scholarly journals Kinetic modelling for heavy metal adsorption using Jordanian low cost natural zeolite (fixed bed column study)

2014 ◽  
Vol 5 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Reyad Al Dwairi ◽  
Waid Omar ◽  
Sura Al-Harahsheh

Low cost Jordanian natural zeolite (ANZ1 and ANZ2) of type phillipsite-chabazite obtained from Jabal al Ataitahat south Jordan were tested experimentally as adsorbent material for the removal of lead (Pb) and lithium (Li) ions from the effluent industrial wastewater streams. The experimental breakthrough curves were obtained from fixed bed experiments and analysed using the Thomas and Yoon and Nelson kinetic models to evaluate the adsorbent performance. The rate constants for the Thomas model for the removal of lead ions using the adsorbents ANZ2 and ANZ1 were 0.201 and 0.2345 mL/min/mg, respectively. The Thomas model adsorption capacity for the removal of lead ions using the adsorbents ANZ2 and ANZ1 were 34.7 and 23.64 mg/g, respectively. The estimated rate constants for the Yoon and Nelson model for the two ANZ2 and ANZ1 were 0.038 and 0.05 min–1, respectively. The kinetic data fitted well to both models. The rate constants for the Thomas model for the removal of lithium ions using the adsorbents ANZ1 and ANZ2 were 0.134 and 0.1005 mL/min/mg, respectively, where the Thomas model adsorption capacity for the removal of lithium ions using the adsorbents ANZ1 and ANZ2 were 18.65 and 21.43 mg/g, respectively.

2015 ◽  
Vol 5 (4) ◽  
pp. 542-549 ◽  
Author(s):  
Waid S. Omar

The potential of natural zeolite as a low-cost adsorbent was investigated for the removal of zinc from aqueous solution using a continuous fixed bed column. The zeolite tested was taken from the same source (Jabal Uniza in south Jordan) and subjected to crushing and sieving only, without any treatment. The two samples tested are UNZ1 (0.42–0.841 mm) and UNZ2 (0.21–0.42 mm). The Thomas model analysis of the measured breakthrough curves revealed that the adsorbent UNZ2 has a higher value of adsorption capacity to zinc ions (50.75 mg/g) than UNZ1 (33.68 mg/g). The time to 50% breakthrough was determined by the Yoon and Nelson model. It has been found that the time needed to reach 50% breakthrough is 2,006 minutes and 3,171 minutes for UNZ1 and UNZ2, respectively. This indicated that UNZ2 provides better performance with larger service time. Both UNZ1 and UNZ2 agreed to a high degree with the Thomas and Yoon and Nelson models.


Author(s):  
P. Sáez ◽  
A. Rodríguez ◽  
J. M. Gómez ◽  
C. Paramio ◽  
C. Fraile ◽  
...  

AbstractIn this paper, the gallium (III) ions’ adsorption onto protonated clinoptilolite (H-CLP) was investigated both in batch and fixed-bed column experiments. Regarding batch experiments, the influence of some parameters such as adsorbent dosage, size particle, and temperature was studied, determining that a dosage of 10 g/L for an initial pollutant concentration of 40 mg/L leads to a removal percentage over 85% regardless of particle size and temperature. On the other hand, adsorption of gallium onto H-CPL is an endothermic and spontaneous process in the studied temperature range, concluding that the maximum adsorption capacity was 16 mg/g for 60 °C. Concerning to the effect of the presence of other cations in solution, such as Na+, K+, or Ca2+, gallium adsorption capacity only drops by 20%, although the initial concentration of other cations in the solution is 50 times higher than gallium concentration. This means that clinoptilolite has a high affinity for gallium which can be very favorable for further selectivity tests. A crucial factor for this high selectivity could be the protonation of clinoptilolite which allows working without modifying the pH of the aqueous solution with acid. In the fixed-bed experiments, breakthrough curves were obtained, and the effect of operation variables was determined. A breakpoint value of 254 min for 64 g of adsorbent and flow rate of 9.0 mL/min (7.0 BV/h) were obtained, when treating a pollutant volume of 33 BV. Additionally, the breakthrough curves were fitted to different models to study the particle size effect, being the best fit corresponding to the Adams–Bohart model. This fact confirmed the influence of particle size on adsorption kinetics. Graphical Abstract


2021 ◽  
Vol 24 (1) ◽  
pp. 1-7
Author(s):  
Alaa Taha ◽  
Khalid M. Mousa

The intention of this study was to explore the efficiency and feasibility of adsorption of Reactive Blue dye (H3R) used in textile industries using Raw wheat straw (RWS) and Modified wheat straw (MWS) as a low-cost adsorbent. Wheat straw was modified using cationic surfactant (CTAB) to study the improvement of dye removal. The properties of Raw and Modified wheat straw are studied by means of Fourier transform infrared (FTIR) and scanning electron microscope (SEM) analyses to determine the functional groups and the nature of their surface. Continuous experiments were done by fixed-bed column to study the characteristics of the breakthrough curve using different bed heights and flow rates. Results showed that the breakthrough time increases with increasing bed height and decreasing flow rate, in turn results into higher removal capacity. Results also showed a higher flow rate lead a lower adsorption capacity due to insufficient residence time. Bed depth service time model (BDST), Adam-Bohart and Thomas models were used to predict the breakthrough curves and to determine the adsorption capacity of the column. The highest bed capacity of 12.95 and 32.2 mg/g for MWS was obtained using 10 mg/L, 10 cm bed height at 10 mL/min and 30 mL/min respectively.


2012 ◽  
Vol 518-523 ◽  
pp. 3115-3119
Author(s):  
Yan Qiang Li ◽  
Xiao Feng Ren ◽  
Shao Hua Chen ◽  
Xiu Rong Zhao ◽  
Run Ping Han

The effect of bed depth on adsorption ability of natural zeolite to removal methylene blue (MB) from aqueous solution in the fixed-bed column was studied. The results showed that the increase in column height favored the MB removal form solution. The equilibrium uptake of MB onto unit mass zeolite increased with the bed depth growth. The experimental data were fitted to Yan model using linear and nonlinear regression analysis, respectively. The experimental points and the predicted curves using the Yan model were compared and the error analysis was performed. The results indicated that Yan model were good to predict the breakthrough curves and both two methods can be used to obtain the parameters of Yan model and to predict the breakthrough curves.


2012 ◽  
Vol 599 ◽  
pp. 305-308 ◽  
Author(s):  
Ping Fang ◽  
Chao Ping Cen ◽  
Hong Tao Zhang ◽  
Zi Jun Tang ◽  
Ding Sheng Chen ◽  
...  

Efficient and cost-effective sludge-based adsorbents were developed and the adsorption of VOCs on the sludge-based adsorbents was studied in a fixed bed reactor. The results indicate that the adsorption of VOCs on sludge-based adsorbents is typical physical adsorption, the dynamic adsorption capacity of VOCs on adsorbents sharply increases as the VOCs concentration is increased at first, then increasing gradually, at last retains stable with the change of VOCs concentration. The dynamic adsorption capacity of sludge-based adsorbents for VOCs is O-Xylene > Butylcetate > Toluene > Ethylacetate > Benzene > Propanone > n-Hexane, the maximum dynamic adsorption capacity is 0.247, 0.225, 0.192, 0.186, 0.180, 0.176, 0.133g/g, respectively. Meanwhile the adsorption of VOCs on sludge-based adsorbents corresponds to the Langmuir adsorption isotherm equations. The sludge-based adsorbent is a low-cost alternative to activated carbon for VOCs treatment, and this technology is a promising method for the VOCs removal.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Bo Bai ◽  
Xiaohui Xu ◽  
Changchuan Li ◽  
Jianyu Xing ◽  
Honglun Wang ◽  
...  

The adsorptive removal of antibiotics from aqueous solutions is recognized as the most suitable approach due to its easy operation, low cost, nontoxic properties, and high efficiency. However, the conventional regeneration of saturated adsorbents is an expensive and time-consuming process in practical wastewater treatment. Herein, a scalable adsorbent of magnetic Fe3O4@chitosan carbon microbeads (MCM) was successfully prepared by embedding Fe3O4 nanoparticles into chitosan hydrogel via an alkali gelation-thermal cracking process. The application of MCM composites for the adsorptive removal of doxycycline (DC) was evaluated using a fixed-bed column. The results showed that pH, initial concentration, flow rate, and bed depth are found to be important factors to control the adsorption capacity of DC. The Thomas and Yoon-Nelson models showed a good agreement with the experimental data and could be applied for the prediction of the fixed-bed column properties and breakthrough curves. More importantly, the saturated fixed bed can be easily recycled by H2O2 which shows excellent reusability for the removal of doxycycline. Thus, the combination of the adsorption advantage of chitosan carbon with catalytic properties of magnetic Fe3O4 nanoparticles might provide a new tool for addressing water treatment challenges.


Clay Minerals ◽  
2015 ◽  
Vol 50 (1) ◽  
pp. 91-101 ◽  
Author(s):  
I. Nuić ◽  
M. Trgo ◽  
J. Perić ◽  
N. Vukojević Medvidović

AbstractThe removal of lead and zinc from a binary solution by fixed bed depths (40, 80 and 120 mm) of a natural zeolite was examined at a flow rate of 1 mL/min. The results obtained were fitted to the Bed Depth Service Time (BDST) model and the parameters of the model (q and k) were used to design a column system for flow rates of 2 and 3 mL/min at a bed depth of 80 mm. The experimental results were in excellent agreement with those predicted and experimental breakthrough curves for the binary systems were obtained. This approach facilitates the design of effective binary column processes without additional experimentation. Two major design parameters, the Empty Bed Contact Time (EBCT) and the zeolite usage rate, were calculated. The highest EBCT value of 13.56 min represents the optimal conditions for the binary (Pb+Zn) solution.


Author(s):  
Hua Chang ◽  
Tao Ma ◽  
Ling Liu ◽  
Hua-Qiang Yin ◽  
Xue-Dong He

The adsorption capability of carbon dioxide on 13X molecular sieve (13XMS) was investigated in a fixed-bed apparatus with two-road gas mixing system by dynamic column breakthrough method with helium as carrier gas at helium purification conditions of high-temperature gas-cooled reactor (HTGR). Experiments were performed at temperatures of 5°C ∼35 °C and low carbon dioxide partial pressure range of 10∼150Pa. By analyzing the breakthrough curve, both equilibrium adsorption capacity and kinetic adsorption capacity at breakthrough point were determined. Based on mass-transfer zone model, the experimental breakthrough curves at different operation conditions were analyzed. The carbon dioxide isotherm on 13XMS was fitted well by Langmuir model and the enthalpy of adsorption of carbon dioxide was estimated.


2016 ◽  
Vol 19 (1) ◽  
pp. 7-16 ◽  

<p>In this study, nanocomposite of ceria sawdust (CeO<sub>2</sub>/SD) synthesized by precipitation method was utilized for removal of As (III) ions from aqueous solutions. Study of the process was done in column system. Characterization of the nano sized adsorbent particles was carried out using XRD and SEM techniques. The effects of important parameters, such as the value of initial pH, the flow rate, the influent concentration of arsenic and bed depth were studied in the column system. The Thomas model was applied for treatment of the adsorption data at different flow rate, influent concentration and bed depth. The bed-depth/service time analysis (BDST) model was also applied at different bed depth to predict the breakthrough curves. The two models were found suitable for describing the bio sorption process of the dynamic behavior of the CeO<sub>2</sub>/SD adsorbent in column investigation. Based on Thomas model, the equilibrium adsorption reached 8.28 mg g<sup>−</sup><sup>1</sup> when a As(III) polluted solution with influent concentration of As 10 mg l<sup>-1 </sup>passed through the column with a flow rate of 2 ml min<sup>−</sup><sup>1</sup>. All the results suggested the presented nanocomposite as an efficient and cost effective adsorbent for removal of As (III) ions from aqueous solutions.</p>


2013 ◽  
Vol 68 (10) ◽  
pp. 2158-2163 ◽  
Author(s):  
Shenglong Zhang ◽  
Randi Zhang ◽  
Wei Xiao ◽  
Runping Han

Natural peanut husk (NPH) modified with hexadecyl trimethyl ammonium bromide (CTAB) was used as adsorbent to remove 2,5-dimethoxy-4-chloroaniline (DMCH) from solution in a fixed-bed column. Fourier transform infrared spectroscopy analysis and X-ray fluorescence of NPH and modified peanut husk (MPH) showed that CTAB had been introduced onto the surface of NPH. The effects of flow rate and bed depth on breakthrough curves were studied. The Thomas model and the Yan model were selected to fit the column adsorption data and the results showed that the Yan model was better at predicting the breakthrough curves. The adsorption quantity was up to 6.46 mg/g according to the Yan model. The bed depth service time model was used to calculate the critical bed depth from experimental data and it was directly related to flow rate. As a low-cost adsorbent, MPH is promising for the removal of DMCH from solution.


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