沈北新区浅层地下水污染风险评价

发布时间：2019-03-30 15:52

【摘要】：地下水是支撑国民经济和生态环境可持续发展的战略资源,浅层地下水是很多城乡结合部和农村地区的重要饮用水源。城市扩张和农业集约经营对地下水环境的影响日益明显。地下水的污染威胁到生态系统安全和居民的身体健康。选择典型的城乡过渡区,开展污染水平、空间分布、区域生态风险和人体健康风险评价,对于指导城市扩展和农业集中开发过程中的土地利用优化与地下水环境管理具有重要的理论意义和现实价值。本文选择城市扩张和农业集约化经营的典型地区—沈阳沈北新区作为研究案例区,通过采样测试、统计分析、模型分析等手段,综合评价了地下水部分指标的污染程度、空间分异特征、区域生态风险与人体健康风险。主要得出如下结论:1)平水期沈北新区浅层地下水质总体较好。硝酸盐、亚硝酸盐、Fe、Mn、Cd、Pb、Hg、As、Cr~(6+)、六六六、滴滴涕和多环芳烃均有检出,其中硝酸盐、亚硝酸盐、Fe、Mn、Cd超标率较高,分别达到35%、12%、46%、76%和19%;2)硝酸盐、Fe、Mn空间变异性强,空间异质性主要受自然条件等结构性因素控制,Cd、Pb、Hg空间变异性中等,As、六六六、滴滴涕和多环芳烃空间变异性弱,Cd、Pb、Hg、As、六六六、滴滴涕和多环芳烃空间异质性的形成主要受城市化、工业化和农业集约经营等人为活动随机因素的影响;3)沈北新区地下水固有脆弱性呈现西北至东南梯次降低的趋势,通过与污染源、综合污染指数叠加分析,发现西部的石佛寺和兴隆台街道,中部从南到北方向的道义、新城子和黄家街道具有较高的生态风险;4)沈北新区浅层地下水大部分地区尚不存在饮用途径的健康风险,只有前进农场等设施农业集中的局部致癌危害指数超过了可接受范围。5)沈北新区地下水的风险管理重在针对超标率较高的硝酸盐、Fe、Mn和检出率高、存在潜在风险的六六六和与多环芳烃;空间上控制城市和设施农业的扩展规模,加强社会经济发展过程中污染物质的排放管理。
[Abstract]:Groundwater is a strategic resource to support the sustainable development of national economy and ecological environment. Shallow groundwater is an important drinking water source in many rural and urban areas. The influence of urban expansion and agricultural intensive management on groundwater environment is becoming more and more obvious. The pollution of groundwater threatens the safety of ecosystem and the health of residents. Select a typical urban-rural transitional area, carry out pollution level, spatial distribution, regional ecological risk and human health risk assessment, It is of great theoretical and practical value to guide the optimization of land use and the management of groundwater environment in the process of urban expansion and agricultural centralized development. In this paper, Shenyang Shenbei New area, a typical area of urban expansion and intensive agricultural management, is chosen as the case area. By means of sampling test, statistical analysis and model analysis, the pollution degree of some indexes of groundwater is evaluated comprehensively. Spatial differentiation characteristics, regional ecological risk and human health risk. The main conclusions are as follows: 1) the shallow underground water quality in Shenyang North New area is good in general. Nitrate, nitrite, Fe,Mn,Cd,Pb,Hg,As,Cr~ (6), BHC, DDT and PAHs were detected, and the excess rates of nitrate, nitrite and Fe,Mn,Cd were 35% and 12%, respectively. 46%, 76% and 19%; 2) nitrate and Fe,Mn have strong spatial variability, and spatial heterogeneity is mainly controlled by structural factors such as natural conditions. The spatial variability of Cd,Pb,Hg is moderate, that of As, DDT and PAHs is weak, and that of Cd,Pb,Hg, is weak. The formation of spatial heterogeneity of As, DDT and PAHs was mainly influenced by the random factors of man-made activities such as urbanization, industrialization and intensive management of agriculture. 3) the inherent vulnerability of groundwater in Shenbei New area shows a decreasing trend from northwest to southeast. Through superimposed analysis with pollution sources and comprehensive pollution index, it is found that Shifo Temple and Xinglongtai Street in the west and the morality of the central part from the south to the north are found. Xinchengzi and Huangjia streets have high ecological risk; 4) there is no health risk of drinking route in most areas of shallow groundwater in Shenbei New area. Only the local carcinogenic hazard index in facilities such as Qianjin Farm exceeded the acceptable range. 5) the risk management of groundwater in Shenbei New area is focused on the higher nitrate, Fe,Mn and detection rate, which are higher than the standard rate, and the risk management of groundwater in Shenbei New area is very important. There are potential risks of hexachlorocyclohexane and polycyclic aromatic hydrocarbons; The scale of expansion of urban and facility agriculture is controlled in space, and the emission management of pollutants in the process of social and economic development is strengthened.
【学位授予单位】：沈阳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X824

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