scholarly journals Removal of Cr(VI) from wastewater by silver-loaded natural clinoptilolite

2021 ◽  
Vol 280 ◽  
pp. 06008
Author(s):  
Marinela Panayotova
Keyword(s):  
Order Kinetic ◽  
Water And Wastewater Treatment ◽  
Rate Limiting Step ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Water And Wastewater ◽  
Natural Clinoptilolite ◽  
Modified Clinoptilolite ◽  
Rate Limiting ◽  
Order Kinetic Equation

Presence of hexavalent chromium, Cr(VI), in water is an important environmental and human health problem. Natural zeolites are widely accepted as non-expensive adsorbents for sustainable remediation, however they are not effective in removing metals in anionic form. The paper presents study on use of silver (Ag) modified natural clinoptilolite to immobilize Cr(VI) ions from model and real neutral to slightly alkaline wastewater. Increasing the initial pollutant concentration increases the removed amount (80 % removal from model wastewater in 45 min at initial concentration of 30 mg Cr(VI)/L). The pseudo-second order kinetic equation best describes the Cr(VI) immobilization by the Ag-modified zeolite, which is indicative for the chemical nature of the rate-limiting step of the process. The data obtained are best fitted to the Freundlich adsorption isotherm. The Ag-modified clinoptilolite removes in 30 min over 80 % of Cr(VI), over 75 % of Cu(II) and over 70 % of Zn(II) that present simultaneously in an industrial wastewater. Due to its ability to remove Cr(VI) species, in combination with some heavy metal ions, some organic pollutants and exhibited antibacterial activity, silver loaded clinoptilolite seems to be a possible multifunctional reagent in the water and wastewater treatment and deserves further investigation.

Removal of Mg from spring water using natural clinoptilolite

Clay Minerals ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 81-92 ◽  
Author(s):  
S. Tomić ◽  
N. Rajić ◽  
J. Hrenović ◽  
D. Povrenović
Keyword(s):  
Ion Exchange ◽  
Kinetic Studies ◽  
Spring Water ◽  
Zeolite A ◽  
Zeolitic Tuff ◽  
Rate Limiting Step ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Natural Clinoptilolite ◽  
Rate Limiting

AbstractNatural zeolitic tuff from Brus (Serbia) consisting mostly of clinoptilolite (about 90%) has been investigated for the reduction of the Mg concentration in spring water. The sorption capacity of the zeolite is relatively low (about 2.5 mg Mg g-1for the initial concentration of 100 mg Mg dm-3). The zeolitic tuff removes Mg from water solutions by ion exchange, which has been demonstrated by energy dispersive X-ray analysis (EDS). The extent of ion exchange was influenced by the pH and the initial Mg concentration. Kinetic studies revealed that Lagergen's pseudo-second order model was followed. Intra-particle diffusion of Mg2+influenced the ion exchange, but it is not the rate-limiting step. Rather than having to dispose of the Mg-loaded (waste) zeolite, a possible application was tested. Addition to a wastewater with a low concentration of Mg showed that it could successfully make up for the lack of Mg micronutrient and, accordingly, enabled the growth of phosphate-accumulating bacteriaA. Junii, increasing the amount of phosphate removed from the wastewater.

scholarly journals Highly efficient removal of Sb(V) from water by franklinite-containing nano-FeZn composites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Huiqing Wu ◽  
Qingping Wu ◽  
Jumei Zhang ◽  
Qihui Gu ◽  
Weipeng Guo ◽  
...  
Keyword(s):  
Great Promise ◽  
Order Kinetic ◽  
Water And Wastewater Treatment ◽  
Cost Performance ◽  
Pentavalent Antimony ◽  
Adsorption Data ◽  
Reaction Column ◽  
Water And Wastewater ◽  
Weakly Magnetic ◽  
Order Kinetic Equation

AbstractThe existence of toxic and carcinogenic pentavalent antimony in water is a great safety problem. In order to remove antimony(V) from water, the purpose of this study was to prepare a novel graphene nano iron zinc (rGO/NZV-FeZn) photocatalyst via hydrothermal method followed by ultrasonication. Herein, weakly magnetic nano-Fe–Zn materials (NZV-FeZn, GACSP/NZV-FeZn, and rGO/NZV-FeZn) capable of rapid and efficient Sb(V) adsorption from water were prepared and characterised. In particular, rGO/NZV-FeZn was shown to comprise franklinite, Fe0, and graphite. Adsorption data were fitted by a quasi-second-order kinetic equation and Langmuir model, revealing that among these materials, NZV-FeZn exhibited the best Sb removal performance (543.9 mgSb gNZV-FeZn−1, R2 = 0.951). In a practical decontamination test, Sb removal efficiency of 99.38% was obtained for a reaction column filled with 3.5 g of rGO/NZV-FeZn. Column regenerability was tested at an initial concentration of 0.8111 mgSb L−1, and the treated water obtained after five consecutive runs complied with the GB5749-2006 requirement for Sb. rGO/NZV-FeZn was suggested to remove Sb(V) through adsorption-photocatalytic reduction and flocculation sedimentation mechanisms and, in view of its high cost performance, stability, and upscalable synthesis, was concluded to hold great promise for source water and wastewater treatment.

scholarly journals Evaluation of Pb (II) Removal from Water Using Sodium Alginate/Hydroxypropyl Cellulose Beads

2020 ◽  
Vol 148 ◽  
pp. 02002 ◽  
Author(s):  
Rodel Guerrero ◽  
Catherine Acibar ◽  
Christine Marie Alarde ◽  
Jane Maslog ◽  
Christine Joy Pacilan
Keyword(s):  
Adsorption Capacity ◽  
Sodium Alginate ◽  
Contact Time ◽  
Hydroxypropyl Cellulose ◽  
Order Kinetic ◽  
Hydrogel Beads ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Rate Limiting ◽  
Adsorption Kinetic Model

This study examined the removal of Pb2+ ions from aqueous solution with two different lead concentrations using a hydrogel-forming polymer based on hydroxypropyl cellulose (HPC) and sodium alginate (SA). The feasibility of the adsorption behavior of SA/HPC beads has been investigated with three varying ratios of 50:50, 75:25 and 100:0 under a stir condition. The adsorption experiments were done to determine the effects of contact time, lead concentration and SA-HPC ratio to the adsorption capacity of SA-HPC hydrogel beads. The results showed that the ratio 75:25 showed higher adsorption capacity compared to 100:0 and 50:50. It showcased 47.72 mg/g adsorption capacity and 95.45% adsorption percentage after three hours of contact time. The adsorption kinetic model indicated that the adsorption of Pb2+ ions onto the beads followed a pseudo-second order kinetic equation. This means that the adsorption mechanism shows a chemisorption process and its sole rate-limiting step is intraparticle diffusion.

scholarly journals Equilibrium, Kinetics and Thermodynamics of the Bleaching of Palm Oil Using Activated Nando Clay

2018 ◽  
pp. 1-13
Author(s):  
Nwabanne, Joseph T. ◽  
Onu, Chijioke E. ◽  
Nwankwoukwu, Okwudili C.
Keyword(s):  
Palm Oil ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Bleaching Efficiency ◽  
Rate Limiting Step ◽  
Equilibrium Data ◽  
Intra Particle Diffusion ◽  
Different Temperatures ◽  
Pseudo Second Order ◽  
Rate Limiting

The effectiveness of Nando clay in the bleaching of palm oil was studied in this work. The clay was prepared by activating it with hydrochloric acid. The bleaching was carried out at different temperatures, adsorbent dosage and particle sizes. The result suggests that increase in temperature and adsorbent dosage increases the bleaching efficiency while the increase in particle size decreases the bleaching efficiency. Both the pseudo-first-order and the pseudo-second-order kinetic models describe efficiently the experimental data of the bleaching process. Intra-particle diffusion though involved in the adsorptive bleaching mechanism, is not the sole rate-limiting step in the bleaching of palm oil with activated Nando clay. The equilibrium data were described better by Langmuir and Freundlich models. The enthalpy, entropy and activation energy were determined to be 6.127 KJ/mol, 3.982 KJ/mol and 15.281 KJ respectively. The free energy was found to vary between- 3.999 to- 3.760 KJ/mol. The result indicates that bleaching efficiency of up to 96% can be obtained with the activated clay as an adsorbent.

scholarly journals A High-Efficiency Approach for the Synthesis of N235-Impregnated Resins and the Application in Enhanced Adsorption and Separation of Vanadium(V)

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 358 ◽  
Author(s):  
Bo Chen ◽  
Shenxu Bao ◽  
Yimin Zhang ◽  
Ruwei Zheng
Keyword(s):  
Chemical Reaction ◽  
High Efficiency ◽  
Order Kinetic ◽  
Equilibrium Time ◽  
Rate Limiting Step ◽  
Reaction Constant ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Enhanced Adsorption ◽  
Rate Limiting

Trialkylamine (N235)-tributyl phosphate (TBP) impregnated resins (N-TIRs) were prepared, so as to evaluate the effects of the addition of TBP on the preparation and adsorption performance of N235-impregnated resins (NIRs). The results show that TBP can obviously increase the impregnation ratio and shorten the impregnation equilibrium time of the N-TIRs when compared to that of the NIRs (57.73% versus 36.95% and 5 min versus 240 min). It is confirmed that TBP can interact with N235 during the impregnation process, which shorten the adsorption equilibrium time and increases the adsorption capacity of the N-TIRs for V(V) when compared to that of the NIRs (6 h versus 10 h and 50.95 mg·g−1 versus 46.73 mg·g−1). The kinetics fitting results demonstrate that the adsorption of V(V) onto N-TIRs and NIRs all conform to pseudo-second order kinetic model and chemical reaction is the rate-limiting step of the whole adsorption process. In the meanwhile, the reaction constant (Ks) implies that the chemical reaction rate of V(V) with the impregnated extractants in N-TIRs is faster than that in NIRs. The N-TIRs present higher stability and selectivity than NIRs. This study manifests that the addition of a secondary reagent may be a potential and novel technique on the preparation of SIRs and the enhancement of adsorption and separation for ions.

scholarly journals Removal of copper from an electroplating industrial effluent using the native and modified spirogyra

2018 ◽  
Vol 78 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Nimra Ilyas ◽  
Sadia Ilyas ◽  
Sajjad-ur-Rahman ◽  
Sidra Yousaf ◽  
Aqsa Zia ◽  
...  
Keyword(s):  
Industrial Effluent ◽  
Order Kinetic ◽  
Sorption Data ◽  
Freundlich Model ◽  
First Order ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Rate Limiting

Abstract In the present study, biosorption behavior of a green filamentous alga, spirogyra in its native and modified states was investigated for copper removal from an electroplating industrial effluent. For this, the effluent containing 194 mg·L−1 Cu2+ in sulfate medium was contacted with both forms of spirogyra, under the parametric variations of effluent pH, adsorbent dosage, contact time, and sorption temperature. The study revealed spirogyra as a prominent candidate for removing contaminant metal cation; however, at the same condition, biosorption capacity of modified biomass in gel form was higher than the native spirogyra. At the optimized condition with 6 g sorbent dosage treated to 100 mL effluent for 30 min at pH 6.0 and temperature 20 °C, the maximum 82.8% and 96.4% copper could be adsorbed by the native and modified spirogyra, respectively. The batch sorption data using native biomass followed pseudo-first-order kinetic; exhibiting the multilayer sorption mechanism via surface diffusion could be defined by the Freundlich model. In contrast, the sulfuric acid treated modified spirogyra followed pseudo-second-order kinetics and intra particle diffusion as the rate-limiting step.

Synthesis and Characterization of Chitosan templated Mesoporous Silica: Efficient use of Mesoporous Silica in the removal of Cu(II) from Aqueous Solutions

2016 ◽  
Vol 4 (2) ◽  
pp. 105-112
Author(s):  
Lalchhing puii ◽  
◽  
Seung-Mok Lee ◽  
Diwakar Tiwari ◽  
◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Aqueous Solutions ◽  
Background Electrolyte ◽  
Second Order ◽  
Order Kinetic ◽  
Sorption Data ◽  
Column Reactor ◽  
Wide Ph Range ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order

A mesoporous silica was synthesized by annealing (3-Aminopropyl) triethoxysilane grafted chitosan at 800˚C. The mesoporous silica was characterized by the XRD (X-ray diffraction) analysis. The BET specific surface area and pore size of silica was found to be 178.42 m2/g and 4.13 nm. The mesoporous silica was then employed for the efficient remediation of aqueous solutions contaminated with Cu(II) under batch and column reactor operations. The mesoporous silica showed extremely high per cent removal of Cu(II) at wide pH range i.e., pH ~2.0 to 7.0. Relatively a fast uptake of Cu(II) was occurred and high percentage removal was obtained at initial concentrations studied from 1.0 to 15.0 mg/L. The equilibrium state sorption data were utilized for the Langmuir and Freundlich adsorption isotherm studies. Moreover, the effect of an increase in background electrolyte concentrations from 0.0001 to 0.1 mol/L NaNO3 was assessed for the uptake of Cu(II) by mesoporous silica. The equilibrium sorption was achieved within 240 min of contact and the kinetic data is best fitted to the pseudo-second-order and fractal like pseudo-second-order kinetic models. In addition, the mesoporous silica was used for dynamic studies under column reactor operations. The breakthrough curve was then used for the non-linear fitting of the Thomas equation and the loading capacity of the column for Cu(II) was estimated.

Adsorption Properties of Phenol and Aniline Removal by Poly Aluminium Chloride from the Aqueous Phase

2014 ◽  
Vol 955-959 ◽  
pp. 610-617
Author(s):  
Wang Bin Cheng ◽  
Jie Ding ◽  
Xian Shu Liu ◽  
Chun Miao Liu
Keyword(s):  
Aqueous Phase ◽  
Hydrogen Adsorption ◽  
Adsorption Properties ◽  
Aluminium Chloride ◽  
Order Kinetic ◽  
Potential Measurement ◽  
Phenol Adsorption ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Order Kinetic Equation

In this paper, poly aluminium chloride (PAC) was used to remove phenol and aniline from the aqueous phase .The adsorption properties of this process was investigated by zeta potential measurement, infrared spectroscopy and the analysis of pollutants structure and adsorption kinetic. The results described that not only electrostatic attraction but hydrogen adsorption were the main mechanism of both the phenol adsorption and the aniline adsorption. The pseudo second-order kinetic equation could best describe these two adsorption kinetics. The calculated activated energy of adsorption processes of phenol and aniline were 47.2KJ/mol and 44KJ/mol, respectively, which indicated that the adsorption process was chemisorption. Friedrich model was fitter to describe the adsorption isotherm of these two adsorption processes.

scholarly journals Study on the Adsorption Kinetics of Acid Red 3B on Expanded Graphite

2008 ◽  
Vol 5 (4) ◽  
pp. 802-809 ◽  
Author(s):  
Xiu-yan Pang ◽  
Fei Gong
Keyword(s):  
Activation Energy ◽  
Adsorption Kinetics ◽  
Adsorption Process ◽  
Expanded Graphite ◽  
Chemical Oxidation ◽  
Adsorption Rate ◽  
Order Kinetic ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

Expanded graphite (EG) is a kind of important adsorbent for organic compound such as oil and dyes. We have investigated the adsorption kinetics characteristics of this adsorbent for dye. EG was prepared with 50 mesh crude graphite through chemical oxidation intercalation of potassium permanganate and vitriol, and dye of acid red 3B was used as model sorbate. We have studied the adsorption kinetic models and rate-limiting step of the process. Adsorption rate and activation energy of the adsorption process were calculated. Kinetic studies show that the kinetic data are well described by the pseudo second-order kinetic model. The equilibrium adsorbance increases with the increase of the initial acid red 3B concentration. Initial adsorption rate increases with the increase of the initial dye concentration and temperature. Adsorption process of acid red 3B on EG has small activation energy. Internal diffusion appears to be the rate-limiting step for the adsorption process.

scholarly journals Removal of Paracetamol from Wastewater by Calcined Gypsum: Adsorption and Kinetics Study

2020 ◽  
Vol 3 (1) ◽  
pp. 11-18
Author(s):  
Hossam Al-Itawi
Keyword(s):  
Aqueous Solutions ◽  
Minor Effect ◽  
Recrystallization Process ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Calcined Gypsum ◽  
A Minor ◽  
Two Stages ◽  
Rate Limiting ◽  
Best Fit

It has been established that the presence of paracetamol in wastewaters can cause a potential risk to the environment. This work examined the possibility of using calcined gypsum in removing paracetamol from aqueous solutions. At neutral pH conditions, calcined gypsum was successful in removing paracetamol via adsorption, from aqueous solutions with a removal efficiency that ranged between 56.8 to 65.3 % of an initial concentration of 600 ppm. Increased temperature (from 20 to 500C) had a minor effect on the removal % of paracetamol while increasing the initial calcined gypsum dose (from 0.5 gm to 3 gm) and contact time (up to 15 min) increased by the removal % of paracetamol. Thermodynamically, the adsorption of paracetamol by calcined gypsum process was found to be spontaneous and endothermic, and more likely a physical process, while kinetically; the Pseudo-Second order model was found to be the best fit compared to the Elovich model. The removal process mainly consists of two stages, and it could be deduced from the kinetic behavior of paracetamol adsorption that the recrystallization process can be another rate-limiting step in the process.

Sign in / Sign up

Export Citation Format

Share Document