scholarly journals Sorption performance of cysteine-modified bentonite in heavy metals uptake

2009 ◽  
Vol 74 (7) ◽  
pp. 833-843 ◽  
Author(s):  
Hossein Faghihian ◽  
Massoud Nejati-Yazdinejad
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Metal Binding ◽  
Heavy Metal Ions ◽  
Sorption Isotherms ◽  
Local Clay ◽  
Lead And Cadmium ◽  
Sorption Parameters ◽  
Thiol Ligand ◽  
Heavy Metals Uptake

A local clay, bentonite (N-Ben), was modified by the biologically-based ligand, cysteine (Cys), through a simple sorption technique. The modified sorbent (Cys-Ben) demonstrated affinity for soft and moderately soft heavy metal ions (HMI), such as Cd(II) and Pb(II), probably as a result of the soft basic character of the thiol ligand side chains. The resulting modified system was effective for metal binding with capacities of 0.503 and 0.525 mmol g-1, for Pb(II) and Cd(II), respectively. Comparative batch experiments were performed for removing lead and cadmium from aqueous solutions. The sorption parameters were derived from a Langmuir fit to the sorption isotherms of the studied ions. The study showed that the sorption capacity of Cys-Ben was higher than that of N-Ben for these ions. The effect of pH was examined over the range 2.0-6.0. The sorption capacities of Cys-Ben showed that this modified clay is a good sorbent for the examined heavy metal ions.

scholarly journals Application of ANN to the Sorption Equilibrium Modelling of Heavy Metal Ions on Clinoptilolite

2012 ◽  
Vol 19 (2) ◽  
pp. 227-237 ◽  
Author(s):  
Elwira Tomczak ◽  
Wladyslaw Kaminski
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Sorption Isotherms ◽  
Initial Step ◽  
Training Data ◽  
Sorption Equilibrium ◽  
Network Training ◽  
Mineral Sorbent ◽  
Number Of Publications

Application of ANN to the Sorption Equilibrium Modelling of Heavy Metal Ions on Clinoptilolite The latest achievements in the field of mathematical modelling include the application of artificial neural networks (ANN). A growing interest in the ANN is confirmed by the number of publications devoted to the applicability of ANN in chemical, process and environmental engineering. A recent dynamic development of ANN provided an efficient and universal tool that is used to solve many tasks, including modelling, approximation and identification of objects. The initial step of applying the network to a given process consists in the determination of weights of the proposed neural network structure. This is performed on the basis of training data. A network that is properly trained allows correct information to be obtained on the basis of other data which have not been used in the network training. In most cases the network training is performed on the basis of a known mathematical model. However, the training of a network can be also performed using experimental data. In this paper, the sorption isotherms were predicted by means of a multilayer perceptron (MLP). Calculations were made using a training program written in Matlab, which took advantage of the Lavenberg-Marquardt procedure. In the last decade a growing interest is observed in inexpensive and very cheap adsorbents to remove heavy metal ions. Clinoptilolite is the mineral sorbent extracted in Poland used to remove heavy metal ions from diluted solutions. Equilibrium experiments were carried out to estimate sorptivity of a clinoptilolite and its selectivity towards Cu(II), Zn(II) and Ni(II) ions for multicomponent solution. Calculations with the use of MLP enabled description of sorption isotherms for one, two and three ions which were present at the same time in the solution. The network also enabled an analysis of sorption of the single ion, taking into account the effect of its concentration.

scholarly journals Functionalization of PET Track-Etched Membranes by UV-Induced Graft (co)Polymerization for Detection of Heavy Metal Ions in Water

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1876 ◽  
Author(s):  
Maxim V. Zdorovets ◽  
Ilya V. Korolkov ◽  
Arman B. Yeszhanov ◽  
Yevgeniy G. Gorin
Keyword(s):  
Water Quality ◽  
Heavy Metal ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Heavy Metal Ions ◽  
Anodic Stripping Voltammetry ◽  
Stripping Voltammetry ◽  
Water Quality Monitoring ◽  
Lead And Cadmium ◽  
Platinum Layer

Nowadays, water quality monitoring is an essential task since environmental contamination and human exposure to heavy metals increased. Sensors that are able to detect ever lower concentrations of heavy metal ions with greater accuracy and speed are needed to effectively monitor water quality and prevent poisoning. This article shows studies of the modification of flexible track-etched membranes as the basis for the sensor with various polymers and their influence on the accuracy of detection of copper, cadmium, and lead ions in water. We report the UV-induced graft (co)polymerization of acrylic acid (AA) and 4-vinylpyridine (4-VPy) on poly(ethylene terephthalate) track-etched membrane (PET TeMs) and use them after platinum layer sputtering in square wave anodic stripping voltammetry (SW-ASV) for detection of Cu2+, Cd2+, and Pb2+. Optimal conditions leading to functionalization of the surface and retention of the pore structure were found. Modified membranes were characterized by SEM, FTIR, X-ray photoelectron spectroscopy (XPS) and colorimetric analysis. The dependence of the modification method on the sensitivity of the sensor was shown. Membrane modified with polyacrylic acid (PET TeMs-g-PAA), poly(4-vinylpyridine) (PET TeMs-g-P4VPy), and their copolymer (PET TeMs-g-P4VPy/PAA) with average grafting yield of 3% have been found to be sensitive to µg/L concentration of copper, lead, and cadmium ions. Limits of detection (LOD) for sensors based on PET TeMs-g-PAA are 2.22, 1.05, and 2.53 µg/L for Cu2+, Pb2+, and Cd2+, respectively. LODs for sensors based on PET TeMs-g-P4VPy are 5.23 µg/L (Cu2+), 1.78 µg/L (Pb2+), and 3.64 µg/L (Cd2+) µg/L. PET TeMs-g-P4VPy/PAA electrodes are found to be sensitive with LODs of 0.74 µg/L(Cu2+), 1.13 µg/L (Pb2+), and 2.07 µg/L(Cd2+). Thus, it was shown that the modification of membranes by copolymers with carboxylic and amino groups leads to more accurate detection of heavy metal ions, associated with the formation of more stable complexes.

Potentiostatic Electrochemical Preparation of Bismuth Nanoribbons and its Application in Biologically Poisoning Lead and Cadmium Heavy Metal Ions Detection

2015 ◽  
Vol 27 (10) ◽  
pp. 2341-2346 ◽  
Author(s):  
Rajkumar Devasenathipathy ◽  
Raj Karthik ◽  
Shen-Ming Chen ◽  
Veerappan Mani ◽  
V. S. Vasantha ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Electrochemical Preparation ◽  
Lead And Cadmium ◽  
Metal Ions Detection

scholarly journals Sorption of lead and cadmium ions from aqueous solutions using modified zeolite

2018 ◽  
pp. 16-22
Author(s):  
Madina Telkhozhayeva ◽  
Gulziya Seilkhanova ◽  
A. Rakhym ◽  
Ainur Imangaliyeva ◽  
Dina Akbayeva
Keyword(s):  
Heavy Metal ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Exchange Capacity ◽  
Static Exchange Capacity ◽  
Cadmium Ions ◽  
Modified Zeolite ◽  
Lead And Cadmium ◽  
Static Conditions

The processes of lead and cadmium ions sorption by modified zeolite of Chankanai deposit were studied. Chitosan was used as a surface modifier due to its properties: nontoxicity, biodegradability and biocompatibility. The adsorption process was carried out at room temperature (295 K) and pH 7 under static conditions. The synthesized sorbent has been characterized by scanning electron microscopy (SEM), elemental analysis; the concentrations of Pb(II) and Cd(II) ions before and after adsorption were determined using atomic absorption spectroscopy (AAS). The Si/Al ratio of the zeolite was found to be 1.66, which showed the prospects of using this material as a source object. The static exchange capacity (SEC) of sorbents and the extraction degree of heavy metal ions were determined and compared. It was found that the removal of heavy metal ions increased with the increase of contact time (removal efficiency was 99.1±1.2% for Pb2+ and 83.4±1.2% for Cd2+). The adsorption capacity values of the modified zeolite for metal ions were (0.86±0.03) mg/g for Cd(II) and (0.68±0.03) mg/g for Pb(II). Chitosan-modified zeolite proved to be an effective adsorbent for removal of lead and cadmium ions from aqueous solutions.

The Studies of Adsorption of Heavy Metal Ions of Lead and Copper by Distillers' Grains

2011 ◽  
Vol 695 ◽  
pp. 77-80 ◽  
Author(s):  
Juan Feng ◽  
Xiao Yan Lin ◽  
Xue Gang Luo ◽  
Jia Quan Rao ◽  
Chun Yan Zhang
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Removal Rate ◽  
Structural Characteristics ◽  
Sorption Isotherms ◽  
Distillers Grains ◽  
Sorption Data ◽  
Adsorption Behaviors ◽  
Heavy Metal Wastewater

The absorption of Cu2+ and Pb2+ in the heavy metal wastewater by distillers' grains can not only solve the problem of environmental pollution, but also change distillers' grains waste into resource. Structural characteristics of distillers' grains and its adsorption behaviors for the heavy metal ions of Cu2+ and Pb2+ were studied and effects of various parameters including pH, temperature, distillers' grains dose, initial Cu2+ and Pb2+ concentration and absorbed time on the absorption of Pb2+ and Cu2+ were evaluated. Sorption isotherms were also investigated. Results show that the rough surface, loose internal structure and hydroxy and amide groups of the distillers' grains are beneficial to the adsorption of Cu2+ and Pb2+ in the wastewater. The removal rate of the distillers' grains for Pb2+ (20.00 mg L−1) and Cu2+ (20.00 mg L−1) are, respectively, 96.72% and 87.70% under optimized conditions. The equilibrium sorption data are well demonstrated by Langmuir model.

scholarly journals Water purification from heavy metal ions by nano-sized Fe0/kaolinite composites

2020 ◽  
pp. 96-103
Author(s):  
I.A. Kovalchuk ◽  
◽  
V.Yu. Tobilko ◽  
A.I. Bondarieva ◽  
Yu.M. Kholodko ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Sorption Isotherms ◽  
Active Surface ◽  
Toxic Heavy Metal ◽  
Physicochemical Features ◽  
Sorbent Materials ◽  
Effective Sorbent ◽  
Sorption Characteristics

We have investigated the physicochemical features of the purification of wastewater that are complex on its content and include a mixture of heavy metal ions (Cu(II), Cd(II), Zn(II), Co(II), Cr(VI)). The phase of a composition and structural-sorption characteristics of synthesized nano-sized Fe0/kaolinite composites were studied. It was found that the obtained materials have much better sorption properties for the extraction of heavy metals from aqueous solutions in comparison with natural kaolinite. Calculations of sorption isotherms according to the Freundlich equation are done. Based on isotherms, the average values of specific sorption per unit of an active surface of the mineral at the content of heavy metal ions in the initial solutions of 300 μmol/dm3 were determined. They range from 0.42 to 17.1 μmol/g for Cr(VI) to Cu(II) ions. It has also been found that similar values for the modified samples are much larger and range from 13.8 to 80.27 μmol/g for ions from Cr(VI) to Cu(II). It is shown that composite sorbents based on nano-sized zero-valent iron and dispersed kaolinite silicate are effective sorbent materials for the purification of water contaminated with toxic heavy metal ions that are commonly found in wastewater of the galvanic and hydrometallurgical industries.

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