肥料施用下稻田中有机质的赋存及其对地表水污染的评估方法

发布时间：2018-03-28 09:55

本文选题：农业非点源　切入点：有机质　出处：《浙江大学》2015年硕士论文

【摘要】：农业非点源污染主要由施入农业用地的肥料、农药与其它有机或无机营养物质的流失所造成的。有机质从农业用地的流失是目前存在于农业与环境的问题之一。有机质的流失造成土壤碳库的损失,引起周边水体的高量有机碳污染,威胁饮用水水源安全,若与饮用水处理中的消毒剂发生反应将生成致癌的消毒副产物,直接威胁人体健康。因此,研究有机质的“源”(农业非点源)与有机质的“汇”(地表水体)具有显著的环境意义。由于农业非点源污染的复杂性、间歇性、分散性,对有机质从“源”至“汇”的迁移过程进行研究非常困难且实用性不显著。因此,本研究着重于有机质的“源”——对有机质的流失进行源头控制；有机质的“汇”——对已受到有机质非点源污染的地表水体水质进行评估。本文对有机质的一类“源”,即肥料施用下的稻田为对象进行了研究,以期为对有机质的流失进行源头控制提供科学依据。稻田土壤与某些肥料(如有机肥)含有高量的有机质,可能流失至周边水体造成有机质污染。首先,本文以稻田土壤中的有机质为研究对象,于2012年至2014年在嘉兴种植区开展田间小区试验,研究了不同肥料种类与不同肥料施用量下土壤有机碳(Soil organic carbon, SOC)含量(g kg-1)与存贮量(Mg ha-1),以期了解土壤有机质的特性以及施肥对土壤有机质的影响。其次,本文以稻田田面水中的有机质为研究对象,于2013年在嘉兴同一水稻种植区开展田间小区试验,研究了稻田田面水中溶解性有机碳(Dissolved organic carbon, DOC)的含量、有机质作为消毒副产物(Disinfection byproducts, DBPs)前体物的反应性及其动态变化特征,以期为农业非点源有机质的减排提供科学依据。研究表明,施用有机肥(猪粪)显著影响土壤有机碳含量与存贮量,0-20cm土层的SOC含量与存贮量随有机肥施用量的增加而增加,但在施肥量高达一定程度时,SOC含量与存贮量不再增长,说明可能已经达到饱和。施肥不影响20cm以下的土壤有机碳含量与存贮量。回归分析0～5cm,5～20cm与0-100cm土层或土壤剖面的SOC贮存量与有机肥的碳输入,分别得到10.5%、29.4%与36.4%的土壤碳固定率。有机肥施入量越高,稻田田面水中溶解性有机质的含量越高,通过排水或径流导致的溶解性有机质的输出风险也越大。使有机肥的施入与预报的降雨或灌溉之间的时间间隔相隔1周以上,将是非常好的水肥管理模式,使之既满足作物营养需求又降低溶解性有机质的输出风险。按照这种改良的灌溉排水模式,稻田土壤成为DOC的碳汇而非DOC输出至周边水体的源。本文亦对有机质的一类“汇”,即流域水体为对象进行了研究,以期为对已受到有机质非点源污染的地表水体水质进行评估提供科学依据。本研究于2014年于杭州余杭区鸬鸟镇的流域开展试验,选取未受到污染的上游源头以及仅受到稻田面源污染的水体作为水样采集点,研究了三维荧光光谱结合荧光区域积分方法在指示有机质污染中的应用,以期为评估水体水质安全、预警水体污染事件提供科学依据。研究表明,水质常规指标DOC浓度与254nm下特定紫外吸光度(Specific UVA254, SUVA254)不适合作为有机质污染指标并用于评估饮用水水源地流域水质或预警水源污染事故。春、夏、秋三季的荧光区域积分指标的3次系统聚类分析结果表明,三维荧光光谱的荧光区域积分指标适合作为有机质污染指标并用于评估饮用水水源地流域水质或预警水源污染事故。
[Abstract]:Agricultural non-point source pollution mainly by applying fertilizer for agriculture, pesticide and other organic or inorganic nutrient loss. The organic matter from the agricultural land loss is one of the currently existing in the agricultural and environmental problems. The organic matter caused by the loss of soil carbon losses caused by the high amount of organic carbon the pollution of the surrounding water, drinking water security threats, and if the treatment of drinking water disinfectant to react to carcinogenic disinfection by-products, a direct threat to human health. Therefore, the research of organic matter "source" (agricultural non-point source) and organic matter "sinks" (surface water) has significant environmental significance due to the complexity of agricultural non-point source pollution intermittent, dispersion, migration of organic matter from the "source" and "sink" of very difficult and the practicality is not significant. Therefore, this study focuses on the source of organic matter" The organic matter loss and controlling the source of organic matter; "sinks" - has been on surface water quality of organic matter of non-point source pollution was evaluated. The organic matter in a kind of "source", namely fertilizer under paddy field was studied as the object, in order to provide a scientific basis for carrying out the source control of the organic matter. The loss of paddy soil and some fertilizer (such as organic fertilizer) organic matter contain high amounts of possible loss to the surrounding water caused by organic pollution. First, the organic matter in paddy soil as the research object, from 2012 to 2014 to carry out field trials in Jiaxing planting area, study the soil organic carbon of different kinds of fertilizer with different fertilizer application amount (Soil organic carbon, SOC) (g kg-1) and the content of storage (Mg HA-1), in order to understand the influence of properties of soil organic matter and organic fertilization on soil. In this paper, the organic matter in surface water of paddy field as the research object, planting area to carry out field trials in Jiaxing with a rice in 2013, on the surface water of paddy field of dissolved organic carbon (Dissolved organic carbon, DOC) the content of organic matter as disinfection by-products (Disinfection, byproducts, DBPs) reaction and the dynamic characteristics of the precursor, in order to provide scientific foundation for agricultural non-point source organic matter reduction. The study shows that the application of organic fertilizer (pig manure) significantly affect soil organic carbon content and storage capacity, storage capacity and increase the content of SOC 0-20cm soil with organic fertilizer increased, but the amount of fertilizer up to a certain extent, the content of SOC and the amount of storage is no longer growing, that may have reached saturation. Fertilization does not affect soil organic carbon content and storage under 20cm. Regression analysis of 0 ~ 5cm, 5 ~ 20cm and 0-100cm soil layer or The soil SOC storage and organic carbon input, 10.5% respectively, soil carbon sequestration rates of 29.4% and 36.4%. Organic fertilizer is higher, the content of surface water of paddy field of dissolved organic matter is higher, the risk caused by the output dissolved drainage or runoff of organic matter is also larger. The organic fertilizer and forecast rainfall or irrigation intervals separated by more than 1 weeks, will be very good water and fertilizer management model that can meet the nutrient requirement of crops and reduce output risk of dissolved organic matter. According to this modified model of irrigation and drainage, paddy soil carbon sink become DOC instead of DOC output to the surrounding water source. The organic matter is a kind of "sink", is the study of the water basin is carried out, in order to provide scientific basis for the assessment of surface water quality has been the organic matter of non-point source pollution in this research. Valley in 2014 in Hangzhou District of Yuhang luniao town to carry out the test, select the headwaters not polluted water and paddy fields only affected by non-point source pollution as water sampling points, the study of 3D fluorescence regional integration method based on indication of organic pollution in the application, in order to evaluate the water quality and safety, provide according to the early warning of water pollution incidents. Scientific research shows that conventional water quality indicators of the concentration of DOC and 254nm under specific ultraviolet absorbance (Specific UVA254, SUVA254) is not suitable as a pollution index of organic matter and is used to assess the drinking water source water quality or water pollution accident early warning. In spring, summer, autumn three season of the 3 regional fluorescence integral index system cluster analysis showed that the fluorescent region integral indicator of three-dimensional fluorescence spectra of organic matter and suitable as pollution indicators for assessment of drinking water source water quality or pre Pollution accident of police water source.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52;X712

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