بررسی کارایی نانولوله‌های کربنی چند جداره مغناطیسی شده با نانو ذرات اکسید آهن در حذف فلوراید از محلول های آبی

Background and purpose: Contamination of drinking water with fluoride due to natural and human activities is a serious problem that threatens human health. Long-term and excessive consumption of water containing fluoride could lead to endocrine glands diseases and Alzheimer's disease. Adsorption process is an effective and popular method for removal of fluoride, so the purpose of this research was magnetizing multiwall carbon nanotubes with nano iron oxide and using it as an adsorbent for fluoride removal from aqueous solution. Materials and methods: Co-precipitation method used for synthesized magnetic nano composite and its characteristics were investigated by SEM, TEM, XRD and VSM techniques. The effect of independent variables such as contact time, pH, temperature, adsorbent dose and initial concentration on fluoride removal was analyzed by response surface methodology (box-Behnken design method) and ANOVA. Results: The optimum condition was obtained at pH= 3, 2g/L sorbent dosage in 2h contact time and 45oC temperature. Isotherms and kinetics results showed that the Langmuir model and pseudo-second order were correlated by data with R2>0.98 and R2>0.941, respectively. Thermodynamic values revealed that fluoride adsorption process was endothermic and spontaneous. Conclusion: In this study synthesized adsorbent was found efficient in fluoride removal (98.5% adsorption in optimal condition) and due to magnetic ability it can be easily separated from the samples by an external magnet. Therefore, it can be applied in removal of fluoride from drinking water.