Kinetics and influential factors of nanoscale iron-facilitated nitrate nitrogen removal

Abstract

Song, Y. & Song, S. (March-April, 2017). Kinetics and influential factors of nanoscale iron-facilitated nitrate nitrogen removal. Water Technology and Sciences (in Spanish), 8(2), 93-103.

In this paper, a new nanoscale iron adsorbent was prepared using the liquid phase reduction method. The effects of the initial nitrate nitrogen concentration, pH, and reaction temperature on the nitrate nitrogen removal efficiency of the nanoscale iron were investigated. The experimental results indicated that the initial nitrate nitrogen concentration significantly affected the reaction rate, but not the removal efficiency of the nanoscale iron. In addition, the optimal pH for the removal of nitrate nitrogen was 2.0. As the temperature increased, the nitrate nitrogen removal rate increased. A pseudo-second-order kinetic equation, in which the nitrate nitrogen concentration at reaction time t was used as the initial concentration, was developed in order to determine the reaction rate constant k at different temperatures. According to the results, the maximum value of k (0.014 mg/(L/min)) was observed at 50°C. The reaction activation energy Ea was approximately 17.18 kJ/mol. The reaction was primarily influenced by the mass transfer. In a neutral solution, in this case water, the reduction product of the nitrate nitrogen was ammonia nitrogen.