The simultaneous removal of reactive and disperse dyes by Electrocoagulation Process with a bipolar connection of combined Iron and Aluminum electrodes: Experimental design and  Kinetic studies

This study concerns the ability of electrocoagulation process to remove simultaneously disperse and reactive dyes by using combined iron and aluminum electrodes in bipolar mode. A statistical experiment design (Response Surface Methodology: RSM) was adopted to model the process and to optimize the parameters influencing the removal efficiency of the dyes. The mathematical model is established, using a rotatable central composite design uniform to study the empirical relationships between two responses (Removal efficiency, energy consumption) and five factors: initial pH, current density, the concentration of supporting electrolyte, time and stirring speed. This treatment, therefore, led to a removal efficiency that can reach more than 95% with low consumption energy of 9 kWh/Kg of removed dye. Kinetic, isotherm adsorption and thermodynamic studies were undertaken with the optimized parameters. Electrocoagulation mechanism was modeled using adsorption kinetics and isotherm models, it is sited were on the insoluble iron and aluminum flocs. This study shows that the Freundlich model fit the adsorption isotherm, the kinetic of the electrocoagulation is better presented by the pseudo- second-order kinetic, the adsorption is endothermic and spontaneous for both dyes. Analysis of the sludge allowed quantifying the role of each electrode in removing dyes.

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Effective Removal of Malachite Green from Aqueous Solutions Using Magnetic Nanocomposite: Synthesis, Characterization, and Equilibrium Study

Adsorption Science & Technology ◽

10.1155/2021/2359110 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Ali Q. Alorabi

Keyword(s):

Surface Area ◽

Malachite Green ◽

Chemical Activation ◽

Aqueous Media ◽

Kinetic Studies ◽

Cost Effective ◽

Magnetic Nanocomposite ◽

Bet Surface Area ◽

Isotherm Models ◽

Order Kinetic

In this work, magnetized activated Juniperus procera leaves (Fe3O4@AJPL) were successfully prepared via chemical activation of JPL and in situ coprecipitation with Fe3O4. A Fe3O4@AJPL nanocomposite was successfully applied for the elimination of malachite green (MG) dye from aqueous media. The prepared Fe3O4@AJPL adsorbent was characterized by SEM, EDX, TEM, XRD, FTIR, TGA, and BET surface area analyses. The BET surface area and pore size of the Fe3O4@AJPL nanocomposite were found to be 38.44 m2/g and 10.6 nm, respectively. The XRD and FTIR results indicated the formation of a Fe3O4@AJPL nanocomposite. Different parameters, such as pH of the solution (3–8), adsorbent dosage (10–100 mg), temperature (25–45°C), contact time (5-240 min), and initial MG concentrations (20–350 mg/L), for the elimination of the MG dye using Fe3O4@AJPL were optimized and found to be 7, 50 mg, 45°C, 120 min, and 150 mg/L, respectively. The nonlinear isotherm and kinetic studies exhibited a better fitting to second-order kinetic and Langmuir isotherm models, with a maximum monolayer adsorption capacity of 318.3 mg/g at 45°C, which was highly superior to the previously reported magnetic nanocomposite adsorbents. EDX analyses confirmed the presence of nitrogen on the Fe3O4@AJPL surface after MG adsorption. The calculated thermodynamic factors indicated endothermic and spontaneous processes. The desorption of MG dye from Fe3O4@AJPL was performed using a solution of 90% ethanol. Finally, it could be concluded that the designed Fe3O4@AJPL magnetic nanocomposite will be a cost-effective and promising adsorbent for the elimination of MG from aqueous media.

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Sustainable Development of Enhanced Luminescence Polymer-Carbon Dots Composite Film for Rapid Cd2+ Removal from Wastewater

Molecules ◽

10.3390/molecules25153541 ◽

2020 ◽

Vol 25 (15) ◽

pp. 3541

Author(s):

Mohammed Abdullah Issa ◽

Zurina Z. Abidin

Keyword(s):

Composite Film ◽

Removal Efficiency ◽

Carbon Dots ◽

Isotherm Models ◽

Synthetic Approach ◽

Blue Color ◽

Order Kinetic ◽

Cds Film ◽

Doped Carbon Dots ◽

Nitrogen Doped Carbon

As a remedy for environmental pollution, a versatile synthetic approach has been developed to prepare polyvinyl alcohol (PVA)/nitrogen-doped carbon dots (CDs) composite film (PVA-CDs) for removal of toxic cadmium ions. The CDs were first synthesized using carboxymethylcellulose (CMC) of oil palms empty fruit bunch wastes with the addition of polyethyleneimine (PEI) and then the CDs were embedded with PVA. The PVA-CDs film possess synergistic functionalities through increasing the content of hydrogen bonds for chemisorption compared to the pure CDs. Optical analysis of PVA-CDs film was performed by ultraviolet-visible and fluorescence spectroscopy. Compared to the pure CDs, the solid-state PVA-CDs displayed a bright blue color with a quantum yield (QY) of 47%; they possess excitation-independent emission and a higher Cd2+ removal efficiency of 91.1%. The equilibrium state was achieved within 10 min. It was found that adsorption data fit well with the pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption uptake was 113.6 mg g−1 at an optimal pH of 7. Desorption experiments showhe that adsorbent can be reused fruitfully for five adsorption-desorption cycles using 0.1 HCl elution. The film was successfully applied to real water samples with a removal efficiency of 95.34% and 90.9% for tap and drinking water, respectively. The fabricated membrane is biodegradable and its preparation follows an ecofriendly green route.

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Enhanced biosorption of Cr(VI) using cotton fibers coated with chitosan – role of ester bonds

Water Science & Technology ◽

10.2166/wst.2018.284 ◽

2018 ◽

Vol 78 (3) ◽

pp. 476-486 ◽

Cited By ~ 1

Author(s):

Sergio I. Rojas ◽

Diana C. Duarte ◽

Sergio D. Mosquera ◽

Felipe Salcedo ◽

Juan P. Hinestroza ◽

...

Keyword(s):

Hexavalent Chromium ◽

Freundlich Isotherm ◽

Kinetic Studies ◽

Chitosan Solution ◽

Cotton Fibers ◽

Isotherm Models ◽

Order Kinetic ◽

Amino Groups ◽

Removal Capacity

Abstract We report on the role of ester bonds in the enhanced removal of hexavalent chromium from water using cotton fibers coated with chitosan. Adsorption capacities up to five times higher than those of the unmodified fibers were observed when the cotton fibers were exposed to an NaOH, followed by citric acid (0.97 M), and a chitosan solution (2%). We found that the use of NaOH favors the formation of ester bonds over amide bonds on the surface of the cotton fibers. This increase in the surface density of ester bonds generates an increase in the amount of exposed amino groups from the chitosan, hence increasing the removal capacity of the modified fibers. Experimental results also reveal that the adsorption is induced by the electrostatic attraction between the protonated amino groups on the surface and the negatively charged chromium ions in the water. Adsorption isotherms and kinetic studies indicated that the adsorption process fits the Langmuir and the Freundlich isotherm models as well as the pseudo-first and pseudo-second order kinetic models. These results can open a new avenue for the manufacturing of fibers with enhanced removal capacities for hexavalent chromium.

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Parametric, equilibrium and kinetic studies on the removal of mercury using ion exchange resin

Water Practice & Technology ◽

10.2166/wpt.2017.037 ◽

2017 ◽

Vol 12 (2) ◽

pp. 305-313 ◽

Cited By ~ 2

Author(s):

N. Rajamohan ◽

M. Rajasimman

Keyword(s):

Freundlich Isotherm ◽

Kinetic Studies ◽

Strong Acid ◽

Ion Exchange Resin ◽

Second Order ◽

Isotherm Models ◽

Order Kinetic ◽

Acid Cation ◽

Pseudo Second Order ◽

Langmuir Constants

This experimental research was an investigation into removal of mercury by using a strong acid cation resin, 001 × 7. Parametric experiments were conducted to determine the optimum pH, resin dosage, agitation speed and the effect of change in concentration in the range of 50–200 mg/L. High resin dosages favoured better removal efficiency but resulted in lower uptakes. Equilibrium experiments were performed and fitted to Langmuir and Freundlich isotherm models. Langmuir model suited well to this study confirming the homogeneity of the resin surface. The Langmuir constants were estimated as qmax = 110.619 mg/g and KL = 0.070 L/g at 308 K. Kinetic experiments were modeled using Pseudo second order model and higher values of R2 (>0.97) were obtained. The Pseudo second order kinetic constants, namely, equilibrium uptake (qe) and rate constant (k2), were evaluated as 59.17 mg/g and 40.2 × 10−4 g mg−1 min−1 at an initial mercury concentration of 100 mg/L and temperature of 308 K.

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Green synthesis of Quercus coccifera hydrochar in subcritical water medium and evaluation of its adsorption performance in BR18 dye

Water Science & Technology ◽

10.2166/wst.2020.607 ◽

2020 ◽

Author(s):

Mohammed Saleh ◽

Zeynep Bilici ◽

Yasin Ozay ◽

Erdal Yabalak ◽

Mutlu Yalvac ◽

...

Keyword(s):

Removal Efficiency ◽

Subcritical Water ◽

Freundlich Isotherm ◽

Kinetic Studies ◽

Isotherm Models ◽

Suitable Model ◽

Water Medium ◽

Quercus Coccifera ◽

Intraparticle Diffusion Model ◽

The Relationship

Abstract In this study, we investigated the production conditions of hydrochar produced from Quercus coccifera, which is an inexpensive and easy available adsorbent, for the adsorption of Basic Red 18 (BR18) azo dye. Hydrochar was produced in the eco-friendly subcritical water medium (SWM). The effects of the pH (2–10), adsorbent size (45–106 μm), adsorbent dose (0.5–1.5 g/L), dyes concentrations (40–455 mg/L), and contact time (5–120 min) were studied through the optimization experiments. The optimum condition was obtained at pH 10, particle size of 45 μm, particle amount of 1.5 g/L, dyes concentration of 455 mg/L, and 60 minutes. The removal efficiency increased sharply for the first 5 min after that the removal efficiency reached a steady state at the 60 min with maximum removal of 88.7%. The kinetic studies for the adsorption of BR18 dye in aqueous solution using hydrochar showed the second-order kinetics. Langmuir and Freundlich isotherm models were used to explain the relationship between adsorbent and adsorbate and Freundlich isotherm was the most suitable model because of its high regression coefficient (R2) value. The intraparticle diffusion model was used to determine the adsorption mechanism of the BR18 onto Q. coccifera fruit. Desorption studies were also carried out using different type acids and different molarity.

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Removal of Cadmium from Industrial Wastewater using Electrocoagulation Process

Journal of Engineering ◽

10.31026/j.eng.2020.01.03 ◽

2019 ◽

Vol 26 (1) ◽

pp. 24-34 ◽

Cited By ~ 1

Author(s):

Mohammed Alameen Salem ◽

Najwa Majeed

Keyword(s):

Heavy Metal ◽

Removal Efficiency ◽

Applied Voltage ◽

Industrial Wastewater ◽

Batch Reactor ◽

Operating Parameters ◽

Initial Concentration ◽

Initial Ph ◽

Electrocoagulation Process ◽

Aluminum Electrodes

Cadmium is one of the heavy metal found in the wastewater of many industries. The electrocoagulation offers many advantages for the removal of cadmium over other methods. So the removal of cadmium from wastewater by using electrocoagulation was studied to investigate the effect of operating parameters on the removal efficiency. The studied parameters were the initial pH, initial concentration, and applied voltage. The study experiments were conducted in a batch reactor with with two pairs of aluminum electrodes with dimension and 2mm in thick with 1.5 cm space between them. The optimum removal was obtained at pH =7, initial concentration = 50 mg/L, and applied voltage = 20 V and it was 90%.

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Removal of zinc ions as zinc chloride complexes from strongly acidic aqueous solutions by ionic exchange

Open Chemistry ◽

10.2478/s11532-014-0504-8 ◽

2014 ◽

Vol 12 (8) ◽

pp. 821-828 ◽

Cited By ~ 9

Author(s):

Emilia Gîlcă ◽

Andrada Măicăneanu ◽

Petru Ilea

Keyword(s):

Kinetic Studies ◽

Sorption Kinetics ◽

Exchange Capacity ◽

Second Order ◽

Isotherm Models ◽

Ionic Exchange ◽

Order Kinetic ◽

Zinc Ions ◽

Chloride Complexes ◽

Pseudo Second Order

AbstractThe aim of this study was to compare several anion exchangers and to investigate the capacity of Amberlite IRA410 to remove zinc as chloride [ZnCl3]− from hydrochloric solutions (1 M). Influence of the process parameters such as stirring rate, resin quantity and zinc initial concentration over the removal process, was considered. The highest experimental ionic exchange capacity between the considered anionic exchangers, in the same working conditions (500 rpm, 5 g resin and 500 mg L−1), was obtained for Amberlite IRA410, 8.34 mg g−1. With an increase of zinc ions concentration, ionic exchange capacity increased up to 19.31 mg g−1 (1100 mg L−1). The experimental data were analysed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The results were also analyzed using sorption kinetics models, pseudo-first-, pseudo-second-order, intra-particle and film diffusion models. From the Dubinin-Radushkevich and Temkin isotherm models the mean free energy and heat of sorption were calculated to be 7.45 kJ mol−1, respectively 1×10−4 kJ mol−1, which indicates that zinc sorption is characterized by a physisorption process. Kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model.

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Parametric and adsorption kinetic studies of methylene blue removal from simulated textile water using durian (Durio zibethinus murray) skin

Water Science & Technology ◽

10.2166/wst.2015.247 ◽

2015 ◽

Vol 72 (6) ◽

pp. 896-907 ◽

Cited By ~ 18

Author(s):

S. M. Anisuzzaman ◽

Collin G. Joseph ◽

D. Krishnaiah ◽

A. Bono ◽

L. C. Ooi

Keyword(s):

Methylene Blue ◽

Adsorption Capacity ◽

Dye Adsorption ◽

Freundlich Isotherm ◽

Kinetic Studies ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Durio Zibethinus

In this study, durian (Durio zibethinus Murray) skin was examined for its ability to remove methylene blue (MB) dye from simulated textile wastewater. Adsorption equilibrium and kinetics of MB removal from aqueous solutions at different parametric conditions such as different initial concentrations (2–10 mg/L), biosorbent dosages (0.3–0.7 g) and pH solution (4–9) onto durian skin were studied using batch adsorption. The amount of MB adsorbed increased from 3.45 to 17.31 mg/g with the increase in initial concentration of MB dye; whereas biosorbent dosage increased from 1.08 to 2.47 mg/g. Maximum dye adsorption capacity of the durian skin was found to increase from 3.78 to 6.40 mg/g, with increasing solution pH. Equilibrium isotherm data were analyzed according to Langmuir and Freundlich isotherm models. The sorption equilibrium was best described by the Freundlich isotherm model with maximum adsorption capacity of 7.23 mg/g and this was due to the heterogeneous nature of the durian skin surface. Kinetic studies indicated that the sorption of MB dye tended to follow the pseudo second-order kinetic model with promising correlation of 0.9836 < R2 < 0.9918.

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Adsorption of Arsenite from Aqueous Solutions Using Granola Modified Lemon Peel

Avicenna Journal of Environmental Health Engineering ◽

10.5812/ajehe.11667 ◽

2017 ◽

Vol 4 (1) ◽

pp. 11667-11667 ◽

Cited By ~ 1

Author(s):

Mohammad Hossien Salmani Nodoushan ◽

Zinab Parvizi ◽

Fatemah Mirzai Nodoushan ◽

Mohammad Taghi Ghaneian

Keyword(s):

Aqueous Solutions ◽

Removal Efficiency ◽

Ph Value ◽

Kinetic Equations ◽

Isotherm Models ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Adsorption Experiment ◽

Lemon Peel ◽

Health Group

The arsenite species is a common form of arsenic in nature and ground waters and is categorized as a major public health group. In the present study, the arsenite ions from contaminated solutions were removed by adsorption on the granola modified lemon peel. The arsenite adsorption on lemon peel was investigated by various concentrations of arsenite with 0.2 g/100 mL of adsorbent at a range of pH 3 - 10 and a constant temperature of 25°C for 0 to 240 minutes using batch experiments. Data of the adsorption experiment were analyzed by the pseudo-first and second- order kinetic equations. The Freundlich and Langmuir isotherm models were used to understand the adsorption relationship between the arsenite ions and functional groups on the lemon peel. pH equal to 5.2 was recorded as pHzpc of this adsorbent in aqueous solution. The optimum condition was obtained at 60 minutes, pH value 8, and 2 mg/L of arsenite, with a removal efficiency of 88%. The maximum adsorption capacity of granola lemon peel was 27 mg.g-1 in Langmuir model. Lemon peel adsorbent presented good removal efficiency for arsenite in contaminated aqueous solutions and real water.

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Comparative Study of Ni-Zn LHS and Mg-Al LDH Adsorbents of Navy Blue and Yellow F3G Dye

Indonesian Journal of Chemistry ◽

10.22146/ijc.21175 ◽

2018 ◽

Vol 16 (1) ◽

pp. 36 ◽

Cited By ~ 6

Author(s):

Idha Yulia Ikhsani ◽

Sri Juari Santosa ◽

Bambang Rusdiarso

Keyword(s):

Adsorption Capacity ◽

Freundlich Isotherm ◽

Second Order ◽

Isotherm Models ◽

Disperse Dyes ◽

Order Kinetic ◽

Initial Ph ◽

Isotherm Adsorption ◽

Order Kinetic Model ◽

Pseudo Second Order

Adsorption of disperse dyes from wastewater onto Ni-Zn LHS (layered hydroxide salts) and Mg-Al LDH (layered double hydroxides) has been compared in this study. Effects of initial pH solution, contact time and initial dye concentration were investigated. The ability of the adsorbent to be reused was also studied. The results showed that acidic condition was favorable for the adsorption of each dyes onto both adsorbent. The adsorption kinetics was studied using pseudo-first-order, pseudo-second-order and Santosa’s kinetics models. The experimental data fits well with the pseudo-second order kinetic model. The equilibrium adsorption data were analyzed using Langmuir and Freundlich isotherm models. The results showed that adsorption of navy blue onto both adsorbent followed Freundlich isotherm adsorption, while yellow F3G followed Langmuir isotherm adsorption. In the application for the adsorption the wastewater containing dyes, Ni-Zn LHS has a better adsorption capacity of 52.33 mg/g than that of Mg-Al LDH that 30.54 mg/g. Calcination of the adsorbent which has already been used increased the adsorption capacity of Mg-Al LDH to 84.75 mg/g, but decreased the adsorption capacity of the Ni-Zn LHS to 42.65 mg/g.

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