第二松花江流域典型灌区土壤—水稻系统中汞和砷含量特征与环境风险评估

发布时间：2018-04-22 12:02

本文选题：第二松花江流域 + 土壤-水稻系统　；参考：《中国科学院研究生院（东北地理与农业生态研究所）》2015年硕士论文

【摘要】：第二松花江流域各灌区的水稻种植区为吉林省水稻生产优势区。各灌区灌溉水引用于第二松花江水,二松流经吉林省工业与人口密集区,可能受纳于处理、半处理或未处理的生活污水和工业废水,该河流历史上还曾受到过严重的污染。本文以第二松花江流域典型灌区土壤与水稻为研究对象,采用GIS空间分析、累积评价、潜在风险评价与健康风险评价等方法,揭示了土壤与稻米中汞和砷含量现状,探讨了污染来源,分析了水稻各部位的分布规律,研究了土壤与稻米的风险情况。主要结论如下:1.参照吉林省水稻土壤背景值和国家环境质量标准(GB 15618-1995),各灌区Hg和As含量大部分都超过了背景值,少部分超出国家一级标准,仅永舒榆与松沐灌区土壤个别样本中Hg含量超过二级标准。说明灌区土壤质量基本上不会对植物生长造成危害,但因人类生产生活等活动使得As、Hg在土壤中已有一定程度的累积。2.二松流域典型灌区稻米Hg含量介于0.000045~0.01mg/kg之间,As含量范围在0.00016~0.061mg/kg之间,稻米中Hg和As含量均在我国食品卫生安全范围内。各灌区稻米中Hg平均含量排列顺序为永舒渝(YSY)松渝(SY)前郭(QG)松城(SC)饮马河(YMH)伊通河(YTH)松沐(SM);而As平均含量由大到小为饮马河伊通河松沐松渝永舒渝松城前郭。3.Hg和As在成熟期水稻各不同部位的含量分布规律为根茎叶稻米。4.分布特征和相关性分析表明,土壤中的As和Hg来源不同,而两者的来源都主要与人类活动有关。其中引用二松干流水源灌溉的灌区土壤中Hg的来源很可能与水源灌溉有关,而土壤中As的来源可能与含As化肥农药施用等因素有关。土壤理化性质影响分析结果显示,土壤As与OM、N极显著正相关;土壤Hg与p H极显著负相关,而与OM极显著正相关。稻米中Hg含量与土壤中Hg呈显著正相关性,稻米中Hg与As互为显著正相关关系。土壤K对稻米Hg和As的影响达到显著正相关水平,但稻米Hg和As与土壤p H、OM、N及P的相关性不显著。5.参照吉林省水稻土壤背景值与国家土壤一级标准,采用的累积指数法与潜在生态危害指数法的评价结果均表明,第二松花江流域各灌区土壤未受到严重的生态污染危害,但受到了人类活动影响,已造成了土壤中Hg和As含量的一定程度的累积,其中永舒榆、松沐与饮马河灌区Hg累积最严重。6.稻米的健康风险评价结果表明,各灌区稻米中Hg、As不存在人体健康风险。但以US EPA的参数值人体最大允许摄入量RFD(reference dose)值为依据所得的评估结果表明,稻米Hg对人体健康无明显影响,但局部地区稻米中As存在健康风险隐患。
[Abstract]:The rice growing area in the second Songhua River valley is the dominant area of rice production in Jilin Province. The irrigation water of each irrigation district is used in the second Songhua River, and the second pine flows through the industrial and densely populated areas of Jilin Province, and may be absorbed in the treated, semi-treated or untreated domestic sewage and industrial wastewater. The river has also been seriously polluted in history. The present situation of mercury and arsenic content in soil and rice was revealed by GIS spatial analysis, cumulative assessment, potential risk assessment and health risk assessment. The source of pollution and the distribution of rice were analyzed. The risk of soil and rice was studied. The main conclusions are as follows: 1. Referring to the background value of rice soil in Jilin Province and the national environmental quality standard (GB15618-1995N), most of the Hg and as contents in each irrigation district exceeded the background value, and a few exceeded the national first class standard. Only the content of Hg in some soil samples of Yongshu and Songmu irrigation areas exceeded the second class standard. The results showed that the soil quality in irrigated area was not harmful to plant growth, but the accumulation of Ash Hg in soil was to a certain extent due to human activities such as production and living. The Hg content of rice in the typical irrigation area of Ersong River Basin was between 0.000045~0.01mg/kg and 0.00016~0.061mg/kg, and the Hg and as contents in rice were both in the range of food hygiene and safety in China. The order of the average content of Hg in rice in each irrigation district is YSYYYSYYSYYYYY) QG (SCM) YMHH) YTH) SMN, while the average content of as is 3.3Hg and 3.Hg in Yitong River, Yitong River, YT River, YTH River, YTH River, YTH River, Yinma River, Yitong River, Yitong River, Yitong River, Yitong River, Yitong River, Yitong River, YTH River, YTH River, YTH River, Y@@ The distribution law of as content in different parts of rice at maturity stage was as follows: rhizome, leaf and rice. 4. The distribution characteristics and correlation analysis showed that the sources of as and Hg in soil were different, and both of them were mainly related to human activities. The source of Hg in the soil of irrigated area with water source of Ersong main stream is probably related to water source irrigation, while the source of as in soil may be related to the application of chemical fertilizer and pesticide containing as. The results of soil physical and chemical property analysis showed that soil as was significantly positively correlated with OMN, soil Hg was negatively correlated with pH and OM significantly positively correlated. There was a significant positive correlation between Hg content in rice and Hg in soil, and significant positive correlation between Hg and as in rice. The effect of soil K on Hg and as in rice reached a significant positive correlation level, but the correlation between Hg and as in rice and soil pHOMN and P was not significant. 5. According to the background value of rice soil in Jilin Province and the first grade national soil standard, the results of the cumulative index method and the potential ecological hazard index method showed that the soil of the irrigation areas in the second Songhua River Basin was not seriously damaged by ecological pollution. However, the accumulation of Hg and as in soil has been caused by human activities, among which the accumulation of Hg in Yongshu, Songmu and Yinmahe irrigation areas is the most serious. The results of rice health risk assessment showed that there was no human health risk in rice. However, based on the maximum allowable intake (RFD(reference) of US EPA, the results showed that rice Hg had no significant effect on human health, but there were health risks in local rice.
【学位授予单位】：中国科学院研究生院（东北地理与农业生态研究所）
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;X56;X82

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