地下水中铁离子对三氮迁移转化的影响研究

发布时间：2018-04-04 18:45

本文选题：地下水　切入点：三氮　出处：《东华理工大学》2015年硕士论文

【摘要】：地下水是人类赖以生存的重要饮用水水源,但是近些年,随着工业发展和农业生产日益发达,出现了工业生产污水被大量排放、垃圾淋滤液渗透、采矿冶炼废弃物堆放以及农药化肥大量施用等现象,这使得地下水不断受到污染,其中三氮的污染较为普遍。我国东北地区由于地质条件原因使得地下水环境中存在高浓度的铁离子,造成了大量铁离子与三氮共存的现象。铁是常见的变价元素,普遍存在于地下水和土壤环境中,它在土壤和水环境中的存在形态是多种多样的,并且在不同的氧化还原条件和酸碱性下铁元素各种形态之间可以互相转化,进而影响并改变氮素的存在形态。因此,研究地下水中铁离子对三氮迁移转化的影响,对地下水污染的阻断和修复具有重要的理论价值和实际意义。本文以氮污染物作为研究对象,选用铁离子作为氮迁移转化的一种影响因素,通过静态实验和动态土柱模拟实验,研究了地下水中铁离子对三氮迁移转化的影响,揭示了地下水中三氮在铁离子影响下的迁移转化规律。在此基础上,结合实际场地,验证室内实验结果。通过研究,获得了以下一些主要成果和认识:(1)铁离子浓度对环境中的物理指标均有明显的影响。随着Fe2+浓度的升高,p H值、溶解氧以及氧化还原电位的值均呈下降趋势。(2)铁离子浓度对三氮的转化产生了明显的影响。随着Fe2+浓度的升高,有利于硝氮转化为氨氮,溶液中硝氮浓度呈下降趋势,而氨氮浓度升高。(3)高浓度Fe2+对地下水中三氮的迁移转化产生了巨大的影响。(4)氨氮在粘土和铁离子含量较高的介质中迁移速度较慢。出水口中氨氮的迁移量较小,而硝氮和亚硝氮的含量有所增大。低浓度铁离子介质更利于氨氮的穿透。(5)现场研究与室内实验研究结论一致。但由于现场场地的条件更复杂,研究中需尽量将尽可能影响因素考虑在内。本垃圾填埋场附近地下水流向及各监测井周边地形地貌都对三氮的迁移转化产生了影响。
[Abstract]:Groundwater is an important source of drinking water for human survival. However, in recent years, with the development of industry and agricultural production, industrial production sewage has been discharged in large quantities, and garbage leachate permeates.The accumulation of mining and smelting wastes and the extensive application of pesticides and fertilizers make the groundwater continuously polluted, among which the pollution of trinitrogen is more common.Due to geological conditions, there are high concentrations of iron ions in groundwater environment in Northeast China, which results in the coexistence of iron ions and trinitrogen.Iron is a common variable value element, it is widely found in groundwater and soil environment, and its forms in soil and water environment are various.Under different redox conditions and acid-base conditions, iron forms can be transformed into each other, thus affecting and changing the forms of nitrogen.Therefore, it is of great theoretical and practical significance to study the effect of iron ions in groundwater on the transport and transformation of trinitrogen, which is of great theoretical value and practical significance to the interruption and remediation of groundwater pollution.In this paper, the effects of iron ions on the transport and transformation of nitrogen in groundwater were studied by static experiment and dynamic soil column simulation experiment.The migration and transformation of trinitrogen in groundwater under the influence of iron ions are revealed.On this basis, combined with the actual site, verify the results of indoor experiments.Through the study, we have obtained the following main results and the understanding that the concentration of iron ion has obvious influence on the physical indexes in the environment.With the increase of Fe2 concentration, the values of dissolved oxygen and redox potential showed a decreasing trend.With the increase of the concentration of Fe2, it is favorable for the conversion of nitrate to ammonia, and the concentration of nitrate in the solution tends to decrease.However, the high concentration of Fe2 has a great influence on the transport and transformation of trinitrogen in groundwater. (4) the rate of migration of ammonia nitrogen in clay and iron ion medium is slower than that in the medium with high concentration of iron ions.The transport amount of ammonia nitrogen in outlet was small, but the contents of nitrate nitrogen and nitrite nitrogen increased.Low concentration iron ion medium is more favorable to the penetration of ammonia nitrogen.However, as the site conditions are more complex, the study should take into account the factors as much as possible.The flow direction of groundwater near the landfill and the topography around each monitoring well have an effect on the transport and transformation of nitrogen.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X523;P641.12

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