Robab Mohammadi
Abstract
In this research, Fe3O4, Fe3O4/graphene oxide (Fe3O4/GO) and polyaniline-Fe3O4/GO with various content of polyaniline were prepared and characterized by different analysis methods such as XRD, SEM, EDX, and FT-IR. The prepared samples were used to remove methyl red as an anionic dye from aqueous solutions. ...
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In this research, Fe3O4, Fe3O4/graphene oxide (Fe3O4/GO) and polyaniline-Fe3O4/GO with various content of polyaniline were prepared and characterized by different analysis methods such as XRD, SEM, EDX, and FT-IR. The prepared samples were used to remove methyl red as an anionic dye from aqueous solutions. Polyaniline-Fe3O4/GO nanocomposite showed high catalytic activity, which is partly because of the sensitizing influence of polyaniline and the low recombination rate due to the graphene oxide electron scavenging property. The photodegradation reaction fit well to a Langmuir-Hinshelwood kinetic model implying the reaction rate is depended on initial adsorption step. Also, in polyaniline-Fe3O4/GO samples, the polyaniline content can play a significant role in affecting photocatalytic activity of photocatalysts. Based on results, when the content of polyaniline is more increased above its optimum value, the photocatalytic performance decreased. Furthermore, the efficiency of polyaniline-Fe3O4/GO nanocomposite was investigated to compare between adsorption and photodegradation of methyl red from aqueous solution. Based on results, the removal rate of methyl red via polyaniline-Fe3O4/GO nanocomposite under photocatalytic process was considerably higher than the adsorption process. To understand the nature of adsorption procedure, the equilibrium adsorption isotherms were investigated. The linear correlation coefficients of Langmuir and Freundlich isotherms were obtained. Based on results, Langmuir isotherm model fitted the experimental data better than Freundlich isotherm model. According to the Langmuir isotherm model, the maximum adsorption capacity of polyaniline-Fe3O4/GO nanocomposite for sequestering methyl red was about 101.72 mg g–1.
Hamzeh Adelpour Abdoli; Kamal Alizadeh; Payman Hashemi
Abstract
A magnet-enhanced solid-phase extraction technique utilizing spherical core–shell nanomagnetic agarose particles wasA magnet-enhanced solid-phase extraction technique utilizing spherical core–shell nanomagnetic agarose particles was devised to extract remdesivir from serum samples. These ...
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A magnet-enhanced solid-phase extraction technique utilizing spherical core–shell nanomagnetic agarose particles wasA magnet-enhanced solid-phase extraction technique utilizing spherical core–shell nanomagnetic agarose particles was devised to extract remdesivir from serum samples. These nanomagnetic agarose particles underwent activation through the epichlorohydrin method and were subsequently modified using quercetin dihydrate as a ligand to facilitate remdesivir extraction. To quantify the target analyte, high-performance liquid chromatography (HPLC) was employed following preconcentration via the developed method. The influence of various analytical variables, including pH, ionic strength, magnet passes, and adsorbent quantity, was systematically examined and optimized using a multivariate central composite design approach. Under optimal conditions, five consecutive analyses demonstrated a remdesivir recovery rate of 99.4%, with a relative standard deviation of 3.66%. The method’s detection limit (3σ) for remdesivir was determined to be 0.027 mg L−1. This extraction technique was successfully validated for the quantification of remdesivir in serum samples
hamidreza rahmani; Mohsen Nekoeinia; seyyed hossien banitaba
Abstract
Anthropogenic activities contribute to the accumulation and mobilization of heavy metals within the soil matrix, which functions as a terminal reservoir for these pollutants and thereby poses substantial ecological and human health risks. This study evaluated the impact of a fossil-fueled thermal power ...
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Anthropogenic activities contribute to the accumulation and mobilization of heavy metals within the soil matrix, which functions as a terminal reservoir for these pollutants and thereby poses substantial ecological and human health risks. This study evaluated the impact of a fossil-fueled thermal power plant in Isfahan Province, Iran, on heavy metal accumulation in the surrounding topsoil. Fifty surface soil samples were collected, and the concentrations of eight toxic metals—Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn—were determined. Statistical analyses, including factor analysis and Pearson correlation, revealed three distinct metal groupings: Group I (Ni, Pb, Cd), Group II (Cu, Cr, Co), and Group III (Zn, Mn). Group I metals were associated with both natural and anthropogenic sources, while Groups II and III were primarily linked to geogenic origins. To quantify contamination levels, the contamination factor (CF) and geoaccumulation index (Igeo) were calculated. The results indicated moderate to high contamination levels for Pb and Cd, with Cd exhibiting very high CF values across all samples. Furthermore, multivariate calibration using principal component regression (PCR) and partial least squares regression (PLS) was employed to predict the pollution load index (PLI). Both methods demonstrated accurate and robust performance in predicting the PLI across calibration and prediction datasets, with R² values ranging from 0.861 to 0.965.
