【作者】 陈静；

【导师】 黄玉明；

【作者基本信息】 西南大学 ， 环境科学， 2008， 硕士

【摘要】 嘉陵江是长江水系中流域面积最大的支流,流经重庆市主城区,于朝天门码头汇入长江。嘉陵江流域水质对于重庆市经济发展和水资源的保护具有重要影响。本研究于2006年6月至2007年5月一年中,每月分别在重庆嘉陵江流域上游至下游16个采样点采集表层水样,2007年4月采集生物样品（鱼样）,研究和探讨了嘉陵江水环境中有毒重金属元素Pb、Cr的污染状况和迁移、转化规律。主要内容如下:1.原子荧光法测定水中痕量铅的分析方法研究建立了水中铅的氢化物发生原子荧光分析方法,优化了铁氰化钾、KBH₄、氢氧化钠、草酸钠及盐酸浓度,获得了满意的分析条件。在优化的实验条件下,原子荧光强度在0-10μg/L范围内与铅浓度呈现良好的线性关系,方法检出限为0.045μg/L,对4.00μg/L的铅标准溶液进行11次平行测定,相对标准偏差（RSD）为1.63%。将本法用于嘉陵江水中铅的测定,获得满意结果。2.嘉陵江表层水中铅、铬的环境行为研究（1）嘉陵江表层水中溶解态金属Pb含量低于国家地表水环境质量标准GB3838-2002中的Ⅰ类标准,溶解态Cr的含量属于Ⅱ-Ⅳ类标准。个别采样点水中溶解态Cr含量的属于Ⅴ类标准,超出了饮用水标准的限值。（2）重金属Pb无明显的岸边污染源,而Cr存在点污染源。（3）丰水期溶解态金属Pb、Cr含量均大于枯水期。雨水对江边土壤和城市的冲刷使大量含Pb和Cr的污染物随着雨水及城市污水流入江水中,对水体中Pb和Cr的含量产生较大影响。（4）金属Pb的形态分布与悬浮物密切相关。金属Pb主要以颗粒态形态存在,占总量的60%以上。溶解态金属Pb的含量与SS含量存在显著线性相关性（p＜0.01）。（5）溶解态金属Pb与Cr含量随时间或空间变化的规律相似。3.嘉陵江鱼类样品中铅、铬的分析鱼肉中金属Pb、Cr的含量均未超过淡水鱼卫生标准,出现个别鱼肉中铬超标现象。鱼肉中Cr的含量高于截留前和其他流域的数值。不同组织中Pb含量的关系为鱼鳃＞鱼肝＞鱼肉。重金属元素在鱼体内的富集系数顺序为Pb＞Cr。更多还原

【Abstract】 As the largest tributary in the Yangtze River basin,Jialing River is located in the Chongqing City and merged into Yangtze River in Chaotianmen dock.The water quality of the Jialing River has important significance for the development of the Chongqing city and the protection of water resource in the Jialing River basin.The surface Water samples were taken monthly from June 2006 to May 2007 at 16 sites distributed following the stream flow direction of the river.Fish samples were collected in April 2007.The fate of toxic heavy metals（Pb,Cr）in Jialing River was studied.The major contents are described as follows:1.Study on determination of trace lead in water samples by hydride generation atomic fluorescence spectrometryA hydride generation atomic fluorescence spectrometric detection method has been developed for the determination of lead in water samples.The effect of potassium ferricyanide,KBH₄,sodium hydroxide,sodium oxalate and hydrochloric acid were investigated and their concentations were optimized.The experimental results show that the atomic fluorescence intensity was linear with lead concentration in the range of 0-10μg/L and the detection limit（3s）for lead was 0.045μg/L under optimized conditions.The relative standard deviation was 1.63%（n=11）for 4.00μg/L lead standard solution.The proposed method has been applied successfully to the analysis of lead in Jialing River water.2.Concentration and fate of the dissolved trace elements（Pb,Cr）in surface water of the Jialing River（1）The concentrations of the studied metals were found to be below the international guideline and acceptable concentration for drinking water except some value for Cr.（2）No obvious Pb pollution resources exist in the studied area,whereas potential Cr pollution resources do.（3）The concentration of Pb and Cr in dry season is lower than that in wet season.This can be attributed to runoff from the city and the soil loss into the rivers in the wet reason.（4）The species of the trace metals were influenced by the SS concentration.Pb was found predominantly to exist in the particulate phase with more than 60%fraction.The concentration of dissolved Pb is well correlated with the content of SS（p<0.01）.（5）Both the spatial variations and temporal trends between Pb and Cr are similar.3.Concentration of Pb and Cr in fish samplesThe content of Pb and Cr in fish muscles is below the national standard,except one sample for Cr.Compared with the values of before-impoundment of Three Gorges and other rivers,the content of Cr in fish muscles is higher.The content of Pb in different organs decreased in the order:fish gills> fish liver> fish.Enrichment factor for the fish muscles decreased in the order:Pb>Cr.更多还原