水力空化装置设计模拟及强化降解苯酚的研究

摘要

根据水力学原理,自制水力空化装置,基于Fluent软件模拟空化装置中文丘里管内部场的分布,并用其联合Fenton试剂强化降解模拟苯酚废水.考察了空化时间,入口压力,溶液pH值和苯酚初始浓度对苯酚降解效果的影响.实验结果表明:空化时间为120min,入口压力为0.4MPa,pH值为3.0,初始浓度为60mg/L时苯酚降解效果最好,降解率可达55.74%.水力空化/Fenton对模拟苯酚废水降解结果显示,当加入H2O2浓度为120mg/L,Fe2+的浓度为30mg/L,空化120min,降解率可达96.62%,较单独使用水力空化时降解率提高了40.88%,较单独使用Fenton时降解率提高了55.65%.动力学研究表明,苯酚降解近似为一级反应,其强化因子f为2.46.最后,采用水力空化/Fenton联用处理新疆宜化实际煤气化废水,苯酚和COD降解率60min分别可达72.9%和78.6%,120min分别可达78.3%和84.2%.%Based on hydraulic principle, the hydraulic cavitation device was self-made. And the Fluent software was employed to simulate the distribution of internal fields, such as pressure, flow velocity and steam holdup in the Venture tube installed in the device, where the degradation process of simulated phenol wastewater was strengthened by adding Fenton reagent. The effects of cavitation time, inlet pressure, solution pH and initial phenol concentration on the degradation of phenol were investigated. The results showed that the highest degradation ratio of 55.74% was achieved under the conditions of 60 mg/L initial phenol concentration, 3.0 pH value, 0.4 MPa inlet pressure and 120 min cavitation time. Under the combination of hydrodynamic cavitation and Fenton reagent in the presence of H2O2 concentration of 120 mg/L, Fe2+ concentration of 30 mg/L and cavitation time of 120 min, the degradation ratio of phenol reached to 96.62%, which were 40.88% and 55.65% higher than that obtained under hydraulic cavitation or Fenton reagent alone respectively. Kinetic studies indicated that the degradation of phenol was approximately the first order reaction, and the calculated enhancement factor f was 2.46. Finally, the Xinjiang Yihua actual coal gasification wastewater was tested by combined using the hydraulic cavitation device and Fenton reagent. The results displayed that when the sample was treated for 60 min and 120 min, the corresponding of phenol/COD degradation ratios were 72.9%/78.6% and 78.3%/ 84.2%, respectively.