scholarly journals Experimental Studies on the Removal of Aluminium Ions from Synthetic Aqueous Solution by Hydroxyapatites

2021 ◽  
Vol 68 (4) ◽  
pp. 821-832
Author(s):  
Doina Humelnicu ◽  
Inga Zinicovscaia ◽  
Ionel Humelnicu ◽  
Maria Ignat

In this work we have presented the results obtained in the adsorption behavior of hydroxyapatite with different treatment towards aluminium ions from synthetic wastewaters. Experiments were performed in batch technique at different pH values, temperatures, sorbent dosage, contact time and initial aluminium concentration. The thermodynamic studies on the adsorption process of aluminium onto hydroxyapatite indicated that the process is spontaneous and endothermic. The Langmuir, Freundlich, Flory-Huggins, Dubinin-Radushkevich and Temkin equilibrium models were applied to the description of experimental data. The adsorption of aluminium follows the Langmuir adsorption isotherm. The kinetics of adsorption was evaluated using the pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models. The rate of aluminium adsorption was successfully described by a pseudo-second-order kinetic model. The obtained results indicated that hydroxyapatite treated with Pluronic P123 surfactant has a higher sorption capacity toward aluminium ions (117.65 mg g−1) than hydroxyapatite treated with Pluronic F127 surfactant (109.89 mg g−1) while untreated hydroxyapatite exhibited the lowest one (104.17 mg g−1).

2015 ◽  
Vol 11 (6) ◽  
pp. 3685-3697 ◽  
Author(s):  
Naghmouchi Nahed ◽  
Nahdi Kais

Natural clay from Nabeul region (north of Tunisia) was investigated for the removal of two anionic textile dyes (RR120 and BB150) from aqueous solution. The raw clay was characterized by means of XRD, IR spectroscopic, chemical analysis, cation exchange capacity and BET surface area analysis.Adsorption studies were carried out under various parameters such as pH, contact time, initial dye concentration and temperature. The adsorption kinetic data was tested by pseudo-first order, pseudo second-order and intra-particle diffusion kinetic models. The equilibrium data were analyzed using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. The thermodynamic parameters (DH°, DS° and DG°) of the adsorption were also evaluated. The adsorption process was found spontaneous and endothermic in nature. The kinetics of adsorption were best described by pseudo-second order kinetic model. The Langmuir adsorption model totally agrees with the experimental data. 


2020 ◽  
Vol 12 (23) ◽  
pp. 10048
Author(s):  
Heng Wei ◽  
Jiankun Sun ◽  
Bin Zhang ◽  
Rongzhan Liu

Industrial latex sludge as raw material was made into sulfonated latex sludge (SLS) and latex sludge active carbon (LSC) adsorbents by sulfonate and pyrolysis treatment to remove textile dye cationic blue X-GRRL from aqueous solution. The adsorption properties of SLS and LSC for X-GRRL were studied and compared by investigating the experimental parameters such as adsorbents dosage, pH, contact time and initial concentration. The kinetics of adsorption on SLS and LSC followed the pseudo-second-order kinetic model well. The adsorption isotherm and thermodynamic studies were further used to evaluate and compare the adsorption process of X-GRRL on SLS and LSC. The maximum adsorption capacities were 1219.6 mg/g for SLS and 476.2 mg/g for LSC according to the Langmuir model, respectively. These findings not only provide a sustainable strategy to turn industrial solid waste latex sludge into useful material for environment remediation, but also develop an efficient adsorbent for the treatment of dye wastewater.


2021 ◽  
Vol 12 (2) ◽  
pp. 156-162
Author(s):  
A.S. Muhammad ◽  
M.A. Abdurrahman

A batch adsorption process was carried out by optimizing, the effect of contact time (10min to 180min) and initial concentration (5mg/l to150mg/l). The adsorbent was characterized using FTIR spectra and SEM, and the result obtained showed shifting and disappearance of peaks after adsorption. The results of the adsorption kinetics, which includes the correlation coefficient 0.9771 and the agreement between the amount adsorbed experimentally (1.472mg/g) and the calculated amount absorbed(1.196mg/g) revealed that MB was adsorbed satisfactory according to the pseudo second-order kinetic model.


Author(s):  
Atef A. A. Sweed ◽  
Ahmed A. M. Awad

This work aims to maximize the utilization of sugar cane cultivation and manufacture waste in Aswan Governorate, Egypt and turn it into biochar, which can be used to clean the environment from dangerous metals. Sugarcane organic wastes (filter cake, bagasse and sphere) biochars as waste bio-adsorbent materials were obtained using the pyrolysis at 350 and 700°C and 90 min residence time under limited oxygen conditions. Two batch trails were conducted to study the effects of biochar pH and shaking time on the adsorption of Pb ion from solution in precedence of soil and biochar. Models to study the kinetics of the adsorption process as pseudo-first-order and pseudo-second-order models were used.The results showed that the absorbed or precipitated (at high suspension pH) amount of Pb decreased in the order: soil treated with biochar bagasse pyrolysis at 350°C (BB350) > soil treated with biochar sphere pyrolysis at 350°C (SB350) > soil treated with biochar filter cake pyrolysis at 350°C (FB350) > soil only. At pH 9 maximum amounts of Pb of 1.794, 1.706 and 1.688 mg/g were adsorbed or precipitated on the soil treated with BB350, SB350 and FB350 respectively. However, Pb was maximum adsorbed or precipitated (1.33 mg/g) on the soil only at pH 8. The highest removal efficiency of Pb2+ from the solution was85% with treated the soil with SB350 while the lowest one was 55.5% occurred with the soil that was not treated with biochar at a shaking time of 80 minutes. The adsorption of Pb2+ by the soil in presence or absence biochars different fitted the pseudo second order kinetic model for all tested treatments (R2 ranged from 0.9901 for the soil treated with BB350 to 0.9994 for that treated with SB350).


Author(s):  
Mohamed Nasser Sahmoune ◽  
Krim Louhab ◽  
Aissa Boukhiar

Dead streptomyces rimosus was found to be an effective biosorbent for the removal of chromium from industrial tanning effluents. A sorption level of 65 mg/g was observed at pH 4.8 while the precipitation effect augmented this value at a higher pH range. Chromium desorption increased with decreasing desorption agents pH (including HCl and H2SO4) to a maximum value of 95% at approximately zero pH. The biosorption data of trivalent chromium by streptomyces rimosus has been used for kinetic studies based on fractional power, Elovich, pseudo-first order and pseudo-second order rate expressions. The time-dependent Cr (III) biosorption data were well-described by a pseudo-second-order kinetic model. The intraparticle diffusion is not the rate-limiting step for the whole reaction. It was found that the biosorption equilibrium data fit well with the Langmuir model.


2011 ◽  
Vol 413 ◽  
pp. 148-153 ◽  
Author(s):  
Xue Na Hu ◽  
Ya Han ◽  
Jia Yan Li ◽  
Jun Yan Wu ◽  
Jian Rong Chen ◽  
...  

Thiol-functionalized MCM-48 (SH-MCM-48) was synthesized by co-condensation method, with co-templates of cetyltrimethylammonium bromide (CTAB) and nonionic poly (ethylene oxide)–poly (propylene oxide)–poly (ethylene oxide) triblock copolymer (Pluronic P123). The resulting material was characterized by XRD and FT-IR spectrum. The potential of SH-MCM-48 for adsorption Zn (II) from aqueous solution was examined. Batch adsorption studies were carried out to investigate the effect of experimental parameters including pH, metal ions concentration and adsorption time. The maximum adsorption capacities of Zn (II) onto SH-MCM-48 were 30.12, 34.01 and 38.02 mg g-1 at the temperature of 303, 313 and 323K, respectively. The adsorption kinetics data were found to follow the pseudo-second-order kinetic model, and adsorption isotherms were fitted well with Langmuir and Freundlich models. Moreover, the adsorption thermodynamic parameters (△G0, △H0 and △S0) were measured, and indicated that the adsorption was an exothermic and spontaneous process.


2020 ◽  
pp. 004051752095848
Author(s):  
Huiyu Jiang ◽  
Xiaodong Hu ◽  
Asfandyar Khan ◽  
Jinbo Yao ◽  
Muhammad Tahir Hussain

In this study, gardenia yellow solution is used to dye 100% cotton fabric. The dyeing rate curve and adsorption isotherms were recorded to explore the thermodynamic model and to calculate the corresponding parameters. A definite concentration of gardenia yellow solution was placed under the xenon arc lamp for irradiation to test its photodegradability. Absorbance of the solution was measured at different degradation times and the corresponding varying curve of the absorbance was drawn to explore the photodegradation reaction order of the natural colorant and consistent parameters were calculated. The experimental results proved that the dyeing of cotton fabric with gardenia yellow colorant followed the pseudo second order kinetic model whereas adsorption isotherm followed the Langmuir model and the photodegradation process followed the second order kinetic model. Values of different parameters were calculated: reaction rate constant k = 2.26 × 10–3 (mg · L−1)1−m h−1, the correlation coefficient R2 = 0.994, and half decay time t1/2 = 5.82 h.


2020 ◽  
Vol 168 ◽  
pp. 00050
Author(s):  
Vadym Korovin ◽  
Yurii Pohorielov ◽  
Yurii Shestak ◽  
Oleksandr Valiaiev ◽  
Jose Luis Cortina

Kinetics of scandium recovery by TVEX containing tributyl phosphate was studied from the clarified leaching solution of salt chlorinator cake. To assess the contribution of each diffusion phase, experimental data were analyzed using a graphic method. To define the contribution of chemical interaction into the scandium extraction process, recovery kinetics was quantitatively described using pseudo-first order, pseudo-second order kinetic models and Elovich equation in linearized form. It was established that recovery kinetics was most accurately described with the pseudo-second-order model.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5156
Author(s):  
Dororthea Politi ◽  
Dimitrios Sidiras

This study investigated the potential use of spruce sawdust that was pretreated with diethylene glycol and sulfuric acid for the removal of hexavalent chromium from wastewater. The sawdust pretreatment process was conducted at different temperatures and times. The adsorbent was characterized by quantitative saccharification, scanning electron microscopy, and Brunauer–Emmet–Teller surface area analysis. Adsorption capacity was studied for both batch and column processes. The experimental adsorption isotherms were simulated using seven isotherm models, including Freundlich and Langmuir models. By using the Langmuir isotherm model, the maximal Cr(VI) adsorption capacity of organosolv-pretreated spruce sawdust (qm) was 318.3 mg g−1. Furthermore, the kinetic data were fitted to Lagergren, pseudo-second-order, and intraparticle diffusion models, revealing that the adsorption of Cr(VI) onto spruce sawdust pretreated with diethylene glycol and sulfuric acid is best represented by the pseudo-second-order kinetic model. Three kinetic models, namely, the Bohart–Adams model, Thomas model, and modified dose–response (MDR) model, were used to fit the experimental data obtained from the column experiments and to resolve the characteristic parameters. The Thomas adsorption column capacity of the sawdust was increased from 2.44 to 31.1 mg g−1 upon pretreatment, thus, demonstrating that organosolv treatment enhances the adsorption capability of the material.


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