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山东省基本农田土壤重金属含量分布特征及其环境容量研究

The Research of the Distribution Characteristics of Heavy Metals and the Environmental Capacity of Fundamental Farmland in Shandong Province

【作者】 张丽娜

【导师】 成杰民;

【作者基本信息】 山东师范大学 , 环境科学, 2010, 硕士

【摘要】 工业发展、城市化以及农用化学用品的大量使用使土壤重金属污染日益严重。大面积土壤重金属污染导致农作物产量和产品品质下降,极大损害了人们的身体健康。研究重金属环境容量分布特征及动态变化有助于正确认识并合理利用有限的土壤环境容量。本论文在查阅资料和实地调查的基础上,在占山东省90%三大主要土类(棕壤、褐土、潮土)基本农田布设60个采样点,采集耕层土壤,分析土壤样品中Cu、Zn、Pb、Cd有效态含量和全量。研究山东省土壤重金属分布特征和活性情况。根据土壤背景值和临界值资料,研究山东省土壤环境容量分布特征并与上世纪80年代研究结果比较,获得其变化动态。其目的是,为区域制定土壤环境质量标准、农田灌溉用水标准、污泥施用量标准等提供基础数据。为区域土壤环境质量评价、土壤污染物预测、重金属总量控制等提供科学依据。本文获得主要研究结果如下:(1)60个样点中,位于曲阜防山、济南市济阳县、文登市、海阳市、枣庄市的5个样点的Cu全量超过了国家二级标准,占调查样点8.33%,其余样点均低于国家土壤二级标准;位于青岛市平度市云山镇的1个样点的Zn全量超过了国家二级标准,占调查样点1.67%,其余样点均低于国家土壤二级标准;位于防山、苍山县两个样点的Pb全量值超过了国家二级标准,占调查样点3.33%;Cd的全量均低于国家土壤二级标准。总起来说,全省农田土壤调查范围内10%样点Cu有效态含量低于Cu缺乏临界值,属于较低的肥力水平,88.3%样点能够达到中等及以上肥力水平,所以从Cu有效态含量水平上来说,山东省农田土壤肥力水平总体上是可以的。(2)山东省土壤重金属综合污染指数为0.1051-1.4742。在调查的60个采样点中有10%样点属于轻度污染,90%样点土壤环境质量状况良好。综合污染指数最大值出现在枣庄市山亭区、泰安宁阳县、曲阜防山、临沂苍山县、济南济阳县、文登市均出现P综>1的样点。进一步追根求源,控制土壤污染是十分必要的。(3)山东省近20年来农田土壤重金属其中Pb元素变化幅度最大,尤其是在褐土中,近20年全量增加了5.81倍,Cd元素在棕壤中变化幅度最小,20年仅增加了1.33倍;四种重金属元素在三种土壤中变化幅度最大的是褐土,其次是潮土,变化幅度最小的是棕壤。近20年山东省农田土壤Cu有效态数值略有升高。褐土、潮土、棕壤中Zn的有效态数值增加了数十倍,其增长幅度巨大。有效态数值的大小与人类健康的关系更加密切,应引起我们的高度重视。土壤Cu的有效性指数降低,Zn有效性指数则大幅增加,(4)山东省三种土壤中各种重金属元素的静态环境容量排序均为:Pb>Zn>Cu>Cd。褐土中的Pb静态环境容量最大,达到了528.21 kg·hm-2。Cu元素的相对环境容量并不是很高,高容量区较少,Zn元素的相对环境容量还是比较高的,中等环境容量以上的占了2/3,Pb元素的相对环境容量是比较高的,有2/3都属于中、高容量区,Cd元素全部属于中容量区或者高容量区,总体来说单元素的相对环境容量值还是比较大的。综合相对环境容量值还不是很高,有半数属于中容量区,低容量区占据1/3以上,高容量区仅3个,分别位于枣庄市山亭区、青岛的平度市和青岛的莱西市,超载区1个,位于曲阜境内。(5)对山东省重金属环境容量年限预测的研究中,假定了污染物的三种输入量,当输入量等于控制输入量时,在一定的时间内会达到极限年限,当输入量大于控制输入量时,导致极限年限明显缩短,此时达到环境容量年限的长短主要取决于不同重金属在不同土壤类型中残留率的不同。严格遵循年输入量低于年控制容量的原则,才能实现生态的可持续发展,实行总量控制是防止和治理土壤污染有效可行的措施。

【Abstract】 The development of industry, urbanization and wide usage of agricultural chemicals lead to soil pollution of heavy metals. The serious soil pollution of heavy metals significantly reduces the quantity and quality of the agricultural output, which is quite harmful for human health. The study of the distribution of soil-environmental capacity of heavy metals and its dynamical behavior makes it possible for us to understand and effectively implement the limited soil-environmental capacity.Based on the existing materials and field survey, 60 sampling spots are selected in farmland Shandong Province, which covers the three main kinds of soils, brown soil, cinnamon soil and calcareous soil. The topsoil is collected from the 60 sampling spots and the availability and the whole volume of Cu, Zn, Pb and Cd in the samples are analyzed. With the materials on soil-background value and critical value, the characteristics of the soil-environmental capacity distribution of Shandong Province are studied and compared with the results in 1980’s to capture the dynamic behavior. The objective of this research is to provide the basic data for the establishment of the soil-environmental quality standard, farmland watering standard, amount of sludge application and etc. This research works as a scientific basis for regional soil-environmental quality evaluation, soil pollution prediction, heavy metals total amount control, and etc.The main achievements of this research are summarized as follows:1.The 5 sampling spots in Fangshan of Qufu, Jiyang of Jinan, Wendeng, Haiyang, Zaozhuang, from the total 60 reach the National Secondary Standards; the others are lower than the standards. The Zn availability of one sampling spot in Yunshan Town, Pingdu City, Qingdao reaches the National Secondary Standards; the others are lower than the standards. The Pb availabilities of two sampling spots, Fangshan and Cangshan, reach the National Secondary Standards. The Cd availabilities of all the sampling spots are lower than the National Secondary Standards. The Cu availabilities of 10% of the sampling spots are lower than the Cu critical value, which means the farmland soils there are in a low fertility level. The Cu availabilities of 86% of the sampling spots are larger than or equal to medium fertility level. Thus, from the viewpoint of Cu availability, the farmland soil fertility is in a considerable level in totality.2.The soil heavy metal comprehensive pollution index of Shandong Province is 0.1051—1.4742. The research shows that 10% of the 60 sampling spots of interest are lightly polluted, and soil-environment qualities of 90% of the sampling spots are in good condition. Shanting of Zaozhuang, Ningyang of Taian, Fangshan of Qufu, Cangshan of Linyi, Jiyang of Jinan and Wendeng City take the largest value of the pollution indexes. The research result strongly motivates the control of soil pollution.3.In the past 20 years, Pb in farmland soil varied significantly, which especially in brown soil, has increased 5.81 times. Cd in cinnamon soil has changed the lest, and has increased only 1.33 time in the past 20 years. Brown soil is with the largest variation of the volume of the four heavy metals, followed by calcareous soil. In the past 20 years, the Cu availability in farmland soil in Shandong Province has increased a little. The Zn availability in the three kinds of soils has increased more than ten times. Human health is closely related to the availability, which should be highly respected.4.The sequence of the static environmental capacity is Pb>Zn>Cu>Cd in all three kinds of soils. The static environmental capacity of Pb in cinnamon soil is 528.21kg/hm2, which is the largest. The relative environmental capacity of Cu is not so large, and there are few high-capacity regions. The relative environmental capacity of Zn is comparatively large, and more than 2/3 of the sampling spots are larger than medium environmental capacity. The relative environmental capacity of Pb is also comparatively large, and more than 2/3 of the sampling spots are larger than medium environmental capacity. Comprehensive relative environmental capacity is not very large, more than half number of the sampling spots are with medium capacities. More than 1/3 number of the sampling spots are with low capacities, while there are only three sampling spots with high capacities, which are Shanting of Zaozhuang, Pingdu of Qingdao and Laixi of Qingdao. One sampling spot is overloaded, which is in Qufu.5.In the study of heavy metals environmental availability prediction, three kinds of inputs of pollution are assumed. If the input equals the controlled input, then the year of limitation is in several years time; if the input is larger than the controlled input, then the year of limitation is sooner. In the later case, whether sooner or later depends on the differences between the residual rate of different heavy metals in different soil types. The sustainable development of the ecology can be achieved only if the principle of input per year less than controlled capacity per year is obeyed. Total capacity control is a feasible and effective way to prevent soil pollution.

【关键词】 土壤重金属环境容量
【Key words】 soilheavy metalsenvironmental capacity
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