浙北淡水养殖区主要污染物调查和初步分析

发布时间：2018-03-10 12:33

本文选题：浙北地区　切入点：淡水养殖　出处：《南京农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：中国的水产养殖业发展迅猛,为国人提供了大量优质动物蛋白。但由于高密度养殖、投饲过剩加之废水排放缺乏有力约束,水产养殖引起的富营养污染问题日渐严重;另一方面,外界污染对水产品质量安全已经构成严重威胁。浙北地区是我国淡水养殖的传统地区和最为发达的地区之一,为了摸清该地区水产养殖的富营养污染和重金属污染现状,为今后科研工作提供基础性数据,开展了本次污染调查。研究选取了浙北地区的湖州、嘉兴两地,历时两年时间,采取随机抽样的方法进行调查。其中,富营养污染共调查了 35家养殖场的水源水和池塘水情况。运用了离子色谱仪、可见分光光度计、总有机碳分析仪等仪器分析了包括氨氮、硝酸盐氮、亚硝酸盐氮、高锰酸盐指数、化学需氧量、总有机碳在内的六个个富营养污染参数。分析结果显示:未经过处理的养殖水质指标除亚硝酸盐氮外,超标率显著高于外界进水,高锰酸盐指数、化学需氧量的Ⅲ类水标准超标率已经超过500%。当前大部分养殖用水是以直排的形式重新进入外界水环境中,因此目前的水产养殖方式可能会对外界水环境产生富营养的污染影响。重金属污染调查采集了包括河流沉积物在内的181份底泥样品。使用原子吸收分光光度计和原子荧光分光光度计测定经过微波消解的底泥样品中的铜、锌、铬、铅、镉、汞、砷七种物质的含量。采用综合污染指数法、潜在生态危害指数法两种方法进行评价,结果显示:大部分采样点重金属含量处于轻度污染水平,部分区域的个别元素已经呈现中度甚至重度污染水平,其中以河流沉积物中的镉污染水平为最高。综合污染指数法由于兼顾到污染指数最大值对土壤环境质量影响,安全范围比潜在生态危害指数法的评价结果更小。
[Abstract]:China's aquaculture industry is developing rapidly, which provides a large number of high quality animal protein for Chinese people. However, due to high density aquaculture, overfeeding and lack of effective constraints on wastewater discharge, the eutrophic pollution caused by aquaculture is becoming more and more serious. On the other hand, external pollution has posed a serious threat to the quality and safety of aquatic products. Northern Zhejiang is one of the traditional and most developed areas in China for freshwater culture. In order to find out the status of eutrophication and heavy metal pollution in aquaculture in this area, and to provide basic data for future scientific research, the pollution investigation was carried out. The study selected Huzhou and Jiaxing in northern Zhejiang for two years. A random sampling method was used to investigate the source water and pond water of 35 farms with eutrophic pollution. Ion chromatograph and visible spectrophotometer were used. The total organic carbon analyzer and other instruments have analyzed ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, permanganate index, chemical oxygen demand, etc. Six eutrophic pollution parameters including total organic carbon. The results show that the untreated aquaculture water quality indexes, except nitrite nitrogen, exceed the standard rate significantly higher than the external influent, and the permanganate index. The standard rate of Category III water exceeded 500. At present, most of the water used in aquaculture is re-entered into the external water environment in the form of direct discharge. As a result, the current aquaculture practices may have eutrophic effects on the external water environment. The heavy metal pollution survey collected 181 sediment samples, including river sediments, using atomic absorption spectrophotometer (AAS) and atomic absorption spectrophotometer (AAS). Determination of copper in microwave digested sediment samples by atomic fluorescence spectrophotometer, The contents of zinc, chromium, lead, cadmium, mercury and arsenic were evaluated by comprehensive pollution index method and potential ecological hazard index method. Some elements in some regions have been exposed to moderate or even severe pollution levels, among which cadmium pollution level in river sediments is the highest. The comprehensive pollution index method takes into account the effect of maximum pollution index on soil environmental quality. The safety range is smaller than that of the potential ecological hazard index method.
【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X714

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