scholarly journals Shell biomass material supported nano-zero valent iron to remove Pb 2+ and Cd 2+ in water

2020 ◽  
Vol 7 (10) ◽  
pp. 201192
Author(s):  
Zheng Wang ◽  
Xique Wu ◽  
Shengxu Luo ◽  
Yanshi Wang ◽  
Zhuang Tong ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Metal Ion ◽  
Metal Removal ◽  
Langmuir Model ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Mixed Solution ◽  
Adsorption Sites ◽  
Adsorption Capacities ◽  
Order Kinetic Model

Nanoscale zero-valent iron (NZVI) has a high adsorption capacity for heavy metals, but easily forms aggregates. Herein, preprocessed undulating venus shell (UVS) is used as support material to prevent NZVI from reuniting. The SEM and TEM results show that UVS had a porous layered structure and NZVI particles were evenly distributed on the UVS surface. A large number of adsorption sites on the surface of UVS-NZVI are confirmed by IR and XRD. UVS-NZVI is used for adsorption of Pb 2+ and Cd 2+ at pH = 6.00 in aqueous solution, and the experimental adsorption capacities are 29.91 and 38.99 mg g −1 at optimal pH, respectively. Thermodynamic studies indicate that the adsorption of ions by UVS-NZVI is more in line with the Langmuir model when Pb 2+ or Cd 2+ existed alone. For the mixed solution of Pb 2+ and Cd 2+ , only the adsorption of Pb 2+ by UVS-NZVI conforms to the Langmuir model. In addition, the maximum adsorption capacities of UVS-NZVI for Pb 2+ and Cd 2+ are 93.01 and 46.07 mg g −1 , respectively. Kinetic studies demonstrate that the determination coefficients ( R 2 ) of the pseudo first-order kinetic model for UVS-NZVI adsorption of Cd 2+ and Pb 2+ are higher than those of the pseudo second-order kinetic model and Elovich kinetic model. Highly efficient performance for metal removal makes UVS-NZVI show potential application to heavy metal ion adsorption.

scholarly journals Removal Study of Crystal Violet and Methylene Blue From Aqueous Solution by Activated Carbon Embedded Zero-Valent Iron: Effect of Reduction Methods

2021 ◽  
Vol 9 ◽  
Author(s):  
Yongmei Wang ◽  
Tiantian Chen ◽  
Xiaolin Zhang ◽  
Teza Mwamulima
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Kinetic Model ◽  
Specific Surface ◽  
Surface Area ◽  
Crystal Violet ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Order Kinetic Model

Zero valent iron (ZVI) particles were embedded into porous materials to avoid aggregation and separation problems in the controlled synthesis process. To investigate the adsorption mechanism of crystal violet and methylene blue, activated carbon (AC) and AC-based ZVI extraction by solid-phase and liquid-phase reduced approaches was conducted. Characterization methods of specific surface area, scanning electron microscopy (SEM), and x-ray diffractograms (XRD) were used to elucidate the structure of adsorbents, and the adsorption capacities of crystal violet and methylene blue were obtained under experimental conditions of various pH values (2.0–10.0), adsorption times (0–72 h), and temperatures (30–50°C). The adsorption of crystal violet/methylene blue was controlled by both chemisorption and reduction. The adsorption processes were fitted to a pseudo-second-order kinetic model, and that of reduction kinetics was suitable to pseudo-first-order kinetic model. The thermodynamic study revealed that the adsorption of crystal violet and methylene blue was endothermic and spontaneous, and the adsorption isotherms fitted well to the Langmuir model. Different adsorption capacities of crystal violet and methylene blue on various adsorbents were found, indicating that both the properties of adsorbents (pore size, specific surface area, and chemical functional groups) and the structures of adsorbates had significant effect on the removal of dye molecules.

Extraction of Heavy Metals from Aqueous Medium by Husk Biomass: Adsorption Isotherm, Kinetic and Thermodynamic study

2019 ◽  
Vol 233 (2) ◽  
pp. 201-223 ◽  
Author(s):  
Khalida Naseem ◽  
Rahila Huma ◽  
Aiman Shahbaz ◽  
Jawaria Jamal ◽  
Muhammad Zia Ur Rehman ◽  
...  
Keyword(s):  
Metal Ions ◽  
Aqueous Medium ◽  
Contact Time ◽  
Metal Ion ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Adsorption Sites ◽  
Order Kinetic Model

Abstract This study describes the adsorption of Cu (II), Co (II) and Ni (II) ions from wastewater on Vigna radiata husk biomass. The ability of adsorbent to capture the metal ions has been found to be in the order of Ni (II)>Co (II) and Cu (II) depending upon the size and nature of metal ions to be adsorbed. It has been observed that percentage removal of Cu (II), Co (II) and Ni (II) ions increases with increase of adsorbent dosage, contact time and pH of the medium but up to a certain extent. Maximum adsorption capacity (qmax) for Cu (II), Co (II) and Ni (II) ions has been found to be 11.05, 15.04 and 19.88 mg/g, respectively, under optimum conditions of adsorbent dosage, contact time and pH of the medium. Langmuir model best fits the adsorption process with R2 value approaches to unity for all metal ions as compared to other models because adsorption sites are seemed to be equivalent and only monolayer adsorption may occur as a result of binding of metal ion with a functional moiety of adsorbent. Pseudo second order kinetic model best interprets the adsorption process of Cu (II), Co (II) and Ni (II) ions. Thermodynamic parameters such as negative value of Gibbs energy (∆G°) gives information about feasibility and spontaneity of the process. Adsorption process was found to be endothermic for Cu (II) ions while exothermic for Co (II) and Ni (II) ions as signified by the value of enthalpy change (∆H°). Husk biomass was recycled three times for removal of Ni (II) from aqueous medium to investigate its recoverability and reusability. Moreover V. radiata husk biomass has a potential to extract Cu (II) and Ni (II) from electroplating wastewater to overcome the industrial waste water pollution.

KINETICS AND ISOTHERM STUDIES OF Pb(II) IMPRINTED CARBOXYMETHYL CHITOSAN–PECTIN-PEGDE

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Budi Hastuti ◽  
Dwi Siswanta ◽  
Mudasir Mudasir ◽  
Triyono Triyono
Keyword(s):  
Adsorption Isotherm ◽  
Kinetic Model ◽  
Metal Ion ◽  
Diglycidyl Ether ◽  
Carboxymethyl Chitosan ◽  
Second Order ◽  
Order Kinetic ◽  
Freundlich Adsorption Isotherm ◽  
Order Kinetic Model ◽  
Chelation Reaction

Pectin and chitosan are biomaterials that capable to act as biosorbent. Pectin has active groups, such as carboxyl, methoxyl, and hydroxyl (OH), while chitosan has amine group (–NH2) and hydroxyl (OH) as the active site metal ion absorber. Integration of two biopolymers is conducted by using a suitable cross-linker agents that are expected to form stable and more organized structure. This structure facilitate metal ions to enter and to form chelation reaction. Thus, it has great capacity for metal adsorption. A modified natural adsorbent pectin-chitosan has been synthesized by reacting of -OH group among pectin (Pec) and chitosan with Poly(ethylene glycol) Diglycidyl Ether (PEGDE) crosslinker agent to form a stable and an acidic medium-resistance adsorbent. Prior to increasing the active group of the adsorbent, chitosan was attached with acetate to form Carboxymethyl Chitosan (CMC). Furthermore, the CMC-Pec-PEGDE adsorbent was imprinted with Pb (II) to afford Pb(II) imprinted-CMC-Pec-PEGDE adsorbent in order to improve the selective sorption of Pb(II) metal ion. All of the functional groups attached on the synthesized adsorbents were characterized by Fourier Transform Infrared (FT-IR) Spectrometry. The kinetics and thermodynamics bath sorption of Pb(II) on Pb(II) imprinted-CMC-Pec-PEGDE film adsorbent have been investigated including the optimal condition for adsorption. The pseudo first-order and second-order kinetic model were investigated in order to determine the adsorption mechanism. The results indicated that all of the three adsorbent, CMC, CMC-Pec-PEGDE, and Pb(II) imprinted-CMC-Pec-PEGDE followed a pseudo-second-order kinetic model. Furthermore, adsorption studies of Pb(II) ion on CMC and CMC–Pec-PEGDE found to follow Langmuir adsorption while on imprinted-CMC-Pec-PEGDE followed Freundlich adsorption isotherm. The adsorption isotherm parameters of CMC and CMC-Pec-PEGDE adsorbents were ΔG° of 24.8 and 23.1 kJ mol-1, respectively. While Pb(II) imprinted-CMC-Pec-PEGDE followedisotherm model with ΔG° of 9.6 kJ mol-1.

Lead removal from aqueous solutions by natural Greek bentonites

Clay Minerals ◽  
2013 ◽  
Vol 48 (5) ◽  
pp. 771-787 ◽  
Author(s):  
A. Bourliva ◽  
K. Michailidis ◽  
C. Sikalidis ◽  
A. Filippidis ◽  
M. Betsiou
Keyword(s):  
Kinetic Model ◽  
Metal Ion ◽  
Measurement Techniques ◽  
Ion Concentration ◽  
Area Measurement ◽  
Lead Removal ◽  
Order Kinetic ◽  
Solution Ph ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model

AbstractThree bentonite samples (B1, B2, B3) from Milos Island, Greece, were investigated by XRD, AAS, DTA-TG, FTIR and specific surface area measurement techniques. A laboratory batch study has been performed to investigate the adsorption characteristics of lead ions (Pb2+) onto natural bentonite samples. The effect of various physicochemical factors that influence adsorption, such as solution pH (2–6), adsorbent dosage (1–10 g L–1), contact time (20–360 min), and initial metal ion concentration (5–150 mg L–1) was studied. A number of available models like the Lagergren pseudo first-order kinetic model, the pseudo second-order kinetic model and intra-particle diffusion were utilized to evaluate the adsorption kinetics. The adsorption of Pb2+ was modelled with the Langmuir, Freundlich and D-R isotherms. The maximum Pb2+ adsorption capacities for B1, B2 and B3 were 85.47 mg g–1, 73.42 mg g–1 and 48.66 mg g–1, respectively.

scholarly journals Equilibrium and kinetics studies for the adsorption of Ni2+ and Fe3+ ions from aqueous solution by graphene oxide

2017 ◽  
Vol 19 (3) ◽  
pp. 120-129 ◽  
Author(s):  
Wojciech Konicki ◽  
Małgorzata Aleksandrzak ◽  
Ewa Mijowska
Keyword(s):  
Graphene Oxide ◽  
Kinetic Model ◽  
Metal Ion ◽  
Second Order ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Intraparticle Diffusion Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract In this study, the adsorption of Ni2+ and Fe3+ metal ions from aqueous solutions onto graphene oxide (GO) have been explored. The effects of various experimental factors such as pH of the solution, initial metal ion concentration and temperature were evaluated. The kinetic, equilibrium and thermodynamic studies were also investigated. The adsorption rate data were analyzed using the pseudo-first-order kinetic model, the pseudo-second-order kinetic model and the intraparticle diffusion model. Kinetic studies indicate that the adsorption of both ions follows the pseudo-second-order kinetics. The isotherms of adsorption data were analyzed by adsorption isotherm models such as Langmuir and Freundlich. Equilibrium data fitted well with the Langmuir model. The maximum adsorption capacities of Ni2+ and Fe3+ onto GO were 35.6 and 27.3 mg g−1, respectively. In addition, various thermodynamic parameters, such as enthalpy (ΔHO), entropy (ΔSO) and Gibbs free energy (ΔGO), were calculated.

scholarly journals Removal of Nickel from Aqueous Solutions by Natural Bentonites from Slovakia

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 282
Author(s):  
Matej Šuránek ◽  
Zuzana Melichová ◽  
Valéria Kureková ◽  
Ljiljana Kljajević ◽  
Snežana Nenadović
Keyword(s):  
Kinetic Model ◽  
Gibbs Energy ◽  
Adsorption Process ◽  
Effect Of Temperature ◽  
Standard Entropy ◽  
Order Kinetic ◽  
Processing Conditions ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, the removal of nickel (Ni(II)) by adsorption from synthetically prepared solutions using natural bentonites (Lieskovec (L), Hliník nad Hronom (S), Jelšový Potok (JP), and Stará Kremnička (SK)) was investigated. All experiments were carried out under batch processing conditions, with the concentration of Ni(II), temperature, and time as the variables. The adsorption process was fast, approaching equilibrium within 30 min. The Langmuir maximum adsorption capacities of the four bentonite samples used were found to be 8.41, 12.24, 21.79, and 21.93 mg g–1, respectively. The results best fitted the pseudo-second-order kinetic model, with constant rates in a range of 0.0948–0.3153 g mg–1 min. The effect of temperature was investigated at temperatures of 20, 30, and 40 °C. Thermodynamic parameters, including standard enthalpy (ΔH0), Gibbs energy (ΔG0), and standard entropy (ΔS0), were calculated. The adsorption of Ni(II) by bentonite samples was an endothermic and spontaneous process. These results indicated that, of the bentonite samples used, the natural bentonites from JP and SK were most suitable for the removal of nickel from synthetically prepared solutions.

scholarly journals Efficient Removal 17-Estradiol by Graphene-Like Magnetic Sawdust Biochar: Preparation Condition and Adsorption Mechanism

2020 ◽  
Vol 17 (22) ◽  
pp. 8377
Author(s):  
Yahui Zhou ◽  
Shaobo Liu ◽  
Yunguo Liu ◽  
Xiaofei Tan ◽  
Ni Liu ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
First Order ◽  
Micropore Filling ◽  
Order Kinetic Model ◽  
Pseudo First Order

The occurrence of environmental endocrine disrupting chemicals (EDCs) in aquatic environments has caused extensive concern. Graphene-like magnetic sawdust biochar was synthesized using potassium ferrate (K2FeO4) to make activated sawdust biochar and applied for the removal of 17-estradiol (E2). The characterization showed that the surface morphology of five graphene-like magnetic sawdust biochars prepared with different preparation conditions were quite different. The specific surface area and pore structure increased with the increment of K2FeO4 addition. The results have shown that graphene-like magnetic sawdust biochar (1:1/900 °C) had the best removal on E2. The experimental results indicated that pseudo-first-order kinetic model and the Langmuir model could describe the adsorption process well, in which the equilibrium adsorption capacity (qe,1) of 1:1/900 °C were 59.18 mg·g−1 obtained from pseudo-first-order kinetic model and the maximum adsorption capacity (qmax) of 1:1/900 °C were 133.45 mg·g−1 obtained from Langmuir model at 298K. At the same time, lower temperatures, the presence of humic acid (HA), and the presence of NaCl could be regulated to change the adsorption reaction in order to remove E2. Adsorption capacity was decreased with the increase of solution pH because pH value not only changed the surface charge of graphene-like magnetic sawdust biochar, but also affected the E2 in the water. The possible adsorption mechanism for E2 adsorption on graphene-like magnetic sawdust biochar was multifaceted, involving chemical adsorption and physical absorption, such as H-bonding, π-π interactions, micropore filling effects, and electrostatic interaction. To sum up, graphene-like magnetic sawdust biochar was found to be a promising absorbent for E2 removal from water.

Kinetics of Reductive Dechlorination of DDT in Soil with Zero-Valent Iron

2011 ◽  
Vol 295-297 ◽  
pp. 1236-1239
Author(s):  
Yin Hai Lang ◽  
Min Jie Wang ◽  
Nan Nan Wang
Keyword(s):  
Kinetic Model ◽  
Reductive Dechlorination ◽  
Reaction Rate ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
First Order ◽  
Reaction Rate Constants ◽  
Order Kinetic Model ◽  
Pseudo First Order ◽  
Kinetics Of

In this study, reductive dechlorination of DDT compounds by zero-valent iron in Jiangxi red soil was investigated. DDT compounds were effectively dechlorinated by zero-valent iron. The pseudo-first-order kinetic model for 2,4¢-DDT and 4,4¢-DDT reduction with zero-valent iron was proposed. The reaction rate constants for 2,4¢-DDT and 4,4¢-DDT were 1.19´10-2(min-1) and 1.44´10-2(min-1), respectively. The dechlorination of 2,4¢-DDT and 4,4¢-DDT were mainly affected by the specific surface area of iron. The data from the variable-pH experiments (between 3.6 and 8.8) suggested that pH does not play a role in the rate-determination step.

Optimization of lead (II) biosorption in an aqueous solution using chemically modified aerobic digested sludge

2011 ◽  
Vol 63 (1) ◽  
pp. 129-135 ◽  
Author(s):  
R. Darvishi Cheshmeh Soltani ◽  
A. Rezaee ◽  
Gh Shams Khorramabadi ◽  
K. Yaghmaeian
Keyword(s):  
Kinetic Model ◽  
Metal Ion ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Municipal Wastewater Treatment ◽  
Digested Sludge ◽  
Biosorption Capacity ◽  
Order Kinetic Model

Biosorption of Pb(II) by using digested sludge obtained from a municipal wastewater treatment plant in Tehran was examined. The aims of this investigation were biosorption of Pb(II) ions onto chemically treated digested sludge with hydrogen peroxide (H2O2) solution and determination of kinetic and isotherm of biosorption. Biosorption capacity of two types of sludge (treated and untreated) for biosorption of Pb(II) ions was investigated as function of initial Pb(II) concentration and pH using batch biosorption systems. The equilibrium biosorption capacity increased with increasing of initial metal ion concentrations and pH for both of digested sludge. The pseudo-second order kinetic model was found to be slightly suitable than the pseudo-first order kinetic model to correlate the experimental data for two types of digested sludge (R2>0.9). Regarding the applicability of the isotherm models, the freundlich model was found to be suitable than the other isotherm models. According to obtained qmax from Langmuir isotherm, biosorption of Pb(II) by H2O2 treated digested sludge was found to perform better than untreated digested sludge. The maximum biosorption capacity was given 185.19 and 144.93 mgg−1 for H2O2 treated and untreated digested sludge, respectively. Also, the constant of energy (B) between the Pb(II) ions and the adsorbent surface, calculated using BET isotherm model, obtained 5401 and 3401 for H2O2 treated and untreated digested sludge, respectively. These results indicate the usefulness of H2O2 treated digested sludge as a biosorbent for Pb(II) biosorption.

scholarly journals Studies of adsorption thermodynamics and kinetics of Cr(III) and Ni(II) removal by polyacrylamide

2012 ◽  
Vol 77 (3) ◽  
pp. 393-405 ◽  
Author(s):  
Zavvar Mousavi ◽  
Abdorrahman Hosseinifar ◽  
Vahdat Jahed
Keyword(s):  
Kinetic Model ◽  
Metal Ions ◽  
Correlation Coefficients ◽  
Second Order ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data

Polyacrylamide (PAA), as an adsorbent was investigated for the removal of Ni(II) and Cr(III) metal ions from their synthesized aqueous solutions. The different variables affecting the adsorption capacity of the adsorbent such as contact time, pH of the sorption medium, metal ions concentration and temperature of the solution were investigated on a batch sorption basis. The adsorption equilibrium data fitted best with the Langmuir isotherm model. The maximum adsorption capacities found to be 84.03 and 32.67 mg g-1 of the polyacrylamide for Cr(III) and Ni(II), respectively. Three kinetic models including the pseudo-first-order, pseudo-second-order and intraparticle diffusion equations were selected to follow the adsorption process. Kinetic parameters such as rate constants, equilibrium adsorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. It was indicated that the adsorption of both ions onto polyacrylamide could be described by the pseudo-second-order kinetic model. Different thermodynamic parameters such as ?H?, ?S? and ?G? have also been evaluated and it has been found that the sorption was feasible, spontaneous and exothermic.

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