Elnaz Iravani, Mohammadhadi Dehghani, Amirhossein Mahvi, Noushin Rastkari,
Volume 6, Issue 2 (9-2013)
Abstract
Background and objectives: Bisphenol A (BPA) is an endocrine disrupting chemical that releases to the environment through effluents of its producing factory, pulp and paper mill factories, and plastics industry. The purpose of this study was to investigate adsorption isotherms of removing BPA from aqueous solutions using single walled carbon nanotubes (SWCNTs).
Materials and methods: This study was an empirical investigation. Our experiments were conducted discontinuously using 50 mL of sample in each test. The variables of this study were the contact time (5, 15, 30, 60, 90, 120 min), the initial concentration of BPA (2, 5 , 20, 50 mg/L), and pH (3, 5, 6, 9, 11). The concentrations of BPA were measured using UV-Vis spectrophotometer.
Results: The maximum adsorption capacity was found to be 71.42 mg/g. The results of our experiments showed that maximum adsorption capacity at equilibrium was achieved at t = 60 min and pH = 9. Moreover, increasing the initial concentration is associated with an increase in adsorption capacity until it becomes constant.
Conclusion: The BPA adsorption on SWCNT follows Freundlich-Langmuir isotherm.
Ali Kazemi, Habibollah Younesi, Nader Bahramifar,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objectives: bisphenol A and nonylphenol are xenoestrogen materials used as a monomer of plastics in widely volume in the production of plastic materials especially mineral water bottles and disposable plastic containers. In this study, we investigated the potential of migration of bisphenol A and nonylphenol from disposable plastic containers into water at different temperatures and also from mineral water into water at different temperatures. Materials and Methods: We conducted bisphenol A and nonylphenol extraction from each sample through liquid-liquid extraction. For identification and quantitative determination of bisphnol A and nonylphenol, we used gas chromatography equipped with mass detector, and for quantitative determination of these two compounds, we used high-performance liquid chromatography equipped with fluorescence detector. Results: We found that increasing temperature increased significantly the rate of migration of these two compounds in the water. Moreover, it was revealed that only the presence of bisphenol A in water of mineral water bottles was detected and the increase in temperature also increases the rate of migration bisphenol A into water. Conclusion: In general, results of this study showed that improper storage of mineral water bottles and also use of disposable plastic containers for hot drinks would result in increasing consumer exposure to these compounds.
