scholarly journals Comparison of Cation Anion Dye Removal Characteristics between Kelp-based Magnetic Biochar and Pine-based Magnetic Biochar

2020 ◽  
Vol 42 (6) ◽  
pp. 308-318 ◽  
Author(s):  
Hee So Oh ◽  
Jae-Soo Chang
Keyword(s):  
Adsorption Capacity ◽  
Iron Oxides ◽  
Second Order ◽  
Kinetics Model ◽  
Isotherm Models ◽  
Adsorptive Capacity ◽  
Magnetic Biochar ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Surface Modified

Objectives:This study investigates the adsorption capacity of magnetic biochar (KB-Fe) derived from kelp for two dyes, Congo red (CR) and crystal violet (CV), which have different charge characteristics. The adsorption capacities were compared to magnetic biochar (PB-Fe) derived from pine.Methods:Pristine biochars (KB, PB) were produced through the pyrolysis of kelp and pine sawdust at 500℃. Magnetic biochars (KB-Fe, PB-Fe) were produced by treatment of 60 g of biomass in 1 L of 0.1 M FeCl<sub>3</sub>･6H<sub>2</sub>O and pyrolysis of the raw materials at 500℃. The fundamental characteristics of the biochars were analyzed, and the adsorption capacities of the biochars for the CR and CV dyes were evaluated based on two adsorption isotherm models, two adsorption kinetics models, and adsorption characteristics based on changes to the pH between 5 and 11.Results and discussion:CR adsorption by all biochars decreased with an increase in pH. When KB and PB were surface-modified with magnetic iron oxides, their adsorption capacity for CR increased. CV adsorption by all biochars increased with pH. When KB and PB were surface-modified with magnetic iron oxides, their adsorption capacity for CV considerably decreased. According to the Langmuir isotherm model, the adsorption capacity for CR was in the order of KB-Fe, KB, PB-Fe, and PB, and the adsorption capacity for CV was in the order of KB, PB, PB-Fe, and KB-Fe. The CR adsorption was better described by the pseudo-second order kinetics model for all biochars, with the exception of KB-Fe. CV adsorption was also better described by the pseudo-second order kinetics model for all biochars, with the exception of KB.Conclusions:The results show that kelp biochar has great potential for the adsorptive removal of CR and CV compared to pine-based biochar. In addition, it was demonstrated that surface modification of kelp biochar with magnetic iron oxides can significantly improve its adsorptive capacity for anionic dyes; however, its adsorptive capacity for cationic dyes decreases.

scholarly journals Modified Spruce Sawdust for Sorption of Hexavalent Chromium in Batch Systems and Fixed-Bed Columns

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5156
Author(s):  
Dororthea Politi ◽  
Dimitrios Sidiras
Keyword(s):  
Sulfuric Acid ◽  
Adsorption Capacity ◽  
Hexavalent Chromium ◽  
Diethylene Glycol ◽  
Fixed Bed ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order

This study investigated the potential use of spruce sawdust that was pretreated with diethylene glycol and sulfuric acid for the removal of hexavalent chromium from wastewater. The sawdust pretreatment process was conducted at different temperatures and times. The adsorbent was characterized by quantitative saccharification, scanning electron microscopy, and Brunauer–Emmet–Teller surface area analysis. Adsorption capacity was studied for both batch and column processes. The experimental adsorption isotherms were simulated using seven isotherm models, including Freundlich and Langmuir models. By using the Langmuir isotherm model, the maximal Cr(VI) adsorption capacity of organosolv-pretreated spruce sawdust (qm) was 318.3 mg g−1. Furthermore, the kinetic data were fitted to Lagergren, pseudo-second-order, and intraparticle diffusion models, revealing that the adsorption of Cr(VI) onto spruce sawdust pretreated with diethylene glycol and sulfuric acid is best represented by the pseudo-second-order kinetic model. Three kinetic models, namely, the Bohart–Adams model, Thomas model, and modified dose–response (MDR) model, were used to fit the experimental data obtained from the column experiments and to resolve the characteristic parameters. The Thomas adsorption column capacity of the sawdust was increased from 2.44 to 31.1 mg g−1 upon pretreatment, thus, demonstrating that organosolv treatment enhances the adsorption capability of the material.

Removal of hazardous pharmaceutical dyes by adsorption onto papaya seeds

2014 ◽  
Vol 70 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Caroline Trevisan Weber ◽  
Gabriela Carvalho Collazzo ◽  
Marcio Antonio Mazutti ◽  
Edson Luiz Foletto ◽  
Guilherme Luiz Dotto
Keyword(s):  
Aqueous Solutions ◽  
Second Order ◽  
Isotherm Models ◽  
Order Model ◽  
Application Range ◽  
First Order ◽  
Adsorption Capacities ◽  
Effects Of Ph ◽  
Pseudo Second Order ◽  
Papaya Seeds

Papaya (Carica papaya L.) seeds were used as adsorbent to remove toxic pharmaceutical dyes (tartrazine and amaranth) from aqueous solutions, in order to extend application range. The effects of pH, initial dye concentration, contact time and temperature were investigated. The kinetic data were evaluated by the pseudo first-order, pseudo second-order and Elovich models. The equilibrium was evaluated by the Langmuir, Freundlich and Temkin isotherm models. It was found that adsorption favored a pH of 2.5, temperature of 298 K and equilibrium was attained at 180–200 min. The adsorption kinetics followed the pseudo second-order model, and the equilibrium was well represented by the Langmuir model. The maximum adsorption capacities were 51.0 and 37.4 mg g−1 for tartrazine and amaranth, respectively. These results revealed that papaya seeds can be used as an alternative adsorbent to remove pharmaceutical dyes from aqueous solutions.

scholarly journals Enhancing Adsorption Capacity of Clay and Application in Dye Removal from Waste Water

2014 ◽  
Vol 39 ◽  
pp. 35-51 ◽  
Author(s):  
O.T. Ogunmodede ◽  
O.L. Adebayo ◽  
A.A. Ojo
Keyword(s):  
Waste Water ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Kinetic Models ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Small Surface ◽  
Intercalation Process ◽  
Pseudo Second Order

Natural clay has been considered as a potential absorbent for removing pollutants from water and waste water. Nonetheless, the effective application of clay for water treatment is limited due to small surface area and presence of net negative surface charge, leading to it low adsorption capacity. The absorption capacity was boosted via intercalation of CaO derived from snail shell (SS). The methylene blue sorption potential, PZC, and the surface area of unmodified clay sample were substantially enhanced by the intercalation process. The process of sorption of MB from solution was analyzed using five different isotherm models (Langmuir, Freundlich, Temkin, Harkins-Jura, and Halsey isotherm equations). The value of the Langmuir monolayer sorption capacity qm (mg/g) increased from 50.12 to 88.71, PZC values increased from 4.50 to 7.40, and the surface area (m2/g) value increased from 27 m2/g to 123 m2/g after the intercalation process. The experimental data were fitted into two kinetic models: Lagergren pseudo-first order and the chemisorptions pseudo-second order. It was observed that chemisorptions pseudo-second order kinetic model described the sorption process with high coefficients of determination (r2) better than pseudo first other kinetic models. The modification caused no change in the clay surficial microstructure but increased the lattice spacing of the clay framework.

scholarly journals Effectiveness of Alkali-Acid Treatment in Enhancement the Adsorption Capacity for Rice Straw: The Removal of Methylene Blue Dye

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Nady A. Fathy ◽  
Ola I. El-Shafey ◽  
Laila B. Khalil
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Rice Straw ◽  
Acid Treatment ◽  
Low Cost ◽  
Second Order ◽  
Isotherm Models ◽  
Blue Dye ◽  
Acid Modification ◽  
Pseudo Second Order

The effectiveness of alkali-acid modification in enhancement the adsorption capacity of rice straw (RS) for removing a basic dye was studied. The obtained adsorbents were characterized by slurry pH, pHPZC, iodine number, methylene blue number, FTIR, and SEM analyses. Adsorption of methylene blue (MB) was described by the Langmuir, Freundlich, Tempkin, and Redlich-Peterson isotherm models. Effects of contact time, initial concentration of MB dye, pH of solution, adsorbent dose, salt concentration of NaCl, and desorbing agents on the removal of MB were reported. Kinetic studies were analyzed using the pseudo-first-order, pseudo-second-order, and the intraparticle diffusion models and were found to follow closely the pseudo-second-order model. Equilibrium data were best represented by the Langmuir and Redlich-Peterson isotherms. The adsorption capacities were varied between 32.6 and 131.5 mg/g for untreated and treated RS samples with NaOH-1M citric acid (ARS-1C), respectively. Adsorption behavior of the ARS-1C sample was experimented in a binary mixture containing methylene blue (basic) and reactive blue 19 (acidic) dyes which showed its ability to remove MB higher than RB19. Overall, the results indicate that the alkali-acid treatment proved to be potential modification for producing effective low-cost adsorbents for the removal of the basic dyes from wastewater.

Chromium (VI) adsorption onto activated sulfate lignin

2009 ◽  
Vol 4 (2) ◽  
Author(s):  
Nassima Tazrouti ◽  
Moussa Amrani
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Analytical Data ◽  
Order Equation ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Adsorption Model ◽  
Chromium Vi ◽  
Pseudo Second Order

Activated lignin having surface area of 1023 m2.g-1 has been prepared from sulfate lignin that was treated by 30 % H2O2 and carbonized at 300 °C in order to test the chromium (VI) adsorption from aqueous solution. The influence of contact time, pH, initial concentration of adsorbent and adsorbate and temperature on the adsorption capacity were investigated. The maximum removal of Cr(VI) was found to be 92,36 % at pH=2 and contact time of 80 min. Optimal concentration of lignin and Cr(VI) were found to be 3.8 g.l-1 and 180 mg.l-1, respectively. The adsorption kinetics was tested pseudo-first-order and pseudo-second-order equation. The analytical data were fitted well in a pseudo-second-order equation and the rate of removal of chromium was found to speed up with increasing temperature. Activation energy for the adsorption process was found to be 18.19 Kj.mol-1. The Langmuir and Freundlich adsorption isotherm models were applied to describe the isotherm and isotherm constants for the adsorption of Cr (VI) on lignin. These constants and correlation coefficients of the isotherm models were calculated and compared. Results indicated that Cr (VI) uptake could be described by the Langmuir adsorption model. The maximum adsorption capacity (qm) of Cr (VI) on lignin was 75.75 mg.g-1 at temperature of 40°C. The dimensionless equilibrium parameter (RL) signified a favorable adsorption of Cr (VI) on lignin and was found between 0.0601 and 0.818 (0&lt;RL&lt;1). The thermodynamic parameters like ΔG°, ΔS° and ΔH° were calculated and it has been found that the reaction was spontaneous and endothermic in nature. This study indicates that lignin has the potential to become an effective and economical adsorbent for removal Cr (VI) from the waste water.

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

2018 ◽  
Vol 16 (1) ◽  
pp. 36 ◽  
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.

Fabrication of a novel graphene oxide/β-FeOOH composite and its adsorption behavior for copper ions from aqueous solution

2015 ◽  
Vol 44 (22) ◽  
pp. 10448-10456 ◽  
Author(s):  
Tingshun Jiang ◽  
Lu Yan ◽  
Lei Zhang ◽  
Yingying Li ◽  
Qian Zhao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Copper Ions ◽  
Removal Rate ◽  
Second Order ◽  
Adsorption Behavior ◽  
Kinetics Model ◽  
Pseudo Second Order

A graphene oxide/β-FeOOH composite was prepared and its adsorption capacity was evaluated by Cu2+removal. The adsorption process was well fitted with the pseudo-second-order kinetics model. The removal rate of Cu2+reached 93.8%.

Adsorption of geosmin and 2-methylisoborneol onto granular activated carbon in water: isotherms, thermodynamics, kinetics, and influencing factors

2019 ◽  
Vol 80 (4) ◽  
pp. 644-653
Author(s):  
Lingfei Ma ◽  
Fangyuan Peng ◽  
Haipu Li ◽  
Chaoyi Wang ◽  
Zhaoguang Yang
Keyword(s):  
Particle Size ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Granular Activated Carbon ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Pseudo Second Order ◽  
Adsorption Entropy ◽  
Natural Organic Material

Abstract Adsorption was found to be an acceptable treatment option to remove geosmin (GSM) and 2-methylisoborneol (2-MIB). It is meaningful to investigate the adsorption capacity of granular activated carbon (GAC) for the two algal odorants in water, and the influences of natural organic material (NOM) and particle size. The adsorption process was studied with the four isotherm models (Langmuir, Freundlich, Temkin, and modified Freundlich), four kinetic models (pseudo first-order, pseudo second-order, Elovich, and intra-particle), and thermodynamics. The results showed that the adsorption of both compounds could be best described by the modified Freundlich isotherm and pseudo second-order model, and the obtained thermodynamic parameters (changes in heat of adsorption, entropy, and Gibbs free energy) revealed that the adsorption was endothermic and spontaneous. Downsizing the particle size of GAC was effective for improving the adsorption capacity and rate. The concentrations of the two odorants could be reduced from 500 ng L−1 to less than 10 ng L−1 with the presence of NOM (&lt;20 mg L−1 total organic carbon, TOC).

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 Removal of Rhodamine B from aqueous solution by ZnFe2O4 nanocomposite with magnetic separation performance

2017 ◽  
Vol 19 (4) ◽  
pp. 65-74 ◽  
Author(s):  
Wojciech Konicki ◽  
Daniel Siber ◽  
Urszula Narkiewicz
Keyword(s):  
Aqueous Solution ◽  
Kinetic Model ◽  
Adsorption Capacity ◽  
Rhodamine B ◽  
Second Order ◽  
Isotherm Models ◽  
Separation Performance ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Magnetic ZnFe2O4 nanocomposite (ZnFe-NC) was used as an adsorbent for the removal of Rhodamine B (RB) from aqueous solution. The synthesized nanocomposite was characterized by XRD, SEM, HRTEM, BET and FTIR. The effects of various parameters such as initial RB concentration (5–25 mg L−1), pH (3.4–11.1) and temperature (20–60°C) were investigated. The adsorption capacity at equilibrium increased from 5.02 to 9.83 mg g−1, with the increase in the initial concentration of RB from 5 to 25 mg L−1 at pH 7.0 and at 20°C. The experimental results indicated that the maximum RB removal could be attained at a solution pH of 4.4 and the adsorption capacity obtained was 6.02 mg g−1. Kinetic adsorption data were analyzed using the pseudo-first-order kinetic model, the pseudo-second-order model and the intraparticle diffusion model. The adsorption kinetics well fitted using a pseudo-second-order kinetic model. The experimental isotherm data were analyzed using two isotherm models, namely, Langmuir and Freundlich. The results revealed that the adsorption behavior of the RB onto ZnFe-NC fitted well with the Langmuir isotherm model. In addition, various thermodynamic parameters, such as standard Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) have been calculated.

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