Characterization and Application of Clinoptilolite for Removal of Heavy Metal Ions from Water Resources (original) (raw)
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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.
Evaluation of Heavy Metal Removal from Wastewater Using Iranain Modified Natural Clinoptilolite
Asian Journal of Chemistry, 2013
In this study, the absorption properties of the natural zeolite (from east of Iran) with respect to some heavy metal cations in water solution were investigated. Clinoptilolite, a natural zeolite, was used for the removal of Cu 2+ , Co 2+ , Ni 2+ and Cd 2+ ions from water samples. The batch method has been employed. Satisfactory result was obtained by using pretreatment condition and regeneration. The percentage adsorption and distribution coefficient were determined for the absorption cations as a function of sorbate concentration. In the ion exchange evaluation, two sorption isotherms, Langmuir and Freundlich have been studied. Cation exchange selectivity can be given as Cd 2+ > Cu 2+ > Co 2+ >Ni 2+. These results show that these natural zeolites can be used efficiently for removal of heavy metal species from wastewater.
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.
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.
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.
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.
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.
Natural and modified zeolite to improve the adsorption of heavy metals from aqueous solutions
The present work describes the characterization of natural zeolites and adsorption results for Pb +2 , Cd +2 , Fe +2 and Mn +2 from aqueous solutions. The zeolitic-rich tuff samples provided from Bulgarian Beli Bair (BB) and Beli Plast (BP) deposits and from North Chile (NCl), were characterized by their chemical and mineralogical composition, adsorption and ion exchange properties and X ray analysis. The average content of clinoptilolite for both samples was found to be more than 75%. The materials had ion exchange capacity (NH4 +) varying from 107 to 121 meq/100g respectively. Thermo-chemical modification of natural clinoptilolite from BB and BP was made in order to increase the ion exchange capacity up to 180 meq/100g. Results showed almost complete removal (>90 %) of the all metal ions studied. Activations of NCl-zeolite (118 m 2 /g) by pre-treatment with various ions greatly enhanced the Mn adsorption, in that order and mechanisms involved were elucidated. The maximum adsorption capacity (pH 6) were decreasing for activation with NaCl (21.3 mg Mn 2+ /g), NaOH (20.9 mg Mn 2+ /g), Na2CO3 (19.7 mg Mn 2+ /g), NH4Cl (18.5 mg Mn 2+ /g) and natural (7.1 mg Mn 2+ /g). The Langmuir isotherm model showed excellent correlation to the equilibrium data, and maximum capacity to adsorption depends of the activation type realized before the adsorption. The treatment of heavy metals bearing solutions using filter packets and stirred flasks was studied experimentally. The filters were made by a special technology following standard requirements in Bulgaria; i.e.: particle size distribution, mass ratio (g/m 2) and permeability. These filters purified the waters substantially lowering the metal ion concentrations well below sanitary standard limits. The reduction of Pb +2 was about 18 times, Mn +2 , more than 20 times and Fe +2 and Cd +2 , 50 times. The total reduction of the heavy metals was more than 25 times and varied within the limits of 5 to 14 mg/L after the third stage treatment. Best results were obtained with blends of BB and BP natural clinoptilolite at 50:50 ratios and after the thermo-chemical treatment.
Asian Journal of Environment & Ecology, 2018
The adsorption mechanism of Cd, Fe, and Ni, ions on natural (clinoptilolite) zeolites, a regional low-cost natural available adsorbent was studied in a batch adsorption system. The effect of several parameters such as contact time, zeolite dose, particle size, the effect of pH, and initial concentration of metal ions in the adsorption process was estimated. The optimum adsorption was found to occur at pH 6.0, adsorbent dose 1.0 g/L, and initial concentration 2, 20 and 10 mg/L for Cd, Fe, and Ni, respectively. The adsorption efficiency also increases with decreasing particle size of zeolites and the effect of retention time on adsorption ratio shows that 80% of the Cd, Fe, and Ni, are adsorbed by zeolite during first 120 minutes. Under these optimum conditions, the removal efficiency was 78.8, 89.1, and 65.5% of Cd +2 , Fe +3 and Ni +2 , ions, respectively. Sorption data have Original Research Article Abd El-Azim and Mourad; AJEE, 7(1): 1-13, 2018; Article no.AJEE.41004 2 been interpreted in terms of Langmuir and Freundlich isotherms. The adsorption efficiency of heavy metals in industrial wastewater as application mode was also investigated using zeolites and these results showed that natural zeolites hold great potential to remove cationic heavy metal species from industrial wastewater and confirms the potential use of zeolite for the removal of heavy metals from industrial wastewater via adsorption. It was concluded that zeolite is very promising for the removal of metal ions from aqueous solution and hence we encourage the utilization of zeolites in environmental applications.
Heavy metal removal with mexican clinoptilolite
Water Research, 2001
}This paper describes the interactions of Pb(II), Cd(II), and Cr(VI) competing for ion-exchange sites in naturally occurring clinoptilolite. Dissolved Pb and Cd were effectively removed within 18 h in batch reactors, with higher removal efficiencies (>95%) in the acidic pH range. The presence of Cr(VI), which can interact with these metals to form anionic complexes, significantly diminished the Pb and Cd removal efficiencies. A decrease in the efficiency of clinoptilolite to remove Pb was also observed in the high (! 10) pH range. This was attributed to the formation of anionic hydroxo-complexes with little affinity for cationic ion exchange sites. Pb outcompeted Cd for ion exchange sites in a flow-through column packed with clinoptilolite (contact time=10 s). The preferential removal of Pb in column, but not in batch reactors, reflects that competitive retention can be affected by contact time because diffusion kinetics may influence the removal efficiency to a greater extent than equilibrium partitioning. Phenol, which was tested as a representative organic co-contaminant, slightly hindered heavy metal removal in batch reactors. This was attributed to the formation of organometallic complexes that cannot penetrate the zeolite exchange channels. Altogether, these results show that natural zeolites hold great potential to remove cationic heavy metal species from industrial wastewater. Nevertheless, process efficiency can be hindered by the presence of ligands that form complexes with reduced accessibility and/or affinity for ion exchange.