scholarly journals Sorption of vanadium (V) and nickel (II) on amorphous silic

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 253-260
Author(s):  
O. A. Timoshchik ◽  
◽  
E. A. Shchelokova ◽  
A. G. Kasikov ◽  
M. V. Bryukhanova ◽  
...  

The sorption of vanadium (V) and nickel (II) from aqueous solutions on amorphous silica obtained from metallurgical slags of the Kola MMC is considered, and the optimal conditions for the metal sorption process are determined. It is established that the maximum sorption of metals is achieved at pH 2.0–4.0, at a temperature of 40 °C and a process time of 60 minutes for nickel and 90 minutes for vanadium.

2012 ◽  
Vol 573-574 ◽  
pp. 150-154
Author(s):  
Yun Bo Zang ◽  
Nai Ying Wu

In this study, removal of copper ions from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, EDTA and addition sequences at room temperature. It is found that HTlc could reduced copper ions concentration effectively. The kinetics closely fit pseudo-second order kinetics with necessary time 9 h to reach equilibrium. The sorption process followed langmuir model. The maximum sorption capacity calculated was found to be 39.4 mg/g. The presence of EDTA and addition sequences could affect sorption of Cu(II) onto HTlc.


2020 ◽  
Vol 85 (10) ◽  
pp. 1371-1382
Author(s):  
Sladjana Meseldzija ◽  
Jelena Petrovic ◽  
Antonije Onjia ◽  
Tatjana Volkov-Husovic ◽  
Aleksandra Nesic ◽  
...  

This study is aimed to evaluate the possibility of lemon peel, as an agro-industrial waste, to remove Fe2+, Zn2+ and Mn2+ from single aqueous solutions and mining wastewater. For this purpose, the influence of various parameters: sorption time, initial pH solution, initial metal ion concentration and a dose of sorbent on the sorption process were studied in batch experiments. The experimental equilibrium data have been analysed utilizing linearized forms of Langmuir, Freundlich, Temkin and Dubinin?Radushkevich isotherms. The Langmuir isotherm provided the best theoretical correlation of the experimental equilibrium data for Fe2+, Zn2+ and Mn2+, with the maximum sorption capacities of 4.40, 5.03 and 4.52 mg g-1, respectively. The percentage of targeted ions removal from single aqueous solutions was 92.9 % (Zn2+), 84.5 % (Fe2+) and 78.2 % (Mn2+). Regarding the sorption capability of lemon peel in mining wastewater, the maximum removal of Fe2+, Zn2+ and Mn2+ from mining wastewater was 49.62, 33.97 and 9.11 %, respectively. In addition, the potential reusability of the lemon peel as sorbent was investigated through desorption study in 0.1M of CH3COO4, HCl and HNO3 solution. The highest rate of desorption was achieved in 0.1 M HCl solution, reached a value of 55.19 % for Mn2+ and 37.24 % for Zn2+, while for Fe2+ the highest value of 25.82 % was achieved in 0.1M HNO3 solution.


Author(s):  
Tomasz Jóźwiak ◽  
Urszula Filipkowska ◽  
Paula Bugajska ◽  
Małgorzata Kuczajowska-Zadrożna ◽  
Artur Mielcarek

The influence of the degree of deacetylation of chitosan from the range of DD = 75–90% on the effectiveness of sorption of nitrates from aqueous solutions was investigated. The scope of the research included: determining the effect of pH on the effectiveness of N-NO3 binding on chitosan sorbents and determining the sorption capacity of chitosan sorbents with different degrees of deacetylation after 5, 15, 30 and 60 minutes. The effectiveness of sorption of nitrates on chitosan sorbents increased in the series DD=75% < DD=85% < DD=90%. Regardless of the degree of deacetylation, the sorption effectiveness of nitrates on chitosan was the highest at pH 4. The amount of nitrate-related sorbents was the highest after 30 min of sorption. A process time which was too long resulted in desorption of nitrates. The maximum sorption capacity for chitosan with the degree of deacetylation DD = 75, 85 and 90% was 0.59 mg N-NO3/g, 0.60 mg N-NO3/g and 0.87 mg N-NO3/g, respectively.


2021 ◽  
Vol 6 (2) ◽  
pp. 64-68
Author(s):  
Ihor Petrushka ◽  
◽  
Oksana Bratus ◽  
Kateryna Petrushka ◽  
◽  
...  

The results of adsorption properties of complex natural sorbents in relation to the neutralization of zinc ions from wastewater are presented. The adsorption isotherm of Zn2+ ions on complex sorbents (clinoptilolite-shungite) (1:1) according to Langmuir and Freundlich models is constructed, the type of adsorption isotherms according to S. Brunauer classification is established. The value of the maximum sorption capacity of Gmax complex sorbents for Zn2+ ions is calculated. The peculiarities of the sorption process of zinc ions with the formation of a monomolecular layer based on the calculated coefficients of the Langmuir and Freundlich were found. The optimal conditions for the dependence of the degree of absorption of Zn2+ ions by complex sorbents on the duration of the sorption process are determined. The ratio "solid (complex sorbent) - liquid" was determined experimentally.


Author(s):  
Paula Bugajska ◽  
Urszula Filipkowska ◽  
Tomasz Jóźwiak ◽  
Małgorzata Kuczajowska-Zadrożna

The article presents the effectiveness of orthophosphate sorption from aqueous solutions depending on the deacetylation degree of chitosan flakes. The first stage of the research was to determine the pH value at which the sorption process was the most effective (from the pH range 2–11). In the second stage, research was carried out to determine the maximum sorption capacities of chitosan with deacetylation degrees of 75%, 85% and 90% in relation to PO43-. The highest effectiveness of orthophosphate removal on chitosan, regardless of its deacetylation degree, was obtained at pH 4. At pH 2 and 3, the chitosan flakes dissolved. This study showed that the sorption effectiveness of phosphorus compounds depends on the deacetylation degree of chitosan. Along with the increase in deacetylation degree, the sorption capacity of chitosan also increases in relation to orthophosphates. It is related to the higher number of amino groups in the structure of chitosan, which are responsible for the sorption of pollutants in the form of anions. The maximum sorption capacity of chitosan-DD = 75% in relation to biogen was 5.13 mg/g, chitosan-DD = 85% was 5.65 mg/g, and chitosan-DD = 90% was 5.91 mg/g. After 60 minutes, the desorption process had begun and was most likely caused by an increase in the pH of the solution. Due to chitosan's ability to neutralise the sample and the associated risk of desorption, the time of sorbent contact with sewage cannot be longer than 60 minutes.


Author(s):  
J. W. Mellowes ◽  
C. M. Chun ◽  
I. A. Aksay

Mullite (3Al2O32SiO2) can be fabricated by transient viscous sintering using composite particles which consist of inner cores of a-alumina and outer coatings of amorphous silica. Powder compacts prepared with these particles are sintered to almost full density at relatively low temperatures (~1300°C) and converted to dense, fine-grained mullite at higher temperatures (>1500°C) by reaction between the alumina core and the silica coating. In order to achieve complete mullitization, optimal conditions for coating alumina particles with amorphous silica must be achieved. Formation of amorphous silica can occur in solution (homogeneous nucleation) or on the surface of alumina (heterogeneous nucleation) depending on the degree of supersaturation of the solvent in which the particles are immersed. Successful coating of silica on alumina occurs when heterogeneous nucleation is promoted and homogeneous nucleation is suppressed. Therefore, one key to successful coating is an understanding of the factors such as pH and concentration that control silica nucleation in aqueous solutions. In the current work, we use TEM to determine the optimal conditions of this processing.


2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.


2003 ◽  
Vol 21 (2) ◽  
pp. 189-198
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Rana Saeidi ◽  
Salam Abu Zaid

As in Part I, non-activated (natural) and chemically activated oak shells were evaluated for their ability to remove phenol and Methylene Blue (as a typical dye component) from aqueous solutions. Batch adsorption experiments were conducted to investigate the effect of contact time, sorbent concentration, phenol concentration and the pH of the solution on the sorption process. Activated oak shells adsorbed more phenol than natural oak shells under the same conditions. A decrease in sorbent concentration or an increase in phenol concentration or solution pH resulted in an increase in phenol uptake by the oak shells. The uptake of Methylene Blue increased with decreasing sorbent concentration and with an increase in the dye concentration, but decreased significantly with solution pH. According to the fractional factorial design technique, the sorbent type employed (natural or activated) had the most significant influence on phenol or Methylene Blue uptake followed by sorbent concentration and then sorbate concentration. Interaction amongst the different operating variables played an important role in the uptake of phenol or Methylene Blue dye by the adsorbent considered.


2008 ◽  
Vol 26 (9) ◽  
pp. 693-703 ◽  
Author(s):  
P. Senthil Kumar ◽  
K. Kirthika ◽  
K. Sathish Kumar

The removal of hexavalent chromium, Cr(VI), from aqueous solutions under different conditions using an anion-exchange resin (AXR) as an adsorbent was investigated under batch conditions. Such studies indicated that the percentage adsorption decreased with increasing initial Cr(VI) concentration, with the maximum removal of such ions occurred at a pH value of ca. 2.0. Both the Langmuir and Freundlich isotherm models were capable of reproducing the isotherms obtained experimentally. The sorption process was rapid during the first 20 min with equilibrium being attained within 30 min. The process followed first-order kinetics. The results demonstrate that such anion-exchange resins can be used for the efficient removal of Cr(VI) ions from water and wastewater.


Author(s):  
Л.А. Марченко ◽  
Т.Н. Боковикова

Проведен анализ состава сточных вод предприятий молочной промышленности. Исследованы технические характеристики сорбционных материалов, способных восстановить состав ресурса до норм ПДК. Установлено, что применение двухстадийной очистки модельных растворов с использованием на 1й стадии процесса коагуляции, на 2й сорбции позволяет увеличить эффективность очистки до 92. Оценена сорбционная емкость сорбентов и проанализированы факторы, на нее влияющие. Подобраны оптимальные условия проведения процесса сорбции в зависимости от условий и характера объектов очистки. The analysis of the wastewater composition of the dairy industry was carried out. The technical characteristics of a number of sorption materials that can restore the composition of the resource to the MPC standards are investigated. It is shown that the use of twostage purification of model solutions using on the first stage of the coagulation process, on the second stage, the sorption process, allows increase the cleaning efficiency up to 92. The sorption capacity of sorbents was evaluated and the factors affecting it were analyzed, the optimal conditions for the sorption process were selected depending on the conditions and nature of the objects to be cleaned.


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