黄河三角洲滨海湿地石油烃和重金属空间分布规律与潜在生态风险研究

发布时间：2018-09-09 19:21

【摘要】：黄河三角洲是我国珍稀的生态湿地,同时是胜利油田所在地,石油开发与生态保护并重,因此,开展该区域的环境污染研究具有重要意义,有利于该地区的可持续发展。本文以黄河三角洲滨海湿地为研究区域,调查分析了该区域土壤的石油烃和重金属含量,利用石油烃特征参数探究了土壤中石油烃的来源,采用相关性分析法和主成分分析法探究了土壤中重金属的来源,并采用地积累指数法和潜在生态风险指数法对重金属的生态风险进行了评价。此外,针对黄河三角洲油田的广泛分布,本次研究对比分析了油井处和非油井处土壤的石油烃和重金属的污染状况,主要结果如下:(1)从正构烷烃及其参数的角度来看,位于油井处的点19-46和点20-64的正构烷烃含量受石油污染的影响比较大;点20-44、19-16,及黄河入海口附近的点20-26的土壤也可能受到了某种程度的原油或者其他化石燃料燃烧的影响;位于黄河河滩的点19-31土壤中的正构烷烃可能来自藻类等浮游生物;位于植被覆盖较多区域的点19-9和20-69正构烷烃可能主要来源于高等植物;而同样位于植被覆盖较多区域的点21-6和点28-1表现出较为明显的陆地高等植物输入的特点。位于油井处的点19-46、20-64及位于油田附近的点20-69,受油田开发的直接或间接影响,位于黄河入海口附近的点20-26的样品可能吸纳了来自黄河沿途人为污染物,因此它们的总石油烃含量超标。(2)研究区表层土壤中大部分重金属含量都低于国家一级标准,但是Cd元素均值接近于一级标准,As元素均值比二级标准还高一点,且经计算重金属Cd和As的潜在生态风险等级为轻度或偏中度污染,需要引起重视。总体来看,老黄河口、黄河口、化工厂附近和部分油井处,重金属含量相对较高,潜在生态风险指数和地积累指数也较高,因此污染程度相对较高,需引起注意。表层土壤重金属Zn、Pb、Cr与Cu可能来自一种污染源,Ni与As可能来自另外一种污染源。它们的分布可能受到农药、化肥、石油产业等工农业污染的影响。表层土壤的重金属分布还受到土壤颗粒粒级的影响。(3)研究区土壤剖面大部分地层的重金属含量都较低,且低于山东省土壤背景值,也未超过国家一级标准。油井处和非油井处的重金属As、Cd的剖面含量超标率都较高。这一结果与表层土壤结论一致。油井处土壤剖面重金属含量随深度的增加有降低的趋势,而非油井处正好相反。重金属Cd、Pb、Cu、Zn的相关性较强,因此它们可能来自同一种源;而重金属Ni和As可能来自另一种污染源。油井处和非油井处土壤重金属可能来源于工农业污染。这一研究结论与表层土壤较为接近。土壤剖面中重金属Cd和As的潜在生态风险指数和地积累指数相对较高,但都在中度及以下,污染并不严重;其他重金属的污染程度都很低。(4)总体上来说,所研究样品中石油烃与重金属含量的相关性不大,多数呈弱负相关,其中石油烃与重金属Pb、As存在一定程度的正相关关系。土壤中的石油烃可能影响了重金属的迁移,致使油井处的土壤随着深度的增加其中的重金属含量逐渐减少;而非油井处正好相反。
[Abstract]:The Yellow River Delta is a rare ecological wetland in China, and it is also the site of Shengli Oilfield. Oil exploitation and ecological protection are equally important. Therefore, it is of great significance to carry out environmental pollution research in this area, which is conducive to the sustainable development of this area. The source of petroleum hydrocarbons in soil was studied by using the characteristic parameters of petroleum hydrocarbons. The source of heavy metals in soil was studied by correlation analysis and principal component analysis. The ecological risk of heavy metals was evaluated by land accumulation index and potential ecological risk index. The main results are as follows: (1) From the point of view of n-alkanes and their parameters, the content of n-alkanes at points 19-46 and 20-64 at oil wells is greatly affected by oil pollution; The soil at Point 20-26 near the estuary may also be affected by the burning of crude oil or other fossil fuels to some extent; the N-alkanes in Point 19-31 near the Yellow River beach may come from plankton such as algae; and the N-alkanes at Points 19-9 and 20-69 in areas with more vegetation cover may mainly come from higher plants. Points 21-6 and 28-1, which are also located in areas with more vegetation cover, exhibit obvious characteristics of terrestrial higher plant input. Points 19-46,20-64 at oil wells and 20-69 near oil fields may be directly or indirectly affected by oil field development. Points 20-26 near the Yellow River estuary may have absorbed samples from the Yellow River. The contents of heavy metals in the surface soil of the study area were lower than the first-class national standard, but the average value of Cd element was close to the first-class national standard, the average value of As element was a little higher than the second-class national standard, and the potential ecological risk of heavy metals Cd and As was calculated to be mild or moderate. In general, the contents of heavy metals in the old Yellow River Estuary, the Yellow River Estuary, the vicinity of chemical plants and some oil wells are relatively high, and the potential ecological risk index and geoaccumulation index are also high, so the pollution degree is relatively high, which should be paid attention to. The distribution of heavy metals in the surface soil is also affected by the grain size of the soil. (3) The content of heavy metals in most strata of the soil profile in the study area is low, and is lower than the background value of the soil in Shandong Province, and no more than the national level. Heavy metals such as Cd, Pb, Cu and Zn are strongly correlated, so they may come from the same species. Heavy metals in soils at oil wells and non-oil wells may come from industrial and agricultural pollution. This conclusion is close to that of surface soils. The potential ecological risk index and accumulation index of heavy metals Cd and AS in soil profiles are relatively high, but both are moderate and below. (4) Generally speaking, the correlation between petroleum hydrocarbons and heavy metals in the studied samples is not significant, and most of them are weakly negative. There is a certain degree of positive correlation between petroleum hydrocarbons and heavy metals Pb, As. With the increase of depth, the content of heavy metals gradually decreases, while that of non oil wells is just the opposite.
【学位授予单位】：鲁东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53;X826

【相似文献】