Mercury as a hazardous material caused health problem in humans.In this study,mercury vapor removed from air by nickel-coated on multi-walled carbon nanotubes(Ni-MWCNTs)as a novel sorbent.Amalgamation of mercury with Ni-MWCNTs was achieved by solid-gas phase removal method(SGPR).In bench scale set up, the mercury vapor generated and moved to sorbent at optimized flow rate.After thermal desorption of Ni-MWCNTs at 200oC, the mercury vapor flowed to quartz glass cell with argon gas and determined by cold vapor atomic absorption spectrometer technique(CV-AAS).In optimized conditions,25 mg of Ni-MWCNTs and MWCNTs with different size from 30-100nm was used.The adsorption capacity of sorbents was obtained 194 mg g-1 and 64 mg g-1,respectively.The efficient recovery was obtained at optimized conditions such as, temperature of 25-40 and flow rate of 200 mL min-1.So, Ni-MWCNTs had good potential for removal of mercury vapor from the air and can be used as a low cost and efficient sorbent in industrial workplace
The water, wastewater and air are the main sources of aniline in environment. Aniline has a toxic effect in the human body and environment and so, must be determined by novel techniques. In this study, the activated carbon with microwave heating methods (MHM-ACNPs) were used for extraction aniline from waters by dispersive ionic liquid solid phase extraction procedure (D-IL-SPE) and compared to the activated carbon (AC). For this purpose, the mixture of acetone, ionic liquid and 30 mg of MHM-ACNPs/AC added to 100 mL of water samples at pH=8. After sonication for 10 min, the benzene ring in aniline as electron acceptor was chemically adsorbed on carboxylic groups of MHM-ACNPs as electron donors (MHM-ACNPs-COO─……C6H5-NH2) and then, the adsorbent was collected by IL phase in bottom of conical centrifuging tube. Finally, the aniline was released from MHM-ACNPs in remained solution by changing pH and the concentration of aniline determined by GC-FID.
Antibiotics and pharmaceutical products cannot remove by conventional sewage treatment. In this work, an effective adsorbent magnetic multiwalled carbon nanotube (Fe3O4@MWCNTs) was synthesized by co-precipitation of MWCNTs with Fe3O4 and used for removal of Metronidazole from aqueous solutions. Response surface methodology on central composition design (CCD) was applied for designing of experiments and building of models for Metronidazole removal before a determination by HPLC. Four factors including pH, the adsorbent dose, time, and temperature were studied and used for the quadratic equation model to the prediction of optimal points. By solvent the equation and considering the regression coefficient (R2 =0.9997), the optimal points obtained as follows: pH =2.98; adsorbent dosage =2.16 g; time =22 min and temperature = 37.9 o C. The isotherm study of adsorption showed that the metronidazole adsorption on Fe3O4@MWCNTs follows the Langmuir model. The maximum adsorption capacity (AC) is 215 mg g-1 obtained from Langmuir isotherm.
In this research, meta-(4-bromobenzyloxy) benzaldehyde thiosemicarbazone (MBBOTSC) as a novel ligand was synthesized from the reaction between meta-(4-bromobenzyloxy) benzaldehyde and thiosemicarbazide under basic condition in water and ethanol as solvents. Ligand has the ability to chelate ions and therefore, it was used to form a complex and extract ions. Then, the cadmium ions in water and wastewater samples were separated based on MBBOTSC by ultrasound assisted-dispersive-ionic liquid-liquid microextraction method (USA-D-ILLME) before determination by AT-F-AAS. The MBBOTSC ligand was added to the mixture of the ionic liquid/acetone (IL/AC, [OMIM][PF6]) and then injected by syringe to 50 mL of water samples at pH 6-7. The sample was put into the ultrasonic accessory for 5 minutes, after complexation (Ligand-Cd; RS…Cd….RS), the water sample was centrifuged for 3 min for phase separation. Due to complexation and back-extraction of Cd in liquid phase, the amount of Cd ions in the water samples was determined by AT-F-AAS . In optimized conditions, the Linear ranges and LOD for 50 mL of water samples were obtained 1-36 μg L-1 and 0.3 μg L-1, respectively (Mean RSD= 1.26%). The validation results were successfully achieved by spiking real samples and using ET-AAS.
Heavy metals (HMs) are considered as the major environmental pollutants that accumulated in soil and plant. Consumption of such contaminated plants by humans and animals would ultimately harm the health of communities. This study aims to evaluate the amount of copper(Co), cadmium(Cd), and lead(Pb) in soil and cultivated plants that are irrigated by the city of Zabol’s wastewater. Also, the heavy metals determined in 20 mL of Zabol’s water based on Bis(triethoxysilylpropyl)tetrasulfide (S4[C3H6Si(OEt)3]2, TEOSiP-TS) modified on MWCNTs as an adsorbent by the uniform dispersive -micro-solid phase extraction (UD-µ-SPE) at optimized pH. In this study, 52 samples including wheat, corn grain, and wild spinach, as well as agricultural soil were selected randomly from three village stations. The concentrations of heavy metals in plants, soils, and water samples were measured using a flame atomic absorption spectrometer (F-AAS). By optimizing parameters, the linear range (LR) and the detection limit (LOD) of Cu, Cd, and Pb were obtained 1.5-1000 μg L-1, 1-200 μg L-1, 5-1500 μg L-1 and 0.5 μg L-1, 0.25 μg L-1, 1.5 μg L-1, respectively in water samples (RSD%<2). This study indicates that irrigation of agricultural fields using wastewater causes the accumulation of heavy metals in soil and plants.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.