Effect Of Temperature ◽  
Acid Activation ◽  
Uranyl Ions ◽  
Order Model ◽  
Efficient Removal ◽  
Removal Process ◽  
Modification Process ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

AbstractThe paper addresses the modifications of the most common mineral clay “kaolinite” for U(VI) removal from aqueous solutions. A new modified Egyptian natural kaolinite (Ca-MK) was prepared by coating kaolinite with calcium oxide. Another modification process was utilized by calcination and acid activation of kaolinite (E-MK). The Egyptian natural kaolinite (E-NK) and the two modified kaolinites were characterized by different techniques SEM, EDX, XRD, and FTIR. The removal process were investigated in batch experiments as a function of pH, contact time, initial U(VI) concentration, effect of temperature, and recovery of U(VI) were studied. The equilibrium stage was achieved after 60 min and the kinetic data was described well by pseudo-second order model. Isothermal data was better described by the Langmuir isotherm model, indicating the homogeneous removal process. Also the removal process was studied on different temperature 293, 313, and 323 K. The thermodynamic parameters ΔH°, ΔS°, and ΔG° were calculated. The thermodynamic results pointed to the endothermic and favorable nature of the U(VI) removal process in the three kaolinite adsorbents. This study indicated that (Ca-MK) has higher CEC and can be used as a new adsorbent for highly efficient removal of U(VI) from aqueous solutions.

Studies on Phosphate Removal from Aqueous Solution by Honeycomb-Cinder Slag

2012 ◽  
Vol 217-219 ◽  
pp. 862-865
Author(s):  
Li Jun Wang ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang
Keyword(s):  
Aqueous Solution ◽  
Phosphate Removal ◽  
Solution Temperature ◽  
Phosphate Adsorption ◽  
Order Model ◽  
Solution Ph ◽  
Initial Ph ◽  
Desorption Study ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The feasibility of using honeycomb-cinder slag as an adsorbent for phosphate removal from aqueous solution was investigated in batch experiments as a function of initial pH, contact time, adsorbent dose, and solution temperature. The results indicated that the solution pH significantly influenced the phosphate adsorption; 1440 min was enough to reach equilibrium for any concentration. Langmuir isotherm model gave well fit for phosphate adsorption, and the adsorption process followed pseudo second-order model. Desorption study exhibited that the phosphate adsorption on the honeycomb-cinder slag is not completely reversible. Results showed that honeycomb-cinder slag could be used as an adsorbent to uptake phosphate from wastewater.

Preparation of cationic waste paper and its application in poisonous dye removal

2013 ◽  
Vol 67 (11) ◽  
pp. 2560-2567 ◽  
Author(s):  
Fan Yang ◽  
Xiaojie Song ◽  
Lifeng Yan
Keyword(s):  
Low Cost ◽  
Aqueous Suspension ◽  
Order Kinetic ◽  
Acid Orange 7 ◽  
Anionic Dyes ◽  
Experimental Conditions ◽  
Adsorption Models ◽  
Acid Orange ◽  
Initial Ph ◽  
Pseudo Second Order

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.

Adsorption of Methylene Blue from Aqueous Solution Using Honeycomb-Cinder

2012 ◽  
Vol 550-553 ◽  
pp. 2259-2262
Author(s):  
Song Bo Cui ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Dye Wastewater ◽  
Batch System ◽  
Adsorption Data ◽  
Adsorption Processes ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Mb Adsorption

The adsorption behavior of methylene blue (MB) dye from aqueous solutions onto honeycomb-cinder (HC) and its acid-activated product was investigated in a batch system. The results showed the adsorption capacity was decreased for raw HC samples with the increase of pH value, while it was increased for activated samples. The adsorption data were fit with Langmuir isotherm model for MB adsorption by all samples. The MB adsorption capacity on samples was increased from 2.62 mg/g to 7.81 mg/g and 7.00 mg/g after acid-activated by HCl and H2SO4, respectively. The adsorption processes of MB followed pseudo-second-order kinetics with a coefficient of correlation≥0.99. This study demonstrated that acid-activated HC has superior adsorbing ability for MB than raw HC and can be used as alternative adsorbents in dye wastewater treatment.

Adsorption of PtCl62− from Hydrochloric Acid Solution by Chemically Modified Lignin Based on Rice Straw

2018 ◽  
Vol 71 (12) ◽  
pp. 931 ◽  
Author(s):  
Baoping Zhang ◽  
Bowen Shen ◽  
Meichen Guo ◽  
Yun Liu
Keyword(s):  
Hydrochloric Acid ◽  
Acid Solution ◽  
Rice Straw ◽  
Hydrochloric Acid Solution ◽  
Photoelectron Spectroscopy ◽  
Selective Adsorption ◽  
Adsorption Time ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Modified Lignin

A novel adsorbent with the properties of selective adsorption based on rice straw was used to adsorb PtCl62− from hydrochloric acid solution by batch sorption. Many influencing factors for PtCl62− adsorption, such as initial concentration of PtCl62−, adsorption time, and concentration of hydrochloric acid, were optimized. The results suggested that the saturation adsorption capacity of PtCl62− was 218.8mgg−1 and the equilibrium adsorption time was 120min. The adsorbent had excellent selectivity on PtCl62− when the concentration of hydrochloric acid was lower than 0.5molL−1. The adsorption fitted well with the Langmuir isotherm model and pseudo-second-order kinetics model. The adsorption mechanism was investigated by FT-IR and X-ray photoelectron spectroscopy analyses and it indicated that PtIV was reduced to PtII by hydroxy groups and then coordinated with N through ion exchange between Cl− and PtCl42−.

Biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus

2012 ◽  
Vol 66 (8) ◽  
pp. 1699-1707 ◽  
Author(s):  
A. K. Giri ◽  
R. K. Patel ◽  
P. C. Mishra
Keyword(s):  
Aqueous Solutions ◽  
Bacillus Cereus ◽  
Contact Time ◽  
Living Cells ◽  
Optimum Conditions ◽  
Order Model ◽  
Initial Concentration ◽  
Pseudo Second Order ◽  
Biomass Dosage ◽  
Batch Biosorption

In this work, the biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus has been reported. The batch biosorption experiments were conducted with respect to biosorbent dosage 0.5 to 15 g/L, pH 2 to 9, contact time 5 to 90 min, initial concentration 1 to 10 mg/L and temperature 10 to 40 °C. The maximum biosorption capacity of B. cereus for As(V) was found to be 30.04 at pH 7.0, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data were fitted to linearly transformed Langmuir isotherms with R2 (correlation coefficient) >0.99. Bacillus cereus cell surface was characterized using AFM and FTIR. The metal ions were desorbed from B. cereus using both 1 M HCl and 1 M HNO3. The pseudo-second-order model was successfully applied to predict the rate constant of biosorption.

scholarly journals Adsorption of strontium on different sodium-enriched bentonites

2017 ◽  
Vol 82 (4) ◽  
pp. 449-463 ◽  
Author(s):  
Sanja Marinovic ◽  
Marija Ajdukovic ◽  
Natasa Jovic-Jovicic ◽  
Tihana Mudrinic ◽  
Bojana Nedic-Vasiljevic ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Adsorption Capacity ◽  
Textural Properties ◽  
X Ray Diffraction ◽  
Order Model ◽  
Surface Areas ◽  
Alkaline Conditions ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ph Range

Bentonites from three different deposits (Wyoming, TX, USA and Bogovina, Serbia) with similar cation exchange capacities were sodium enriched and tested as adsorbents for Sr2+ in aqueous solutions. X-Ray diffraction analysis confirmed successful Na-exchange. The textural properties of the bentonite samples were determined using low-temperature the nitrogen physisorption method. Significant differences in the textural properties between the different sodium enriched bentonites were found. Adsorption was investigated with respect to adsorbent dosage, pH, contact time and the initial concentration of Sr2+. The adsorption capacity increased with pH. In the pH range from 4.0?8.5, the amount of adsorbed Sr2+ was almost constant but 2?3 times smaller than at pH ?11. Further experiments were performed at the unadjusted pH since extreme alkaline conditions are environmentally hostile and inapplicable in real systems. The adsorption capacity of all the investigated adsorbents toward Sr2+ was similar under the investigated conditions, regardless of significant differences in the specific surface areas. It was shown and confirmed by the Dubinin?Radushkevich model that the cation exchange mechanism was the dominant mechanism of Sr2+ adsorption. Their developed microporous structures contributed to the Sr2+ adsorption process. The adsorption kinetics obeyed the pseudo-second-order model. The isotherm data were best fitted with the Langmuir isotherm model.

scholarly journals Photocatalytic Degradation of Naphthalene By UV/Zno: Kinetics, Influencing Factors and Mechanisms

2021 ◽  
Vol 37 (1) ◽  
pp. 65-70
Author(s):  
Aram Dokht Khatibi ◽  
Kethineni Chandrika ◽  
Ferdos Kord Mostafapour ◽  
Ali Akbar Sajadi ◽  
Davoud Balarak
Keyword(s):  
Wastewater Treatment ◽  
Reaction Time ◽  
Aqueous Solutions ◽  
Aromatic Hydrocarbons ◽  
Contact Time ◽  
Initial Concentration ◽  
Applied Study ◽  
Batch System ◽  
Initial Ph ◽  
Conventional Wastewater Treatment

Conventional wastewater treatment is not able to effectively remove Aromatic hydrocarbons such as Naphthalene, so it is important to remove the remaining antibiotics from the environment. The aim of this study was to evaluate the efficiency of UV/ZnOphotocatalytic process in removing naphthalene antibiotics from aqueous solutions.This was an experimental-applied study that was performed in a batch system on a laboratory scale. The variables studied in this study include the initial pH of the solution, the dose of ZnO, reaction time and initial concentration of Naphthalene were examined. The amount of naphthalene in the samples was measured using GC.The results showed that by decreasing the pH and decreasing the initial concentration of naphthalene and increasing the contact time, the efficiency of the process was developed. However, an increase in the dose of nanoparticles to 0.8 g/L had enhance the efficiency of the process was enhanced, while increasing its amount to values higher than 0.8 g/L has been associated with a decrease in removal efficiency.The results of this study showed that the use of UV/ZnOphotocatalytic process can be addressed as a well-organized method to remove naphthalene from aqueous solutions.

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