黄河三角洲土壤重金属空间分布及其对土壤微生物群落的影响

发布时间：2018-05-10 11:21

本文选题：黄河三角洲 + 土壤　；参考：《曲阜师范大学》2017年硕士论文

【摘要】：近年来,随着工农业的迅速发展,一系列环境问题也随之出现,其中土壤重金属污染问题日益引起人类重视,已成为环境科学研究中的焦点之一。重金属污染的来源主要包括固体废弃物的堆放、污水灌溉、农用物资的使用以及大气沉降等几个方面。重金属是一种持久性的有毒污染物,具有隐藏性和积聚性等特点,进入土壤环境后不易被生物降解,移动性太差,滞留时间长,治理困难,久而久之,在土壤中其浓度会逐渐增大,当浓度超过土壤生态系统的自净能力时,就会威胁生态系统平衡,导致生态功能失调,并能够通过食物链迁移进入生物体内,进而危害人类健康。土壤微生物群落作为土壤生态系统中的重要组分之一,对土壤生态系统的结构和稳定性起了至关重要的作用。土壤重金属含量可能会影响土壤微生物群落结构和多样性,因此探讨土壤重金属对土壤微生物群落的影响,可为土壤生态系统的稳定或者受损生态系统的修复提供一定的参考依据。本研究以黄河三角洲湿地国家自然保护区内的核心区、缓冲区和实验区的土壤为研究对象,对土壤中六种重金属的含量、分布特征及其对土壤中微生物(包括细菌、真菌和放线菌)群落结构的影响做了研究,主要研究结果如下。1.黄河三角洲湿地内表层重金属的含量与山东省土壤环境背景值相比,核心区、实验区和缓冲区内的所有样点Cd的含量均超过了环境背景值,Mn的含量均小于环境背景值;核心区和实验区内1号样点的Cu、Pb、Zn,3、4号样点的Zn都超过了环境背景值;实验区内4号样点的Cu超过了环境背景值;缓冲区内1、2、3号样点的Pb和Zn,3号样点的Cu和1号样点的Cr均超过了环境背景值。通过分析得出黄河三角洲湿地内污染最严重的重金属是Cd,其次为Zn、Pb、Cu,区域内Cr和Mn没有明显的重金属累积现象。相关性分析的结果表明,六种重金属元素与有机质、总氮和总磷之间呈极显著正相关。2.黄河三角洲湿地中核心区、缓冲区和实验区内重金属的污染状况基本相似,没有显著差异,重金属之间的相关性稍有不同。水平分布上,核心区内的Cd与Cu、Pb、Zn含量,Cu与Mn、Pb、Zn含量,Mn与Pb、Zn、Cr含量,Pb与Zn、Cr含量,Zn与Cr含量呈极显著正相关,Cd与Mn含量呈显著正相关。缓冲区内重金属Cd与Pb、Zn,Cu与Mn、Zn、Cr,Pb与Zn、Cr,Zn与Cr、Mn之间呈极显著正相关,Cd与Cr,Mn与Pb、Cr呈显著正相关。实验区内Cd与Pb、Zn、Cr,Cu和Mn,Zn和Cd、Mn、Pb、Cr之间呈显著正相关。垂直分布上,相关性分析结果显示,重金属的含量随着土壤深度的变化没有明显的规律性。总体来说,土壤表层的重金属含量比较高,呈现表面累积性。核心区和实验区内重金属的含量随土壤深度增加的变化波动的趋势比较平缓,缓冲区内各重金属含量随深度的变化呈现较大的波动性。3.土壤中重金属含量对土壤微生物指标和群落多样性的影响研究结果表明,土壤中六种重金属的含量与微生物生物量碳、生物量氮和微生物商呈显著或极显著负相关,说明随着重金属含量增加,微生物生物量随之降低。多种重金属的综合作用与土壤中的脲酶、过氧化氢酶、磷酸酶和蔗糖酶的酶活性有一定的负相关关系,对酶活性产生了一定的抑制作用,表明土壤微生物量碳、微生物量氮、微生物商和酶活性等指标能够在一定程度上反应土壤受重金属影响的情况。土壤重金属的综合污染对土壤微生物的群落数量和多样性指数均产生一定的影响,重金属含量对微生物的群落生长产生一定的抑制作用,其中重金属Cu对真菌、重金属Cr对细菌菌落的生长有明显的抑制作用;重金属含量与微生物多样性指数之间的关系不显著。说明微生物的菌落数和多样性在某种程度上不能用来表征土壤重金属的污染水平。
[Abstract]:In recent years, with the rapid development of industry and agriculture, a series of environmental problems have emerged. Among them, the problem of soil heavy metal pollution has attracted more and more attention and has become one of the focus of environmental science research. The source of heavy metal pollution mainly includes the stacking of solid waste, sewage irrigation, the use of agricultural materials and atmospheric settlement. In several aspects, heavy metal is a persistent toxic pollutant, which has the characteristics of hidden and accumulation. It is not easy to be biodegraded after entering the soil environment. The mobility is too poor, the retention time is long, and the treatment is difficult. In the soil, the concentration will increase gradually. When the concentration exceeds the self purification capacity of the soil ecosystem, it will be threatened. Ecological system balance, resulting in ecological dysfunction, and can migrate through the food chain into the organism, and then harm human health. As one of the important components of the soil ecosystem, soil microbial community plays an important role in the structure and stability of soil ecosystem. Soil heavy metal content may affect soil. Soil microbial community structure and diversity, so the study of the influence of soil heavy metals on soil microbial community can provide some reference for soil ecosystem stability or damaged ecosystem restoration. This study is based on the core area, buffer zone and experimentation area in the National Nature Reserve of the Yellow River delta wetland. The content of six heavy metals in soil, distribution characteristics and the influence of the soil microbes (including bacteria, fungi and actinomycetes) community structure in soil are studied. The main results are as follows: the content of heavy metals in the surface of the.1. the Yellow River delta wetland is compared with the background value of the soil environment in Shandong Province, the core area, the experimentation area and the buffer zone. The content of all Cd in all samples exceeded the environmental background value, and the content of Mn was less than the environmental background value; the Zn of Cu, Pb, Zn and 3,4 samples in the core and experimentation area at the 1 sample point exceeded the environmental background value; the Cu in the No. 4 point in the experimentation area exceeded the environmental background value; the Pb and Zn in the 1,2,3 sample point in the buffer zone and the Cu and number 1 of the 3 sample point. The point of Cr exceeded the environmental background value. Through analysis, the most polluted heavy metal in the the Yellow River delta wetland was Cd, followed by Zn, Pb, Cu, and there was no significant accumulation of heavy metals in Cr and Mn in the region. The results of correlation analysis showed that the six heavy metal elements were positively correlated with organic matter, total nitrogen and total phosphorus.2. the Yellow River The pollution status of heavy metals in the core area, buffer zone and experimentation area in the delta wetland is basically similar, there is no significant difference, and the correlation of heavy metals is slightly different. On the level distribution, Cd and Cu, Pb, Zn content, Cu and Mn, Pb, Zn content, Mn and Pb, Zn, Cr content, content and content are very significant positive correlation There is a significant positive correlation between heavy metals Cd and Pb, Zn, Cu and Mn, Zn, Cr, Pb and Zn, Cr, Zn and Cr. There is no obvious regularity in the change of soil depth. In general, the heavy metal content in the soil surface is high, showing the accumulation of surface. The trend of heavy metal content in the core area and experimentation area is relatively gentle with the increase of soil depth, and the heavy metal content in the buffer zone presents a larger fluctuation.3. with the depth of the soil. The effect of heavy metal content in soil on soil microbial index and community diversity showed that the content of six heavy metals in soil was significantly negatively correlated with microbial biomass carbon, biomass nitrogen and microbial business, indicating that microbiological biomass decreased with the increase of heavy metal content. The action has a certain negative correlation with the enzyme activity of urease, catalase, phosphatase and invertase in the soil, and has a certain inhibitory effect on the enzyme activity. It shows that soil microbial biomass carbon, microbial biomass nitrogen, microbial business and enzyme activity can reflect the influence of heavy metals on Soil in a certain range. Soil weight. The comprehensive pollution of metals has a certain effect on the community number and diversity index of soil microbes. Heavy metal content has a certain inhibitory effect on the growth of microbial community. Heavy metal Cu has obvious inhibitory effect on the growth of fungi and heavy metal Cr on bacterial colonies; heavy metal content and microbial diversity index The relationship between the number of bacteria and the diversity of microorganisms can not be used to characterize the level of heavy metal pollution in some extent.

【学位授予单位】：曲阜师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53;S154.3

【参考文献】