黄河三角洲主要土壤类型重金属环境容量研究

发布时间：2018-07-08 11:03

本文选题：环境容量 + 重金属　；参考：《山东大学》2017年硕士论文

【摘要】：环境容量是环境科学研究的基本内容之一,一般通过数学模型来表征不同环境单元,不同评价物质容量的大小,其计算的结果对某一区域污染物环境质量标准的制定、控制和治理目标、以及环境影响评价等层面具有良好的指导作用。随着环境科学的发展,环境容量的分类也更加细化,不再是传统的根据环境介质分为大气、水、土壤、生物四大类。根据不同的环境单元、污染物的类型、评价目的,有着各种各样的分类。环境容量主要包括客观性、稳定性、变更型、有限性、可控性几大特征。对于环境容量的研究,重要的发展趋势是定量描述的准确化,尤其是对于各种环境介质中自净作用以及各种污染物质的迁移转化所形成的那部分额外容量的计算,需要更加详细科学化的考究。此外根据不同环境单元的特点,如何来良好的把握评价地区的地域性及使得最后的结果更具评价意义也是主要发展的趋势之一。土壤是人们主要粮食作物的供给来源,孕育生命的摇篮,土壤质量的安全与人们的健康息息相关,随着社会经济的发展,越来越多的污染物通过各种各样的途径进入到土壤中,引起土壤污染,破坏了原有的土壤环境质量。土地资源是一个环境区域最基本的要素之一,其配置使用的合理与否,将对该地经济的发展以及环境的质量产生巨大的影响。对土壤环境容量的研究能够在制定土壤环境质量标准、农用水灌溉标准、土地资源的合理开发利用以及污染物总量控制方面有良好的应用价值。黄河三角洲有着大面积的待开发的土地,有丰富的土地后备资源,不同的植物群落形成了多种多样的生境。然而由于其特殊的地理位置,其生态环境较为脆弱,但是随着经济的发展,人类的生产生活并不是以可持续发展为前提,对该地的土地资源进行开发利用,给当地的土地资源的配置以及土壤的健康状况造成了重大影响,出现了土壤盐渍化,淡水资源日渐缺乏等问题。因此本文选取黄河三角洲这一十分具有代表性的区域来进行其中的土壤环境容量研究。主要分三种土壤类型,盐土、潮土和水稻土,选取其中的Cu、Zn、Pb、Cd、As、Hg、Cr七种重金属元素来进行评价。采用现有的数学模型,通过相关实验的测定以及查阅文献书籍获得数据,对其环境容量进行计算评价。分别采用各种金属元素的背景值和现状值对该区域的静态环境容量以及动态环境容量进行了计算,并对同一种重金属元素在不同土壤中的环境容量的差异性做了分析,结果显示:(1)对于静态环境容量而言,在不涉及污染物在土壤中动态变化的条件下,黄河三角洲地区的盐土和潮土对于大部分重金属元素的环境容量较大,水稻土的偏低,大部分元素的环境容量同前两种土壤相比,有显著或极显著的差异性。其中盐土和潮土中Zn的环境容量是水稻土中的2.5倍左右,潮土中Pb的环境容量分别是盐土的1.5倍,水稻土的6倍左右。盐土和潮土占据着黄河三角洲地区的大面积地土地资源,把握重金属在其中含量尺度至关重要,而对于水稻土来说,控制重金属的输入与治理是关键。静态环境容量的大小,主要受土壤中重金属元素的起始值、土壤自身的理化性质、重金属元素自身的性质的影响。因此,静态环境容量的结果对评价某一区域土壤单一的纳污能力以及对重金属的吸附能力有重要意义(2)对于动态环境容量而言,在考虑了污染物在土壤中的动态变化之后,引入年限的概念,计算出年平均动态环境容量,结果表示,随着年限的增加,动态环境容量的大小逐渐趋于一个稳定的值,体现出污染物输出与输入的动态平衡规律,总体来说,年限少,平均动态年容量大,总容量小;年限多,平均小,但是总容量大。动态环境容量的大小主要受到重金属自身的属性以及在土壤中的各种动态变化的影响,因此动态环境容量的计算结果更能综合反映一个区域的纳污能力,能够评价的内容更加广泛。(3)该地区动态环境容量的结果与静态环境容量的结果相比,有些许不同,水稻土中Cd、Hg元素的容量大小有明显的升高,说明对于性质不稳定,易于迁移转化的重金属元素来说,动态变化所带来的额外的环境容量也是评价一个地区环境容量的重要组成部分。总体来看,潮土和盐土的动态环境容量仍然占主要优势,水稻土的环境容量较低。如何加大因重金属元素的变动所产生的额外容量,使得土壤更好的净化,产生优良的土地资源,优化对土地资源的利用,对于潮土和盐土来说是一个关键问题;对于水稻土而言,应及时做好对相关农作物体内重金属的监测以及地下水,深层土壤中的重金属监测,防止二次污染以及对人类健康产生威胁。随着时间的推移,对于静态环境容量而言,根据背景值和现状值计算的结果有所差异,因此,对于不同的评价范围和目的,应选取相应的初始值进行计算。动态环境容量不存在这一现象,尤其是随着年限的增加,所计算的结果更加不受起始值的影响,因此动态环境容量的数学模型应用更加灵活。所有土壤中,不同重金属元素的动态环境容量总是要大于静态环境容量,充分体现出土壤中污染物的吸附解吸、迁移转化、累积与降解等作用。
[Abstract]:Environmental capacity is one of the basic contents of environmental science research. In general, the mathematical model is used to characterize different environmental units and to evaluate the size of material capacity. The results of the calculation have good guidance for the formulation of environmental quality standards for a certain area, control and control targets, and environmental impact assessment. With the development of environmental science, the classification of environmental capacity is also more refined. It is no longer divided into four categories: atmosphere, water, soil and biology. According to different environmental units, types of pollutants and evaluation purposes, there are various kinds of classification. The environmental capacity mainly includes objectivity, stability, change type, finiteness and controllability. Several major features. For the study of environmental capacity, the important development trend is the accuracy of quantitative description, especially for the calculation of the additional capacity formed by the self purification of various environmental media and the transfer of various pollutants, which need more detailed and scientific research. In addition, according to the characteristics of different environmental units, The soil is the supply source of the main food crops and the cradle of life, the safety of soil quality is closely related to the health of people. With the development of the society and economy, more and more pollutants have been found. A variety of ways to enter the soil, causing soil pollution and destroying the quality of the original soil environment. Land resources are one of the most basic elements of an environmental area. The rational allocation and use of the land will have a great impact on the development of the land and the quality of the environment. The soil environmental quality standards, irrigation standards for agricultural water, rational exploitation and utilization of land resources and the total amount control of pollutants have good application value. The the Yellow River Delta has a large area of land to be developed, rich land reserve resources, different plant communities form a variety of habitats. Special geographical location, its ecological environment is relatively fragile, but with the development of the economy, human production and life are not the premise of sustainable development, the land resources for the development and utilization of the land, the distribution of local land resources and the health of the soil have caused a major impact, the emergence of soil salinization, fresh water resources In this paper, the soil environmental capacity of the the Yellow River Delta, which is a very representative area, is selected for the study of soil environmental capacity. It is mainly divided into three types of soil types, salt soil, tidal soil and paddy soil, and select the Cu, Zn, Pb, Cd, As, Hg, Cr and the existing mathematical models, through the existing mathematical models. The environmental capacity of the area is calculated with the background value and the current value of various metal elements, and the difference of the environmental capacity of the same heavy metal elements in different soils is made. The results showed that: (1) for the static environment capacity, the environmental capacity of the saline soil and the tidal soil for most of the heavy metals in the the Yellow River Delta region is larger, the paddy soil is low, and the environmental capacity of most elements is significantly or extremely significant compared with the first two soils. The environmental capacity of Zn in the saline soil and the tidal soil is about 2.5 times that of the paddy soil, and the environmental capacity of the Pb in the tidal soil is 1.5 times that of the saline soil and the paddy soil is about 6 times. The saline soil and the tidal soil occupy a large area of land resources in the the Yellow River Delta region. To control the input and control of heavy metals, the size of the static environmental capacity is mainly influenced by the initial value of the heavy metals in the soil, the physical and chemical properties of the soil itself, and the nature of the heavy metal elements. Therefore, the results of static environmental capacity can be used to evaluate the single pollution capacity of a certain area and to the heavy metals. The adsorption capacity is of great significance (2) for dynamic environmental capacity, after considering the dynamic changes in the soil, the concept of year is introduced to calculate the annual average dynamic environmental capacity. The results show that the size of the dynamic environmental capacity gradually tends to a stable value with the increase of years, reflecting the output and transportation of pollutants. In general, the dynamic equilibrium law, in general, is small, the average dynamic annual capacity is large, the total capacity is small, the number of years is small, the average size is small, but the total capacity is large. The size of the dynamic environmental capacity is mainly influenced by the properties of heavy metal itself and the dynamic changes in the soil. Therefore, the calculation results of dynamic environmental capacity can be reflected more synthetically. (3) compared with the results of static environmental capacity, the results of the dynamic environmental capacity in this area are somewhat different. The capacity of Cd and Hg elements in paddy soil is significantly increased, indicating that the dynamic changes are carried out for the heavy metal elements which are unstable in nature and easy to migrate and transform. The additional environmental capacity is also an important part of evaluating the environmental capacity of a region. In general, the dynamic environmental capacity of the soil and the salt soil still occupies the main advantage, the environmental capacity of the paddy soil is low. How to increase the extra capacity caused by the change of heavy metals, make the soil better clean up, produce good soil The land resources and the utilization of land resources are the key problems for the soil and the saline soil. For the paddy soil, the monitoring of heavy metals in the related agricultural objects and the monitoring of the heavy metals in the deep soil should be done in time. The two pollution and the threat to human health should be prevented. As for the static environment capacity, the results calculated according to the background value and the current situation are different. Therefore, the corresponding initial values should be selected for different range and purpose. The dynamic environmental capacity does not exist, especially with the increase of years, the calculated results are more unaffected by the initial value, so the dynamic ring is not affected. The mathematical model of boundary capacity is more flexible. In all soils, the dynamic environmental capacity of different heavy metals is always greater than that of static environment, which fully reflects the adsorption and desorption of pollutants in the soil, migration and transformation, accumulation and degradation and so on.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53;X26

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