长江下游快速城市化地区水污染特征及源解析:以秦淮河流域为例

明晰区域水污染现状及污染物与污染源之间的关系是实施水环境精细化管理和区域水污染治理对策的前提.水质标识指数法（WQI）和聚类分析（CA）被用于研究2015~2019年秦淮河流域29个监测站点的11个水质参数的时空变化特征,并利用PMF模型和SIAR同位素源解析模型解析秦淮河流域的污染物来源及贡献率.结果表明,秦淮河流域河道水体总体为中度污染,TN浓度超标是流域水体污染的主要原因;2015~2019年WQI值呈现下降的趋势;空间聚类和PMF分析结果显示：①高污染区位于秦淮河下游城市化程度较高的城区、溧水主城和江宁大学城内的河道及牛首山河,污染源主要为生活污水、商服业污水（28.88%）及工业废水排放（27.43%）;②中污染区位于秦淮河下游的江宁开发区和秣陵街道及中上游的禄口街道内河道,主要污染源为城乡生活废水和商服污水（31.62%）、工业废水（27.25%）和内源污染（24.76%）;③低污染区位于秦淮河流域湖熟街道内河道及二、三干河,主要污染源为农村生活污水和生活垃圾（28.79%）及农业非点源污染（24.3%）;云台山河子流域内NO₃^--N是氮污染物在子流域受纳水体中的主要存在形式,SIAR溯源结果显示云台山河子流域的NO₃^--N主要来源于生活污水（61%）和土壤有机氮（34%）.本研究结果可为秦淮河流域水污染治理和水生态保护措施提供科学依据和基础.     

微塑料添加对橘园土壤有机碳矿化的影响

为探究微塑料污染对土壤有机碳矿化的影响,采集湖北当阳橘园土壤,进行室内有机碳矿化培养,研究添加微塑料和秸秆条件下土壤有机碳矿化特征及酶活性变化.结果表明,秸秆和微塑料混施显著影响了土壤有机碳矿化,但仅添加微塑料对土壤有机碳矿化无显著影响.与单施秸秆相比,低量微塑料与秸秆混施处理（PP1+S）显著促进了有机碳矿化,有机碳累积矿化量增加了8.20%,而中高量微塑料与秸秆混施处理（PP2+S和PP3+S）显著降低了有机碳累积矿化量,其中,高量微塑料与秸秆混施对土壤有机碳矿化抑制最明显,降低了10.13%.添加微塑料显著降低了β-葡萄糖苷酶活性,高量微塑料添加对酶活性的抑制最显著,与对照相比,在第1、6和35 d分别降低了20.52%、43.93%和17.79%;但是,添加秸秆缓解了微塑料输入对土壤β-葡萄糖苷酶活性抑制作用.有机碳矿化速率与DOC、MBC含量和β-葡萄糖苷酶活性均呈显著正相关.     

三唑醇杀菌剂在雄性丽斑麻蜥体内的对映选择性降解、蓄积和肝毒性研究

三唑醇(triadimenol, TN)是一种广泛使用的手性三唑类杀菌剂,它含有2个手性中心,4个手性对映体,包括对映体A(A1(R,S)和A2(S,R))以及对映体B(B1(R,R)和B2(S,S))。为了研究三唑醇在爬行动物体内的对映选择性行为和潜在的肝毒性,将雄性丽斑麻蜥分别一次经口暴露和28 d长期暴露于三唑醇(100 mg·kg~(-1) body weight),一次经口暴露结果显示,三唑醇进入大脑和肾中的浓度低于肝、性腺、皮肤和尾,B2(S,S)和B1(R,R)对映体具有相似的代谢速率。代谢过程中A1(R,S)的浓度明显高于A2(S,R),并且在暴露后12 h出现二次上升,这可能是A2(S,R)在体内手性转换为A1(R,S)导致。丽斑麻蜥长期(28 d)暴露于三唑醇后,性腺和肾中无明显蓄积现象,皮和尾中浓度显著高于其他组织,各个组织中三唑醇趋向于保持外消旋状态。三唑醇暴露后肝中主要的代谢基因cyp1a1c、yp3a4c、yp2b1和cyp2d3的表达量都出现明显上升,组织病理学分析进一步显示,三唑醇暴露后的肝组织出现组织空泡、血窦阻塞的症状,说明三唑醇对肝组织具有一定的毒性作用。上述结果为手性农药对爬行动物的生态毒理学评价提供了重要依据。     

三唑醇杀菌剂对雄性丽斑麻蜥性腺系统的对映选择性影响

三唑醇(triadimenol,TN)是一种广泛使用的手性三唑类杀菌剂,它含有2个手性中心,4个手性对映体,其中,对映体A包括A1(R,S)和A2(S,R),对映体B包括B1(R,R)和B2(S,S)。三唑醇被认为是一种潜在的内分泌干扰物,能够影响生物体内雌雄激素的合成。为了研究三唑醇不同对映体和外消旋体对爬行动物性腺系统影响的差异,以雄性丽斑麻蜥为实验动物,将外消旋体和4种对映体(100 mg·kg~(-1)bw)分别经口暴露给雄性蜥蜴28 d。外消旋体和(R,S)对映体暴露后蜥蜴的性腺体细胞指数(GSI)明显低于对照组。(S,R)、(R,S)和(S,S)显著抑制了性腺中性激素合成相关基因(cyp119a、cyp11a、cyp17、hsd-3β、hsd-17β、erα和ar)的表达量,同时降低了血液中睾酮(T)和雌二醇(E2)含量。(R,R)暴露对丽斑麻蜥体内的雌雄激素水平无明显影响。此外,相关性分析表明,外消旋体对性腺中性激素合成相关基因的影响与(R,S)具有较强的相关关系,说明(R,S)可能是外消旋体中生物活性和毒性最高的单体。研究表明,三唑醇对丽斑麻蜥性腺系统的毒性作用具有明显的对映选择性,这为手性农药对爬行动物的生态毒理学评价提供了重要依据。     

Efficient regional ozone control strategies for the eastern United States

When environmental regulatory bodies formulate control plans, it is incumbent upon them to try to achieve the stated goals in an economically efficient manner. The US Environmental Protection Agency (EPA) is presently developing regulations to limit the influence of transported ozone on areas that are having difficulty meeting the ambient air quality standard. EPA has proposed stringent control measures for emissions of nitrogen oxides (NOx) in 22 states of the eastern US. The strategy would necessitate the use of selective catalytic reduction or similar high-performance technology on almost all major power plants in the region, as well as extensive controls on industrial sources. This paper suggests several alternative approaches that would achieve equal or better environmental improvement at lower cost. These include focusing control efforts on sources closer to the North-east Corridor, pushing controls on close-in sources to a higher level of technology performance, and relaxing the stringency of requirements for states remote from ozone problem areas. All the approaches examined are two to three times more cost-effective than EPA's proposed approach in the North-east Corridor.     

Assessing relocation strategies of urban air quality monitoring stations by GA-based compromise programming

This paper presents a GA-based compromise programming technique for assessing the relocation strategy of urban air quality monitoring network with respect to the multi-objective and multi-pollutant design criteria. While the impact of conservative, quasi-stable, and reactive pollutants are considered in the design principles via a simulation analysis, cost, effectiveness, and efficiency characteristics are postulated in the optimization process. Therefore, technical coverage for illustrating the needs of siting air quality monitoring stations (AQMS) includes both the air quality simulation and optimization modeling analyses in a two-stage analytical framework simultaneously. It starts from determining the spatial interrelationship among those candidate sites using various types of air quality simulation models as an integrated means. And the outputs drawn from the simulation models can then be used as the required inputs in the compromise programming model in order to screen all those siting alternatives that may satisfy the planning goals subject to the essential constraints throughout the multi-objective optimization process. For the illustrating purposes, a series of technical settings for finding the optimal relocation scenarios of AQMS were examined in the case study for the city of Kaohsiung in South Taiwan where the long-term violations of official standards of ozone and particulates turn out to be critical. It not only expresses the ideas of relocation strategy but also indicates how to utilize those alternatives in the decision-making process for improving the functionality of air quality monitoring in the urban environment. Experience gained in this study clearly indicates that the more the number of pollutants and objectives considered simultaneously, the higher the number of candidate sites to be selected in the relocation strategy.     

CHANGES IN WATER QUALITY IN THE NEWLY IMPOUNDED SUBTROPICAL FEITSUI RESERVOIR,TAIWAN1

ABSTRACT: Water quality and trophic conditions in the Feitsui Reservoir, a subtropical reservoir, were evaluated with data from a ten-year data base to depict the impacts of river impoundment upon the chemical and biological characteristics of a reservoir, and to discuss the effects of flushing rate on in-lake phosphorus concentrations and phytoplankton growth. The results of the investigation showed that during the incipient impounding period, the water quality in the Feitsui Reservoir was significantly affected by internal loadings from submerged vegetation and soil in the flooded area. Studies of the changes in phosphorus compounds indicated that total phosphorus concentration appeared to approach equilibrium after the seventh year of impoundment and that orthophosphate stabilized after the sixth year of impoundment. Concentrations of both phosphorus forms varied seasonally after attaining stability. Nitrogen compounds (NH₃-N, NO₃-N and NO₂-N) approached equilibrium within three years after impoundment. The seasonal variation in carbon was correlated to the number of phytoplankton. The mean value of the N:P mass ratio has remained over 110 since year seven of impoundment (1990), indicating that phosphorus constitutes the potential limiting nutrient in the growth of phytoplankton. The rapid flushing rate (132.11 and 110.43 yr^-1) in Feitsui Reservoir during the first and second impounding stages was a critical factor influencing the phytoplankton growth response to available nutrients.     

原油对草原植被的影响

为了定量说明落地原油对大庆地区草原植被的影响，选择了四种植物群落进行浇原油试验，浇油厚度为0．2、0．4、0．8cm，浇油时间为秋、春、夏。试验结果表明原油对植物个体的影响因原油量、季节和植物种类的不同而不同，随原油量的增加影响增大。