Iranian Journal of

Background and Objective: Pollutants emitted from industries can endanger human health if they enter the food chain, so environmental monitoring is essential. The aim of this study was to investigate the bioaccumulation of heavy metals including lead, copper and nickel and the level of air pollution tolerance index in Prosopis juliflora and Conocarpus erectus tree species during one-year period (1399-1400) in Mahshahr city.
Materials and Methods: In order to investigate the bioaccumulation of heavy metals by two species of Prosopis juliflora and Conocarpus erectus, 15 stations were selected separately. After recording the coordinates of each tree (station), 4 leaveas were taken from each tree that accounted for total 60 samples. The samples were then transferred to the laboratory and digested then analyzed using atomic absorption spectrometer. For statistical analysis, K.S test was used to normalize data and independent t-tests were applied to determine the level of significance. The correlation between variables were tested by Pearson correlation. Spatial distribution of heavy metals was performed using Ver.10.4 Arc GIS software.
Results: Conocarpus erectus established the highest adsorption value for metals such as lead (0.1223±0.35 mg/kg), copper (0.2101±0.053 mg/kg) and nickel (0.2023±0.094 mg/kg). No significant correlation was observed between heavy metals. Evaluation of air pollution tolerance showed that Conocarpus erectus (6.53±0.026 mg/kg) was more tolerant than Prosopis juliflora (4.77±0.029 mg/kg). Spatial distribution revealed that heavy metals accumulation in the leaves of trees were more obvious in the southest area of the city.
Conclusion: Conocarpus erectus is more tolerant of air pollution than Prosopis juliflora. Therefore, it can be used in areas with the high levels of pollution. Moreover, the spatial distribution of heavy metals’ bioaccumulation illustrated that the south and southeast parts of the city (due to industry concentration) are more affected by the heavy metals pollution which call for more palnting trees.

Background and Objective: N-methylpyrrolidine is a highly potent solvent with toxic and adverse ecological properties that has historically been widely used in the chemical and petrochemical industries. Due to the health and safety، toxicity and environmental effects of effluents containing NMP، these effluents should be pre-treated before biological treatment methods. The aim of this study was to remove N-methylpyrrolidone by photo- Fenton process.
Materials and Methods: For testing, solutions such as sulfuric acid, iron sulfate 7, oxygenated water, sodium hydroxide and distilled water were added to N-methypyrrolidine compounds in the reactor. Then, the removal process was investigated in two stages: complete mixing and adding solutions.
Results: The results revealed that the Fenton process cannot be used successfully to treat the hypothetical refinery effluent containing NMP. However، the photo-phanton process mineralized and degraded the NMP composition. Increase in 30% H₂O₂ concentration to the optimal dose of 1 mL led to the highest degradation (94%) and decrease in COD level of solution (42.1%).
Conclusion: It can be concluded that advanced oxidation by photo-phanton reaction can be a promising advanced oxidation technology for decomposition and pre-treatment of NMP-containing wastewaters for further biological treatment.