Abstract:For the purpose of reducing the concentration of ammonia nitrogen and total nitrogen of spent liquor of T acid crystallization, which was pre-treated by complex extraction process, Fenton oxidation and ammonia evaporation was tested in order to create the favourable condition for the following biological treatment. The influence of fenton oxidation, pH, gas-liquid volume ratio, temperature and reaction time on the removal efficiency of ammonia nitrogen and total nitrogen was investigated. The experimental results showed that concentration of ammonia nitrogen was reduced by Fenton oxidation, which enhanced the removal of ammonia nitrogen and total nitrogen. The removal of ammonia nitrogen and total nitrogen increased significantly after Fenton oxidation. It was found that the removal of ammonia nitrogen and total nitrogen increased with increasing pH, temperature and gas-liquid volume ratio. The removal of ammonia nitrogen exceeded 99% and total nitrogen exceeded 97% at pH 11, gas-liquid volume ratio of 3000, temperature of 95℃and 120min of reaction time. It was also found that ammonia removal rate of spent liquor of T-acid crystallization by evaporation followed the first-order kinetic equation and the reaction rate constant k was 0.00883min-1. The Arrhenius equation was fitted as ln(k)=-1.97161-1016.5026/RT, R2=0.9959, where the activation energy was 8451.20J/mol and the pre-exponential factor was 0.139min-1. It was concluded that ammonia evaporation was the effective method of treating spent liquor of T-acid crystallization containing high concentration of ammonia nitrogen and may be applied in industry.