Removal of Mn(II), Fe(III) and Cr(III) from aqueous solutions using Bulgarian clinoptilolite (original) (raw)
Related papers
2018
The aim of this article is characterization of natural zeolite (clinoptilolite) and its application for removal of heavy metals from aqueous solution. Characterization of the natural zeolite from Beli Plast deposit, Kardjali, was conducted using: classical chemical analysis, XRD, SEM/EDS, DTA/TG/DTG, XRF, FTIR and BET. Based on the results of the chemical composition, XRD, SEM/EDS and FTIR analyses, it is evident that the major component of the working material (~ 95%) is clinoptilolite. In fact, the working material is alumino-silicate with high silicate module and it is of clinoptilolite type. The applied material has the specific surface area of 31.3 m 2 /g determined by BET method with nitrogen adsorption. The maximum capacity of clinoptilolite towards zinc, nickel and cobalt removal under the studied conditions is approximately 3.5 mg/g, for copper and manganese is approximately 4.5 mg/g and for lead ions is approximately 30 mg/g. Natural zeolite (clinoptilolite) was used as a potential raw material for the purpose of removal of Cu(II), Zn(II), Mn(II), Pb(II), Co(II) and Ni(II) ions from model solutions. The experimental results were obtained in a laboratory scale batch glass reactor with continuous stirring at 400 rpm. The adsorption of studied heavy metal ions from solution were efficiently onto used adsorbent and approximately 90% from ions were removed from single ion solutions. Generally, it can be concluded that studied clinoptilolite is a potential raw material for effective removal of heavy metals ions from various types of waste waters.
Adsorption of toxic metals by natural and modified clinoptilolite
Annali di chimica, 2007
The chromium, cobalt and lead removal from aqueous solution by natural and modified zeolites was examined by using a batch-type method. Clinoptilolite samples used in this study were supplied from Bigadiç, Turkey. All samples were modified with HNO3 or NaOH to improve the adsorption capacity for heavy metals. The removal efficiencies and kinetics of heavy metals such as chromium, cobalt and lead on natural and modified zeolites were determined. The effects of the initial metal concentration on the removal percentage of heavy metal ions were studied. Freundlich and Langmuir isotherm constants and correlation coefficients were found and the equilibrium process was described by the Freundlich isotherm. The adsorption kinetic was tested and then it indicates the process to be diffusion controlled.
Adsorption of heavy metal cations by Na-clinoptilolite: Equilibrium and selectivity studies
Journal of Environmental Management (Impact Factor: 3.06). 05/2014 DOI:http://dx.doi.org/10.1016/j.jenvman.2014.02.007; 137:69–80., 2014
This paper summarizes the conclusions of experiments conducted on the adsorption of Cd2+, Co2+, Cu2+, Mn2+, Ni2+, Pb2+ and Zn2+ onto zeolite. The focus of the experiments was to establish the influence of the initial pH of the contact solution as well as the selectivity of zeolite on the efficiency of the adsorption process. To this end, experimental adsorption isotherms were established for the pH values ranging from 1 to 4 by using the Na-form of clinoptilolite (particle size range 0.5–1 mm) as an adsorbent. Langmuir, Freundlich and Dubinin-Raduschkevich isotherm models were used to validate the experimental data and the Gibbs free energy was calculated based on the distribution coefficient. From the Langmuir model, correlations between the maximum adsorption capacity and selected physical–chemical parameters of the cations studied were established. The results of the experiments suggest that the selectivity of zeolite is strongly influenced by the pH of the contact solution, dehydration energy of cations, diffusion coefficient and the pH at which the precipitation of hydroxides occurs.
Environmental Science and Pollution Research, 2018
The performance of modified clinoptilolites (zeolites) from two different sources (South Africa and the USA) for the adsorption of Ni 2+ , Cd 2+ and Pb 2+ from synthetic industrial effluent contaminated with metal concentration levels at 50, 150 and 500 ppm was evaluated. The selectivity of the clinoptilolite for the adsorption of Ni 2+ , Cd 2+ and Pb 2+ was investigated with mixed feed solutions containing all three ions in equal concentrations and single-component concentrations containing only one of the ions. The homoionic forms of the clinoptilolite were made of Na + , K + and Ca 2+. Batch experiments were then conducted to measure the uptake of metals by the zeolites. The zeolites were characterised using SEM, XRD and BET. The South African clinoptilolite showed a higher surface area and pore volume (17.52m 2 /g and 0.047cm 3 /g respectively) than the USA zeolite (12.26m 2 /g and 0.028cm 3 /g respectively) for the Na + homoionic form. According to the equilibrium studies, the selectivity sequence was found to be Pb 2+ > Cd 2+ > Ni 2+ , with good fits being obtained using Langmuir and Freundlich adsorption isotherms for low metal concentrations. Examples of equilibrium adsorption capacities for RSA and USA clinoptilolite modified with Na + for Pb were 26.94 mg/g and 27.06 mg/g when RSA-Na + and USA-Na + were used respectively. The adsorption was found to depend on the homoionic form of the zeolite and to a lesser extent the source of the zeolite. The selectivity of a particular zeolite for a particular heavy metal can be altered by the homoionic form of the zeolite. Overall, the adsorption capacity of the USA clinoptilolite was higher than the adsorption capacity of the SA clinoptilolite, revealing the potential of clinoptilolite in metal-polluted industrial effluent treatment.
Heavy Metal Adsorption by Clinoptilolite from Aqueous Solutions
2005
The chromium, cobalt and cadmium removal from wastewaters by natural and modified zeolites was examined by using a batch-type method. A clinoptilolite-type Turkey natural zeolite was pretreated with HCl and HNO3 to improve the adsorption capacity for heavy metals. The removal efficiencies and kinetics of heavy metals such as chromium, cobalt and cadmium on natural and modified zeolites were determined. The kinetics of adsorption indicates the process to be diffusion controlled.
Spectroscopic study of heavy metals sorption on clinoptilolite
Physics and Chemistry of Minerals, 2005
Sorption of heavy metal cations (Pb(II), Cr(III), Cd(II), Ni(II)) from aqueous solutions on natural Na-clinoptilolite was studied using atomic absorption spectrometry (AAS) and FT-IR spectroscopy. It was found that the sorption capacity of clinoptilolite decreases in the following order: Pb(II) (22,600 mg/kg), Cr(III) (21,200 mg/kg), Cd(II) (10,400 mg/kg) and Ni(II) (6,200 mg/kg). In the FT-IR spectra of the samples, in the region of pseudolattice vibrations (500-800 cm À1 ), systematic changes connected with the type of cation and its concentration in the initial solution were observed. The proportions of ion exchange and chemisorption in the whole process of sorption were also estimated. It was found that the amount of cations sorbed on clinoptilolite depended on the concentrations and pH of the solutions used as well as on the contact time of zeolite-solution system. After 120 min of the reaction, despite the metal type, 90-100% of the total amount of cations were immobilized.
IJERT-Removal of Heavy Metals from Aqueous Solution using Clinoptilolite and Stilbite
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/removal-of-heavy-metals-from-aqueous-solution-using-clinoptilolite-and-stilbite https://www.ijert.org/research/removal-of-heavy-metals-from-aqueous-solution-using-clinoptilolite-and-stilbite-IJERTV3IS110384.pdf Heavy metals are highly toxic and they must be removed from the polluted streams. Аdsorption by zeolites is currently considered to be very suitable for wastewater treatment because of its simplicity and cost effectiveness. The aim of this investigation was to compare adsorption efficiency of heavy metals (Cu, Zn, Mn and Pb) from aqueous solution using two different types of natural zeolite: clinoptilolite from Bulgaria and stilbite from Macedonia. The obtained information will be basis for further research for acid mine drainage treatment with zeolite. The adsorption of Cu, Zn, Mn and Pb from aqueous solution using clinoptilolite and stilbite is effective. Copper and zinc ions are better adsorbed using stilbite, manganese ion is better adsorbed using clinoptilolite as adsorbent and for lead ion a both of used adsorbent gave a similar results. According to the maximum adsorption capacity (q e) was determine the selectivity of clinoptilolite and stilbite, for the respective heavy metal ions. The selectivity series obtained about clinoptilolite was: Pb 2+ > Cu 2+ > Zn 2+ > Mn 2+ , and about stilbite was Pb 2+ > Cu 2+ > Zn 2+ > Mn 2+. From the kinetic modelling, the pseudo-second order kinetic model gave a better fits than pseudo-first order kinetic model for adsorption of Cu, Zn, Mn and Pb onto clinoptilolite and stilbite.
Heavy metal removal from industrial wastewater by clinoptilolite
Journal of Environmental Science and Health, Part A, 2007
The adsorption of copper and zinc ions onto the modified diatomite with sodium hydroxide and manganese oxide (Mn-DM) was studied in isotherm batch solutions. The analysis of Cu (II) and Zn (II) results showed the effect of contact time and adsorbent dosage on the adsorption process performed in solutions with individual and combined metal ions, allowing observations of the selectivity and preference of modified diatomite in capturing Cu (II) and Zn (II). The paper also analysed the effect of supplementing peat on the adsorption process, at various ratios to the modified diatomite, to obtain the optimised filter composition with highest adsorption efficiency. The obtained data was used to model the kinetics of the adsorption processes for both metal ions.
Journal of Hazardous Materials, 2007
Adsorption of Pb(II) ions from aqueous solution onto clinoptilolite has been investigated to evaluate the effects of contact time, initial concentration and pretreatment of clinoptilolite on the removal of Pb(II). Experimental data obtained from batch equilibrium tests have been analyzed by four twoparameter (Freundlich, Langmuir, Temkin and Dubinin-Radushkevich), four three-parameter (Redlich-Peterson, Sips, Toth and Khan) isotherm models, and kinetic models including the pseudo-first order, the pseudo-second order and Elovich equations using nonlinear regression technique. Of the two-parameter isotherms, Temkin isotherm was the best to describe the experimental data. Three-parameter isotherms have higher regression coefficients (>0.99) and lower relative errors (<5%) than two-parameter isotherms. The best fitting isotherm was the Sips followed by Toth and Redlich-Peterson isotherm equations. Maximum experimental adsorption capacity was found to be 80.933 and 122.400 mg/g for raw and pretreated clinoptilolite, respectively, for the initial concentration of 400 mg/L. Kinetic parameters; rate constants, equilibrium adsorption capacities and related coefficients for each kinetic model were evaluated according to relative errors and correlation coefficients. Results of the kinetic studies show that best fitted kinetic models are obtained to be in the order: the pseudo-first order, the pseudo-second order and Elovich equations. Using the thermodynamic equilibrium coefficients, Gibbs free energy of the Pb(II)-clinoptilolite system was evaluated. The negative value of change in Gibbs free energy (G •) indicates that adsorption of Pb(II) on clinoptilolite is spontaneous.
Removal of Heavy Metals from Aqueous Solution using Clinoptilolite and Stilbite
Heavy metals are highly toxic and they must be removed from the polluted streams. Аdsorption by zeolites is currently considered to be very suitable for wastewater treatment because of its simplicity and cost effectiveness. The aim of this investigation was to compare adsorption efficiency of heavy metals (Cu, Zn, Mn and Pb) from aqueous solution using two different types of natural zeolite: clinoptilolite from Bulgaria and stilbite from Macedonia.