Removal of fluoride from aqueous solution by adsorption onto Kanuma mud

2010 ◽  
Vol 62 (8) ◽  
pp. 1888-1897 ◽  
Author(s):  
Nan Chen ◽  
Zhenya Zhang ◽  
Chuanping Feng ◽  
Miao Li ◽  
Rongzhi Chen ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Fluoride Concentration ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Solution Ph ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Solid Liquid Interface ◽  
Solid Liquid

Kanuma mud, a geomaterial, is used as an adsorbent for the removal of fluoride from water. The influences of contact time, solution pH, adsorbent dosage, initial fluoride concentration and co-existing ions were investigated by batch equilibration studies. The rate of adsorption was rapid with equilibrium being attained after about 2 h, and the maximum removal of fluoride was obtained at pH 5.0–8.0. The Freundlich isotherm model was found to represent the measured adsorption data well. The negative value of the thermodynamic parameter ΔG suggests the adsorption of fluoride by Kanuma mud was spontaneous, the endothermic nature of adsorption was confirmed by the positive ΔH value. The negative ΔS value for adsorbent denoted decreased randomness at the solid/liquid interface. The adsorption process using Kanuma mud followed the pseudo-second-order kinetic model. Fluoride uptake by the Kanuma mud was a complex process and intra-particle diffusion played a major role in the adsorption process. It was found that adsorbed fluoride could be easily desorbed by washing the adsorbent with a solution of pH 12. This indicates the material could be easily recycled.

scholarly journals The Removal of Uranium and Thorium from Their Aqueous Solutions by 8-Hydroxyquinoline Immobilized Bentonite

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Langmuir Isotherm ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.

scholarly journals Construction of Novel Polymerizable Ionic Liquid Microemulsions and the In Situ Synthesis of Poly(Ionic Liquid) Adsorbents

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 454 ◽  
Author(s):  
Aili Wang ◽  
Shuhui Li ◽  
Hou Chen ◽  
Ying Liu ◽  
Xiong Peng
Keyword(s):  
Ionic Liquid ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
In Situ Synthesis ◽  
Scattering Data ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Poly Ionic Liquid

This paper reports the successful construction of novel polymerizable ionic liquid microemulsions and the in situ synthesis of poly(ionic liquid) adsorbents for the removal of Zn2+ from aqueous solution. Dynamic light-scattering data were used to confirm the polymerization media and to illustrate the effect of the crosslinker dosage on the droplet size of the microemulsion. FTIR and thermal analysis were employed to confirm the successful preparation of the designed polymers and characterize their thermostability and glass transition-temperature value. The optimization of the adsorption process indicates that the initial concentration of Zn2+, pH, adsorbent dosage and contact time affected the adsorption performance of poly(ionic liquid)s toward Zn2+. Furthermore, our research revealed that the adsorption process can be effectively described by the pseudo second-order kinetic model and the Freundlich isotherm model.

scholarly journals Kinetic and Thermodynamic Study of Phenol Removal from Water Using Activated Carbon Synthesizes from Avocado Kernel Seed

2016 ◽  
Vol 54 ◽  
pp. 42-57 ◽  
Author(s):  
Kassahun Dejene ◽  
Khalid Siraj ◽  
Shimeles Addisu Kitte
Keyword(s):  
Activated Carbon ◽  
Adsorption Process ◽  
Kinetic Studies ◽  
Persea Americana ◽  
Phenol Removal ◽  
Order Kinetic ◽  
Solution Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Kinetic And Thermodynamic Study

This study was aimed for removal of phenol from water using activated carbon synthesize from avocado kernel seeds by adsorption onto it. For adsorption process cleaned and washed avocado kernel seeds (Persea americana) were dried at 100°C in an oven overnight and carbonization was carried out by increasing the furnace temperature at a rate of 5 °C/min to a final temperature of 800 °C for 160 minutes. Then, the activated carbon was powdered and sieved, washed with distilled water until the solution pH reached 7.0. Optimization of activated carbon was performed through effects of solution pH, contact time; initial phenol concentration and temperature of the adsorption. The kinetic studies of the adsorption process were achieved by verifying various models and the data obtained was best fitted to pseudo-second-order kinetic model. The isotherms models were analyzed with Langmuir, Freundlich and Temkin to validate the adsorption process. It was found that Langmuir model was best fitted to the obtained result for both adsorbents.

scholarly journals Adsorptive removal of direct red 80 and methylene blue from aqueous solution by potato peels: a comparison of anionic and cationic dyes

2021 ◽  
Author(s):  
Khawla Ben Jeddou ◽  
Fatma Bouaziz ◽  
Fadia Ben Taheur ◽  
Oumèma Nouri-Ellouz ◽  
Raoudha Ellouz-Ghorbel ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Fourier Transforms ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Solution Ph ◽  
Model Calculations ◽  
Pseudo Second Order ◽  
Potato Peels

Abstract Adsorption of direct red 80 (DR 80) and methylene blue (MB) from aqueous solutions on potato peels (PP) has been compared. The use of peels in decontamination technology is very promising given the near zero-cost for the synthesis of those adsorbents. The selected potato peels were first analyzed by scanning using electron microscopy (SEM) and Fourier transforms infra red spectroscopy (FTIR). Then the adsorption behavior was studied in a batch system. The adsorption process is affected by various parameters such as the solution pH (2–11), the initial concentration of the dye (20, 50, 100, 150 and 200 mg L−1), the adsorbent dose (0.1%–3%), the temperature (303.16 K, 313.16 K, and 323.16 K), agitation (up to 250 rpm), as well as the contact time. Adsorption isotherms of the studied dye on the adsorbent were determined and compared with the Langmiur, Freundlich and Temkin adsorption models. The results show that the data was most similar to the Freundlich isotherm (R2 = 0.99). The maximum adsorption capacities (Qmax) of MB and DR 80 by the PP at temperatures 303.16 K, 313.16 K and 323.16 K were found to be approximately 97.08 mg g−1; 45.87 mg g−1; 61.35 mg g−1 and 27.778 mg g−1; 45.45 mg g−1; and 32.258 mg g−1. The kinetic data was compared to the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. This revealed that adsorption of methylene blue onto PP abided mostly to the pseudo-second-order kinetic model. Calculations of various thermodynamic parameters such as enthalpy change (ΔH), entropy change (ΔS), and free energy change (ΔG) display the endothermic and spontaneous nature of the adsorption process.

Isothermal, Kinetic, and Thermodynamic Studies of Graphene Oxide Adsorption on Silk

2021 ◽  
Vol 8 (5) ◽  
pp. 18-29
Author(s):  
Arobindo Chatterjee ◽  
Vinit Kumar Jain
Keyword(s):  
Graphene Oxide ◽  
Freundlich Isotherm ◽  
Sorption Process ◽  
Order Kinetic ◽  
Solution Ph ◽  
Thermodynamic Studies ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Isothermal Kinetic ◽  
Kinetics Of

The properties of graphene enriched silk depend on the amount of graphene oxide (GO) adsorption on silk. GO dipping parameters include the GO solution pH, initial GO concentration, dipping time and temperature, and the type of substrate. The effects of GO dipping parameters on the sorption process are studied to achieve the maximum GO adsorption on the silk surface for the preparation of an economical graphene/silk-based textile product. In addition, equilibrium isotherms, kinetics, and thermodynamics of GO adsorption on the silk surface in a batch sorption process are examined to understand the adsorption mechanism. The Freundlich isotherm best describes the adsorption of GO onto the silk. A pseudo-second order kinetic model best describes the kinetics of GO adsorption. Thermodynamic studies reveal that GO adsorption is spontaneous and exothermic.

scholarly journals Sawdust for the Removal of Heavy Metals from Water: A Review

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4318
Author(s):  
Elie Meez ◽  
Abbas Rahdar ◽  
George Z. Kyzas
Keyword(s):  
Heavy Metals ◽  
Adsorption Mechanism ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Suitable Material ◽  
Removal Of Heavy Metals ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
And Control ◽  
Environmental Agencies

The threat of the accumulation of heavy metals in wastewater is increasing, due to their abilities to inflict damage to human health, especially in the past decade. The world’s environmental agencies are trying to issue several regulations that allow the management and control of random disposals of heavy metals. Scientific studies have heavily focused on finding suitable materials and techniques for the purification of wastewaters, but most solutions have been rejected due to cost-related issues. Several potential materials for this objective have been found and have been compared to determine the most suitable material for the purification process. Sawdust, among all the materials investigated, shows high potential and very promising results. Sawdust has been shown to have a good structure suitable for water purification processes. Parameters affecting the adsorption mechanism of heavy metals into sawdust have been studied and it has been shown that pH, contact time and several other parameters could play a major role in improving the adsorption process. The adsorption was found to follow the Langmuir or Freundlich isotherm and a pseudo second-order kinetic model, meaning that the type of adsorption was a chemisorption. Sawdust has major advantages to be considered and is one of the most promising materials to solve the wastewater problem.

Phosphorus removal from aqueous solution using a novel granular material developed from building waste

2017 ◽  
Vol 75 (6) ◽  
pp. 1500-1511 ◽  
Author(s):  
Shengjiong Yang ◽  
Pengkang Jin ◽  
Xiaochang C. Wang ◽  
Qionghua Zhang ◽  
Xiaotian Chen
Keyword(s):  
Granular Material ◽  
Chemical Precipitation ◽  
Phosphate Removal ◽  
Precipitation Process ◽  
Order Kinetic ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Removal Capacity ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, a granular material (GM) developed from building waste was used for phosphate removal from phosphorus-containing wastewater. Batch experiments were executed to investigate the phosphate removal capacity of this material. The mechanism of removal proved to be a chemical precipitation process. The characteristics of the material and resulting precipitates, the kinetics of the precipitation and Ca2+ liberation processes, and the effects of dosage and pH were investigated. The phosphate precipitation and Ca2+ liberation processes were both well described by a pseudo-second-order kinetic model. A maximum precipitation capacity of 0.51 ± 0.06 mg g−1 and a liberation capacity of 6.79 ± 0.77 mg g−1 were measured under the experimental conditions. The processes reached equilibrium in 60 min. The initial solution pH strongly affected phosphate removal under extreme conditions (pH <4 and pH >10). The precipitates comprised hydroxyapatite and brushite. This novel GM can be considered a promising material for phosphate removal from wastewater.

Effects of tall fescue biochar on the adsorption behavior of desethyl-atrazine in different types of soil

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3575-3595
Author(s):  
Wanting Li ◽  
Ruifeng Shan ◽  
Yuna Fan ◽  
Xiaoyin Sun
Keyword(s):  
Tall Fescue ◽  
Adsorption Process ◽  
Exothermic Reaction ◽  
Equilibrium Concentration ◽  
Black Soil ◽  
Adsorption Behavior ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.

scholarly journals Preparation of bio-absorbents by modifying licorice residue via chemical methods and removal of copper ions from wastewater

2021 ◽  
Author(s):  
Xiaochun Yin ◽  
Nadi Zhang ◽  
Meixia Du ◽  
Hai Zhu ◽  
Ting Ke
Keyword(s):  
Adsorption Capacity ◽  
Copper Ions ◽  
Order Kinetic ◽  
Solution Ph ◽  
Chemical Methods ◽  
Simple Strategy ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Surface Active ◽  
Adsorption Desorption

Abstract In this paper, a series of bio-adsorbents (LR-NaOH, LR-Na2CO3 and LR-CA) were successfully prepared by modifying Licorice Residue with NaOH, Na2CO3 and citric acid, which were used as the adsorbents to remove Cu2+ from wastewater. The morphology and structure of bio-adsorbents were characterized by Fourier Transform Infrared, SEM, TG and XRD. Using static adsorption experiments, the effects of the adsorbent dosage, the solution pH, the adsorption time, and the initial Cu2+ concentration on the adsorption performance of the adsorbents were investigated. The results showed that the adsorption process of Cu2+ by the bio-adsorbents can be described by pseudo-second order kinetic model and the Langmuir model. The surface structure of the LR-NaOH, LR-Na2CO3 and LR-CA changed obviously, and the surface-active groups increased. The adsorption capacity of raw LR was 21.56 mg/g, LR-NaOH, LR- Na2CO3 significantly enhanced this value up to 43.65 mg/g, 43.55 mg/g, respectively. After four adsorption-desorption processes, the adsorption capacity of LR-NaOH also maintained about 73%. Therefore, LR-NaOH would be a promising adsorbent for removing Cu2+ from wastewater, and the simple strategy towards preparation of adsorbent from the waste residue can be as a potential approach using in the water treatment.

Mathematical Modelling for Copper and Lead Adsorption on Coffee Grounds

2017 ◽  
Author(s):  
Jurgita Seniūnaitė ◽  
Rasa Vaiškūnaitė ◽  
Kristina Bazienė
Keyword(s):  
Heavy Metals ◽  
Mathematical Modelling ◽  
Adsorption Kinetics ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Sorption Process ◽  
Second Order ◽  
Order Kinetic ◽  
Coffee Grounds ◽  
Pseudo Second Order

Research studies on the adsorption kinetics are conducted in order to determine the absorption time of heavy metals on coffee grounds from liquid. The models of adsorption kinetics and adsorption diffusion are based on mathe-matical models (Cho et al. 2005). The adsorption kinetics can provide information on the mechanisms occurring be-tween adsorbates and adsorbents and give an understanding of the adsorption process. In the mathematical modelling of processes, Lagergren’s pseudo-first- and pseudo-second-order kinetics and the intra-particle diffusion models are usually applied. The mathematical modelling has shown that the kinetics of the adsorption process of heavy metals (copper (Cu) and lead (Pb)) is more appropriately described by the Lagergren’s pseudo-second-order kinetic model. The kinetic constants (k2Cu = 0.117; k2Pb = 0,037 min−1) and the sorption process speed (k2qeCu = 0.0058–0.4975; k2qePb = 0.021–0.1661 mg/g per min) were calculated. After completing the mathematical modelling it was calculated that the Langmuir isotherm better reflects the sorption processes of copper (Cu) (R2 = 0.950), whilst the Freundlich isotherm – the sorption processes of lead (Pb) (R2 = 0.925). The difference between the mathematically modelled and experimen-tally obtained sorption capacities for removal of heavy metals on coffee grounds from aqueous solutions is 0.059–0.164 mg/l for copper and 0.004–0.285 mg/l for lead. Residual concentrations of metals in a solution showed difference of 1.01 and 0.96 mg/l, respectively.

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