汾河干流重金属迁移规律研究

发布时间：2018-06-11 20:27

本文选题：土壤 + 重金属污染　；参考：《太原理工大学》2017年博士论文

【摘要】：流域系统以其独有的特点,承载着其范围内工业、农业及居民生活所需的水资源。汾河流域是山西省工业、农业生产发达、人口集中的主要地区,其中工业产值占全省的46%,农业产值占全省的64%。沿岸地区每年从汾河取水24.3亿立方米,占全省水资源利用总量的46%。同时也承载着流域内人口生产、生活废水的排放和输送。年复一年,周而复始的长期污水排放,给河道、滩地、底泥基质、周边土地以及地下水带来哪些影响?生态修复治理的重点是什么?排污河道资源可持续利用和发展路径何在?这些问题都是亟待人们关注和研究的问题。本文依托山西省设立的专题研究项目《河道主要污染物横向积累迁移规律研究》,以汾河干流中游及下游地区为研究对象,以揭示汾河中下游地区河道、滩地、底泥基质、周边土地以及地下水重金属污染程度、迁移规律及分布特征为目标,在进行汾河典型断面野外规模化系统取样、化验的基础上,进行了以汾河典型断面污染物空间分布特征、溶质运移动力学机理、重金属迁移过程研究、污染预测模型及针对性修复措施、汾河重金属污染物远程监测方案为主要内容的分析与研究。研究结论对类似河流因地制宜采取科学、经济的防治、监测措施具有较好的参考价值,同时为流域尺度深入研究水体污染、扩散提供了借鉴。本论文的研究成果包括:1.以汾河中下游干流流经的三处重点城市河段作为研究区域,选取清徐、临汾、运城三地为采样断面,各断面处地表水、(水平距离120m、纵向深度5m范围)河床土壤及各采样区周边5-24km范围内地下水为样品,研究以重金属铅、镉、铬、汞为主的各类污染物含量、分布特征及扩散规律。2.各采样断面土壤均以砂、粉粒为主,每个断面全部样品及采样原点位置底泥平均粘粒含量顺序为:临汾清徐运城;土壤容重顺序为:运城清徐临汾;土壤含水量顺序为:临汾清徐运城。自然条件下,土壤粒径分布是土壤容重、含水量的重要影响因素。3.各断面河床土壤均为富营养化状态;地表水中汞、镉均为重度污染、铬次之,铅污染程度较轻;地下水以汞污染最为普遍和严重,其次为镉、铬,铅污染较轻;河床底泥及滩地土壤中镉含量接近或超过三级“土壤环境质量标准”,为重度污染,铅、汞污染程度较轻,铬含量较低,没有构成污染;沿岸土壤重金属污染物分布规律大致为沿纵向深度与水平距离的增加,呈减小趋势;各重金属地表富集现象不甚明显且各异。4.研究得出通常情况下影响重金属污染物在土壤中迁移的主要因素为土壤粒径分布、土壤容重、水势梯度、水源污染物浓度及水位因素。5.利用软件模拟河流补给沿岸河床土壤污染物横向扩散模型,预测近岸土壤在污水汇入情况下,重金属污染物横向扩散趋势。6.针对土壤重金属镉的污染现状,提出以控制污染源头为主,在重点污染区域采取由耕改建或采取生物修复措施,并提出一种结合土壤污染物传感器的监测系统方案。土壤重金属迁移过程复杂多样,且周期漫长,采样运输、化验阶段误差不可完全避免,因此尚无法完全准确的建立其预测模型,或及时获取大范围样品分析结论。试验方案或模型建立基于均质土壤进行,在实际应用中应多考虑非均质土对污染物扩散的影响,需结合最新检测手段,实测采样区土壤水动力各项参数。
[Abstract]:The basin system, with its unique characteristics, carries the water resources needed for its industrial, agricultural and residential areas. The Fenhe River Basin is the main area of Shanxi province industry, agricultural production and population concentration, of which the industrial output value accounts for 46% of the province, and the agricultural output value accounts for 2 billion 430 million cubic meters of water from the Fenhe River in the 64%. coastal areas of the province. The 46%. of the total utilization of water resources also carries the population production, the discharge and transportation of domestic wastewater. What are the effects of the long-term sewage discharge on the river, the beach, the bottom mud matrix, the surrounding land and the groundwater? What are the key points of ecological remediation? The sustainable utilization of sewage river resources and the sustainable utilization of sewage. What is the development path? These problems are the problems that need attention and research. This paper, based on the special research project set up in Shanxi Province, is a study of the horizontal accumulation and migration of main pollutants in the river, and takes the middle and lower reaches of the Fenhe River as the research object to reveal the river, beach, sediment matrix and surrounding land in the middle and lower reaches of Fenhe River. As well as the pollution degree of heavy metals and the distribution and distribution characteristics of heavy metals in the groundwater, on the basis of sampling and testing in the field scale system of the typical section of Fenhe River, the spatial distribution characteristics of pollutants in the typical section of Fenhe River, the mechanism of solute transport and movement, the study of the migration process of heavy metals, the prediction model of pollution and the targeted restoration are carried out. Measures, the analysis and study of the remote monitoring scheme for the heavy metal pollutants in Fenhe River are the main contents. The conclusions have good reference value for the scientific, economic prevention and control measures of similar rivers to local conditions. At the same time, it provides a reference for the deep study of water pollution and diffusion in the basin scale. The research results of this paper include: 1. Three key urban rivers in the middle and lower reaches of the middle and lower reaches of the river are selected as the research areas, and three areas of Qingxu, Linfen and Yuncheng are selected as sample sections, surface water at each section, (horizontal distance 120m, 5m range of longitudinal depth) and the 5-24km in the surrounding area of each sampling area are the samples, and the various kinds of pollution mainly of heavy metal lead, cadmium, chromium and mercury are studied. The contents, distribution characteristics and diffusion rules of the soil were all sand and powder, and the order of the average clay content in every sample and sampling site was Yuncheng in Qingxu, Linfen; the order of soil bulk density in Yuncheng, Qingxu and Linfen; the order of soil water content in Linfen, Qingxu, Yuncheng. Under natural conditions, soil particle size The distribution is the soil bulk density, the important influence factor of the water content of.3., the soil of each section of the river bed is eutrophic, and the mercury and cadmium in the surface water are all seriously polluted, the chromium is the second, the lead pollution is lighter, the most common and serious mercury pollution in the groundwater is the cadmium, chromium and lead pollution, and the cadmium content in the sediment and the beach soil in the river bed is close or super. Over three levels of "soil environmental quality standard" for heavy pollution, lead and mercury pollution, low chromium content and no pollution, the distribution regularity of heavy metal pollutants along the coastal soil is approximately decreasing along the vertical depth and horizontal distance, and the concentration of heavy metal surface is not obvious and the different.4. studies get the common situation. The main factors affecting the migration of heavy metal pollutants in soil are soil particle size distribution, soil bulk density, water potential gradient, water pollutant concentration and water level factor.5. using software to simulate the lateral diffusion model of soil pollutants in river bed, and predict the lateral diffusion of heavy metal pollutants in the coastal soil. Trend.6., aiming at the pollution status of heavy metal and cadmium in soil, proposed to control the source of pollution mainly. In the key polluted areas, the measures of reconstructing or taking bioremediation were adopted, and a monitoring system combined with soil pollutants sensor was proposed. The migration process of heavy metals in soil was complex and varied, and the period of sampling and transportation was long. The error can not be completely avoided, so it is not quite accurate to establish its prediction model, or to obtain the conclusion of large range sample analysis in time. The experiment scheme or model is based on homogeneous soil. In practical application, the effect of heterogeneous soil on the diffusion of pollutants should be considered, and the soil water movement in the sampling area should be measured with the latest detection methods. Force each parameter.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X52

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