Organochlorine contaminant concentrations in caddisfly adults (Trichoptera) collected from great lakes connecting channels

Pennsylvania-style light traps were used to capture adult Trichoptera from the St. Marys, St. Clair, Detroit and Niagara rivers, Canada. Adequate biomass was acquired in single, 2-h collections to permit triplicate gas chromatographic analyses of 1–4 g samples for 36 organochlorine contaminants. Contaminant levels varied unpredictably but relatively little among samples taken at monthly intervals over the summer. Samples collected simultaneously from the two sides of the Detroit R. reflected local sediment contaminant patterns, suggesting limited dispersal by adults. Genus-specific differences in contaminant concentrations within the Hydropsychidae and Leptoceridae probably reflect differences in larval habitats and manner of feeding. Contaminant concentrations and relative composition paralleled published reports of contaminants in sediments from collection locations. St. Marys R. caddisflies contained contaminant levels indistinguishable from samples collected at reference sites. St. Clair R. samples contained high levels of compounds associated with petrochemical industries located in the river's upstream reaches. High levels of polychlorinated biphenyls (PCBs) and most other contaminants in Detroit R. samples reflected industrial loadings near Detroit, Michigan. Niagara R. samples contained elevated concentrations of PCBs and pesticides. Cluster analysis grouped samples into five clusters each with unique contaminant composition. These also corresponded to geographic origin: St. Marys, St. Clair, Detroit and upper and lower Niagara rivers. The relative ease of collection and consistent results obtained render adult Trichoptera potentially valuable candidates for surveys of aquatic contamination over a broad range of geographical and ecological conditions.     

氢化物发生原子荧光法测定饮用水中的微量硒

氢化物发生原子荧光法测定饮用水中的微量硒时。仪器条件和试剂的浓度选择很重要。本文对条件的最佳化进行了实验。并对方法的精密度、准确度和检出限进行了讨论。     

Characterization of microbial communities from coastal waters using microarrays

Molecular methods, including DNA probes, were used to identify and enumerate pathogenic Vibrio species in the Chesapeake Bay; our data indicated that Vibrio vulnificus exhibits seasonal fluctuations in number. Our work included a characterization of total microbial communities from the Bay; development of microarrays that identify and quantify the diversity of those communities; and observation of temporal changes in those communities. To identify members of the microbial community, we amplified the 16S rDNA gene from community DNA isolated from a biofilm sample collected from the Chesapeake Bay in February, 2000. The resultant 75 sequences were 95% or more similar to 7 species including two recently described Shewanella species, baltica and frigidimarina, that have not been previously isolated from the Chesapeake. When the genera of bacteria from biofilm after culturing are compared to those detected by subcloning amplified 16S fragments from community DNA, the cultured sample exhibited a strong bias. In oysters collected in February, the most common bacteria were previously unknown. Based on our 16S findings, we are developing microarrays to detect these and other microbial species in these estuarine communities. The microarrays will detect each species using four distinct loci, with the multiple loci serving as an internal control. The accuracy of the microarray will be measured using sentinel species such as Aeromonas species, Escherichia coli, and Vibrio vulnificus. Using microarrays, it should be possible to determine the annual fluctuations of bacterial species (culturable and non-culturable, pathogenic and non-pathogenic). The data may be applied to understanding patterns of environmental change; assessing the health of the Bay; and evaluating the risk of human illness associated with exposure to and ingestion of water and shellfish.     

过氧化聚吡咯/聚乙烯吡咯烷酮修饰碳糊电极测定废水中苯酚

建立了过氧化聚吡咯(OPPy)和聚乙烯吡咯烷酮(PVP)修饰碳糊电极测定废水中苯酚的方法.优化了试验条件,苯酚的氧化峰电流在1.0×10-5 mol/L～1.0×10-3 mol/L之间线性关系良好,检出限为1.0×10-6 mol/L.该电极制作简单,选择性好,测定灵敏度高,精密度与准确度均符合要求.     

Environmental risk assessment of existing chemicals

Most of the existing chemicals of high priority have been released into the environment for many years. Risk assessments for existing chemicals are now conducted within the framework of the German Existing Chemicals Program and by the EC Regulation on Existing Substances. The environmental assessment of a chemical involves:

1. exposure assessment leading to the derivation of a predicted environmental concentration (PEC) of a chemical from releases due to its production, processing, use, and disposal. The calculation of a PEC takes into account the dispersion of a chemical into different environmental compartments, elimination and dilution processes, as well as degradation. Monitoring data are also considered.
2. effects assessment. Data obtained from acute or long-term toxicity tests are used for extrapolation on environmental conditions. In order to calculate the concentration with expectedly no adverse effect on organisms (Predicted No Effect Concentration, PNEC) the effect values are divided by an assessment factor. This assessment factor depends on the quantity and quality of toxicity data available.

In the last step of the initial risk assessment, the measured or estimated PEC is compared with the PNEC. This “risk characterization” is conducted for each compartment separately (water, sediment, soil, and atmosphere). In case PEC > PNEC an attempt should be made to revise data of exposure and/or effects to conduct a refined risk characterization. In case PEC is again larger than PNEC risk reduction measures have to be considered.     

合肥地区重金属污染生物监测的初步研究 --以大蜀山铅镉的白鹭监测为例

将合肥地区大蜀山的白（Egretta garzetta）卵和组织样品，用原子吸收法时样品中的Pb、Cd等重金属污染物进行了检测，结果表明，这2种重金属元素在卵和组织中均有不同程度的检出，其中Cd在卵的内容物中残留量较低。而且这2种重金属污染物在鹭卵不同部分的残留量均有差异；同其他地区类似的研究结果相比，合肥地区鹭卵中重金属残留水平相时较高。     

珍贵油料植物诸葛菜的研究

四川大学植物遗传研究室经过几年的调查研究,发现诸葛菜的农艺性状较好,分枝多、角果多,每果子粒多,千粒重较重,含油量较高,特别是油分品质优异,其营养价值高的脂肪酸如油酸和亚油酸的含量较高,分别为20.32％,和53.17％,其营养价值低的脂肪酸如亚麻酸和芥酸的含量较低,分别为4.76％和0.94％,是油菜优质育种的优异新种源,可以作为油菜远缘杂交育种亲本,并可能选育出优质油料新作物。本文对诸葛菜的开花授粉习性作了观察,对核型特点作了分析,可供育种工作的参考,诸葛菜主产中国。四川大学在国内外首先推荐这种有希望的油料新种源。     

城市人居环境的协调发展度研究——以上海市青浦区为例

城市人居环境的可持续发展体系是一个由人口、社会、资源、环境与经济5个子系统构成的开放巨系统。通过提出综合衡量系统“协调性”和“发展水平”的“协调发展度”模型，研究人居环境复合系统内5个子系统之间协调发展度情况。并运用灰色预测理论构建GM（1，N）动态模型，预测未来几年各子系统之间协调发展的状况。     

有效微生物技术在渗滤液处理中的应用与发展

介绍了有效微生物(EM)的组成、特点及其处理废水的机理;通过与传统的生化法处理垃圾渗滤液的比较,指出了利用EM技术处理垃圾渗滤液的优势,认为该技术不仅能够提高污染物的去除效率,降低污泥产量,而且能够缩短反应器的响应时间;并介绍了EM制剂在国内外的生产情况,对今后EM技术的发展前景提出了展望.     

厦门市生活垃圾的灰色预测与分析

运用灰色关联度分析法,定量分析了影响厦门市生活垃圾产生量的影响因子,发现其主要因子是城市国内生产总值(GDP);利用灰色系统理论建立了该市生活垃圾产生量的GM(1,1)预测模型,并进行预测分析。