T酸废母液蒸氨预处理的动力学研究

为了有效降低经络合萃取处理后的T酸废母液中氨氮和总氮的浓度,为后续生物处理创造条件,对T酸母液进行Fenton氧化和蒸氨预处理,讨论了Fenton氧化、pH值、气液比、温度和反应时间对氨氮和总氮去除效果的影响.结果表明,Fenton氧化降低了T酸废母液的氨氮浓度,有利于氨氮和总氮的去除,去除率增幅明显.蒸氨过程中,氨氮和总氮的去除率随着pH值、温度和气液比的增大而升高,在pH值为11,气液比为3000,温度为95℃的条件下反应120min,氨氮去除率大于99%,总氮去除率大于97%.蒸氨预处理的氨氮去除动力学方程符合一级反应动力学,反应速率常数为k=0.00883min-1.反应的阿伦尼乌斯方程为:ln(k)=-1.97161-1016.5026/RT,R2=0.9959,反应活化能为8451.20J/mol,指前因子为0.139min-1.蒸氨是处理高氨氮T酸废母液有效手段,有工业应用价值.

Ammonia removal kinetics of spent liquor of T-acid crystallization by evaporation

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.