高铁酸钾的制备及预氧化强化混凝效果研究

发布时间：2018-03-11 12:12

  本文选题：高铁酸钾　切入点：预氧化　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：传统的氧化剂,如臭氧、高锰酸盐、次氯酸盐等,在使用过程中很容易产生对环境有毒有害的二次污染物,因此有一定的局限性。高铁酸钾中的高铁酸根具有极强的氧化性,同时,高铁酸钾在使用中不会产生任何二次污染物,其被还原生成的低价铁还兼具混凝/助凝的效果,因此,高铁酸钾是一种高效、清洁、多功能的水处理剂,近年来,已经受到了越来越多的研究者的关注。本文首先利用次氯酸盐氧化法制备了高铁酸钾固体,分析了可能影响高铁酸钾制备产率或纯度的因素,并以红外光谱法对高铁酸钾进行定性分析,随后对比分析了高铁酸钾的三种定量测定方法:氧化还原滴定法、Fe~(2+)-Phen分光光度法(间接分光光度法)和直接分光光度法,得出本论文主要的测定方法。接下来考察了高铁酸钾溶液的在不同条件下的稳定性变化,主要的考察因素有浓度、温度、pH、Fe3+及Si032-。在高铁酸钾的应用部分,考察了高铁酸钾预氧化强化混凝的效果,考察指标有浊度、色度、UV254及TOC,最后初步探索了高铁酸钾预氧化强化混凝对Mn~(2+)的去除效果。主要研究结果如下:在15℃的反应温度或36h的真空干燥时间下制备的高铁酸钾纯度能达到98%左右,铁盐投加量过多时,多余的Fe3+会催化FeO42-的分解而使其产率下降。相对于氧化还原滴定法和间接分光光度法的测定结果,高铁酸钾的直接分光光度法测定误差最高分别仅为0.44%和2.37%,高铁酸钾溶液中残留的Fe(OH)3和Fe(Ⅲ)都会影响高铁酸钾测定的准确性。通过研究高铁酸钾溶液在不同条件下的分解规律发现,高铁酸钾溶液的稳定性随着自身浓度和温度的增大均降低,而高铁酸钾溶液在pH值为10左右时稳定最好,此外,Fe3+促进了高铁酸钾溶液的分解,而向高铁酸钾溶液中投加低浓度(10-30mg/L)Si032-离子有助于提高其稳定性。只投加PAC为对原水的浊度、色度、UV254和TOC的去除率分别为81.67%、38.32%、72.15%和13.48%;而利用高铁酸钾、高锰酸钾及高铁酸钾复合药剂预氧化强化混凝后,浊度去除率分别能达到94.2%、90%和95.8%;色度去除率分别能达到49.22%、42.99%和52.02%;UV254去除率分别能达到84.81%、77.2%和97.34%;TOC去除率分别能达到21.12%、20.92%和 24.11%单独投加PAC对水中Mn~(2+)基本没有去除效果,而通过高铁酸钾预氧化强化混凝后,其对水中Mn~(2+)的去除效果明显提升,高铁酸钾投加量为0.6～0.8mg/L时,剩余锰下降最为明显,而氧化时间在5min内时,对水中Mn~(2+)去除效果最好,随着pH的升高,高铁酸钾对Mn~(2+)的去除率逐渐增大,pH值接近12时,2mg/L的高铁酸钾已经能够去除超过50%的Mn~(2+)。
[Abstract]:Traditional oxidants, such as ozone, permanganate and hypochlorite, can easily produce toxic and harmful secondary pollutants to the environment. At the same time, potassium ferrate does not produce any secondary pollutants in use, and the reduced low iron also has the effect of coagulation / coagulation. Therefore, potassium ferrate is an efficient, clean and multifunctional water treatment agent. In this paper, potassium ferrate solids were prepared by hypochlorite oxidation method, and the factors that may affect the yield or purity of potassium ferrate preparation were analyzed. The qualitative analysis of potassium ferrate was carried out by infrared spectroscopy, and three quantitative determination methods of potassium ferrate were compared and analyzed: redox titration (indirect spectrophotometry) and direct spectrophotometry (direct spectrophotometry). The main determination methods of this paper are obtained. Then the stability of potassium ferrate solution under different conditions is investigated. The main factors are concentration, temperature, pH, Fe _ 3 and Si _ 032-.The main factors are the application of potassium ferrate. The effect of preoxidation of potassium ferrate on coagulation was investigated. Finally, the removal effect of potassium ferrate preoxidation enhanced coagulation on Mn~(2) was preliminarily explored. The main results were as follows: the purity of potassium ferrate prepared under the condition of 15 鈩，

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