过硫酸盐高级氧化法处理含酚废水的实验研究

发布时间：2018-03-09 13:00

  本文选题：过硫酸盐　切入点：苯酚　出处：《内蒙古科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：过硫酸盐高级氧化技术由于能够拓宽传统Fenton反应的p H适用范围、减少含铁污泥数量、提高氧化效率而受到广泛关注。本论文使用热、纳米Fe_3O_4及天然铁矿石三种方式活化过硫酸钠,对比研究不同活化体系对含酚废水的降解效果,考察不同方式活化过硫酸盐高级氧化法降解含酚废水的影响因素,对比不同活化方式降解污染物的机制,探究在最佳反应条件下污染物的降解途径。实验结果表明,对于初始浓度为250 mg/L的苯酚废水,热活化过硫酸钠体系的最佳反应条件是50℃、过硫酸钠:苯酚的物质的量的比为60:1、初始p H为3,在此条件下苯酚的去除率为26.9%;由于去除率较低,因此考虑非均相活化体系,在纳米Fe_3O_4活化体系中,当过硫酸钠与纳米Fe_3O_4投加量均为12.5 m M,初始p H为6.18,温度为50℃的条件下,苯酚去除率可以达到94.97%,降解过程中发生在纳米Fe_3O_4表面的化学反应起主导作用;铁矿石活化体系的最佳反应条件是过硫酸钠与铁矿石投加量均为0.4 g/L,初始p H为6.18,温度为50℃,去除率可以达到89.96%,铁矿石表面的化学反应是主要的速度控制步骤。三种活化体系在酸性条件下起主要作用的活性自由基是硫酸根自由基(SO4-·),强碱性条件下起主要作用的活性自由基是羟基自由基(·OH)。对于固体催化剂纳米Fe_3O_4和铁矿石在重复利用四次后,对初始浓度250 mg/L的苯酚去除率分别为为85.73%和85.69%,表明两种固体催化剂均具有较好的重复利用性和稳定性。通过对比实验可以看出,非均相体系活化过硫酸盐具有更高的处理效率,能够适应更广泛的p H值,在p H值为3~9范围内,纳米Fe_3O_4活化体系、天然铁矿石活化体系反应180 min后对苯酚废水的去除率分别为86.65%~96.53%和82.61%~94.41%。通过紫外光谱分析得到苯酚在活化过硫酸盐体系中降解的中间产物为对苯二酚、邻苯二酚和丁烯化合物,表明过硫酸盐高级氧化法可以有效降解废水中的苯酚。
[Abstract]:Advanced persulfate oxidation technology has attracted wide attention due to its ability to broaden the pH range of traditional Fenton reactions, reduce the amount of ferric sludge and improve oxidation efficiency. Sodium persulfate was activated by nanometer Fe_3O_4 and natural iron ore. The effect of different activation systems on the degradation of phenol-containing wastewater was studied, and the factors affecting the degradation of phenol-containing wastewater by different ways of activated persulfate advanced oxidation were investigated. The mechanism of degradation of pollutants by different activation methods was compared, and the degradation pathway of pollutants was explored under the optimum reaction conditions. The experimental results showed that the initial concentration of phenol wastewater was 250 mg/L. The optimum reaction conditions for thermally activated sodium persulfate system are 50 鈩，

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