Nitrate pollution and its Natural Attenuation Processes in Groundwater

世界卫生组织的建议是，基于饮用水可能导致高铁血红蛋白血症，饮用水中的硝酸盐含量不应超过50毫克/L(或10毫克硝酸氮)。在过去十年中，随着世界许多地区公共供水井中的硝酸盐浓度达到不可接受的水平，显然需要更多地关注地表人类活动与地下水水质之间的联系。本研究通过对千叶、宫古岛、鸟取和中国平原北部不同气候、土地利用条件下地下水中硝酸盐的行为进行研究，以了解地下水中硝酸盐的迁移和衰减过程。主要结论如下：a)湿地与地下水和厌氧条件相结合的一体化系统具有独特的反硝化功能。2)硝态氮在鸟取县重要景观之一的沙丘中迁移迅速。C)宫古岛地下大坝建成后，地下水中硝酸盐浓度尚未增加。今后应做更多的工作来监测农业活动对地下水水质的影响。以及d)污水灌溉措施对地下水质量最显著的影响是高浓度的硝酸盐。污灌区地下水的δ^&lt；15&gt；N值范围为+5~+13‰，主要分布在+7~+11‰之间。污水灌溉方式对地下水水质的负面影响比泵井灌溉方式更大。

The World Health Organization's recommendation is that drinking water should not contain more than 50 mg/L of nitrate (or 10 mg NO_3-N), based on its potential to cause methaemoglobinaemia. In the last decade as nitrate concentrations in public supply wells have reached unacceptable levels in many parts of the world, it has become obvious that more attention needs to be paid to linkages between human activities on the surface and groundwater quality. In this research, we studied the behaviors of nitrate in groundwater of Chiba, Miyakojima Island, Tottori and North China Plain with different climate, land use conditions to make clear the migration and attenuation processes of nitrate in groundwater flow system. Some conclusions can be summarized as the following.a)Wetland has one of its particular functions on denitrification with the Integrated system with groundwater and anaerobic condition. b)Nitrate migrates rapidly in sand dune which is one of most important landscape in Tottori Prefecture. c)Nitrate concentration in groundwater of underground dam in Miyako Island has not been increased alter the dam was completed, yet. More work should be done to monitor the effects of agricultural activities on groundwater quality in future. And d)The most significant effect of wastewater irrigation practices on groundwater quality is a high nitrate concentration. Groundwater in wastewater irrigated area have δ^<15>N values ranging from +5 to +13‰, and dominantly between +7 and +11‰. Wastewater irrigation practice had more negative impact on groundwater quality than irrigation with pumping wells in the NCP.