环草隆与镉复合污染对城市土壤微生物生态功能的影响研究
文献类型：学位论文
| 作者 | 谷盼妮 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 陈卫平 ; 王美娥 |
| 关键词 | 环草隆，镉，氮矿化，基础呼吸，土壤酶，剂量-效应关系，siduron, cadmium, nitrogen mineralization, basal respiration, soil enzyme, dose-effect relationship |
| 其他题名 | Effects of Combined Pollution by Siduron and Cadmium on the Microbial Ecological Functions in Urban Soil |
| 学位专业 | 生态学 |
| 中文摘要 | 城市土壤是城市生态系统的主要组成部分，也是城市化的主要风险受体。随着城市化高度发展，城市土壤重金属污染与绿化农药污染现象越来越严重。环草隆是北方城市应用较为广泛的一种草坪除草剂，重金属镉是土壤中常见的重要污染物，二者在土壤生态系统中存在联合暴露的潜在风险。目前，有关土壤复合污染联合生态毒性效应的研究大多还局限于室内模拟实验，但室内模拟实验所获得的研究结果与野外实际情况之间的联系备受争议。而野外土壤由于污染物浓度相对较低、变化范围相对较小、干扰因素过多等因素，直接应用于联合生态效应评估的困难也较大。因此，还需要以实验室研究结果为指导，通过一定的数学方法使实验室结果与野外调查结果相联系，最后达到野外土壤复合污染联合生态效应的评估。 本研究采用野外重金属污染土壤与实验室人工模拟相结合的方式，研究了城市草坪典型除草剂环草隆和重金属Cd复合污染对重金属污染土壤有机氮矿化量、基础呼吸、脲酶、芳基硫酸酯酶、蔗糖酶和碱性磷酸酶活性的影响，揭示了城市土壤农药与重金属复合污染的生态风险产生机制，为城市土壤重金属和除草剂复合污染生态风险评价提供基础数据和技术方法。主要研究结论如下： 通过对城市土壤基本理化性质、重金属含量及生化指标的分析结果表明，研究选取的三个样点土壤都存在一定程度的重金属污染，其重金属综合污染指数分别为8.89、17.2和57.8。有机氮矿化量、基础呼吸、芳基硫酸酯酶和碱性磷酸酶活性与土壤基本理化性质及重金属含量呈显著或极显著相关关系，而脲酶和蔗糖酶活性与土壤基本理化性质及重金属含量的相关关系没有达到显著水平。 环草隆污染对土壤微生物生态功能的影响研究表明，土壤有机氮矿化、基础呼吸、芳基硫酸酯酶和碱性磷酸酶对环草隆污染响应较为敏感，脲酶和蔗糖酶对环草隆污染不敏感。环草隆浓度为0～1000 mg·kg-1范围内，和污染较轻的样点N土壤的碱性磷酸酶活性变化率的线性相关关系显著，和污染较为严重的样点D和G土壤的芳基硫酸酯酶活性变化率的线性关系显著。土壤中环草隆对样点D和G土壤芳香硫酸酯酶活性、对样点N土壤碱性磷酸酶活性变化率的EC10分别为568 mg·kg-1、1306 mg·kg-1（抑制值）和56 mg·kg-1（激活值）、99 mg·kg-1，EC50分别为1901 mg·kg-1、3806 mg·kg-1、2321 mg·kg-1。 环草隆与镉复合污染对土壤有机氮矿化量、基础呼吸及相关酶活性的影响研究表明，环草隆与镉单一及复合污染对各试验指标的影响均达到极显著水平(P<0.01)。与镉复合污染能明显改变环草隆的微生物毒性效应，并且Cd对环草隆毒性效应的影响与二者浓度配比有很大关系，Cd浓度由1 mg·kg-1升高到10 mg·kg-1，环草隆与样点G土壤有机氮矿化量变化率的线性关系由正相关变为负相关。复合污染下，根据剂量-效应关系计算的EC50值27.6～848 mg·kg-1，远远高于环草隆草坪建议施用量(3.33 mg·kg-1)。土壤中环草隆与镉复合污染的联合毒性效应受土壤理化性质及重金属含量影响较大，另外，二者复合效应也会随污染物浓度及试验指标的不同而发生变化。 |
| 英文摘要 | Urban soil is the main component of urban ecological systems and the key risk receptor from urbanization. Heavy metal and green land agrochemical pollutions in urban soils have been widely reported with the expanding of urbanization. In northern cities, siduron is widely used in lawn management, and soil contamination of heavy metal like Cd commonly exists in urban green land. Thus, combined exposure of siduron and Cd is very likely in the urban green land soil ecosystem. Now studies on soil combined pollution are still confined to laboratory simulation, but results from laboratory experiments are controversial compared with the actual situation of field soils. Meanwhile, due to low content and small variation as well as many interference factors, it is also difficult to apply field soil directly to the ecological effect evaluation. So the combination of laboratory results with field survy is needed to reach ecological evaluation of combined pollution in field soil. In this research, heavy metals polluted urban soils were selected to evaluate the ecological risk of combined pollution of heavy metals and herbicide. Combined effects of siduron and Cd on soil organic nitrogen mineralization, basal respiration and the activities of urease, arylsulfatase, invertase and alkaline phosphatase were studied based on laboratory experiments. The combined ecological risk of siduron and Cd on urban soil was revealed. It can provide basic data and technical methods for the ecological risk assessment of combined pollution by heavy metals and herbicide in urban soil. The main conclusions are as follows: The analysis on heavy metals polluted urban soil indicated that the three studied soils were all polluted by heavy metals and the comprehensive pollution index were 8.89, 17.2 and 57.8, respectively. The correlation between soil organic nitrogen mineralization, basal respiration, arylsulfatase, alkaline phosphatase activities and soil properties, heavy metals was significant, while the correlation were not significant between urease, invertase activities and soil properties, heavy metals. The study on the toxic effect of siduron on soil microbial ecological function indicated that: The soil organic nitrogen mineralization, basal respiration, arylsulfatase and alkaline phosphatase activities were sensitive to siduron pollution, while urease and invertase activities were insensitive. In the range of siduron concentrations from 0 mg·kg-1 to 1000 mg·kg-1, significant linear correlations were observed between siduron concentrations and the change rates of alkaline phosphatase activity in slightly heavy metal polluted soil N. Significant linear relationships were also observed between siduron concentrations and the change rates of arylsulfatase activities in soil D and G which were more seriously heavy metal polluted. The EC10s of the effect of siduron on the change rates of arylsulfatase activities in soil D and G and on the change rates of alkaline phosphatase activity in soil N were 568 mg·kg-1, 1 306 mg·kg-1 (inhibiting value) and 56 mg·kg-1 (activation value), 99 mg·kg-1, respectively. And EC50s were 1901 mg·kg-1, 3806 mg·kg-1, 2321 mg·kg-1, respectively. The study on combined effects of siduron and Cd on soil organic nitrogen mineralization, basal respiration and soil enzyme activities indicated that: the single and combined effects of siduron and Cd on experimental indexes were markedly significant (P<0.01). Presence of Cd obviously changed the toxic effect of siduron on microorganisms and the effect of Cd was dependent on concentration of siduron and Cd. When Cd concentrations increased from 1 mg·kg-1 to10 mg·kg-1, the linear relationship between siduron concentrations and the change rate of organic nitrogen mineralization in soil G changed from positively to negatively. Under combined pollution, the EC50s (27.6～848 mg·kg-1) obtained based on the dose-effect relationship were well above the suggested dosage of siduron (3.33 mg·kg-1). The combined effects of siduron and Cd on these selected indexes were greatly influenced by soil physical and chemical properties and heavy metal contents. In addition, the combined effects both varied with their concentrations and experimental indexes. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34492]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 谷盼妮. 环草隆与镉复合污染对城市土壤微生物生态功能的影响研究[D]. 北京. 中国科学院研究生院. 2015. |
入库方式： OAI收割
来源：生态环境研究中心
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