【作者】 许秀泉；

【导师】 高建恩；

【作者基本信息】 中国科学院研究生院（教育部水土保持与生态环境研究中心） ， 土壤学， 2014， 博士

【摘要】 随着全球水资源紧张加剧，在中国及世界许多地区，雨水不仅作为生产用水，而且作为生活用水得到广泛应用，但作为饮用水源的水质问题研究薄弱，研究雨水作为饮用水源的水质变化对饮水安全影响具有重要意义。本研究针对黄土区微型蓄雨设施中水体污染物时空分布及对饮水安全影响等方面存在的问题，选取与人体健康密切相关的水体典型污染物作为研究对象，通过理论分析和室内外试验相结合的方法，重点研究了蓄集雨水典型污染物时空变化规律及作用机制，取得主要成果如下：1、蓄雨水体水质随时间变化规律。雨水贮存过程中，污染物含量随时间增加呈现逐渐降低，在20~30天内达到稳定的趋势，该变化趋势符合水体自净作用影响规律。分析了贮存过程中沉降、扩散、降解和源汇等作用对污染物迁移转化影响，概化了污染物随时间变化过程，建立了基于降解和源汇的计算公式，验证结果表明浊度和COD模拟结果较理想；含氮化合物影响因素复杂，其模拟结果具有一定偏差，但变化趋势一致，说明该公式在一定程度上反应蓄雨水体污染物随时间变化。计算与实测结果表明，蓄雨设施贮存雨水20~30天后水体污染物含量较低，为适宜取水时段，该结论对饮水安全具有重要实际意义。2、蓄雨水体水质的空间变化服从重力与扩散相互作用规律。实测结果表明，贮存雨水污染物含量沿垂线分布呈现两端高、中间低的特征，主要受底层沉积物质和表层水体漂浮物两个主要污染源及水体生物的影响，本质是重力和扩散相互作用的结果。基于重力与扩散的相互作用，根据贮存水体边界条件，给出了污染物沿垂线分布的公式，利用实测的浊度和COD资料验证，发现模拟结果存在一定偏差，但分布趋势一致，表明该公式在一定程度上揭示了水体污染物的空间分布规律，但计算较复杂。为了计算方便，依据实测资料给出了污染物沿垂线方向的经验性关系。上述研究结果表明，在相对水深0.4~0.6h处污染物含量最低，为适宜取水位置。该结论对蓄雨设施饮水安全提供了技术保障。3、不同蓄雨材料对蓄雨水体水质影响。试验结果表明，蓄雨水体水质变化的稳定阶段主要受扩散作用影响，微型蓄雨设施材料对水体影响较大。进一步研究表明，采用新型材料MBER（a Material Becoming Earth into Rock）土壤固化剂的蓄水设施水体污染物时空分布与其它常用材料一致，但土壤固化剂对比水泥材料蓄水污染物含量降低15~20%，空间分布上水体中部位置相对浊度和COD含量分别降低15%和8%左右。分析表明，与水泥材料相比，土壤固化剂与土壤及水的相互作用，产生了更多的具有吸附作用的Ca(OH)2等产物，强化了水体的自净作用。上述结果表明MBER土壤固化剂作为蓄雨设施材料具有水质好的优势，作为安全饮水工程材料具有可行性。4、安全蓄雨水质的简易评价方法研究。针对饮用水监测指标过多，水质不易评价的问题，研究发现，不同的污染物成分多数具有一定的联系，可以通过统计分析排除内在联系，优化出浊度、COD、易溶离子（如硝酸根）和pH共4个指标作为总体控制指标来评价水体水质状况。利用4个指标建立了以安全饮水为目标的雨水水质评价方法，经过实测资料分析和与其它方法的比较，表明该方法在评价雨水适宜饮用问题上，具有直观、可靠和实用的特点。5、安全蓄雨设施对典型地区雨水利用的水质保障作用。在地表水为苦咸水，地下水为高氟水的定边白云山地区，农村庭院以固化土及水泥等为材质的蓄雨设施水体水质监测结果表明，使用期内水质基本符合饮水安全要求，取水拟在水体中上部。而在黄土高原丘陵沟壑区小流域的塘、河、库蓄集雨水监测结果表明，除部分水体浊度和COD含量较高以外，水质基本符合饮水安全要求。蓄雨设施不但有助于解决小流域尺度的饮水安全问题，同时具有防治水土流失的作用。更多还原

【Abstract】 Under the press of globle water resource shortage, harvested rainwater has beenwidely used to provide not only process water but also domestic water consumption inChina and many other coutries. It is an important issue to investigate water qualityvariation of harvested rainwater as drinking water source in micro-storage facilities and itsinfluence on safety of drinking water. Aiming at a number of problems with water qualityissue during rainwater utilization, the paper took some typical water quality parametersclosely related to human health as researcher object, studied characteristics and mechanismof the spatio-temporal variability of the referred pollutants, by means of indoor andoutdoor experiment and theoretical analysis. The main conclusions are listed as follows:1. Simulation and analysis of temporal variation of typical pollutants concentration inharvested rainwater. During storage process, the concentration of pollutants graduallyreduced with time, and reached a stable trend in20~30days, which agreed with effect ofself-purification. According to the measured results of temporal variation in pollutantsconcentration, the temporal migration process changes of pollutants could be dividend intothree stages, viz. the early settlement-dominant period, the transition period and thediffusion-dominant period. A numerical model was established for describing the temporalchanges of pollutants in small and micro-rainwater utilization engineering, validated andevaluated. And turbidity and COD werer verified well by the monitoring results; nitrogencompounds had a certain deviation, but a rational trend.20-30days after storage wasrecommended as suitable time for utilization.2. Simulation and analysis of vertical distribution of typical pollutants concentrationin rainwater. Turbidity and COD contents are high at two ends and low in the middle alongthe vertical line, due to sediment at the bottom and floating debris at the surface andbiological activities. Sediment and floating debris are two main pollution sources. Alongthe vertical line, the measured relative pollutant content was positively correlated to thepower function of relative distance from the pollution source. Several types of vertical distribution were given based on the measured data. So low pollutant content appears inthe middle, and cleanness of surface and bottom could improve harvested rainwater quality.A numerical model was established for describing the vertical distribution of pollutants insmall and micro-rainwater utilization engineering, validated and evaluated, and wasverified by the monitoring results, which had certain deviation, but credible usage. Arelative depth of0.4-0.6h was was recommended as suitable zone for utilization.3. The effect of MBER soil stabilizer, compared with cement material, as constructionmaterials on water quality was studied. With the effect of soil stabilizer, during storagetime, the pollutants concentration decreased about15~20%; as for the vertical distribution,the relative concentration decreased about8~12%. The effect of solidified soil usingMBER soil stabilizer was due to the hydrate reaction of solidified soil and reactionproducts. Soil stabilizer could strengthen self-purification of water to some extent, whichcould reduce the amount of turbidity, COD and some ions such as nitrate and nitrite.Results showed that the water quality did not exceed the standard for drinking water inChina for distribute water supply. Results in this research were valuable for popularizationand application of MBER soil stabilizer in rainwater utilization from point view of waterquality issue.4. A suitable water quality assessment method was given. Turbidity, COD, ions (suchas nitrate) and pH were chosen as the main factors or indicators for describing thecharacterization of rainwater quality using statistics analysis method. The rainwater qualityassessment method was presented as a result to security drinking water quality. Throughdata analysis and comparison, the method is intuitive, reliable and targeted.5. The suitability of different spatial scales of rainwater utilization was investigated.Harvested rainwater utilization in the rural single family courtyard, small watershed wasinvestigated and evaluated. Results showed that: rainwater utilization had great potentialin solving the rural household in dingbian. Rational utilization of rainwater resources is asuitable strategy to alleviate the problem of drinking water safety in rural area.更多还原