Zinc(II) desorption by Sargassum filipendula biomass in batch and in fixed-bed column for multiple sorption-regeneration cycles

2009 ◽  
Vol 60 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Araceli A. Seolatto ◽  
Maurício M. Câmara ◽  
Eneida S. Cossich ◽  
Célia R. G. Tavares ◽  
Edson A. Silva

The reusability of the alga Sargassum filipendula was studied in batch reactor and in fixed-bed column in order to investigate Zn(II)-laden biomass regeneration. Four types of desorbing solutions at two different concentrations were tested and the results obtained to the desorption efficiencies were higher than 90% for three of the agents. Ten consecutive sorption-regeneration cycles at a flow rate of 8 mL/min were carried in fixed bed column with the feed concentration of 50 mg/L and using two eluent solutions: H2SO4 (0.1 M) and MgSO4 (3.5% at pH 3), which showed the best ability to elution tests in batch system. The column was used for a period of 30 days. The adsorption capacity decreased the passing of cycles, but the total amount of zinc removed after 10 cycles was approximately 8 times greater than if the biomass had been used for only one time, for both agents tested. Therefore, the regeneration in the Sargassum filipendula column through the two desorbing agents tested showing high efficient use of biomass and facilitating the process of treatment of wastewater containing metals that has successive exchanges of biomass.

2014 ◽  
Vol 70 (2) ◽  
pp. 192-199 ◽  
Author(s):  
Yanyan Wang ◽  
Xiang Zhang ◽  
Qiuru Wang ◽  
Bing Zhang ◽  
Jindun Liu

We used natural resources of halloysite nanotubes and alginate to prepare a novel porous adsorption material of organic–inorganic hybrid beads. The adsorption behaviour of Cu(II) onto the hybrid beads was examined by a continuous fixed bed column adsorption experiment. Meanwhile, the factors affecting the adsorption capacity such as bed height, influent concentration and flow rate were investigated. The adsorption capacity (Q0) reached 74.13 mg/g when the initial inlet concentration was 100 mg/L with a bed height of 12 cm and flow rate of 3 ml/min. The Thomas model and bed-depth service time fitted well with the experimental data. In the regeneration experiment, the hybrid beads retained high adsorption capacity after three adsorption–desorption cycles. Over the whole study, the new hybrid beads showed excellent adsorption and regeneration properties as well as favourable stability.


2011 ◽  
Vol 356-360 ◽  
pp. 1139-1144
Author(s):  
Qi Gang Cen ◽  
Meng Xiang Fang ◽  
Jia Ping Xu ◽  
Zhong Yang Luo

In this study, a commercial activated carbon was assessed as adsorbent for post-combustion CO2 capture. The breakthrough adsorption experiments were conducted in a fixed-bed column with simulated flue gas of 12% CO2. The effects of feed flow rate and adsorption pressure on breakthrough time and CO2 adsorption capacity were evaluated. The column efficiency was introduced to estimate the percentage of the utilization of the bed adsorbent capacity. At a higher flow rate, the breakthrough time, breakthrough capacity and column efficiency decreased. Conversely, increasing adsorption pressure was favorable to CO2 adsorption by the increase in breakthrough time, CO2 adsorption capacity and the column efficiency. During the experiments, temperature changes were detected at three positions inside the column to track the movement of breakthrough front.


2017 ◽  
Vol 13 (4) ◽  
pp. 803-806 ◽  
Author(s):  
Abdurrahman Garba ◽  
Hatijah Basri ◽  
Noor Shawal Nasri ◽  
Umar Hayatu Siddiq ◽  
Abdul Rasheed Abdul Rahman

The treated rice husk has been evaluated as a sorbent for removing lead (II) from aqueous solutions in fixed-bed studies. In this paper, the effects of flow rate (3 and 9 mL/min), bed depth (0.9, 1.8 and 2.8 cm) and influent lead concentration of (5 and 20 mg/L) on the adsorption capacity of the adsorbent in a fixed-bed column were investigated. The highest adsorption capacity (78 %) on a 20 mg/L Pb (II) solution was achieved within a flow rate of 9 mL/min and a bed depth of 2.8 cm. The experimental data obtained from the adsorption process was correlated with the Thomas, Adams– Bohart and Yoon–Nelson models. The results of the parameters indicated Adams–Bohart model fitted well over the other models.


2016 ◽  
Vol 74 (10) ◽  
pp. 2297-2304 ◽  
Author(s):  
Dalia I. Sánchez-Machado ◽  
Jaime López-Cervantes ◽  
Ma. A. Correa-Murrieta ◽  
Reyna G. Sánchez-Duarte

A fixed bed column packed with chitosan-sodium tripolyphosphate (CTPP) beads was used to remove aqueous Fe (III) ions. The adsorption of Fe (III) ions on CTPP beads was found to be dependent on operating conditions, such as the flow rate, adsorbent bed length, and feed concentration. The experimental data were assessed with Thomas, Adams-Bohart and Yoon-Nelson models to predict the breakthrough curves using linear regression. The breakthrough curves were better fitted with the Thomas and Yoon-Nelson models when the flow rate was varied and the feed concentration and the bed height of the column were fixed. Therefore, chemical adsorption may be the limiting step that controls the continuous adsorption process. The Adams-Bohart model presented a good fit to the experimental data, showing that external mass transfer was controlling the adsorption process in the initial part of the breakthrough curves. The parameters obtained from the continuous adsorption assays may be used as a basis for designing columns packed with CTPP beads for the removal of Fe (III) ions.


2018 ◽  
Vol 78 (4) ◽  
pp. 751-763 ◽  
Author(s):  
Rihab Beji ◽  
Wissem Hamdi ◽  
Aida Kesraoui ◽  
Mongi Seffen

Abstract The present study evaluates the phosphorus (P) adsorption by alkaline soil in fixed bed column mode operation. The effects of flow rate, bed height, and initial P concentration on breakthrough curves were evaluated. Data confirmed that both the breakthrough and exhaustion time increased in parallel with the rise in bed height and the decline in flow rate and initial P concentration. The adsorption capacity was observed to increase with decreasing flow rate and bed height and increasing initial concentration. Moreover, continuous adsorption experiments were conducted using three salts (NaCl, KCl and CaCl2) with the same concentration (0.01 M) to investigate the P adsorption behavior in saline conditions. The results showed that all three salts improve the P adsorption in the soil column. Consequently, the bed performance was significantly enhanced with salts addition. The maximum adsorption capacity of 13.47 mg g−1 for P, 16.13 mg g−1 for P-NaCl, 22.10 mg g−1 for P-KCl, 30.05 mg g−1 for P-CaCl2 was attained at an initial influent concentration of 300 mg g−1, bed height of 22 cm, and flow rate of 10 mL min−1. TheCaCl2 addition was therefore the most effective in increasing P adsorption. Thomas, Yoon-Nelson and Clark models were applied to experimental results to forecast the breakthrough curves by nonlinear regression analysis. Meanwhile, the bed depth service time model was employed to examine the effective model parameters in scaling up the process using linear regression analysis. The values of correlation coefficient (R2) and the sum of squared error evidenced that the Thomas model is the most appropriate model to fit the experimental data. The reusability experiment showed that the adsorbent material still had high P adsorption capacity, and tolerable desorption efficiency.


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.


2021 ◽  
Author(s):  
Hemant Singh ◽  
Sankalp Raj ◽  
Rishi karan singh rathour ◽  
Jayanta Bhattacharya

Abstract Bimetallic Metal organic framework (MOF) has garnered interest over the years with its application in various environmental remediation. In this study, Fe-Al-1,4-Benzene di-Carboxylic acid (FeAl(BDC)) MOF was synthesized, and adsorptive removal of Rhodamine B dye in batch and unique hybrid FeAl (BDC)-River sand fixed-bed column was achieved. The experimental data from the batch studies corroborated well with the Pseudo second-order (PSO) and Freundlich adsorption isotherm models. Furthermore, a fixed-bed column study was conducted to assess the effect of varying flow rate (2, 5, 8 mL/min), bed height (5, 9, 13 cm), and feed concentration (10, 20, 30 mg/L) on the adsorption performance of FeAl(BDC) in continuous mode of operation. A uniform mixture of river sand and FeAl(BDC) by weight ratio (9:1) was achieved prior to packing the column. The column study reveals that Sand-FeAl(BDC) can achieve the maximum adsorption capacity of 113.05 mg/g at a flow rate of 5 mL/min, feed concentration of 20 mg/L, and bed height of 13 cm. The experimental data of the column study were successfully fitted with BDST, Thomas, Yoon-Nelson, and Dose-response models. The fitting parameter values from the BDST model raise the scope of possible upscaling of the fixed-bed column. Hence, it is proposed that these River sand-FeAl(BDC)-based filters can be widely used in areas facing critical contamination and in poor communities with a high demand for water.


2018 ◽  
Vol 8 (11) ◽  
pp. 2221 ◽  
Author(s):  
Olga Długosz ◽  
Marcin Banach

Vermiculite has been used for the removal of Cu 2 + and Ag + from aqueous solutions in a fixed-bed column system. The effects of initial silver and copper ion concentrations, flow rate, and bed height of the adsorbent in a fixed-bed column system were investigated. Statistical analysis confirmed that breakthrough curves depended on all three factors. The highest inlet metal cation concentration (5000 mg/dm3), the lowest bed height (3 cm) and the lowest flow rate (2 and 3 cm3/min for Ag + and Cu 2 + , respectively) were optimal for the adsorption process. The maximum total percentage of metal ions removed was 60.4% and 68.7% for Ag+ and Cu2+, respectively. Adsorption data were fitted with four fixed-bed adsorption models, namely Clark, Bohart–Adams, Yoon–Nelson and Thomas models, to predict breakthrough curves and to determine the characteristic column parameters. The adsorbent was characterized by SEM, FTIR, EDS and BET techniques. The results showed that vermiculite could be applied as a cost-effective sorbent for the removal of Cu 2 + and Ag + from wastewater in a continuous process.


2011 ◽  
Vol 287-290 ◽  
pp. 1620-1625
Author(s):  
Yan Wu ◽  
Zai Fang Deng ◽  
Yang Tao ◽  
Xue Gang Luo

Fixed-bed column studies for the removal of Ag(Ⅰ) and Cr(Ⅲ) from individual aqueous solutions using puffed rice husk were investigated in this work. The experiments were conducted to study the effect of important column parameters such as bed height, feed flow rate and feed initial concentration of solution. It was found that increasing bed depth yielded longer service time while increase in influent concentration and flow rate resulted in faster breakthrough. Bed Depth Service Time (BDST) model was applied to analyze the experimental data and the model parameters were evaluated. Good agreement of the experimental breakthrough curves with the model predictions was observed.


2017 ◽  
Vol 36 (1-2) ◽  
pp. 215-232 ◽  
Author(s):  
Jaime López-Cervantes ◽  
Dalia I Sánchez-Machado ◽  
Reyna G Sánchez-Duarte ◽  
Ma A Correa-Murrieta

A continuous adsorption study in a fixed-bed column was carried out using a chitosan–glutaraldehyde biosorbent for the removal of the textile dye Direct Blue 71 from an aqueous solution. The biosorbent was prepared from shrimp shells and characterized by scanning electron microscopy, X-ray diffraction, and nuclear magnetic resonance spectroscopy. The effects of chitosan–glutaraldehyde bed height (3–12 cm), inlet Direct Blue 71 concentration (15–50 mg l−1), and feed flow rate (1–3 ml min−1) on the column performance were analyzed. The highest bed capacity of 343.59 mg Direct Blue 71 per gram of chitosan–glutaraldehyde adsorbent was obtained using 1 ml min−1 flow rate, 50 mg l−1 inlet Direct Blue 71 concentration, and 3 cm bed height. The breakthrough curve was analyzed using the Adams–Bohart, Thomas, and bed depth service time mathematical models. The behaviors of the breakthrough curves were defined by the Thomas model at different conditions. The bed depth service time model showed good agreement with the experimental data, and the high values of correlation coefficients (R2 ≥ 0.9646) obtained indicate the validity of the bed depth service time model for the present column system.


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