【作者】 魏伟；

【导师】 许建； 孙庆业；

【作者基本信息】 安徽大学 ， 环境科学， 2012， 硕士

【摘要】 安徽铜陵地区矿产资源储藏丰富,是我国重要的矿集区,长期的矿山开采活动产生的大量重金属污染物进入河流,为河流生态环境带来压力。本文以铜陵地区河流为研究对象,依据野外调查采样及室内分析的方法对河流(包括上覆水和沉积物)的重金属等常规理化性质、浮游植物和底栖动物的群落结构和多样性变化进行了研究,并采用PCR-DGGE法对沉积物微生物和周丛微生物的群落多样性进行了研究,分析了河流上覆水和沉积物污染状况；探讨了环境因子对生物多样性的影响；并对河流生态健康进行了多指标综合评价。结果表明：(1)铜陵地区河流水质重金属污染以Cd污染为主,其次是As和Zn污染,顺安河、新桥河和黄浒河三条流经矿区的河流水质重金属污染较其他河流严重；非金属污染成分以TN为主,其次是COD污染。按综合污染指数分级,水质严重污染的v类采样点占8.06%,重污染的Ⅳ类采样点11.29%,轻污染的Ⅲ类采样点62.90%,尚清洁的Ⅱ类采样点占17.74%,没有清洁的Ⅰ类采样点。(2)铜陵地区河流沉积物中重金属含量远高于上覆水,二者具有较高同步性。沉积物重金属除Cr外,空间分布都表现出基本相同的规律,顺安河上游、新桥河、黄浒河三个流经矿区的河段,重金属含量远高于其他未流经矿区的河流。沉积物中As. Cd、Cu、Pb、Zn、Fe等元素之间都有较高相关性；Cr与其它各重金属元素相关性较低,积累比较独特。沉积物理化性质中TP含量与沉积物中重金属有较高相关性,其他理化性质与沉积物重金属含量相关性不显著。应用Hankanson潜在生态风险指数法和地积累指数法进行沉积物重金属风险评价结果基本相同,Cd, As. Cu污染较严重,Cr污染较轻。(3)铜陵地区河流中顺安河、新桥河的采样点沉积物细菌多样性指数较低,钟仓河采样点细菌多样性指数最高,根据典型相关分析(CCA)分析,沉积物环境因子中TC. NH3-N. Zn、Cr对沉积物细菌群落的影响达到显著性水平；铜陵地区河流中钟仓河、西北部圩渠采样点周丛细菌多样性指数最低,根据CCA分析,上覆水环境因子中NH3-N、TN、COD、TP对周丛细菌群落的影响达到显著性水平,沉积物环境因子中NO3-N、Cd、Zn、TC、NH3-N对周丛细菌群落的影响达到显著水平。(4)铜陵地区河流浮游植物共8门96属203种(含变种),硅藻和绿藻为优势种；底栖动物主要为软体动物,共4纲7科11种,铜锈环棱螺为优势种。各河流中黄浒河、新桥河、顺安河藻类密度较低,钟仓河藻类密度最高；黄浒河、西北部圩渠、新桥河藻类多样性较低,东北部圩渠多样性指数最高。根据CCA分析,上覆水环境因子中COD、TN、NH3-N对浮游植物群落的影响达到显著性水平。(5)铜陵地区河流生态系统健康评价结果显示,超过一半采样点处在“较差”等级,“疾病”等级采样点占15%,铜陵地区河流生态系统健康受损较为严重。评价指标体系中栖息地环境和水生生物指标的权重依次为0.4027和0.3409,是对铜陵地区河流生态系统的影响最大的两个指标类型。水生生物指标中,周丛微生物和沉积物微生物指标权重相对较高；上覆水理化指标中TNw权重最高,TPw和重金属Cuw、Znw等也有较严重影响,沉积物理化指标中；TCs权重最高,其次为重金属Fes,重金属Zns、Crs及TNs等在理化指标中权重也较高。更多还原

【Abstract】 Tongling area of Anhui province is rich in mineral resources. It’s an important mineral concentration of copper, iron, gold and sulfur in our country. Abundant of heavy metal pollutants produced by long-term mining activities were disposed into rivers. The river ecosystem health was badly infective affected. In this paper, the quality of the water and sediment in rivers and the diverse of aquatic organisms was studied. The content heavy metal and other physicochemical properties of the rivers(including overlying water and sediment) and the community structure and diversity of phytoplankton and benthos were analyzed, based on field investigation and laboratory analysis. The diversity of sediment microbe and attached microbe were analyzed by the method of PCR-DGGE. The pollution status of overlying and sediment of the rivers was analyzed. The influence that environmental factors had on the bacterial diversity and community compositon were discussed. And the multi-variable assessment of river ecosystem health was undertook. The results indicated that:(1) Cd was the primary metal pollution factor of overlying water. As and Zn caused serious water pollution, too. The heavy metal pollution of overlying water in three rivers, Shunan river, Xinqiao river and Huanghu river, which flowed through the mining area was more seriously than other rivers. TN was the primary nonmetallic pollution factor of overlying water, and COD caused serious pollution, too. There are altogether82.26%sections that had suffered pollution of different degree, according to the synthesis pollution index’s gardening. Among them, there were8.06%sections that had suffered serious pollution,11.29%sections that had suffered heavy pollution,62.90%sections that had suffered light pollution. Among them, there were17.74%sections that its water quality was somewhat clean, none were clean.(2) The heavy metal contents in sediments were far higher than that in overlying water, the metal contents of the two phase observed higher levels of synchrony. The heavy metal in sediments all indicated the same distribution regularity that the heavy metal contents in sediments of the river flowed through the mining area were much higher than that in other rivers, except Cr. Heavy metal elements As, Cd, Cu, Pb, Zn and Fe in sediments, had high correlation between each other. Cr had low correlation with other elements, and had a unique way of accumulation. The content of TP in sediments had high correlation with the contents of all heavy metal elements, while the contents of other normal normal physicochemical properties had low correlation with the contents of heavy metal elements. Hankanson potential ecological risk index and geoaccumulation index were used conducting environmental risk assessment, and the results of two methods were similar. The heavy metal elements Cd, As and Cu were the main polluted elements, Cr was less polluted.(3) The diversity of sediment microbe in Shunan river and Xinqiao river were much lower, while the diversity of sediment microbe in Zhongcang river is the highest. According to the analysis by CCA, the sediments environment factors C, NH3-N, Zn and Cr had an significance level influence to the bacteria community in sediments. The diversity of attached microbe in Zhongcang river and Northwestern river were much lower. According to the analysis by CCA, the overlying water environment factors NH3-N, TN,COD and TP had an significance level influence to the attached bacteria community, and the sediments environment factors NO3-N, Cd, Zn, C and NH3-N had an significance level influence to the attached bacteria community.(4)A total of203phytoplankton species were identified, belonging to96genera of8phyla. The main phylum were Bacillariophyta and Chlorophyta. A total of11species of zoobenthos were identified, belonging to7families of4classes. The dominant species were Bellamya aeruginosa. The phytoplankton cell densities in Huanghu river, Xinqiao river and Shunan river were much lower, while the phytoplankton cell density in Zhongcang river was the highest. The diversities of phytoplankton in Huanghu river, Xinqiao river and Shunan river were much lower, while diversity of phytoplankton in Northeast river were the highest. According to the analysis by CCA, the overlying water environment factors COD, TN and NH3-N had an significance level influence to the phytoplankton community. (5) The multi-variable assessment of river ecosystem health in Tongling area showed that2of60sites were "healthy" level,16were "sub-healthy" level,33were "poor" level, and last9were "sick" level, suggesting the serious degradation of river ecosystem in Tongling. The weights of habitat quality indicator and biological indicator which were the most influential indicators of the assessment index system were0.4027and0.3409. Among the physicochemical properties of overlying water, the weight of TNWwas the highest, and TPW, Cu w and Zn wwere important influential indices to the river ecosystem. Among the physicochemical properties of sediments, the weight of TCS was the highest, and Zn s, Crs and TNs were important influential indices to the river ecosystem.更多还原