不同离子对铁锰氧化物催化氧化去除地下水中氨氮的影响

发布时间：2018-11-20 19:48

【摘要】：近年来,由于环境污染,地下水氨氮超标的现象越来越普遍。研究证明铁锰氧化物催化氧化地下水中氨氮相较于生物法具有滤料成熟期短,能够同步去除铁锰等多种污染物等优点。但由于我国幅员辽阔,地下水水质变化很大,铁锰氧化物催化氧化氨氮这种技术在其他地区的应用可能会出现新的问题,为了进一步完善铁锰氧化物催化氧化氨氮的理论,本实验主要研究内容为不同离子对铁锰氧化物催化氧化去除地下水中氨氮的影响。实验利用已持续运行2年的石英砂滤柱中试系统,通过改变进水中不同离子的种类和离子浓度,考察了不同浓度离子对石英砂滤料表面活性氧化膜催化氧化水中氨氮性能的影响。结果表明:高浓度钠离子、钾离子、氯离子、硫酸根离子、碳酸氢根离子对滤料去除氨氮性能基本没有影响,去除率均达到了87%以上。高浓度钙离子对滤料去除氨氮性能影响很大,当氯化钙进水浓度为1000 mg/L,去除率降低到了51%。停止投加钙离子后,滤料去除氨氮的性能可在8~9 h内恢复。对滤料表面进行微观表征发现滤料表面钙的含量大幅上升,滤料的比表面积、孔体积降低,影响了滤料与氨氮污染物的接触,造成氨氮去除效率下降。亚铁离子和锰离子对氨氮去除性能的影响很大,当进水中亚铁离子浓度为10 mg/L,去除率降低到了65%。随着进水中亚铁离子浓度的升高,出水中硝氮浓度降低,亚硝氮浓度增加。进水中较高浓度的锰离子会影响铁锰氧化膜对氨氮的去除效果,进水中锰离子浓度超过4 mg/L以上时,氨氮去除率为81%。进水中同时投加锰离子和亚铁离子时,亚铁离子对铁锰氧化膜去除氨氮的影响要比锰离子明显很多,进水中亚铁离子浓度越高,锰离子对铁锰氧化膜去除氨氮的影响越不明显。
[Abstract]:In recent years, due to environmental pollution, the phenomenon of groundwater ammonia nitrogen exceeding the standard is becoming more and more common. It has been proved that the ammonia nitrogen in groundwater catalyzed by iron and manganese oxides has the advantages of shorter maturation period and more simultaneous removal of iron and manganese and other pollutants. However, due to the vast territory of our country and the great changes in groundwater quality, the application of the technology of iron and manganese oxide catalytic oxidation of ammonia nitrogen in other regions may lead to new problems. In order to further improve the theory of iron and manganese oxide catalytic oxidation of ammonia nitrogen, The effect of different ions on the removal of ammonia nitrogen from groundwater by catalytic oxidation of iron and manganese oxide was studied in this experiment. The pilot system of quartz sand filter column, which has been running for 2 years, was used to change the species and concentration of different ions in the influent. The effects of different concentrations of ions on the catalytic oxidation of ammonia and nitrogen in water by surface active oxide film of quartz sand filter were investigated. The results showed that high concentration of sodium ion, potassium ion, chloride ion, sulfate ion and bicarbonate ion had no effect on the removal of ammonia and nitrogen, and the removal rate was over 87%. The high concentration of calcium ion has a great effect on the removal of ammonia and nitrogen, and the removal rate of calcium chloride decreases to 51 when the influent concentration of calcium chloride is 1000 mg/L,. After the addition of calcium ion was stopped, the performance of ammonia nitrogen removal could be recovered in 8 ~ 9 h. Microscopic characterization of the surface of the filter media found that the calcium content on the surface of the filter media increased significantly, and the specific surface area and pore volume of the filter media decreased, which affected the contact between the filter media and ammonia nitrogen pollutants, resulting in a decrease in the removal efficiency of ammonia nitrogen. The effect of ferrous ion and manganese ion on the removal performance of ammonia nitrogen was very great. When the concentration of ferrous ion in influent was 10 mg/L, the removal rate decreased to 65%. With the increase of the iron ion concentration in the influent, the nitrate concentration in the effluent decreased and the nitrite nitrogen concentration increased. The high concentration of manganese ion in the influent will affect the removal effect of ammonia nitrogen by ferromanganese oxide film. When the concentration of manganese ion in the influent is more than 4 mg/L, the removal rate of ammonia nitrogen is 81%. When both mn and Fe ions were added into the influent, the effect of ferrous ion on the removal of ammonia nitrogen by ferromanganese oxide film was more obvious than that by manganese ion. The higher the concentration of ferrous ion in influent, the less the effect of manganese ion on the removal of ammonia nitrogen in ferromanganese oxide film.
【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】：X523

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