scholarly journals Equilibrium and Isotherm Modeling of Toxic dye Adsorption onto Modified Apricot Stone

2018 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Dye Adsorption ◽  
Acid Activation ◽  
Order Kinetic ◽  
Bet Analysis ◽  
Effects Of Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

In the present study, adsorption of toxic dye Diret red 28 (acid benzidinediazo-bis-1- naphtylamine - 4- sulfonique) from aqueous solution was investigated using activated carbon synthesized with Phosphoric Acid activation. The synthesized adsorbent was analyzed using BET, FT-IR and SEM techniques. The BET analysis showed that the area provided by the synthesized activated carbon was 88.01 m2 g-1. The adsorption isotherms of Toxic dye onto ASAC are determined and correlated with common isotherms equations. The smaller RMSE values obtained for the Langmuir and Dubinin-R models indicate the better curves fitting, the monolayer adsorption capacity of toxic dye is found to be 32.85 mg.g-1 at temperature 25 o C and 23.42 mg.g-1 at temperature 65 o C at pH 13. The adsorption of toxic dye was carried out using a batch system and the effects of pH, contact time, adsorbent dosage, initial concentration and temperature on the adsorption capacity of synthesized adsorbent were investigated. Kinetics studies proved that for both metals, the kinetic data follows the pseudo second order kinetic model. In addition, the thermodynamics studies proved that the adsorption process of toxic dye could be considered spontaneous and endothermic.

scholarly journals Synergistic modification of bentonite by acid activation and hydroxyl iron pillaring for enhanced dye adsorption capacity

2020 ◽  
Vol 81 (7) ◽  
pp. 1518-1529
Author(s):  
Huan Xi ◽  
Qingqing Li ◽  
Yan Yang ◽  
Jianfeng Zhang ◽  
Feng Guo ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Dye Adsorption ◽  
Interlayer Spacing ◽  
Acid Activation ◽  
Order Kinetic ◽  
Environmental Friendliness ◽  
Dye Pollutants ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Despite the fact of natural abundance, low cost and environmental friendliness, the far-from-sufficient adsorption capacity of natural bentonite (BT) has limited such a promising application to remove dye pollutants. In this paper, we proposed a facile modification strategy to enhance adsorption performance of bentonite utilizing synergistic acid activation and hydroxyl iron pillaring, by which the adsorbent (abbreviated as S-Fe-BT) exhibited the highest adsorption capacity (246.06 mg/g) and a high rapid adsorption rate for a typical organic dye, Rhodamine B (RhB). This could be ascribed to the increased interlayer spacing, the increased specific surface area, and the optimized OH/Fe ratio after the synthetic modification of the pristine BT. The adsorption behavior of RhB onto S-Fe-BT was well described by the pseudo-second-order kinetic model, indicating a chemical-adsorption-controlled process. Furthermore, its adsorption isotherm matched well with the Langmuir model due to a monolayer adsorption process. This paper opens a promising direction to remove the dye pollution using low cost bentonite adsorbents treated by such a convenient modification strategy.

scholarly journals Study on the adsorption of methylene blue from aqueous solution using hydrogel glucomannan/graphene oxide

2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.

Kinetic Study and Equilibrium Isotherm Analysis of Cationic Dye Adsorption onto Attapulgite and Rectorite

2012 ◽  
Vol 446-449 ◽  
pp. 2960-2963
Author(s):  
Jing Yan Song ◽  
Jing Yang
Keyword(s):  
Low Cost ◽  
Dye Adsorption ◽  
Second Order ◽  
Order Kinetic ◽  
Cationic Dye ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The adsorption properties of the attapulgite and the rectorite were investigated by removal of a cationic dye, methylene blue (MB) from aqueous solution. The attapulgite and the rectorite were characterized by Fourier transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). The analysis of the isotherm equilibrium data using the Langmuir and Freundlich equations showed that the data fitted better with Langmuir model. 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 attapulgite exhibited higher adsorption capacity for MB than rectorite and could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.

scholarly journals Kinetics and Isotherm Studies on Adsorption of Hexavalent Chromium Using Activated Carbon from Water Hyacinth

2021 ◽  
Vol 15 (1) ◽  
pp. 1-8
Author(s):  
Angelica Macalalad ◽  
◽  
Quennie Rose Ebete ◽  
Dominic Gutierrez ◽  
Madelaine Ramos ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Hexavalent Chromium ◽  
Water Hyacinth ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Adsorbate Concentration ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The present study is focused on the use of activated carbon derived from water hyacinth (WH-AC) as adsorbent for the removal of Cr(VI) from aqueous solution. The optimized WH-AC was found to be mesoporous and considered as granular. The surface area of 11.564 m2/g was found to have a good adsorption capacity. The adsorption data of the optimized WH-AC followed a pseudo-second order kinetics and the Freundlich isotherm model. Based on the correlation coefficient obtained from pseudo-second-order kinetic model, the R2 values were all above 0.99, which is closer to unity of one (1) indicating that it followed a chemisorption process. The adsorption capacity of WH-AC increased from 1.98 to 4.68 mg/g when adsorbate concentration increased from 20 to 50 mg/l. The overall study proved that the adsorption by activated carbon derived from water hyacinth can be an alternative and efficient technique in hexavalent chromium removal.

scholarly journals Removal of Direct 50 Dyes from Aqueous Solution Using Natural Clay and Organoclay Adsorbents

2015 ◽  
Vol 12 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Ph Value ◽  
Dye Adsorption ◽  
Hexadecyltrimethylammonium Bromide ◽  
Textile Dye ◽  
Order Kinetic ◽  
Effects Of Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Gibb’S Free Energy ◽  
Isotherm Equations

In this study, hexadecyltrimethylammonium bromide (HDMAB) - bentonite was synthesized by placing alkylammonium cation onto bentonite. Adsorption of textile dye such as direct Yellow 50 on natural bentonite and HDMAB -bentonite was investigated. The effects of pH, contact time,dosage clay and temperature were investigated experimentally .The Langmuir and Freundlish isotherms equations were applied to the data and values of parameters of these isotherm equations were evaluated. The study indicated that using 0.2 g of HDMAB (hexadecyltrimethylammonium bromide) lead to increase the percentage removal(R%) from 78% for pure bentonite to 99 %. The optimum pH value for the adsorption experiments was found to be pH=3 and therefore all the experiments were carried out at this pH value. The pseudo-second-order kinetic model agrees very well with the experimental results.Different thermodynamic parameters such as Gibb’s free energy, enthalpy and entropy of the on-going adsorption process have also been evaluated. The thermodynamic analyses of the dye adsorption on organoclay indicated that the system was endothermic in nature .

scholarly journals A novel activated carbon prepared from grapefruit peel and its application in removal of phenolic compounds

2018 ◽  
Vol 77 (10) ◽  
pp. 2517-2527 ◽  
Author(s):  
Xiao Liu ◽  
Yibei Wan ◽  
Penglei Liu ◽  
Yanzhen Fu ◽  
Weihua Zou
Keyword(s):  
Activated Carbon ◽  
Phenolic Compounds ◽  
Contact Time ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Bet Analysis ◽  
Order Kinetic Model ◽  
Grapefruit Peel ◽  
Pseudo Second Order ◽  
Activating Agent

Abstract The most ideal conditions for preparing activated carbon from grapefruit peel (GPAC) were studied using NH4H2PO4 as a chemical activating agent and the obtained material was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) analysis. The adsorption capacity of the resulting material has been checked using three phenolic compounds (pyrocatechol (CA), 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP)). The adsorption characteristics of phenolic compounds from aqueous solution by GPAC have been investigated as a function of contact time, pH, initial concentration and temperature. The equilibrium experimental data fitted well with Freundlich and Koble–Corrigan isotherms. The adsorption of the three phenolic compounds on GPAC fitted well with pseudo-second-order kinetic model. Different thermodynamic parameters were also evaluated and it was found that the adsorption was spontaneous, feasible and endothermic in nature. Adsorbents were regenerated by 0.1 mol/L NaOH and GPAC could be reused in phenolic compounds removal.

Preparation of Mg-Fe HTLCs and Study on the Adsorption Performance

2014 ◽  
Vol 675-677 ◽  
pp. 647-653
Author(s):  
Hong Bin Lv ◽  
Yao Li ◽  
Wan You Zhang ◽  
Li Juan Xi
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Order Kinetic ◽  
Sulfate Ions ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Ph Range ◽  
Synthesized Materials

Mg-Fe hydrotalcite-like compounds (Mg-Fe-HTLCs) were synthesized via hydrothermal method, and characterized by XRD and FT-IR. The roasted products were used to remove sulfate ions by the adsorptive ability from aqueous solution. The effects of adsorbent dosage, initial pH and temperature on the sulfate ions removal were fully investigated, and the adsorption kinetics and adsorption isotherms were also studied. Results showed that the synthesized materials with CO32- as the interlayer anions had fine crystallinity. The materials of Mg-Fe hydrotalcite-like compounds had a very good adsorption capacity for aqueous solution with the initial sulfate ions concentration was 500mg/L, pH range from 4 to 8 and temperature of 35°C. Moreover, the adsorption equilibrium was about 90 min under the optical condition. The experimental data showed a good compliance with the pseudo-second-order kinetic model, and the adsorption isotherm data met Langmuir models well. It was found that the maximal adsorption capacity reached 151.51mg/g.

Enhanced Adsorption for P-Chlorophenol by Ammonia Modified Activated Carbon

2013 ◽  
Vol 663 ◽  
pp. 807-812
Author(s):  
Guo Yang ◽  
Yan Jie ◽  
Hu Yang ◽  
Chen Hong Zhang
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Functional Groups ◽  
Kinetic Studies ◽  
Effect Of Temperature ◽  
Order Kinetic ◽  
Surface Functional Groups ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Enhanced Adsorption

To investigate the influence of N-containing surface functional groups on adsorption capacity of AC, the activated carbon (AC) was modified with ammonia gas at 650 °C. Surface functional groups were quantitatively analyzing by Boehm titration. The effect of temperature on adsorption capacity suggested higher temperature is favourable. The influence of pH indicated the adsorption was favorable in acidic solution. The adsorption isotherms were fitted by Langmuir model and Freundlich model. Moreover, kinetic studies showed the adsorption of phenol onto adsorbents was followed by pseudo-second-order kinetic model. The adsorption capacity of ammoniated AC for p-chlorophenol was greatly improved.

scholarly journals Functionalized coconut husks for rhodamine-B dye sequestration

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Olugbenga Solomon Bello ◽  
Kayode Adesina Adegoke ◽  
Samuel Oluwaseun Fagbenro ◽  
Olasunkanmi Seun Lameed
Keyword(s):  
Rhodamine B ◽  
Dye Removal ◽  
Dye Adsorption ◽  
Isotherm Models ◽  
Acid Activation ◽  
Order Kinetic ◽  
Operational Parameters ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract This study investigates the efficacy of acid activated coconut husk (CHA) for the removal of rhodamine-B (Rh-B) dye from aqueous solutions. The CHA prepared was characterized using various techniques: SEM, FTIR EDX, Boehm titration and pHpzc, respectively. The effects of different operational parameters including initial concentration, contact time and solution temperatures were examined. Kinetic data for Rh-B dye adsorption onto CHA fitted best to pseudo-second-order kinetic model considering the correlation regression (R2) and the sum of squares of error values. Adsorption data were fitted to Langmuir, Freundlich, Dubinin–Radushkevich and Temkin isotherm models. Langmuir isotherm was the most fitted among all the models used with maximum monolayer sorption capacity of 1666.67 mg g−1 and the highest regression value of 0.99 indicating that CHA has greater affinity for Rh-B dye adsorption due to increased pore development via acid activation. Thermodynamic studies revealed an endothermic adsorption process with the ΔH0 value of 62.77 kJ mol−1. Spontaneity was ascertained based on the negative values of ΔGo (ranging from − 26.38 kJ mol−1 to − 20.93 kJ mol−1). The positive value of ΔS0 (0.276 kJ mol−1 K−1) suggests increased randomness that exists between CHA and Rh-B dye. Cost analysis results revealed that CHA is six times cheaper than commercial activated carbon (CAC), providing a savings of 217 US$ kg−1. CHA adsorbent was found to be suitable for Rh-B dye removal from aqueous solution.

Synthesis of Functionalized Magnetite Titanium Dioxide Nanocomposite for Removal of Acid Fuchsine Dye

2018 ◽  
Vol 21 (8) ◽  
pp. 583-593 ◽  
Author(s):  
Sara Rahnama ◽  
Shahab Shariati ◽  
Faten Divsar
Keyword(s):  
Titanium Dioxide ◽  
Removal Efficiency ◽  
Magnetic Core ◽  
Fractional Factorial ◽  
Order Kinetic ◽  
Sorption Data ◽  
Salt Addition ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Objective: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. Method: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. Results: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). Conclusion: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.

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