淮河干流沉积物重金属污染及其潜在生态危害研究

发布时间：2018-07-11 21:35

本文选题：淮河干流 + 酸可挥发性硫化物　；参考：《山东农业大学》2017年硕士论文

【摘要】：淮河是我国七大水系之一,流域的人口密度在全国居七大流域之首,其经济地位对全国经济举足轻重。近多年来,随着淮河流域的快速发展,大量增加的非农业人口使得城镇的生活污染大大加剧,淮河流域恶性污染事故频繁出现,一些地区更是因为水质恶劣,已造成了饮水困难,淮河流域的污染问题越发严重。河流沉积物可以反映河流中污染物的特性及污染程度。本文为探讨淮河沉积物中重金属的生物毒性,在淮河干流典型河段采集了12个采样点的表层沉积物,测定了沉积物中的酸可挥发性硫化物(AVS)、同步萃取金属(∑SEM)、有机碳(TOC)、重金属(As、Cd、Cr、Cu、Pb和Zn)总量和BCR形态分析等参数,并对TOC、AVS、∑SEM和沉积物粒度之间的相关性与各个采样断面重金属的形态分布进行了分析,并应用平衡分配模型(Eq P Model)、地积累指数法和潜在生态危害指数法评价了沉积物中重金属的潜在生物毒性。本研究得到以下结论:⑴应用Spearman相关性分析结果显示,沉积物TOC与黏土和粉砂呈显著正相关,与砂呈显著负相关,这与以往研究结果细颗粒物质形成的沉积物有机碳较高一致。∑SEM与TOC、黏土和粉砂含量呈显著正相关,与砂含量呈显著负相关,显示∑SEM与金属总量一样,易富集于细颗粒和有机碳含量较高的沉积物中,颗粒物越小,比表面积越大,颗粒物表面就会产生越多的负电荷,因此会吸附更多的重金属离子。⑵通过沉积物中重金属的形态分析结果显示,Cd的弱酸可提取态平均值达到27.5%,说明淮河干流沉积物中重金属Cd处于不稳定的状态,活性较大,其生物利用性高,容易被生物吸收,从而对环境造成危害;As在蚌埠吴家渡的非残渣态较高,Cu在蚌埠闸上和蚌埠吴家渡的可还原态达到41.96%和38.28%,Pb在蚌埠闸上和蚌埠吴家渡采样点的可还原态比例分别达到41.96%和38.28%,因此淮河干流中重金属As、Cu和Pb存在一定的生态风险,需要引起重视。⑶应用平衡分配模型(EqP Model)评价发现,除临淮关断面的TOC小于0.2%,不能应用平衡分配模型进行评价,凤台大桥断面的AVS∑SEM,判断沉积物应无生物毒性外,阜南王家坝、鲁台子、小柳巷和盱眙水文站的ESBAVS,OC130μmol/g,无潜在生物毒性,而淮滨谷堆、老坝头、淮南大涧沟、马头城、蚌埠闸上和蚌埠吴家渡的130μmol/gESBAVS,OC3000μmol/g,具有潜在生物毒性,淮南大涧沟的ESBAVS,OC值达到了1233.9μmol/g,有很强的潜在生物毒性。⑷地积累指数法和潜在生态危害指数法评价结果显示,在阜南王家坝、淮滨谷堆、老坝头、鲁台子、凤台大桥、淮南大涧沟、马头城、蚌埠闸上、蚌埠吴家渡和盱眙水文站采样点沉积物中的重金属均对环境造成了一定的污染,其中重金属Cd均属于几种重金属中生态危害最高的元素,对环境造成的危害较大,其余金属为轻微生态危害,由于Cd的贡献量很大,使得各金属的总危害程度达到了中等到强度的生态危害。综合上述评价结果,淮河干流已有不同程度的重金属污染,应引起有关部门的重视。
[Abstract]:Huaihe is one of the seven major water systems in China. The population density of the river basin is the first in the seven major basins in China. Its economic status is very important to the national economy. In recent years, with the rapid development of the Huaihe River Basin, a large number of non agricultural populations have made the urban life pollution greatly aggravated, and the malignant pollution accidents in the Huaihe basin frequently occur, some of which have occurred. Because of the poor water quality and the difficulty of drinking water, the pollution problem of the Huaihe river basin is more serious. The river sediment can reflect the characteristics and pollution degree of the pollutants in the river. This paper is to explore the biological toxicity of heavy metals in the sediments of Huaihe, and collect the surface sediments of the 12 sampling points in the typical river section of the Huaihe main stream. The acid volatile sulfide (AVS) in the sediments, the simultaneous extraction of metal (TOC), organic carbon (TOC), heavy metals (As, Cd, Cr, Cu, Pb and Zn) and BCR morphological analysis, and the correlation between TOC, AVS, sigma and sediment grain size and the distribution of heavy metals in various sample sections were analyzed and a balanced distribution model was applied. P Model), the potential biotoxicity of heavy metals in sediment was evaluated by the land accumulation index method and the potential ecological hazard index method. The following conclusions were obtained: (1) the results of Spearman correlation analysis showed that the sediment TOC was positively correlated with clay and silt, and negatively correlated with the sand, which was in fine particle shape with previous research results. The organic carbon in the sediments is higher. SEM and TOC have a significant positive correlation with the content of clay and silt, which shows a significant negative correlation with the content of sand. It shows that the sigma SEM, which is the same as the total metal, is easily rich in fine particles and higher organic carbon content, the smaller the particles, the larger the surface product and the more negative charge on the surface of the particles. Therefore, more heavy metal ions will be adsorbed. (2) through the analysis of heavy metals in sediments, the results show that the average value of Cd's weak acid can reach 27.5%, indicating that the heavy metal Cd in the sediment of Huaihe main stream is in a unstable state, its activity is large, its bioavailability is high, and it is easy to be absorbed by the organism, so that the environment is harmful to the environment; As in the sediment is harmful to the environment. The non residue state of Bengbu Wu Jia Du is high, the reducible state of Cu in Bengbu gate and Wu Jia Du of Bengbu reaches 41.96% and 38.28%, and the reducible ratio of Pb in Bengbu gate and Bengbu Wu Jia Du sampling point is 41.96% and 38.28% respectively. Therefore, heavy metals As, Cu and Pb in the main stream of Huaihe are stored in certain ecological risks, and should be paid attention to. 3. The equilibrium distribution model (EqP Model) evaluation found that the TOC of the Fengtai bridge section can not be evaluated by the equilibrium distribution model, except that the AVS Sigma SEM of the section of the Fengtai bridge can be evaluated without biological toxicity, and the ESBAVS of Wangjia dam, Lu Tai Zi, Xiao Liu Xiang and Xuyi water station in Funan, OC130 u mol/g, and no potential biotoxicity, and Huaibin valley. Heap, old dam head, Huainan Dabu gully, Ma head city, Bengbu gate and Wu Jia Du of Bengbu, 130 mu mol/gESBAVS, OC3000 mu mol/g, have potential biological toxicity, ESBAVS in Huainan Dabu gully, OC value reached 1233.9 mu, and have strong potential biotoxicity. 4. Index method of accumulation index and potential ecological hazard index method evaluation results show that in Funan Wang's house The heavy metals in the sediments of the sampling points in the sampling points of the sampling points in the sampling points of the hydrological stations of the Bengbu Wu Jia Du and Xuyi hydrology stations in the Huaibin Valley pile, the old dam head, the old dam, the Fengtai bridge, the Dajian gully of Huainan, the Bengbu gate, the Bengbu gate, the Bengbu gate and the Xuyi hydrological station have caused some pollution to the environment, among which the heavy metals are all the most harmful elements in the heavy metals, which have great harm to the environment. The residual metal is a minor ecological hazard. Because of the great contribution of Cd, the total harm of all metals has reached the ecological harm of medium to medium strength. The result of the above evaluation results that the Huaihe main stream has different levels of heavy metal pollution, which should arouse the attention of the relevant departments.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X522

【参考文献】