锑对不同植物的毒理效应及其土壤生态基准研究

发布时间：2018-03-26 13:28

本文选题：土壤环境基准　切入点：土壤植物　出处：《华北电力大学(北京)》2016年硕士论文

【摘要】：锑(Sb)是一种有毒致癌元素,破坏植物细胞代谢等活动。在土壤中被植物所吸收,积累于根茎叶中,继而进入到食物链,危害人体健康。当前,关于我国土壤中锑的生态毒理数据相对较少,并且试验设计及毒性测试方法等方面欠规范,所选物种敏感性不同、土质不同,真正能用于推导生态基准值的数据严重不足,目前获得的土壤生态毒理效应数据比较零星、分散、缺乏系统整理。导致土壤中锑的环境质量标准制订严重滞后,不利于国家的土壤环境管理。因此,应根据基于生态毒理实验获取污染物的剂量效应关系,建立基于不同评价终点的污染物的毒性阈值,对于不同的环境目标,不同土质及受体,考虑地域差别,对相应参数、评估因子就行校正调整,以适应本土环境条件及特点,最终用于土壤生态基准值的推导。本研究以酒石酸锑钾为目标污染物,选取砂土、潮土、红壤及黑土四种不同类型土壤,向各个土样中添加一系列浓度的酒石酸锑钾溶液进行老化研磨筛分后,按照我国化学品测试方法及ISO标准化方法中相关步骤与原则,进行种子发芽、根伸长试验以及早期生长毒性试验,研究了锑对植物的生态毒理效应并得出锑对植物根伸长及株高10%抑制的毒性阈值(EC1o);同时探讨了土壤性质对毒性阈值的影响,初步构建了可预测不同土壤性质土壤中锑的毒性阈值的模型,推导出锑的生态基准值。试验结果表明：随着锑浓度升高,大麦、小麦、黄瓜种子发芽率及根长呈现先升高后下降的趋势,低浓度锑显示出刺激生长的作用,黄瓜受抑制作用最显著;植物根伸长抑制试验得到大麦、燕麦及油菜的根长与株高,在一系列浓度的外源锑作用下,对根长和株高表现出相似的毒害作用规律,总体呈降低趋势,EC10的值略有不同,在不同土质中的抑制率与显著性有很大差别。通过小麦的早期生长毒性试验得知,植物生物量也会随着锑浓度的升高而降低,低浓度时生物量有所增加,植株干重及鲜重对锑毒害反应敏感,抑制率大,更适宜做评估指标。土壤pH、OC、CEC对锑的毒性阈值影响较大,基于pH、OC及CEC的3因子预测模型可用来预测不同类型土壤中锑的毒性阈值,但仍需大量不同类型土壤及不同植物的毒理试验数据去验证,通过本研究所得数据及查阅文献相关数据,构造物种敏感性分布曲线,推导出HC5值,得到土壤锑生态基准值为23.2mg/Kg,可在一定程度上为我国土壤中锑的生态基准值制定提供参考数据。
[Abstract]:SB) is a toxic carcinogenic element that destroys plant cell metabolism and other activities. It is absorbed by plants in the soil, accumulated in rhizomes and leaves, and then entered into the food chain, endangering human health. There are relatively few ecotoxicological data of antimony in soils in China, and the experimental design and toxicity testing methods are not standardized. The species selected are sensitive and soil quality is different, so the data that can be used to derive the ecological reference value is seriously insufficient. The data of soil ecotoxicological effects obtained at present are scattered, scattered and lack of systematic collation. As a result, the establishment of environmental quality standards for antimony in soil is seriously lagging behind, which is not conducive to the management of soil environment in the country. According to the dose-effect relationship of pollutants based on ecotoxicological experiments, the toxic threshold of pollutants based on different evaluation endpoints should be established. For different environmental targets, different soil quality and receptors, the corresponding parameters should be taken into account. The evaluation factors were adjusted to adapt to the local environmental conditions and characteristics, and were finally used to deduce the soil ecological reference value. In this study, four different types of soil, sandy soil, tidal soil, red soil and black soil, were selected as the target pollutants, and potassium antimony tartrate was used as the target pollutant. After adding a series of concentration of potassium antimony tartrate solution to each soil sample for grinding and screening, seed germination was carried out according to the relevant steps and principles of chemical testing method and ISO standardization method in our country. The ecotoxicological effects of antimony on plants were studied by root elongation test and early growth toxicity test. The toxicity threshold of antimony to plant root elongation and plant height was obtained, and the effect of soil properties on toxicity threshold was discussed. A preliminary model for predicting the toxicity threshold of antimony in soils with different soil properties was established, and the ecological reference value of antimony was derived. The results showed that: with the increase of antimony concentration, barley and wheat, The seed germination rate and root length of cucumber increased first and then decreased, the low concentration of antimony showed the effect of stimulating growth, the inhibitory effect of cucumber was the most obvious, and the root length and plant height of barley, oat and rape were obtained by plant root elongation inhibition test. Under a series of concentrations of exogenous antimony, the root length and plant height showed a similar toxic effect, and the value of EC10 decreased slightly. Through the early growth toxicity test of wheat, the plant biomass also decreased with the increase of antimony concentration, and the biomass increased at low concentration. The plant dry weight and fresh weight were sensitive to antimony toxicity, and the inhibition rate was high, so it was more suitable to be used as an evaluation index. The threshold of antimony toxicity was greatly affected by soil pH ~ (2 +) OCCEC, and the three-factor prediction model based on pH ~ (2 +) OC and CEC could be used to predict the toxicity threshold of antimony in different types of soil. But it still needs a large number of toxicological test data of different types of soil and different plants to verify. The sensitivity distribution curve of structure species is derived from the data obtained from this study and the related data of literature, and the HC5 value is deduced. The ecological reference value of soil antimony is 23.2 mg / kg, which can provide reference data for the establishment of ecological reference value of antimony in Chinese soil to some extent.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X171.5;X53

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