钙基聚合硫酸铁对河湖底泥脱水固磷研究

发布时间：2018-05-24 22:30

  本文选题：聚合硫酸铁 + 钙基改性　； 参考：《湖北工业大学》2017年硕士论文

【摘要】：本论文探讨了用双氧水氧化制备聚合硫酸铁(PFS)并用钙盐对PFS进行改性的实验过程。考察了硫酸用量、过氧化氢用量、反应温度和反应时间等因素对聚合硫酸铁主要成分(全铁含量、Fe2+含量及盐基度)指标的影响。同时,在此基础上,对上述合成的质量优良的PFS进行钙盐改性,并采用响应曲线面优化设计法,创建Box-Behnken数学模型,考察Ca/Fe摩尔比、反应温度和时间对合成产物成分(全铁含量、Fe2+含量及盐基度)的影响,从而得到质量较好的钙基聚合硫酸铁(CaPFS)。借助傅立叶变换红外光谱图、扫描电镜照片观察了PFS及CaPFS的结构与形貌,并进一步考察了本论文合成聚合硫酸铁(Z-PFS)、钙基聚合硫酸铁(CaPFS)和市场常用的聚合硫酸铁(S-PFS)对富磷底泥的固磷脱水效果。通过制备PFS、CaPFS的实验过程研究,得到以下结论:1.实验通过对硫酸、过氧化氢、反应温度和时间四个因素优化,确定:n[SO42-]/n[Fe]T=1.3,n[H2O2]/n[Fe]T=0.70,反应温度和时间分别为50℃、5h,得到产品全铁含量为12.58%,Fe2+含量为0.002%,盐基度为13.84%,为最佳质量产品。2.实验采取响应曲面设计并按照现实条件获得最好合成钙基聚合硫酸铁条件:反应温度、时间和Ca/Fe摩尔比分别为62℃、7h、0.05。所得产品全铁量和盐基度平均值在13.82%和17.95%。经实验验证,全铁量和盐基度测得值与模型预测值偏差仅为0.84%和0.47%。同时,实验借助傅立叶变换红外光谱、与SEM分析表征手段观察了CaPFS的结构与形貌,显示制备的CaPFS为铁与羟基桥联的聚铁类产物。3.与市售的PFS比较发现:在投加量为4.78μg/g时,CaPFS和市售的PFS调理后的底泥,比阻值均达到最低,此时n(Ca)/n(Fe)=0.05的CaPFS比阻值下降到0.40×1012m/kg,市售的PFS比阻下降至0.96×1012m/kg;同时n(Ca)/n(Fe)=0.05的CaPFS处理后底泥上清液磷浓度为0.08mg/L,沉泥滤液中磷浓度为0.44 mg/L,均低于被市售的PFS处理的(0.23mg/L,0.59 mg/L),对应的94.84%和87.34%的磷被固持于底泥之中。以上显示CaPFS提升底泥脱水能力及固磷效能优于市售的PFS。
[Abstract]:In this paper, the experimental process of PFS modified by calcium salt was studied. The effects of the amount of sulfuric acid, hydrogen peroxide, reaction temperature and reaction time on the main components (total iron content, Fe _ 2 content and basicity) of polyferric sulfate were investigated. At the same time, on the basis of this, the PFS with excellent quality was modified by calcium salt, and the Box-Behnken mathematical model was established by using the optimum design method of response curve surface, and the molar ratio of Ca/Fe was investigated. The effect of reaction temperature and time on the composition of the synthesized product (total iron content, Fe _ 2 content and basicity) was investigated, and a better quality calcium polyferric sulfate (CaPFS) was obtained. The structure and morphology of PFS and CaPFS were observed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The dewatering effects of synthetic polyferric sulfate Z-PFS, calcium based polyferric sulfate (CaPFS) and polymeric ferric sulfate S-PFS on phosphorus-rich sediment were further investigated. The experimental process of preparing PFS- CaPFS was studied, and the following conclusions were obtained: 1. 1. Through the optimization of sulfuric acid, hydrogen peroxide, reaction temperature and time, it was determined that: n [so _ 42-] / n [Fe] _ T _ (3) N [H2O2] / n [Fe] T _ (0. 70), reaction temperature and time were 50 鈩，

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