scholarly journals Application of calixpyrrole modified silica for the removal of 4-chlorophenol from aqueous media

2019 ◽  
Vol 10 (2) ◽  
pp. 156-165
Author(s):  
Ismail Ibrahim Abbas ◽  
Bassem Mohamad Riad El Hamaoui ◽  
Hilal Mohamad Jamal Najmeddine

In this research, calixpyrrole modified silica (III) was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and scanning electron microscope (SEM) techniques. The synthesized material was used as an extractant for the removal of 4-chlorophenol from aqueous solution. Its efficiency was examined through both batch and column extraction methods. The effects of temperature, pH, initial chlorophenol concentration and mass of the adsorbent were examined using removal efficiencies. Initial concentration and quantity of adsorbent show a noticeable influence on the uptake capacity of the adsorbent. The kinetics and thermodynamics of chlorophenol removal from aqueous media were also investigated. Kinetic studies indicated that the extraction data can be best represented by pseudo second order model. Column extraction data were analyzed through Thomas, Yoon-Nelson and Yan et al. models to calculate kinetic coefficients and maximum sorption capacity of the modified silica (III). The adsorbent silica was regenerated by acid treatment without changing its properties.

Author(s):  
D. M. Sánchez Nava ◽  
H. López González ◽  
M. T. Olguín ◽  
S. Bulbulian

In this work, the removal of nickel from aqueous solutions by Agave salmiana was investigated. For this purpose the removal of this heavy metal (Ni2+) was carried out in a batch system as a function of contact time, pH, and the initial concentration of the metallic specie in solution. The sorption data were fitted to pseudo-first order and pseudo-second order kinetic models to found the parameteres which describe the processes. It was found that the maximum sorption of the Agave for Ni2+ was at pH 10 and pseudo-second order kinetic model well described the biosorption behavior of this heavy metal by the non-living biomass. Furthermore, the maximum sorption capacity obtained from the isotherm was 10 mgNi/gAgave.


2015 ◽  
Vol 16 (1) ◽  
pp. 115-127 ◽  
Author(s):  
P. Dhanasekaran ◽  
P. M. Satya Sai ◽  
C. Anand Babu ◽  
R. Krishna Prabhu ◽  
K. K. Rajan

Arsenic is a toxic element found naturally in groundwater. Due to its carcinogenicity, risk for heart diseases and diabetes, arsenic needs to be removed from groundwater for potable application. ‘Anjili’ tree sawdust was chemically modified with ferric hydroxide and activated alumina (SFAA) and used as an adsorbent for the removal of arsenic from groundwater. The adsorbent was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) to study the pore structure and surface functional groups. Effect of contact time, initial concentration, pH, particle size and temperature was studied. Arsenic adsorbed by SFAA followed Freundlich adsorption isotherm. Maximum sorption of arsenic by SFAA adsorbent occurred at pH 6.5. Arsenic sorption kinetics followed a pseudo-second-order model. The maximum sorption capacity at 303 K was found to be 54.32 mg/g for As(III) and 77.60 mg/g for As(V). Interference of other ions on the adsorption was in the order of PO43− > SO42− > HCO3− > NO3−.


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.


2014 ◽  
Vol 661 ◽  
pp. 39-44
Author(s):  
Nur Khalida Adibah Md Rodzi ◽  
Senusi Faraziehan ◽  
Alrozi Rasyidah

In this study, biosorption of copper and zinc ions on Baker’s yeast, Saccharomyces Cerevisiae was investigated. The data of batch experiments was used to perform equilibrium and kinetic studies. The experimental results were fitted well to the Langmuir and Freundlich model isotherms. According to the parameters of Langmuir isotherm, the maximum biosorption capacities of copper and zinc ions onto immobilized yeast were 5.408mg/g and 1.479mg/g at 293 Kfor the treated beads. Competitive biosorption of two metal ions was investigated in terms of maximum sorption quantity. The binding capacity for copper ions is more than the zinc ions for both untreated and treated immobilized yeast.While, for the kinetic studies, the pseudo second order model was found the most suitable model for the present systems.


2017 ◽  
Vol 19 (1) ◽  
pp. 107-114 ◽  

<p>In last decades the search for new low cost sorbents that have heavy metal ions binding capabilities is a hot topic in the field of clean-up technologies. In this study,&nbsp; wastes of&nbsp; Romanian silver tree (<em>Abies alba)</em> bark&nbsp; were explored for first time as green and economical sorbent for the removal of Cd(II) ions from aqueous solutions.&nbsp; The effect of various experimental parameters such as initial solution pH, sorbent dose, initial Cd(II) concentration, temperature and contact time has been investigated under batch conditions.&nbsp;</p> <p>The Langmuir and Freundlich models were used to describe the equilibrium isotherms and both models have been fitted very well. According to the evaluation using the Langmuir equation, the maximum sorption capacity of Cd (II) ions on <em>Abies alba</em> bark waste was found to be 11.98<br /> mg g<sup>-1</sup> at 293 K. The thermodynamic parameters showed that the process of Cd(II) sorption on silver fir tree bark was feasible, spontaneous and endothermic. Kinetic data were properly fitted with the pseudo–second order model. The obtained results strongly suggest that Romanian silver tree (<em>Abies alba)</em> bark is eligible as an efficient sorbent for the decontamination of toxic metals from wastewaters.</p>


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nadavala Siva Kumar ◽  
Hamid M. Shaikh ◽  
Mohammad Asif ◽  
Ebrahim H. Al-Ghurabi

AbstractThis study investigated a novel agricultural low-cost bio-waste biochar derived from wood apple fruit shell waste via the pyrolysis method, which is modified by ball milling and utilized to remove toxic phenol and chlorophenols (4-CPh and 2,4-DCPh) from contaminated aqueous media. The ball-milled wood apple fruit shell waste biochar (WAS-BC) sorbent was systematically analyzed by BET, CHN, and FTIR as well as particle size, SEM–EDS, XPS and TGA studies. The sorption equilibrium and kinetic studies exhibit that the sorption capacity was greater than 75% within the first 45 min of agitation at pH 6.0. The uptake capacity of 2,4-DCPh onto WAS-BC was greater than those of 4-CPh and phenol. Equilibrium results were consistent with the Langmuir isotherm model, while the kinetic data were best represented by the Elovich and pseudo-second-order model. The maximum uptake of phenol, 4-CPh, and 2,4-DCPh was 102.71, 172.24, and 226.55 mg/g, respectively, at 30 ± 1 °C. Thus, this study demonstrates that WAS-BC is an efficient, low-cost sorbent that can be used for the elimination of phenol and chlorophenol compounds from polluted wastewater.


2020 ◽  
Vol 24 (8) ◽  
pp. 46-50
Author(s):  
A.V. Svyatchenko ◽  
S.V. Sverguzova ◽  
Zh.A. Sapronova ◽  
I.G. Shaikhiev

For wastewater treatment, native and thermally modified samples of leaf chestnut litter (LCL) were used as sorption material. Studies were carried out to determine the static oil capacity of the sorption material (SM) in relation to the diesel fuel (DF) and water adsorption depending on the particle size. It was established that the oil capacity of chestnut litter depends on the particle size of the biosorption material, the conditions of its heat treatment, and the duration of contact of the SM with the sorbate. It was found that the maximum sorption capacity by DF for LCL250 is 7.17 g/g. It was determined that the purification efficiency of over 95% is achieved with a dosage of LCL250 over 1.0 g/dm3 and a diesel fuel concentration of 210 mg/dm3.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 962
Author(s):  
Kuo-Yu Chen ◽  
Wei-Yu Zeng

Poly-γ-glutamate/apatite (PGA-AP) nanoparticles were prepared by chemical coprecipitation method in the presence of various concentrations of poly-γ-glutamate (γ-PGA). Powder X-ray diffraction pattern and energy-dispersive spectroscopy revealed that the main crystal phase of PGA-AP was hydroxyapatite. The immobilization of γ-PGA on PGA-AP was confirmed by Fourier transform infrared spectroscopy and the relative amount of γ-PGA incorporation into PGA-AP was determined by thermal gravimetric analysis. Dynamic light scattering measurements indicated that the particle size of PGA-AP nanoparticles increased remarkably with the decrease of γ-PGA content. The adsorption of aqueous Cu(II) onto the PGA-AP nanoparticles was investigated in batch experiments with varying contact time, solution pH and temperature. Results illustrated that the adsorption of Cu(II) was very rapid during the initial adsorption period. The adsorption capacity of PGA-AP nanoparticles for Cu(II) was increased with the increase in the γ-PGA content, solution pH and temperature. At a pH of 6 and 60 °C, a higher equilibrium adsorption capacity of about 74.80 mg/g was obtained. The kinetic studies indicated that Cu(II) adsorption onto PGA-AP nanoparticles obeyed well the pseudo-second order model. The Langmuir isotherm model was fitted well to the adsorption equilibrium data. The results indicated that the adsorption behavior of PGA-AP nanoparticles for Cu(II) was mainly a monolayer chemical adsorption process. The maximum adsorption capacity of PGA-AP nanoparticles was estimated to be 78.99 mg/g.


2020 ◽  
Vol 108 (8) ◽  
pp. 615-626
Author(s):  
Mu Lin ◽  
Ivan Kajan ◽  
Dorothea Schumann ◽  
Andreas Türler ◽  
Adelheid Fankhauser

AbstractThirty liters of highly acidic spent nuclear fuel solutions need to be disposed at the “Hot Laboratory (hotlab)” facility in Paul Scherrer Institut (PSI), Switzerland. In order to significantly reduce the γ dose rate before proper disposal treatment, 137Cs must be removed. In the here presented sub-project, the ion-exchange method was evaluated. Two promising sorbents, CLEVASOL® and AMP (ammonium molybdophosphate), and two derived products AMP_PAN (AMP immobilized in polyacrylonitrile) and AMP/SiO2 (AMP immobilized on silica gel) were tested by the batch method using model solutions of important high-yield fission products (Cs, Eu, Zr, Ru, Pd and Ag), as well as U and Pu. The results showed that AMP, AMP/SiO2 and AMP_PAN have higher selectivity for Cs than CLEVASOL® in 0.1–8 M (mol/L) HNO3 solutions. 4 M HNO3 solution was identified as the most suitable condition for Cs-removal with AMP, AMP_PAN and AMP/SiO2 due to the still sufficiently high separation factor of Cs from other metal ions and an acceptable volume increase factor after dilution. The follow-up kinetic studies on AMP, AMP_PAN and AMP/SiO2 indicated that although Cs exchange on AMP and AMP/SiO2 is faster than on AMP_PAN in the first 5 min, they all nearly reach equilibrium after 30 min of contacting time. The isotherm curves of Cs adsorption on AMP, AMP_PAN and AMP/SiO2 in 4 M HNO3 showed that the maximum sorption capacity of Cs is reached asymptotically. The results from Langmuir isotherm modeling agree with results from other publications.


2014 ◽  
Vol 69 (11) ◽  
pp. 2230-2236 ◽  
Author(s):  
G. K. Bakyayita ◽  
A. C. Norrström ◽  
M. Nalubega ◽  
R. N. Kulabako

Untreated and chemically treated Albizia coriaria, Erythrina abyssinica and Musa spp. were studied in batch for uptake of Cd2+ and Pb2+ ions at pH 2.0–9.0 and agitation time of 30–390 min. Optimum biosorption conditions were pH 4 for Pb2+ ions and pH 5 for Cd2+ ions, contact time was 3.5 hours at 24 ± 1 °C for 10 mg/L biosorbent dosage and initial metal ions concentration of 20 mg/L. Chemical treatment had a 10–17% biosorption efficiency enhancement for Cd2+ ions and a 1.6–2.3% reduction effect for Pb2+ ions. The sorption capacities for Cd2+ and Pb2+ ions for treated biosorbents were 1.760–1.738 mg g−1 compared to 1.415–1.539 mg g−1 for untreated materials. The pseudo second-order model suitably fitted the Cd2+ and Pb2+ ions biosorption data with regression coefficients (R2) of 0.9784–0.9999. Fitting of the Ho model to the experimental data showed that the biosorption mechanism for both metal ions studied was mainly a chemisorption process. Therefore, treated A. coriaria, E. abyssinica and Musa spp. were potential biosorbents for remediation of Cd2+ ions and the untreated materials suitable for removing Pb2+ ions from contaminated aqueous media.


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