scholarly journals Treatment of wastewaters contaminated with zinc ions using natural zeolite as adsorbent in a fixed bed column

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.

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.


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.


2019 ◽  
Vol 120 ◽  
pp. 03003
Author(s):  
Huang-Mu Lo ◽  
Kae-Long Lin ◽  
Min-Hsin Liu ◽  
Hsung-Ying Chiu ◽  
Fang-Cheng Lo

Heavy metals from the electroplating wastewater might cause environmental pollution if not well treated. Generally, carbon adsorption might be used for the final step for further trace metals removal. This study investigated the heavy metal Cu adsorption in the fixed bed column with 1, 10 and 100 mg/L influent concentration. Results showed that KAB decreased as influent Cu concentration increased from 1 to 100 mg/L while N0 increased as influent concentration increased from 1 to 100 mg/L as can be found in Adams-Bohart model. R2 was found between 0.8579 and 0.9182. In Thomas model. KTH and q0 showed the similar trend as KAB and N0 in the Adams-Bohart model. KTH decreased as influent Cu concentration increased from 1 to 100 mg/L. q0 increased as influent Cu concentration increased from 1 to 100 mg/L. R2 of regression model was found between 0.9065 and 0.9836. In Yoon-Nelson model. KYN increased as influent Cu concentration increased from 1 to 100 mg/L while τ decreased as influent Cu concentration increased from 1 to 100 mg/L. Results showed that the three models of Adams-Bohart model, Thmoas model and The Yoon-Nelson model were suitable for the description of Cu adsorption by activated carbon.


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.


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


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.


2019 ◽  
Vol 17 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Mohammad Javad Amiri ◽  
Maryam Khozaei ◽  
Antonio Gil

Abstract The Thomas equation is a popular model that has been widely used to predict breakthrough curves (BTCs) when describing the dynamic adsorption of different pollutants in a fixed-bed column system. However, BTCs commonly exhibit unsymmetrical patterns that cannot be predicted using empirical equations such as the Thomas model. Fortunately, adaptive neural-based fuzzy inference systems (ANFISs) can be used to model complex patterns found in adsorption processes in a fixed-bed column system. Consequently, a new hybrid model merging Thomas and an ANFIS was introduced to estimate the performance of BTCs, which were obtained for Cd(II) ion adsorption on ostrich bone ash-supported nanoscale zero-valent iron (nZVI). The results obtained showed that the fair performance of the Thomas model (NRMSE = 27.6% and Ef = 64.6%) improved to excellent (NRMSE = 3.8% and Ef = 93.8%) due to the unique strength of ANFISs in nonlinear modeling. The sensitivity analysis indicated that the initial solution pH was a more significant input variable influencing the hybrid model than the other operational factors. This approach proves the potential of this hybrid method to predict BTCs for the dynamic adsorption of Cd(II) ions by ostrich bone ash-supported nZVI particles. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.


2021 ◽  
Vol 10 (13) ◽  
pp. e58101321154
Author(s):  
Mateus Rodrigues Brito ◽  
Matheus Gomes Arruda ◽  
Marcelo Mendes Pedroza ◽  
Helida Monique Cordasso Fagnani ◽  
Angélica Jaconi ◽  
...  

The biochar of the Pequi peel represents a sustainable alternative in the process of treating effluents through adsorption system. This study investigates the adsorption capacity in a fixed bed column of the activated biochar from pequi peel (ABPP) to remove the components. The biochar was obtained by pyrolysis, which was activated with zinc Chloride - ZnCl₂. Through the Thomas model, it was found that the concentration of Paracetamol of 5 mg L-1 obtained 3.21 mg g-1 of drug adsorption, which was higher than the adsorption obtained with the concentrations of 10 mg L-1 (3.02 mg g-1) and 20 mg L1 (1.22 mg g-1). Methylene blue was tested with a concentration of 3 mg L-1, adsorbing 8.07 mg g-1. The data fit the Thomas model with an R² higher than 0.90. The capacity of ABPP to adsorb methylene blue and Paracetamol was satisfactory, with adsorbing significant.


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.


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