scholarly journals The Immobilization Effect of Natural Mineral Materials on Cr(VI) Remediation in Water and Soil

2020 ◽  
Vol 17 (8) ◽  
pp. 2832 ◽  
Author(s):  
Dading Zhang ◽  
Yanqiu Xu ◽  
Xiaofei Li ◽  
Lina Wang ◽  
Xuwen He ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Freundlich Isotherm ◽  
Soil Toxicity ◽  
Adsorption Model ◽  
X Ray Diffraction ◽  
Isothermal Adsorption ◽  
Adsorption Models ◽  
Natural Mineral ◽  
Isotherm Adsorption ◽  
Molecular Bond

The effects of sepiolite, montmorillonite, and attapulgite on the removal and immobilization of Cr(VI) in water and soil were studied. X-ray diffraction (XRD) characterizations showed that the purities of these three mineral materials decreased in the following order: montmorillonite > attapulgite > sepiolite, and that their surface molecular bond types were similar. The adsorption potential of Cr(VI) in aqueous solutions of the three mineral materials was in the following order: sepiolite > attapulgite > montmorillonite. The adsorption mechanism for attapulgite was consistent with the Freundlich isotherm adsorption model, whereas that for montmorillonite was more consistent with the Langmuir model. Sepiolite had a good fitting effect for both isothermal adsorption models. For montmorillonite and attapulgite, a lower pH corresponded to a higher removal of Cr(VI). For sepiolite, however, the removal efficiency of Cr(VI) from an aqueous solution was the lowest at a pH of approximately 5.0. The results of the soil toxicity characteristic leaching procedure showed that, following the addition of 15% sepiolite, attapulgite, or montmorillonite to the contaminated soil, Cr(VI) concentrations in the leachates decreased by 16.8%, 18.9%, and 15.9%, respectively, and the total Cr concentrations in the leachates were reduced by 21.2%, 29.2%, and 17.6%. Of the three mineral materials, attapulgite demonstrated the highest Cr(VI) immobilization efficiency in soil. This study emphasizes the effect of attapulgite on the immobilization of Cr(VI) in soil and aqueous solutions, thus providing a theoretical basis for the potential application of natural mineral material remediation of Cr(VI)-contaminated aqueous solutions and soils.

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 Kinetika Adsorpsi Zat Warna Metilen Biru Oleh Karbon Aktif Dari Kulit Kemiri (Aleurites moluccana (L) Willd)

2018 ◽  
Vol 6 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Jola Latupeirissa ◽  
Matheis F.J.D.P. Tanasale ◽  
Sigit Hardianto Musa
Keyword(s):  
Methylene Blue ◽  
Active Carbon ◽  
Freundlich Isotherm ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
A Value ◽  
Before And After ◽  
Hazelnut Shell ◽  
Isotherm Adsorption ◽  
Aleurites Moluccana

The adsorption of methylene blue dye by active carbon of hazelnut shell has been done. Through acquired active carbon composing process, where is the hazelnut shell at entry into furnace on temperature 350   for 2 hour, afterwards is cooled and at sieves by sieve 100 mesh. Then by the calsination process in furnace with temperature 450   one was streamed to gas N2 four 2 hours then characterized by X-ray diffraction (XRD) for carbon before activation. The next activated with KOH solution with a concentration 0f 50  four 5 hour, then dried in an ovenat 120℃ for 1 hour and thencharacterized. Weight of the solidacidity before and after activation consecutive (5.3848 x 10-3 dan 42.1554x 10-3) mol g-1. Isotherm adsorption of methylene blue dyes on active carbon  was following the Freundlich isotherm. Adsorption kinetics of methylene blue dyes on active carbon in various concentration of hazelnut shell was controlled with temperature variety at 25  and 30 . The result showed that energy activation was kJ mol-1 and a value isg mg-1 menit-1. Adsorption mechanism of methylene blue dyes on active carbon at various concentration of hazelnut shell is chemical adsorption process.

Adsorption of Ammonium Nitrogen in Water by Rice Husk Charcoal: A Simulation Study

2013 ◽  
Vol 781-784 ◽  
pp. 2063-2066 ◽  
Author(s):  
Jian Gang Han ◽  
Gang Zhao ◽  
Long Shuai Dou ◽  
Yu Jing Jing ◽  
Yong Li Zhu
Keyword(s):  
Rice Husk ◽  
Freundlich Isotherm ◽  
Ammonium Nitrogen ◽  
Ammonium Ion ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Isotherm Adsorption ◽  
Polluted Sites

Rice husk charcoal, a kind of new environmentally friendly biomass materials, which is made from rice husk under anaerobic combustion at 300°C, has been increasingly applied to remedy some polluted sites. Rice husk charcoal was employed to investigate adsorption of ammonium in simulated waste water, using once balance method. It is found that ammonium nitrogen in water can be rapidly adsorbed by rice husk charcoal in 2 min with maximum sorption capacity of 2.6 mg/g (Langmuir isotherm adsorption model). The n value of 1.2 in Freundlich isotherm model indicates that the absorbent is very suitable for rapid removal of ammonium from water. In addition, quasi-second order kinetic equation is well suited to describe ammonium absorption with time (P<0.01). The adsorption mechanism is supposed that rice husk charcoal firstly imbibes in water and much swells, and then ammonium ion diffuses into the micro pore structure and redistributes upon a steady state.

scholarly journals Removal of Zinc from Aqueous Solutions Using Lamellar Double Hydroxide Materials Impregnated with Cyanex 272: Characterization and Sorption Studies

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1263 ◽  
Author(s):  
Nacera Boudaoud ◽  
Hafida Miloudi ◽  
Djamila Bouazza ◽  
Mehdi Adjdir ◽  
Abdelkader Tayeb ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
X Ray Diffraction ◽  
Cyanex 272 ◽  
Removal Of Heavy Metals ◽  
Equilibrium Data ◽  
Double Hydroxide

Removal of heavy metals from wastewater is mandatory in order to avoid water pollution of natural reservoirs. In the present study, layered double hydroxide (LDH) materials were evaluated for removal of zinc from aqueous solutions. Materials thus prepared were impregnated with cyanex 272 using the dry method. These materials were characterized through X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermal analysis. Batch shaking adsorption experiments were performed in order to examine contact time and extraction capacity in the removal process. Results showed that the equilibrium time of Zn (II) extraction is about 4 h for Mg2Al-CO3 and Mg2Al-CO3-cyanex 272, 6 h for Zn2Al-CO3, and 24 h for Zn2Al-CO3-cyanex 272. The experimental equilibrium data were tested for Langmuir, and Freundlich isotherm models. Correlation coefficients indicate that experimental results are in a good agreement with Langmuir’s model for zinc ions. Pseudo-first, second-order, Elovich, and intraparticular kinetic models were used to describe kinetic data. It was determined that removal of Zn2+ was well-fitted by a second-order reaction kinetic. A maximum capacity of 280 mg/g was obtained by Zn2Al-CO3-cyanex 272.

scholarly journals Efficient trapping of cesium ions in water by titanate nanosheets: experimental and theoretical studies

2021 ◽  
Author(s):  
Luyao Lin ◽  
Ye Li ◽  
Jie Wan ◽  
Cong Liu ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
High Efficiency ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Adsorption Model ◽  
Cesium Ions ◽  
Isotherm Adsorption ◽  
Best Fitting ◽  
Pseudo Second Order

Abstract In recent years, TNS has attracted wide attention because of its simplicity in synthesis and high efficiency in ion exchange. The adsorption of cesium ions in aqueous solution by TNS was investigated in this stud. Results show that the removal rate of Cs (I) is about 88% when pH = 5.00 ± 0.05, C0 = 10 ppm and CTNS = 0.1 g/L. The adsorption equilibrium is reached in about 20 minutes and best fits pseudo-second order model, R2 = 0.9998; Compared with the Freundlich isotherm adsorption model and Temkin model, the Langmuir model has the best fitting effect, R2 = 0.9903. The fitting results show the maximum adsorption capacity of TNS for Cs (I) is 200.00 mg/g. The main adsorption mechanism of TNS to cesium ion is ion exchange. Therefore, TNS can be used as a potential adsorbent for effectively adsorbing Cs-containing wastewater.

scholarly journals Fabrication of nano zero valent iron/biopolymer composite with antibacterial properties for simultaneous removal of nitrate and humic acid: Kinetics and isotherm studies

2021 ◽  
Author(s):  
Nazanin Zahra Pourbaghaei ◽  
Mansoor Anbia ◽  
Fatemeh Rahimi
Keyword(s):  
Humic Acid ◽  
Aqueous Solutions ◽  
Desirability Function ◽  
Aqueous Media ◽  
Antibacterial Properties ◽  
Freundlich Isotherm ◽  
Zerovalent Iron ◽  
Simultaneous Removal ◽  
High Antibacterial Activity ◽  
Isotherm Adsorption

Abstract This investigation compared the adsorption behavior of humic acid (HA) on cellulose, chitosan and nano zerovalent iron/chitosan (nZVI/chitosan). Results show that nZVI/chitosan is very effective in the adsorption of HA from aqueous media. The feasibility of using nZVI/chitosan as an adsorbent for the simultaneous removal of nitrate and HA from aqueous media was also studied. Structural analyses of the samples were identified by TEM, FT-IR, EDX, XRD and N2 isotherms. The effects of pH, amount of composite, nitrate concentration, HA concentration and contact time and their interactions on responses were explored by central composite design (CCD) and response surface methodology (RSM). The optimal conditions of pH (5.5), adsorbent amount (0.098 g), reaction time (27 min) and initial concentrations (110 mg/L for nitrate and 30 mg/L for HA) were obtained from desirability function. The adsorption properties of the resulting nanocomposite toward nitrate and HA were investigated through kinetic and isotherm adsorption studies. The adsorption kinetics was found to fit the pseudo-second order model. The results obtained indicate that nitrate uptake fitted well with the Langmuir model while the Freundlich isotherm was the best model for describing the multilayer uptake of HA from aqueous solutions. Moreover, nZVI/chitosan nanocomposite illustrates a very high antibacterial activity against pathogen bacteria strains such as Staphylococcus aureus ATCC 25935, ATCC 25923, and Pseudomonas aeruginosa ATCC 27853. The findings reported in this investigation highlight the potential of using nZVI/chitosan as a promising adsorbent for the simultaneous removal of nitrate and HA from aqueous solutions.

scholarly journals Adsorption of Congo Red from Aqueous Solutions by Porous Soybean Curd Xerogels

2018 ◽  
Vol 20 (3) ◽  
pp. 95-102 ◽  
Author(s):  
Zhao Zhang ◽  
Yanhui Li ◽  
Qiuju Du ◽  
Qi Li
Keyword(s):  
Aqueous Solutions ◽  
Congo Red ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Drying Method ◽  
Solution Ph ◽  
Soybean Curd ◽  
High Quality Protein ◽  
Isotherm Adsorption ◽  
Order Kinetic Model

Abstract Soybean curd is a very popular food containing high-quality protein, polyunsaturated fats, vitamins, minerals and other nutrients. This study aims to prepare porous soybean curd xerogels via a vacuum freeze drying method and uses them as adsorbents to remove congo red from aqueous solutions. The morphology and functional groups of the soybean curd xerogels were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. The adsorption properties of congo red onto the soybean curd xerogels were carried out through investigating the infl uencing experimental parameters such as the drying method, solution pH, adsorbent dose, contact time and temperature. The results showed that the adsorption isotherm data were fitted well to the Freundlich isotherm. Adsorption kinetics of congo red onto the soybean curd followed the pseudo-second-order kinetic model. The thermodynamic parameters, such as ΔG0, ΔH0 and ΔS0, were also determined.

scholarly journals The performance of calcined serpentine to simultaneously remove fluoride, iron and manganese

2021 ◽  
Author(s):  
Xilin Li ◽  
Qi Wang ◽  
Ling Liu ◽  
Siyuan Liu
Keyword(s):  
Kinetic Equation ◽  
Metal Salt ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Manganese Removal ◽  
Isotherm Adsorption ◽  
High Fluoride ◽  
Iron And Manganese ◽  
Order Kinetic Equation

Abstract To solve the problem of high fluoride, iron and manganese concentrations in groundwater, serpentine (Srp) was modified by metal salt impregnation, acid-base activation and calcination, and the effects of these three modifications on removal performance of Srp were compared. Specifically, the effects of the calcined serpentine (Csrp) dose, reaction time, pH, and temperature on the removal performance of F−, Fe2+ and Mn2+ on Csrp were analysed. An isothermal adsorption model and adsorption kinetic equation were established and confirmed through SEM, EDS, XRD and FTIR spectroscopy to analyse the mechanism of removing F−, Fe2+ and Mn2+ by Csrp. The results show that when 3 g/L Csrp was used to treat water samples with 5 mg/L F−, 20 mg/L Fe2+, and 5 mg/L Mn2+ (pH of 6, reaction temperature of 35 °C, and time of 150 min), the removal rates of F−, Fe2+, and Mn2+ were 94.3%, 99.0%, 98.9%, respectively. The adsorption of F−, Fe2+ and Mn2+ on Csrp follows the quasi-second-order kinetic equation and Langmuir isotherm adsorption model. After 5 cycles of regeneration of Csrp, Csrp can still maintain good properties of fluoride,iron and manganese removal.

scholarly journals Preparation and sorption property study of Fe3O4/Al2O3/ZrO2 composite for the removal of cadmium, lead and chromium ions from aqueous solutions

2020 ◽  
Vol 34 (1) ◽  
pp. 105-121
Author(s):  
Fekadu Tsegaye ◽  
Abi M. Taddesse ◽  
Endale Teju ◽  
Minbale Aschalew
Keyword(s):  
Aqueous Solutions ◽  
Mixed Oxides ◽  
Sorption Property ◽  
Freundlich Isotherm ◽  
Experimental Results ◽  
Point Of Zero Charge ◽  
Precipitation Method ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray

Fe-Al-Zr ternary mixed oxides composite was synthesized via co-precipitation method for the removal Pb(II), Cd(II) and Cr(VI) ions from aqueous solutions. The as-synthesized materials were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscope hyphenated with energy dispersive X-ray diffraction (SEM-EDX) and Fourier transform infrared (FTIR) techniques. The pH at the point of zero charge (pHpzc) of the sorbent and effect of ionic strength on sorption were also determined. The batch tests were conducted to optimize the various sorption parameters such as pH, adsorbent dose, contact time, speed of agitation and initial metal concentration. The experimental results showed that the adsorbed amounts of Pb(II), Cd(II) and Cr(VI) tend to decrease with increase in pH. Freundlich isotherm model fits better the equilibrium data for the adsorbent. Kinetic data correlated better with both pseudo first order and pseudo second order kinetic models. The spontaneous nature of the adsorption process was also confirmed from thermodynamic grounds. The nanosized adsorbent exhibited an adsorption efficiency of 96.65%, 96.55% and 97.2% for Cd(II), Cr(VI) and Pb(II), respectively, at optimum condition. Experimental results showed that the nanocomposite was effective for the removal of the title heavy metals from aqueous solution.   Bull. Chem. Soc. Ethiop. 2020, 34(1), 105-121. DOI: https://dx.doi.org/10.4314/bcse.v34i1.10

Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

2010 ◽  
Vol 61 (5) ◽  
pp. 1235-1243 ◽  
Author(s):  
Y. F. He ◽  
F. R. Li ◽  
R. M. Wang ◽  
F. Y. Li ◽  
Y. Wang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Particle Size Analysis ◽  
Lead Ions ◽  
Size Analysis ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb2 + ] = 500 mg L−1, [XBent] = 2 g L−1, pH = 5.0; oscillating 60 min under 200 rpm at 25°C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions—XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

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