کاربردهای شیمی تجزیه
Farzaneh Marahel; Seyed Mehdi Dardari; Zohreh Saadati; Marjan Sheibani
Abstract
This study explores the potential of shrimp shell-derived biochar@starch/CoFe2O4NPs for heavy metals and toxic pollutants removal from aqueous environments. The adsorption of Cd(II) ion was studied under the various conditions, including pH, time, adsorbent dose, and temperature. The adsorption process ...
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This study explores the potential of shrimp shell-derived biochar@starch/CoFe2O4NPs for heavy metals and toxic pollutants removal from aqueous environments. The adsorption of Cd(II) ion was studied under the various conditions, including pH, time, adsorbent dose, and temperature. The adsorption process was best described by the Langmuir isotherm and pseudo-second-order kinetic models, indicating monolayer adsorption and chemisorption-dominated interactions. The maximum adsorption capacity was determined to be 56.6 mgg-1 at 298 °K. Thermodynamic results indicated that the process was spontaneous and exothermic. The calculated thermodynamic parameters, such as ΔG°, ΔH° and ΔS° for Cd(II) ion uptake on the adsorbent surface, come out to be -3.45 kJ mol-1, -17.06 kJ mol-1 and -41.26 J mol-1. K-1, respectively. The removal efficiency Cd(II) ion from actual water samples higher reached 90.0 %, although the efficiency decreased with increasing salt concentration. These findings demonstrate that shrimp shell-derived biochar modified with starch/CoFe2O4NPs is a sustainable, low-cost, and environmentally friendly adsorbent with significant potential for Cd(II) ion remediation in contaminated water systems.
Fatemeh Sabermahani; Iman Aminaei
Abstract
The coconut peel waste (CPW) was chemically spiked with silica nanoparticles to develop a novel nanocomposite (SiO2/CPW). The new nanocomposite was characterized by FTIR, SEM and Dynamic Light Scattering method. Adsorption of Cd ions onto SiO2/CPW was studied in batch mode as a function of pH, contact ...
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The coconut peel waste (CPW) was chemically spiked with silica nanoparticles to develop a novel nanocomposite (SiO2/CPW). The new nanocomposite was characterized by FTIR, SEM and Dynamic Light Scattering method. Adsorption of Cd ions onto SiO2/CPW was studied in batch mode as a function of pH, contact time, adsorbent dosage and initial concentration and temperature. The maximum removal of Cd2+ions was at pH=6.5 and adsorbent dosage=0.1 g. The experiments showed that the adsorption process was quick and about 74.5% of total cadmium was removed within 5 min. Cadmium uptake by the new adsorbent was best described by pseudo-second order model. Using the equilibrium concentration constants obtained at different temperatures, various thermodynamic parameters have been calculated. The results indicated that Cadmium adsorption was feasible, spontaneous, and endothermic. The suggested sorbent proved the great potential in cadmium removal from water and wastewater.
Reyhaneh Rahnama; Sorour Eram
Volume 1, Issue 2 , September 2014, , Pages 106-114
Abstract
A new method for the separation and preconcentration of trace amounts of cadmium in food and water samples by magnetic solid phase extraction (MSPE) with Fe3O4 magnetic nanoparticles (Fe3O4-MNPs) and its determination by flame atomic absorption spectrometry has been developed. For this purpose, Fe3O4-MNPs ...
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A new method for the separation and preconcentration of trace amounts of cadmium in food and water samples by magnetic solid phase extraction (MSPE) with Fe3O4 magnetic nanoparticles (Fe3O4-MNPs) and its determination by flame atomic absorption spectrometry has been developed. For this purpose, Fe3O4-MNPs were synthesized via chemical precipitation method. The extraction of cadmium ions from the aqueous solution was performed with dithizone (DTZ) as the chelating agent. The various parameters affecting the extraction and preconcentration of cadmium were investigated and optimized. In this method, the analyte ions were quantitatively adsorbed on Fe3O4-MNPs and then, Fe3O4-MNPs were easily separated from the aqueous solution by applying an external magnetic field. After extraction and collection of Fe3O4-MNPs, the analyte ions were eluted using 1.0 mol L-1 HNO3 in methanol. Under the optimal conditions, the calibration curve showed an excellent linearity in the concentration range of 0.3–24.0 µg L-1 and the limit of detection was 0.1 µg L-1 of cadmium. The developed method was successfully applied to the determination of cadmium in food and water samples. The results show that, magnetic nanoparticles can be used as a cheap and efficient adsorbent for the extraction and preconcentration of cadmium from real samples for Loratadine.
Foroozan Hasanpour; Zahra Alimirzaei; Masoumeh Taei; Hamed Karimi; R. Samimi
Volume 1, Issue 1 , March 2014, , Pages 44-49
Abstract
Cloud point extraction and spectrophotometric determination of trace quantities of cadmium in some vegetables have been developed. The research area for vegetables analysis was near to the Zarin Shahr where the soil received heavy metals from the Esfahan Steel Company. Cloud point extraction used dithizone ...
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Cloud point extraction and spectrophotometric determination of trace quantities of cadmium in some vegetables have been developed. The research area for vegetables analysis was near to the Zarin Shahr where the soil received heavy metals from the Esfahan Steel Company. Cloud point extraction used dithizone as complexing agent and non ionic surfactant Triton-X114 as micellar phase. Several important variables affecting the separation and determination process were optimized. Under optimized conditions calibration graph was linear in the range of 1.0-180 ng mL-1 with detection limit of 0.2 ng mL-1. Preconcentration of 10 mL of samples gave an enhancement factor of 50. The proposed method was applied for determination of Cd(II) in vegetable samples with satisfactory results.
