Showing 2 results for Zendehdel
Hasan Iravani, Mohammad Javad Jafari, Rezvan Zendehdel, Soheila Khodakarim, Athena Rafieepour,
Volume 10, Issue 1 (3-2020)
Abstract
Introduction: Hydrogen sulfide (H2S) is a toxic gas that has adverse effects on human health and equipment. One of the methods for eliminating of H2S gas is the use of adsorbent substrate. In this study, the effect of adding iron oxides including ferric (Fe2O3) and magnetite (Fe3O4) nanoparticles to ZSM-5 zeolite substrate was investigated on the efficiency of H2S elimination from the air stream.
Methods: In this study, Fe2O3 and Fe3O4 nanoparticles were impregnated in ZSM-5 zeolite in two weight ratios of 3% and 5%. The structural properties of the substrate were studied using XRD, BET and SEM. Then, the efficiency of substrate in removing H2S from air was studied while H2S gas was injected in to a pilot setup, in concentrations of 30, 60, 90 and 120 ppm at three bed temperatures of 100, 200 and 300 o C.
Results: The accuracy of combination and the morphology of inoculated zeolite was confirmed using XRD and SEM. The BET test also showed that the loading of iron oxide nanoparticles on the substrate educed the substrate surface area. The results revealed that increasing the percentage of nanoparticles and increasing the temperature from 100 ° C to 300 ° C increase the time of breakthrough point. The maximum adsorption capacity was obtained equal to 44.449 (mgH2S/g zeolite) for ZSM-5/Fe3O4-5% substrate at 120 ppm concentration.
Conclusion: Iron oxide nanoparticles inoculated in ZSM-5 zeolite substrate increase the capability of eliminating of H2S gas at high temperatures and therefore can be used as a suitable method for the elimination of similar pollutants.
Masoomeh Vahabi Shekarloo, Siamak Ashrafi Barzideh, Rezvan Zendehdel ,
Volume 13, Issue 3 (9-2023)
Abstract
Introduction: Several extraction techniques have been developed in recent years to determine the concentration of volatile metabolites in a biological sample. This study conducted with the aim of using the needle trap device- molecularly imprinted polymer (NTD-MIP) for the co-extraction of n-hexane and methyl ethyl ketone (MEK) in the urine matrix.
Material and Methods: Characterization of MIP was investigated by fourier-transfer infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), and brunauer–emmett–teller (BET). The response surface methodology - central composite design (RSM-CCD) was used to optimize the extraction conditions of n-hexane and MEK with the input variables of absorption temperature, absorption time, salt percent, and stirring speed. Method validation was performed with determination of the precision, accuracy, the limit of detection (LOD), limit of quantification (LOQ), and dynamic linear range.
Results: The optimum conditions were an extraction time of 60 min, an absorption temperature of 65 °C, 22% of salt, and a stirring speed of 250 rpm. The linear ranges of n-hexane and MEK were determined in ranges of 30-500 and 30-4000 µg/L, respectively. The intra-day and enter-day relative standard deviation were evaluated in the range of 3 to 10 and 1 to 7, respectively. The average recovery of n-hexane and MEK were estimated 99.3 ± 0.8 and 99 ± 0.9, respectively.
Conclusion: The HS-NTD method is suggested as a suitable method for determining very low amounts of MEK in urine along with n-hexane.
