宁夏灵武生活垃圾填埋场地下水污染与预测研究

发布时间：2018-03-04 06:00

本文选题：灵武垃圾填埋场　切入点：污染模拟　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：生活垃圾填埋场作为生活垃圾的处理场所和最终归宿,对于城市发展、环境保护、资源合理开发利用等起着举足轻重的作用。填埋法因其投资小、易操作、技术成熟等优势跻身为生活垃圾最主要的处理方法,然而填埋垃圾在自身压实、发酵等生物物理化学作用和降雨的共同作用下会产生大量有机或无机的高浓度渗滤液,若处置不当或发生泄漏,将对周边地下水环境和居民健康带来极大的隐患。本文选取宁夏回族自治区灵武市灵武无害化生活垃圾填埋场为研究对象,在野外实地调研、资料收集、取样分析的基础上,对灵武垃圾填埋场及其周边的地下水进行了水质评价和健康风险评价,用MODFLOW模拟了防渗层未破损和防渗层破损5%的情况下,渗滤液中主要污染物As在地下水中的运移情况,并进行了深入分析和讨论。主要结论如下:(1)研究区补、径、排条件较为简单,补给项为大气降水与侧向径流补给,其中大气降水量为7.79×104m3/a,约占总补给量的30%。地下水的排泄途径为侧向径流排泄,排泄量24.47×104m3/a。(2)研究区地下水中溶解性总固体、氨氮、总硬度、高锰酸盐指数、氟化物和亚硝酸盐氮等指标超标,超标率分别为66.7%、83.3%、83.3%、66.7%、100%和16.7%。取样点的水质综合评价结果均为极差。(3)通过饮用含As地下水导致的致癌风险约为1.99×10-6,通过皮肤接触含As地下水导致的致癌风险值约为3.41×10-11;饮用研究区含氟化物地下水的危害商为3.18,皮肤接触研究区含氟化物地下水的危害商为5.44×10-5。所有水样的饮用途径非致癌风险都大于可接受危害商1。(4)以渗滤液中实测As浓度0.295mg/L作为初始浓度代入模型,对垃圾填埋场及周边地下水分三种情况进行了30年的模拟和预测:在防渗完好情况下,地下水中砷的浓度没有超标;在垃圾填埋场区防渗膜破损5%、渗滤池防渗正常的情况下,地下水中的砷含量增长但未超标,垃圾填埋场渗滤液对地下水产生了影响;在垃圾填埋场区和渗滤池防渗膜均破损5%的情况下,地下水中砷的浓度在渗漏初期就已经超标,且随着模拟时间而增大。模型运行18年,垃圾填埋场区下游140m范围内砷浓度超标。
[Abstract]:As the disposal place and final destination of domestic waste, landfill plays an important role in urban development, environmental protection, and rational exploitation and utilization of resources. Because of its small investment, landfill is easy to operate. Technology maturity and other advantages are among the most important treatment methods for domestic refuse. However, under the combination of biophysical and chemical effects such as self-compaction, fermentation and rainfall, landfill waste will produce a large number of organic or inorganic high concentration leachate. If improper disposal or leakage occurs, it will bring great hidden danger to the surrounding groundwater environment and residents' health. In this paper, Lingwu harmless domestic refuse landfill in Lingwu City, Ningxia Hui Autonomous region, is selected as the research object, and field investigation is carried out in the field. On the basis of data collection and sampling analysis, the groundwater quality and health risk assessment of Lingwu landfill site and its surrounding area were carried out. MODFLOW was used to simulate the condition that the impermeable layer was not damaged and the impermeable layer was damaged by 5%. The transport of as, the main pollutant in leachate, in groundwater is analyzed and discussed in depth. The main conclusions are as follows: 1) in the study area, the conditions of compensation, diameter and discharge are relatively simple, and the recharge terms are atmospheric precipitation and lateral runoff recharge. The atmospheric precipitation is 7.79 脳 10 ~ 4 m ~ (3 / a), accounting for about 30% of the total recharge. The discharge way of groundwater is lateral runoff discharge, and the discharge amount is 24.47 脳 10 ~ (4) m ~ (3 / a) a.f.) the total dissolved solids, ammonia nitrogen, total hardness, permanganate index in groundwater in the study area. Fluorides and nitrite nitrogen and other indicators exceed the standard, The rate of exceeding the standard is 66.7% and 16.77.The comprehensive evaluation results of the water quality of the sampling points are extremely poor.) the carcinogenic risk caused by drinking as groundwater is about 1.99 脳 10 ~ (-6), and the carcinogenic risk value caused by skin contact with as groundwater is about 3.41 脳 10 ~ (-11). The hazard quotient of fluorinated groundwater was 3.18, the hazard quotient of fluorinated groundwater in skin contact study area was 5.44 脳 10 ~ (-5). The non-carcinogenic risk of drinking route of all water samples was higher than that of acceptable hazard quotient (1.44).) the measured as concentration in leachate was 0.295 mg / L. As an initial concentration substitution model, In this paper, three kinds of conditions of landfill and surrounding groundwater are simulated and forecasted for 30 years: in the case of intact seepage prevention, the concentration of arsenic in groundwater is not over the standard; in the case of 5% damage of impervious membrane and normal seepage control of filter in landfill area, the concentration of arsenic in groundwater does not exceed the standard. The content of arsenic in groundwater increases but does not exceed the standard, the leachate of landfill has an effect on the groundwater, and the concentration of arsenic in groundwater has exceeded the standard in the early stage of leakage, when the impervious membrane of landfill site and seepage filter is damaged by 5%, The model was operated for 18 years, and the arsenic concentration exceeded the standard in the range of 140 m downstream of the landfill site.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X523;X799.3

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