论文总字数：16815字

摘 要

随着污水排放标准日趋严厉，给污水处理排放带来了巨大压力。其中，磷排放是重要控制指标之一，目前对于有机膦酸去除技术存在不足，需寻求新技术降解有机膦酸，本文开展CoFe₂O₄催化活化过一硫酸盐产生SO₄^2-·高级氧化有机膦酸研究解决水环境问题。

采用水热法制备CoFe₂O₄作为为催化剂，降解有机膦酸HEDP。采用扫描电子显微镜（SEM），X射线粉末衍射仪（XRD）对制备的CoFe₂O₄进行表征，证明成功合成了CoFe₂O₄。CoFe₂O₄和PMS共同作用相比于单一的PMS或CoFe₂O₄具有更好的降解效果，并且反应后的催化剂可通过磁回收，防止二次污染。

在酸性条件下，CoFe₂O₄/PMS体系降解HEDP降解效率较高，但是随着 pH 值的升高，降解效率逐渐降低。随着PMS浓度的增加，生产自由基的数量逐渐大于自由基之间的淬灭量，降解效率先减少后增加。随着HEDP浓度的增加，HEDP降解效率呈下降趋势，但是HEDP吸附在CoFe₂O₄的吸附量逐渐增加，降解效率先减少后增加。在氯离子存在的的情况下，总磷去除率为53.30%，大于其他三种共存离子在HCO₃^-，CO₃^2-存在的的情况下，HEDP的降解受到抑制，且CO₃^2-抑制能力更强。

在pH=7，CoFe₂O₄的投加量为1.2g/L，PMS的浓度为1mmol/L ，HEDP-Ca的浓度为0.2mmol/L，反应时间3h的条件下，CoFe₂O₄活化降解HEDP的降解效率可达到42.99%。最佳反应条件下，HEDP的降解过程通过拟合发现符合准二级反应动力学。

关键词：CoFe₂O₄ 有机膦酸 PMS

CoFe₂O₄ preparation and removal of organic phosphonic acid

Abstract

As the sewage discharge standard becomes more and more severe, it brings great pressure to the sewage treatment discharge. Phosphorus emission is one of the important control indexes. At present, there is a shortage of organic phosphonic acid removal technology, so it is necessary to seek new technology to degrade organic phosphonic acid. In this paper, advanced organophosphonic acid oxide produced CoFe₂O₄ catalytic activation SO₄^2-·persulfate is studied to solve the water environment problem.

Preparation of CoFe₂O₄ by hydrothermal method as catalyst for degradation HEDP. organic phosphonic acid. The prepared CoFe₂O₄ were characterized by scanning electron microscopy (SEM) and X-ray powder diffractometer (XRD). The CoFe₂O₄ was successfully synthesized CoFe₂O₄ and PMS co-actions have better degradation effect than single PMS or CoFe2O4, and the catalyst after reaction can be recovered by magnetic recovery to prevent secondary pollution.

Under acidic conditions, the degradation efficiency HEDP CoFe₂O₄/PMS system is higher, but with the increase of pH value, the degradation efficiency decreases gradually. As the PMS concentration increases, the amount of free radicals produced is gradually larger than the quenching amount between free radicals, and the degradation efficiency decreases first and then increases. With the increase of HEDP concentration, the HEDP degradation efficiency showed a downward trend, but the adsorption amount of HEDP adsorbed on the CoFe₂O₄ gradually increased, and the degradation efficiency first decreased and then increased. For the presence of chloride ions, the total phosphorus removal rate is 53.30%, which is larger than the other three coexisting ions in HCO₃^-, CO₃^2- present, HEDP degradation is inhibited and the CO₃^2- inhibition ability is stronger.

The degradation efficiency of CoFe₂O₄ activated degradation HEDP can reach 42.99% under pH=7 with a concentration of 1.2 g/L, PMS and a concentration of 0.2 with a reaction time of 3h. At the optimum reaction conditions, the degradation process of HEDP was found to conform to the quasi-second-order reaction kinetics by fitting.

Key Words: CoFe₂O₄; organic phosphonic acid; PMS

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1 有机膦酸的来源与危害 1

1.1.1 有机膦酸概述 1

1.1.2 有机膦酸危害 2

1.2 过一硫酸盐（PMS）高级氧化法研究进展 2

1.2.1 PMS概述 2

1.2.2 PMS优点 2

1.2.4 PMS活化存在的问题 4

第二章 实验材料与方法 6

2.1 仪器与试剂 6

2.1.1 实验仪器 6

2.1.2 实验试剂 6

2.2 催化剂的制备与表征 7

2.3 试验方法 7

2.4 数据处理 8

第三章 结果与讨论 9

3.1 CoFe₂O₄的表征 9

3.2 不同体系中HEDP的降解效率的影响 10

3.3 初始pH值对HEDP降解效率的影响 10

3.4 PMS浓度对HEDP降解效率的影响 11

3.5 不同浓度HEDP降解效率的影响 12

3.6 共存离子对HEDP降解效率的影响 13

3.7 最佳反应条件 14

3.8 钙法除磷 16

第四章 结论 18

参考文献 19

致谢 21

第一章 绪论

1.1 有机膦酸的来源与危害

1.1.1 有机膦酸概述

有机膦酸分为很多类别，主要特征是在分子结构中含有膦酸基团，磷酸基团中的磷原子与碳原子构成稳定的的碳磷键，同时分子中一般还包含羟基、次甲基或羧基等基团。有机膦酸可以按照含膦酸基团的数目分类或者按照分子结构的类型分类。按照前者分类可以将有机膦酸可分为：二膦酸、三瞵酸、四膦酸、五膦酸等。按照后者分类可以将有机膦酸又可分为甲叉膦酸型、同碳二膦酸型、羧酸膦酸型和含其他原子膦酸型^[1]。

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