scholarly journals Batch and fixed-bed column studies for the biosorption of Cu(II) and Pb(II) by raw and treated date palm leaves and orange peel

2017 ◽  
Vol 19 (3) ◽  
pp. 464-478 ◽  

Herein, we describe the batch and fixed-bed column adsorption of Cu2+ and Pb2+ by raw and treated date palm leaves (DP) and orange peel (OP) waste biomass. Contact time, pH, adsorbent dose, and particle size were optimized in batch adsorption experiments, while breakthrough curves obtained in fixed-bed adsorption experiments were used to determine the effects of bed height, initial metal concentration, particle size, and flow rate. The use of treated DP and/or OP in batch adsorption mode increased the removal efficiency of metal ions by 20–30% compared to that observed for raw adsorbents. The equilibration time was estimated as 0.5 h, with rapid metal removal observed during the first 15 min at an optimum pH value of ~5. Increasing the adsorbent dose from 0.5 to 6–7 g enhanced the metal removal efficiency by ~60%, whereas a particle size increase from 50 to 300 µm decreased this value by about 30% for both Cu2+ and Pb2+ and both raw and treated DP/OP. Both breakthrough and exhaust times increased with increasing bed height of the fixed-bed column, and the effect observed for treated DP exceeded that observed for raw DP by a factor of two. Conversely, both breakthrough and exhaust times decreased with increasing initial metal concentration, particle size, and flow rate. Increasing the particle size from 100–150 to 300 µm changed the exhaust time by 8 h when treated DP was used for Pb2+ adsorption. The obtained linear regression coefficients (R2 = 0.9–0.99) suggest that both Thomas and Yoon–Nelson models are well-suited for predicting the adsorption performance of the present system.

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.


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.


2017 ◽  
Vol 18 (2) ◽  
pp. 94-104
Author(s):  
Rozaimi Abu Samah

The main objective of this work was to design and model fixed bed adsorption column for the adsorption of vanillin from aqueous solution. Three parameters were evaluated for identifying the performance of vanillin adsorption in fixed-bed mode, which were bed height, vanillin initial concentration, and feed flow rate. The maximum adsorption capacity was increased more than threefold to 314.96 mg vanillin/g resin when the bed height was increased from 5 cm to 15 cm. Bohart-Adams model and Belter equation were used for designing fixed-bed column and predicting the performance of the adsorption process. A high value of determination coefficient (R2) of 0.9672 was obtained for the modelling of vanillin adsorption onto resin H103.


EKUILIBIUM ◽  
2012 ◽  
Vol 11 (2) ◽  
Author(s):  
Paryanto Paryanto

<p><strong><em>Abstract:</em></strong><em> Nowadays, organic fertilizer is more interesting than anorganic fertilizer, because it doesn’t cause soil degradation and the crops are healthier to be consumed. Manure is the most familiar as an organic fertilizer. This study dealt with producing of liquid organic fertilizer from cow manure in fixed bed column reactor. The reactor operated at 30 <sup>o</sup>C, 40 cmHg and 19.2 mL/s of solvent flowrate. The aim of this study was to find correlation between bed height of manure in column, particle size of manure, concentration of fertilizer and volumetric mass transfer coefficient </em>(<em>k<sub>c</sub>a</em>)<em>. The highest of k<sub>c</sub>a value was obtained at 25 cm of bed height, it was 0.0014 s<sup>-1</sup>. The result shows that bed height of manure is linier to k<sub>c</sub>a. On the other hand, particle size of manure doesn’t give much influence of k<sub>c</sub>a.</em></p><p><strong><em> </em></strong><strong><em>Keywords</em></strong><strong>:</strong><em> extraction, fixed bed, cow manure, liquid organic fertilizer, volumetric mass transfer </em><em>coefficient</em></p>


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1912
Author(s):  
Huijie Zhu ◽  
Qiang Huang ◽  
Mingyan Shi ◽  
Shuai Fu ◽  
Xiuji Zhang ◽  
...  

The effectiveness of nanoscale zero-valent iron(nZVI) immobilized on activated carbon (nZVI/AC) in removing antimonite (Sb(III)) from simulated contaminated water was investigated with and without a magnetic fix-bed column reactor. The experiments were all conducted in fixed-bed columns. A weak magnetic field (WMF) was proposed to increase the exclusion of paramagnetic Sb(III) ions by nZVI/AC. The Sb(III) adsorption to the nZVI and AC surfaces, as well as the transformation of Sb(III) to Sb(V) by them, were both increased by using a WMF in nZVI/AC. The increased sequestration of Sb(III) by nZVI/AC in the presence of WMF was followed by faster nZVI corrosion and dissolution. Experiments were conducted as a function of the pH of the feed solution (pH 5.0–9.0), liquid flow rate (5–15 mL·min−1), starting Sb(III) concentration (0.5–1.5 mg·L−1), bed height nZVI/AC (10–40 cm), and starting Sb(III) concentration (0.5–1.5 mg·L−1). By analyzing the breakthrough curves generated by different flow rates, different pH values, different inlet Sb(III) concentrations, and different bed heights, the adsorbed amounts, equilibrium nZVI uptakes, and total Sb(III) removal percentage were calculated in relation to effluent volumes. At pH 5.0, the longest nZVI breakthrough time and maximal Sb(III) adsorption were achieved. The findings revealed that the column performed effectively at the lowest flow rate. With increasing bed height, column bed capacity and exhaustion time increased as well. Increasing the Sb(III) initial concentration from 0.5 to 1.5 mg·L−1 resulted in the rise of adsorption bed capacity from 3.45 to 6.33 mg·g−1.


Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 349
Author(s):  
Laura Castro ◽  
Fabiana Rocha ◽  
Jesús Ángel Muñoz ◽  
Felisa González ◽  
María Luisa Blázquez

Nanoparticles of iron precipitates produced by a microbial consortium are a suitable adsorbent for metal removal from electroplating industry wastewaters. Biogenic iron precipitates were utilized as adsorbents for chromate and zinc in batch conditions. Furthermore, the iron precipitates were embedded in alginate beads for metal removal in fixed-bed columns, and their performance was evaluated in a continuous system by varying different operational parameters such as flow rate, bed height, and feeding system (down- and up-flows). The influence of different adsorption variables in the saturation time, the amount of adsorbed potentially toxic metals, and the column performance was investigated, and the shape of the breakthrough curves was analyzed. The optimal column performance was achieved by increasing bed height and by decreasing feed flow rate and inlet metal concentration. The up-flow system significantly improved the metal uptake, avoiding the preferential flow channels.


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.


2021 ◽  
Author(s):  
Hameed Muhamad

Biosorption of Cd²+ and Cu²+ by wheat straw (Triticum Sativum) using a batch system and a continuous upflow mode in a fixed bed column was studied. For batch system, the effect of pH over a range from 3.0 to 7.0 and the temperature from 20 to 40ºC on the metal removal was investigated. Various initial metal concentrations from 20 to 150 mg/L were used. Adsorption of metal ions was observed to increase with liquid pH and temperature. Among the three widely used isotherms, namely the Langmuir, Freundlich, and Timken models, the experimental data better fitted the Langmuir isotherm model. For the continuous upflow mode in a fixed bed (4-inch diameter), experiments were performed over a range of flow rate from 0.3-1.0 LPM and varied bed height of 0.5-2.0m. The results obtained also agree (BDST) model. In addition, for estimations of the parameters that are necessary for the design of a fixed bed adsorber in paractical application, the experimental data were fitted to the Thomas, Adams-Bohart, Yan and Yoon-Nelson models. Thomas model appeared to describe the experimental results well. Mathematical model was developed to simulate the concentration changes at the experimental time instances.


2010 ◽  
Vol 6 (5) ◽  
Author(s):  
Boon-Seang Chu ◽  
Siew-Young Quek ◽  
Badlishah Sham Baharin ◽  
Yaakob Bin Che Man

Desorption of vitamin E from silica-packed fixed-bed column was studied as functions of column bed height, column temperature and flow rate of isopropanol. Isopropanol was the desorbing solvent and it was eluted through the columns saturated with vitamin E. The desorption profiles of all systems showed that vitamin E might desorb at two distinct rates simultaneously. The slow desorbing step was the rate-controlling process for recovery of vitamin E. The desorption rate increased with the decrease of column bed height and flow rate, but increased with increasing column temperature. This indicated that the desorption process was an endothermic process. The percentage recovery of vitamin E upon completion of desorption was considered high for all systems, ranging from 94.8 to 98.8%, with vitamin E concentration in the extract of 18.5-21.5%. Although the bed height, column temperature and flow rate were functions of desorption rate, it appeared that percentage recovery and vitamin E concentration in the extract were rather unaffected by the operating conditions tested if the column was eluted by isopropanol for a sufficient time to desorb vitamin E. Nevertheless, the use of isopropanol would be more efficient if desorption was carried out at lower flow rate and higher column temperature.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Nan Li ◽  
Jing Ren ◽  
Lin Zhao ◽  
Zhong-liang Wang

Removal of phosphate from solution using nanosized FeOOH-modified anion resin was studied in fixed bed column. Effect of bed height and flow rate on the breakthrough curves were investigated. Longer breakthrough time was obtained by increasing the bed height and decreasing the flow rate. Bed service depth time (BDST) model was applied to recount the relationship between bed service time and bed height. The value ofN0was calculated to be 21.4 g/L. Yoon-Nelson model, which fitted well with the experimental data, is allowable to estimate the breakthrough curves and characteristic parameters for phosphate adsorption in the column filled with nanosized FeOOH-modified anion resin.


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