Health risk assessment of PAHs in fruit juice samples marketed in city of Tehran,Iran

Environmental Science and Pollution Research - The objective of the present study was to investigate the level of 16 PAHs in fruit juice samples (orange, apple, peach, pineapple, and mango) with...     

Bio-indicators in cadmium toxicity: Role of HSP27 and HSP70

Environmental Science and Pollution Research - Heat shock proteins (HSPs) are a family of proteins that are expressed by cells in reply to stressors. The changes in concentration of HSPs could be...     

Electrocatalytic reduction of nitrate ions from water using polyaniline nanofibers modified gold electrode

Polyaniline (PANI) nanofibers were electrochemically synthesized on gold electrode using ethanol as soft template by the cyclic voltammetry technique. The PANI nanofibers were characterized by Fourier transform infrared spectroscopy, UV-visible spectroscopy, and scanning electron microscopy. Linear sweep voltammetry was used to investigate electrocatalytic activity of the PANI nanofibers modified electrode toward the reduction of nitrate ions. Results showed that the electroreduction process strongly depends on the applied potential. At the potential value of about -0.8 V vs Ag/AgCl, the electroreduction of nitrate anions to nitrite anions was identified as the rate-determining step of the electroreduction process. In the potential range of -0.8 to -1.0 V, reduction of nitrite to hydroxylamine occurs, followed by the reduction to ammonia. At potentials more negative than -1.0 V, nitrite is directly reduced to ammonia. This study demonstrates the effectiveness of PANI nanofibers modified electrode in the electroreduction of nitrate ions compared to traditional reduction methods.     

Antimony induces oxidative stress and cell death in normal hepatocytes

Antimony (Sb) accumulates in the liver which is one of the target organs for metal-mediated toxicity. Although toxicity of Sb was previously investigated, the precise mechanism of Sb-induced hepatotoxicity remains to be determined. The aim of this study was to examine the role of oxidative stress, and mitochondria in the induction of cell death by Sb. Our results showed that liver cell lysis induced by Sb is mediated by reactive oxygen species (ROS) formation, lipid peroxidation and decline of mitochondrial membrane potential (MMP). Antimony-induced ROS formation, lipid peroxidation and reduction of MMP were significantly diminished by antioxidants and ROS scavengers such as dimethyl sulfoxide and mannitol; mitochondrial permeability transition (MPT) pore sealing agents such as carnitine and trifluoperazine; and adenosine triphosphate (ATP) generator, L-glutamine. Antimony-induced ROS formation, lipid peroxidation and fall in MMP were potentiated by glutathione (GSH) depletion via n-bromoheptane. MPT pore sealing agents and ATP generator inhibited hepatotoxicity, indicating Sb-activated cell death via mitochondrial pathway. Pretreatment of hepatocytes with antioxidants and ROS scavengers also blocked cell death induced by Sb, whereas GSH depletion enhances Sb-induced cell death, suggesting that oxidative stress may be directly involved in the reduction of MMP. These findings contribute to a better understanding of the mechanisms that mediate Sb-induced cell death in isolated rat hepatocytes.     

Preparation and Characterization of PVDF/g-C3N4/Chitosan Polymeric Membrane for the Removal of Direct Blue 14 Dye

Journal of Polymers and the Environment - Polyvinylidene fluoride (PVDF)/g-C3N4/Chitosan thin film membranes were prepared by immersing of PVDF/g-C3N4 membrane in solution containing various...     

Youth and sustainable waste management: a SEM approach and extended theory of planned behavior

The present study aims to develop the Theory of Planned Behavior (TPB) to explain comprehensively the establishment of intention and behavior toward source separation of waste. The extended TPB involves the significant structures affecting the behavior along with the original variables of TPB model. Data were gathered from 420 students in Ferdowsi University, Iran, using questionnaires, and analyzed by cluster analysis, discriminant analysis and structural equation modelling techniques (SEM). The cluster analysis identified three distinct grouping according to TPB constructs, and it was validated by discriminant analysis. SEM results displays that motivation had the most important impact on intention, followed by moral obligation, perceived behavior control, subjective norm, situational factor and attitude. Fit statistic of the extended TPB model was good and had better explanatory power compared to the original TPB. It describes 81 and 57% of the variance for intention and behavior toward source separation waste, respectively.     

Competitive sorption of Cd, Cu, Mn, Ni, Pb and Zn in polluted and unpolluted calcareous soils

The objectives of this study were to investigate competitive sorption behaviour of heavy metals (Cd, Cu, Mn, Ni, Pb and Zn) under different management practices and identify soil characteristics that can be correlated with the retention and mobility of heavy metals using 65 calcareous soil samples. The lowest sorption was found for Mn and Ni in competition with the other metals, indicating the high mobility of these two cations. The Freundlich equation adequately described heavy metals adsorption. On the basis of Freundlich distribution coefficient, the selectivity sequence of the metal adsorption was Cu?>?Pb?>?Cd?>?Zn?>?Ni?>?Mn. The mean value of the joint distribution coefficient (K _dΣsp) was 182.1, 364.1, 414.7, 250.1, 277.7, 459.9 and 344.8 l kg^?1 for garden, garlic, pasture, potato, vegetables, wheat and polluted soils, respectively. The lowest observed K _dΣsp in garden soil samples was due to the lower cation exchange capacity and lower carbonate content. The results of the geochemical modelling under low and high metal addition indicated that Cd, Ni, Mn and Zn were mainly retained via adsorption, while Pb and Cu were retained via adsorption and precipitation. Stepwise forward regression analysis showed that clay, organic matter and CaCO₃ were the most important soil properties influencing competitive adsorption of Cd, Mn, Ni and Zn. The results in this study point to a relatively easy way to estimate distribution coefficient values.     

Nitrate adsorption onto surface-modified red mud in batch and fixed-bed column systems: equilibrium,kinetic, and thermodynamic studies

Environmental Science and Pollution Research - This research aimed to develop a novel composite as a low-cost adsorbent for the removal of nitrate ion from aqueous solutions. The characterization...