【作者】 吴文勇；

【导师】 陈鸿汉；

【作者基本信息】 中国地质大学（北京） ， 地下水科学与工程， 2009， 博士

【摘要】 本论文以北京市平原区为主要研究区域,采取地下水水质普查、野外试验与模型改进相结合的方法,得出了主要污染物在包气带的迁移转化规律,量化评价了地下水水质与人类活动的相关关系,改进了DRASTIC模型的评分标准与权重,编制出北京市平原区地下水防污性能区划图,提出了北京市再生水灌溉利用分区。开展了北京市东南郊再生水灌区地下水化学评价,建立了基于GIS的再生水灌区地下水水质基础数据库,得出了地下水碳酸平衡作用、氧化还原作用、淋溶作用、浓缩作用是决定了典型区地下水水质空间分布规律,发现近年来典型区地下水水质总体呈现改善的趋势,再生水灌溉未导致典型区地下水显著污染。空间变异性分析提出了硝氮、亚硝氮、铵氮、氯化物、高锰酸钾指数、总硬度等6项指标是受人类活动影响最为显著的指标。开展了再生水灌溉条件下原位定点精细剖面试验,模拟长期(167年)再生水灌溉不会导致包气带剖面重金属含量显著增加,包气带剖面硝态氮易于迁移,包气带铵氮增加受粘粒含量影响较大,12m、18m包气带对总氮的去除率达到83%以上,对地下水TP含量的去除率达到99%以上,再生水灌溉(167年)条件下表层土壤盐分、土壤碱性具有增加的趋势,但是仍然在适宜范围内(0≤SAR≤10)。再生水长期渗滤条件下监测井(12m)pH值相比变化不显著,再生水在包气带的淋溶过程中盐分增加21%~30%、氯离子含量增加1.5%~16.1%,但是,监测井地下水TDS与对照井差异不显著,说明再生水灌溉对地下水盐分的影响与其它水源补给无显著差异。再生水长期渗滤条件下不同层位土壤PAHs含量变化不显著,与我国一些地区自然背景值相接近,多环芳烃污染源为石油源兼具燃煤污染的特征,可能源于大气降尘及历史污水灌溉,萘、菲、荧蒽、芘与其他组分相比具有更好的迁移性,包气带对多环芳烃的去除率达到95%,试验区域包气带防护性能良好。研究绘制出北京市东南部再生水灌区地下水固有防污性能分区图,提出了土地利用类型、水位降深值评分标准及权重,确定包气带防污性分区阈值,建立了北京市平原区基于人类活动影响的地下水包气带防污性能区划模型(DARSILE),完成了北京市再生水灌溉利用区划,提出了再生水优先发展区、再生水适宜发展区和再生水禁止发展区,面积分别为11.6万hm2、4.8万hm2、15.8万hm2。更多还原

【Abstract】 The objective of ths study is to ascertain the transport and change of main pllutants in the typical vadose zone of Beijing plain based on groundwater investigation, field experiment. The indexs and weight of DRASTIC model is improved by quatifying the relation of human activities and grounderwater pollution, and the allocation map of grounderwater vulnerability and feasible allocation map of reclaimed wastewater irrigation in Beijing plain is drawn out.The time-spatical changes of groundwater quality in the southeast of Beijing plain is determined by carbonate balance, oxidation and deoxdation, concentration, etc.. The groundwater quality has improved in recent years. Reclaimed wastewater irrigation has not negative influence on groundwater from the investigation. Nitrite, nitrogen, ammonia, chloride, potassium permanganate and hardness are the six parameters signifantly affected by human activities.There are no signifance changes of heavy metals and PAHs in vadose profile under treatment 7 (simulation of 167-years reclaimed wastewater irrigation). The nitrogen is easier to transport compared to ammonia, and soil ammonia has high relation of clay particles content. The 12 meter and 18 meter of vadose thichness can remove 83% of total nitrogen, 99% of total phosphorus and 95% of PAHs. soil salt and sodicity is increased under treatment 7, which is still in the feasible range for irrigation(0≤SAR≤10). In the infiltration process of reclaimed wastewater from surface to groundwater (12 meter depth), the pH changes little, chloride increases 1.5%~16.1% and TDS increases 21%~30%, but there is no signifant difference in groundwater quality between treatment and control. There is no difference for salt changes between reclaimed wastewater and other water sources. The PAHs content is close to environmental background value, the pollutant is originated from a mixture of burning of natural gas and gasoline and coal combustion. Nap, Phe, Fla, Pyr is easier to transport compared to others. The typical vadose has low vulnerability.The relation between land use, water table decrese and groundwater pollution and the weight have been ascertained to improve DRASTIC model, the DRASILE model based on human activities has been established to research the feasibility of Beijing plain of reclaimed wastewater irrigation, the threshold to classify groundwater vulnerability for reclaimed wastewater irrigation is ascertained, Beijing plain bas been divided into priority area, feasible area and forbidden area for reclaimed wastewater irrigation with the area of 116 thousand hm2, 48 thousand hm2 and 15.8 thousand hm2 respectively.更多还原