Evaluation of Efficiency of Ammonia Removal from Ekbatan Dam Water Sample Using Modified Multi-wall Carbon Nanotube

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Abstract

Background: Ammonia is one of the most important pollutants in water, which not only is toxic for aquatic animals, but also damages human health. The purpose of this study was evaluation of removal efficiency of ammonia from water samples of Ekbatan Dam using modified multi-walled carbon nanotube.   Methods: In order to evaluate the removal of ammonia from water samples, in a field- lab study during summer 2012, under optimal conditions a batch of modified multi-walled carbon nanotubes were used to study the effects of pH, the amount of adsorbent and kinetics of absorption. Ammonia concentration was measured using spectrophotometer at a wavelength of 200 nm. To determine the adsorption rate constant, experimental data were compared by first-order kinetic model and pseudo second order model and were adjusted to Langmuir isotherms, Freundlich and Compliance. Results: According to the results, at optimum conditions of pH= 6, ammonia removal efficiency of the samples was 88.3 % and at the optimum conditions of 0.01 g of adsorbent dose, adsorption efficiency was 88.2 %. Moreover, under these conditions, the kinetics of the adsorption process followed pseudo-second-order and Langmuir adsorption isotherm with a correlation coefficient of 0.995.   Conclusion: Based on the results, modified multi-walled carbon nanotubes can efficiently adsorb ammonium in acidic pH; therefore, it can be used for removal of this environmental pollutant more than before.  

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