【作者】 焦婷婷；

【导师】 胡锋；

【作者基本信息】 南京农业大学 ， 生态学， 2009， 硕士

【摘要】 多环芳烃(PAHs)是一类典型持久性有机污染物(POPs),对自然环境、人类健康都具有危害作用。环境中90%以上的PAHs最终进入土壤,不但影响土壤的正常功能,而且比较容易进入生物体内、影响作物生长,并通过生物链进入生态系统,从而危害人类健康和整个生态系统的安全。为了科学地评价和控制土壤环境质量,需要建立PAHs的土壤环境质量基准。本文以荧蒽(FLA)为研究对象,研究土壤中添加不同浓度荧蒽后,典型植物生长、土壤生物生长及活性变化的情况,通过拟合“剂量-效应”方程计算对应的土壤荧蒽临界值,为多环芳烃土壤环境质量标准的制定和生态风险评价提供初步的科学依据。主要工作及结论如下：(1)通过盆栽实验研究荧蒽对青菜的毒性效应,研究在不同浓度下植株生物量、根系形态对荧蒽污染的响应情况、植株不同部位对荧蒽的累积情况,并通过“浓度-产量”关系拟合出荧蒽污染下植株的产量效应方程,以青菜减产10%计算出两种土壤的荧蒽临界值。初步结果为：植株生物量和株高以及根重、根总长度、根表面积、根系分叉数等根系形态指标随荧蒽浓度的增加受抑制程度变大,根系受抑制的情况最为明显因此,根系形态可以较精确地表征土壤有机物污染状况；青菜各部位对荧蒽的吸收累积都随土壤中荧蒽浓度的升高而升高,且累积强度根>茎>叶；通过拟合“浓度-产量”效应方程,得知青菜地上部减产10%时,黄棕壤和潮土中荧蒽的临界含量分别是16.17mg·kg-1和2.43mg·kg-1。(2)以蚯蚓(Eisenia foetida)作为指示生物,采用土壤接触法,研究荧蒽对蚯蚓的单一急性毒性。比较分析不同污染浓度对蚯蚓的单一急性毒性症状及剂量—生长抑制率曲线关系,为进一步确定荧蒽的土壤毒理诊断提供实验依据。土壤中荧蒽浓度和蚯蚓的生长抑制率呈显著“剂量-效应”关系,通过多项式拟合,找出了土壤荧蒽浓度和蚯蚓生长抑制率之间的回归关系,以蚯蚓生长抑制率达到15%时土壤荧蒽浓度为临界浓度。作用时间越长,临界浓度越低；相同作用时间内,荧蒽在黄棕壤中的临界浓度高。以培养14d后荧蒽浓度与蚯蚓生长抑制率之间的“剂量-效应”拟合方程,以蚯蚓生长抑制率达到15%时土壤荧蒽浓度为临界浓度,黄棕壤和潮土中荧蒽的临界含量分别是9.26mg·kg-1和11.53mg·kg-1。(3)选用两种水解酶(脲酶、蔗糖酶)和一种氧化还原酶(过氧化氢酶)作为指示指标,通过测定土壤酶活性在不同接触时间、不同污染物浓度作用下的变化,探讨多环芳烃浓度和作用时间与土壤酶活性之间的相关关系模型,为把土壤酶活性作为表征环境质量的一项生态毒理指标提供理论依据。酶活性高低与土壤理化性质有关。随着荧蒽污染浓度的变化,黄棕壤和潮土脲酶、蔗糖酶和过氧化氢酶的活性都受到显著影响。荧蒽浓度越高,脲酶和蔗糖酶的活性越低,而过氧化氢酶的活性随荧蒽浓度增加而增加。更多还原

【Abstract】 Polycyclic Aromatic Hydrocarbons (PAHs), which is a kind of typical Persistent Organic Pollutant (POPs), has obvious harmful effect for humanhealth and environment. It was reported that 90%of PAHs in environment would enter and sink to the soil finally. Then they could not only effect the normal function of soil but also enter to the living body and effect plants’growing, so that enter the ecosystem by the biological chain, and then do harmfulness to humanhealth and the safty of the whole ecosystem.Soil environmental quality criteria for PAHs must be established in order to scientifically assessment and control soil quality. Taking Fluoranthene as research object, this thesis preliminary studied the changes of soil organisms’growth and activities by adding different content of Fluoranthene. By fitting dose-effect equations, several threshold values of soil Fluoranthene concentration were obtained, so that provided scientific basis for establishing PAHs’soil environmental quality criteria and evaluating their ecological risks. The thesis has reference meaning in the development of soil environment quality criteria. The main research contents and results were as follow:(1) According to pot experiment, Fluoranthene’s toxic effect to Chinese cabbage was studied. The preliminary results were:Fluoranthene suppressed significantly the plant height, shoot mass, root mass and they were decreased with increasing concentration of fluoranthene; Several root morphology such as length, surfarea, avgdiam and forks changed significantly to fluoranthene concentration, so root morphology indexes could be the better botanic reference index for organic pollution than plant biomass and height. The cumulant of Fluoranthene in different parts of the Chinese cabbage was related significantly to the Fluoranthene concentration in soil, and in different parts of the plant the accumulation concentration was:root> stem> leaf. By fitting yield effect equation, soil Fluoranthere thresholds for Chinese cabbage yield reduction of 10%were 16.17mg·kg-1 in Yellow Brown Soil and 2.43mg-kg-1 in Alluvial Soil.(2)By using earthworm (Eisenia foetida) as bio-indicator, the effect of acute toxicity of Fluoranthere in single form was studied, so as to find the relationship between Fluoranthere concentration and earthworms’growth inhabition rate. And the correlation was significantly and coud set the concentration as soil Fluoranthene threshold concentration when earthworms’growth inhabition rate was 15%. The longer the culture time the lower the threshold concentration(3)Choosing urease, invertase and catalase as diagnostic indicator, the relationship between activities of different enzymes and concentrations of Fluoranthene added were investigated. The results showed that with the Fluoranthene added, the activities of the three enzymes were all influenced significantly. The ureasse activity and invertase activity were inhibited as the concentration of Fluoranthene increased. However, the activity of catalase was activated by the addition of Fluoranthene. Soil properties could influence certain enzymes’activity.更多还原