Effects of impervious cover on the surface water quality and aquatic ecosystem of the Kyeongan stream in South Korea

The extent of impervious cover in a watershed has been linked to the quality of an urban aquatic environment. The Kyeongan watershed in South Korea was investigated to evaluate the relationship between the total impervious area (TIA) and the aquatic ecosystem of the watershed, including water quality and aquatic life using a relatively high-resolution (0.4 m) image. The TIA was found to be approximately 12% of the watershed, which indicates that the quality of its environment was being adversely affected by it. For water quality, Pearson correlation analyses showed that all water quality parameters studied were found to be positively correlated with TIA at p < 0.01, except for nitrate (NO3-). In addition, the zone with a higher TIA was found to have worse water quality. Some water quality parameters, such as nitrite (NO2-), total phosphorus, and phosphate (PO4(3-)) were highly affected by discharges from wastewater treatment plants. Water quality data suggest that TIA could be used to predict the water quality of streams. For ecological parameters, the diatom index for organic pollution and trophic diatom index were found to be highly correlated with TIA, whereas physical habitat and benthic macroinvertebrates were poorly correlated with TIA. However, the results indicate that the extent of impervious cover can be a useful indicator for predicting the status of specific ecosystem of streams.     

PCR-DGGE技术解析A~2/O工艺好氧单元中微生物群落结构

应用PCR-DGGE方法,追踪了汉沽工业废水处理中好氧工艺的活性污泥系统中微生物群落结构动态变化过程及其微生物群落结构组成。研究结果表明：系统中的微生物群落结构随水质变化而变化,随着培养时间的延长,微生物群落结构趋于稳定,分别属于5大类群,与γ、δ、α、ε变形杆菌（Proteobacterias）、芽孢杆菌（Bacilli）的亲缘关系较近。其中γ变形杆菌是该废水处理过程中的主要菌群,包括Pseudomonas sp.、Rheinheimera sp.、Citrobacter sp.、Klebsiella sp.、Enterbacte-riaceae、Stenotrophomonas maltophilia、Acinetobacter。在整个系统中uncultured Pseudomonas sp.、Halobacillus sp.、Pseudomonassp.、Pseudomonas stutzeri、Acinetobacter sp.可稳定存在于系统中,为该污水处理系统中的优势微生物。因此,提高Halobacillussp.、Pseudomonas sp.、Pseudomonas stutzeri、Acinetobacter sp.菌属在系统中的数量和质量,有利于提高废水生化处理的效果。     

Levels and speciation of arsenic in the atmosphere in Beijing, China

Arsenic levels and speciation in the total suspended particles (TSPs) were quantitatively determined by high performance liquid chromatography on-line coupled with hydride generation atomic fluorescence spectrometry in Beijing, China from February 2009 to March 2011. The high TSP levels fluctuated between 0.07 and 0.79 mg m⁻³, with a mean level of 0.32 ± 0.17 mg m⁻³. The total arsenic concentrations ranged from 0.03 to 0.31 μg m⁻³ (mean: 0.13 ± 0.06 μg m⁻³) in Beijing‘s air. The concentrations of As(III) and As(V) ranged from 0.73 to 20 ng m⁻³ (mean: 4.7 ± 3.6 ng m⁻³) and from 14 to 2.5 × 10² ng m⁻³ (mean: 67 ± 35 ng m⁻³), respectively. As levels and speciation demonstrated relative higher levels in spring and autumn and lower values in summer and winter. As(V) accounted for 81-99% of the extractable species in the TSP samples which showed that As(V) was the major fraction of the extractable As. Organoarsenic species, monomethylarsonate (MMA) and dimethylarsinate (DMA) were not found in all samples. Higher values of enrichment factors demonstrated that arsenic in TSP mainly come from anthropogenic sources. High As and its species levels in air and respiratory exposure (0.30-0.84 μg d⁻¹) attributed to higher excess cancer risk ((4.2 ± 2.0) × 10⁻⁴) for people in Beijing.     

油田采出水处理系统用药剂进展

介绍了油田采出水回注处理包括水质净化和水质稳定两方面。通过应用分析得出最佳药剂投加顺序依次为阻垢剂、杀菌剂、缓蚀剂。指出新型药剂和绿色药剂研究的侧重点,提出开发无毒、无害的绿色工业水处理药剂是重要发展方向。     

海洋石油平台生活污水处理系统杀菌方式优化

目前海洋石油平台生活污水处理系统广泛采用氯片或氯粉杀菌,其采购成本高,稀释浓度不易控制,药剂添加困难。海洋石油平台多数配有造氯系统产生氯水,以限制海生物的附着生长。实验表明:使用合适浓度的氯水能使生活污水达到GB 4914-2008《海洋石油勘探开发污染物排放浓度限值》中的相关要求,优化了杀菌方式。     

长庆油田油气泄漏防治体系建设与应用

为防治油气泄漏事件,长庆油田以重点环境保护目标为对象,按照层级防护、标本兼治、数字预警、分级响应、就地控制的原则,建设油气泄漏防治体系,明确和落实油田公司、厂处、作业区、生产岗位四个层级的防治范围和职责,构建系统参数预警报警、阀门截断、基础防护三道防线,全面提升安全环保的防范能力和水平。保证事故状态下,能够在最短时间、最小范围内进行最有效的处置,实现重点环境保护目标的安全。     

Mean annual (222)Rn concentration in homes located in different geological regions of Poland: first approach to whole country area

The paper presents the results of year-long measurements of radon (²²²Rn) concentration inside 129 buildings in Poland in relation to the geological conditions of their foundation. The authors took into account the division of the country into tectonic units, as well as the lithology of the rocks forming the bedrock of these buildings. As expected, the highest value of mean annual ²²²Rn concentration (845 Bq/m³) was recorded in a building situated in the area of the Sudetes, while the highest geometric mean (characteristic of the expected log-normal data distribution) was calculated based on measurements from buildings located within the East-European craton, in the area of Mazury-Podlasie monocline, where it reached 231 Bq/m³. Such results reflect geological conditions - the occurrence of crystalline rocks (especially U- and Ra-enriched granites and orthogneisses) on the surface in the Sudetes, and of young post-glacial sediments containing fragments of Scandinavian crystalline rocks, also enriched with U and Ra, in the area of Mazury-Podlasie monocline. However, the least expected result of the investigations was finding out that, contrary to the hitherto widespread belief, none of the major tectonic units of Poland can be excluded from the list of those containing buildings with mean annual ²²²Rn concentration exceeding 200 Bq/m³. The mean annual concentration of radon for all the buildings were much higher than the mean concentration value (49.1 Bq/m³) of indoor radon in Poland quoted so far. These results cast a completely new light on the necessity to perform measurements of radon concentration in residential buildings in Poland, no more with reference to small areas with outcrops of crystalline rocks (especially the Sudetes, being the Polish fragment of the European Variscan belt), but for all the major tectonic units within Poland.     

Spatiotemporal dynamics of spring and stream water chemistry in a high-mountain area

The present study deals with the application of the self-organizing map (SOM) technique in the exploration of spatiotemporal dynamics of spring and stream water samples collected in the Chocho?owski Stream Basin located in the Tatra Mountains (Poland). The SOM-based classification helped to uncover relationships between physical and chemical parameters of water samples and factors determining the quality of water in the studied high-mountain area. In the upper part of the Chocho?owski Stream Basin, located on the top of the crystalline core of the Tatras, concentrations of the majority of ionic substances were the lowest due to limited leaching. Significantly higher concentration of ionic substances was detected in spring and stream samples draining sedimentary rocks. The influence of karst-type springs on the quality of stream water was also demonstrated.     

Comparative phototoxicity of nanoparticulate and bulk ZnO to a free-living nematode Caenorhabditis elegans: the importance of illumination mode and primary particle size

The present study evaluated phototoxicity of nanoparticulate ZnO and bulk-ZnO under natural sunlight (NSL) versus ambient artificial laboratory light (AALL) illumination to a free-living nematode Caenorhabditis elegans. Phototoxicity of nano-ZnO and bulk-ZnO was largely dependent on illumination method as 2-h exposure under NSL caused significantly greater mortality in C. elegans than under AALL. This phototoxicity was closely related to photocatalytic reactive oxygen species (ROS) generation by the ZnO particles as indicated by concomitant methylene blue photodegradation. Both materials caused mortality in C. elegans under AALL during 24-h exposure although neither degraded methylene blue, suggesting mechanisms of toxicity other than photocatalytic ROS generation were involved. Particle dissolution of ZnO did not appear to play an important role in the toxicity observed in this study. Nano-ZnO showed greater phototoxicity than bulk-ZnO despite their similar size of aggregates, suggesting primary particle size is more important than aggregate size in determining phototoxicity.     

Nitrogen concentrations in mosses indicate the spatial distribution of atmospheric nitrogen deposition in Europe

In 2005/6, nearly 3000 moss samples from (semi-)natural location across 16 European countries were collected for nitrogen analysis. The lowest total nitrogen concentrations in mosses (<0.8%) were observed in northern Finland and northern UK. The highest concentrations (≥1.6%) were found in parts of Belgium, France, Germany, Slovakia, Slovenia and Bulgaria. The asymptotic relationship between the nitrogen concentrations in mosses and EMEP modelled nitrogen deposition (averaged per 50 km × 50 km grid) across Europe showed less scatter when there were at least five moss sampling sites per grid. Factors potentially contributing to the scatter are discussed. In Switzerland, a strong (r² = 0.91) linear relationship was found between the total nitrogen concentration in mosses and measured site-specific bulk nitrogen deposition rates. The total nitrogen concentrations in mosses complement deposition measurements, helping to identify areas in Europe at risk from high nitrogen deposition at a high spatial resolution.