除铁锰氨氮的接触氧化滤池对地下水中砷（V）的去除效果及机理研究

发布时间：2018-04-18 07:28

本文选题：接触氧化滤池 + 活性铁锰氧化膜　；参考：《西安建筑科技大学》2017年硕士论文

【摘要】：砷是水体中的有毒污染物之一,饮用水砷污染已经成为了全球范围内的严重问题,愈发威胁着人类的健康。砷(V)、铁、锰和氨氮常共存于地下水中,铁锰氧化物作为除砷吸附剂结合了铁氧化物的强吸附性和锰氧化物的氧化性能,具有工艺简单、操作简便、环境友好、经济等优点。本文通过对接触氧化滤池去除地下水中砷(V)、铁、锰和氨氮的效果研究,考察了滤池对四种污染物单独及同步去除的效果,并对不同的水质条件和工艺运行参数对滤池除砷(V)效果的影响进行了分析。结合活性铁锰氧化膜吸附前后的材料表征,除砷(V)的特性及影响因素,探究接触氧化滤池除砷(V)的机理,为接触氧化滤池的工程实践应用提供了技术支持。接触氧化滤池滤料表面的活性铁锰氧化膜所含主要元素为铁和锰,形态呈颗粒状,具有丰富的空隙,为大量污染物吸附于铁锰氧化膜上,提供了较大的接触面积。滤池有较好的单独去除砷(V)、铁、锰、氨氮的能力,抗污染物冲击负荷的能力较强,同时也可以同步高效去除水中砷(V)、铁、锰、氨氮。水中铁、锰的存在可以促进滤池对砷(V)的去除,且高负荷的铁或锰共存时,滤池依然能够保证稳定的除砷(V)能力。当原水p H升高时,砷(V)的去除效果略有下降,但在高砷地下水的p H(7.1~8.7)条件下,滤池除砷(V)效果良好。滤池进水砷(V)负荷或滤池滤速的增大会导致滤层除砷(V)达标深度增加,但中试实验中的进水砷(V)浓度和滤速下,出水均能达标,表现出较优异的抗冲击负荷能力。接触氧化滤池滤料表面的活性铁锰氧化膜对砷(V)的去除机理实验表明,在吸附砷(V)的前后活性滤膜的形态特征没有明显的差别。在组成元素上,吸附前活性铁锰氧化膜的主要组成元素是铁和锰,吸附后有含有砷,表明其具有除砷的能力。在结构上,吸附前后的晶体结构基本没有变化,吸附后活性铁锰氧化膜形成了新的As-O键。活性铁锰氧化膜为性质均一的吸附剂,对砷(V)的饱和吸附容量较大,吸附过程较快,为化学吸附,颗粒内扩散不是控制吸附过程的唯一步骤。活性铁锰氧化膜表面电位和对砷(V)的吸附容量均随p H值的升高而降低,CO_3~(2-)的共存会显著抑制活性铁锰氧化膜的吸附除砷(V)过程。随活性铁锰氧化膜投加量的增加,砷(V)的去除率增大,吸附容量随之降低。
[Abstract]:Arsenic is one of the toxic pollutants in water. Arsenic pollution in drinking water has become a serious problem all over the world, which is increasingly threatening human health.Arsenic, iron, manganese and ammonia nitrogen often coexist in groundwater. Iron and manganese oxides, as adsorbents for arsenic removal, combine the strong adsorbability of iron oxides with the oxidation properties of manganese oxides, which have the advantages of simple process, simple operation, friendly environment, economic and so on.In this paper, the effects of contact oxidation filter on the removal of arsenic, iron, manganese and ammonia nitrogen from groundwater were studied, and the effects of the filter on the removal of four pollutants separately and synchronously were investigated.The effects of different water quality conditions and process parameters on the removal of arsenic and Von in the filter were analyzed.Combined with the characterization of materials before and after adsorption of active ferromanganese oxide film and the characteristics and influencing factors of arsenic removal, the mechanism of arsenic removal in contact oxidation filter was explored, which provided technical support for the engineering application of contact oxidation filter.The active ferromanganese oxide film on the surface of contact oxidation filter is mainly composed of iron and manganese, which is granular in shape and rich in void, which provides a large contact area for a large number of pollutants adsorbed on the ferromanganese oxide film.The filter has better ability of removing arsenic, iron, manganese and ammonia nitrogen alone, and has strong ability to resist the impact load of pollutants. At the same time, it can also simultaneously and efficiently remove arsenic, iron, manganese and ammonia nitrogen in water.The existence of iron and manganese in water can promote the removal of arsenic (V) from the filter, and when the iron or manganese coexists with high load, the filter can still guarantee the stable ability of removing arsenic and Von.When pH increased in raw water, the removal efficiency of arsenic (V) decreased slightly, but under the condition of high arsenic groundwater (pH 7.1 ~ 8. 7), the filter had a good removal effect.The increase of the influent arsenic (V) load or the filter speed of the filter will lead to the increase of the depth of arsenic removal in the filter layer. However, under the concentration and the filtration rate of the influent arsenic (V) in the pilot experiment, the effluent can reach the standard, showing a better ability of resisting the shock load.The removal mechanism of active ferromanganese oxide film on the surface of contact oxidized filter media shows that there is no obvious difference in the morphological characteristics of the active filter membrane before and after the adsorption of as _ (+) _ (V).The main components of the active ferromanganese oxide film before adsorption are Fe and mn, and there is arsenic after adsorption, which indicates that it has the ability to remove arsenic.In terms of structure, the crystal structure before and after adsorption is basically unchanged, and the active ferromanganese oxide film forms a new As-O bond after adsorption.The active ferromanganese oxide film is a homogeneous adsorbent with large saturated adsorption capacity and fast adsorption process. It is chemically adsorbed and the diffusion in particles is not the only step to control the adsorption process.Both the surface potential and the adsorption capacity of active ferromanganese oxide films decreased with the increase of pH value, and the coexistence of CO _ 3O _ 2) significantly inhibited the adsorption of arsenic removal from active ferromanganese oxide films.With the addition of active ferromanganese oxide film, the removal rate of arsenic oxide increases and the adsorption capacity decreases.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.2

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