花土沟油田藻灰岩储层特征与油气关系

岩心观察和铸体片鉴定证实,花土沟油田藻灰岩储层发育,储层岩石类型主要为藻纹层灰岩、藻叠层灰岩、亮晶生屑灰岩、亮晶鲕粒灰岩、陆屑泥晶灰岩、藻泥晶灰岩、藻团粒灰岩等,形成于湖盆中某单一藻类勃发时期,沉积过程受陆源碎屑影响较大,成岩阶段只经历了准同生成岩阶段和浅埋藏阶段,成岩作用较弱,对孔隙度影响不大.孔隙类型主要为受到淡水淋滤溶蚀作用和构造作用而形成的次生孔隙,孔隙结构杂乱,无明显规律性.藻灰岩既是生油岩,又是储集岩体,形成自生自储式油藏的条件非常有利.     

藻毒素的生物降解研究进展

近年来蓝藻水华污染产生的有毒代谢产物藻毒素对水生生态系统和人类健康构成严重的威胁。生物降解技术尤其是生物滤池由于运行维护费用低并且不产生有毒副产物,已广泛应用于去除藻毒素。然而,水处理过程中可能存在的生物降解多种藻毒素效果的信息少有收集,这在越来越多不同种类的藻毒素能同时在水源地中检测出来的情况下更加重要。综述了目前所有藻毒素生物降解性的相关研究进展,分析了影响藻毒素生物降解的因素,并探讨了目前藻毒素生物降解技术如何在水处理过程中应用优化去除藻毒素效果,为运用生物降解方法控制或去除各种藻毒素提供理论指导。     

试论水华的定义

讨论了水华的形成机理、影响因素、类别、危害等相关问题,并在已有相关研究成果和有关标准基础上提出了水华的定义,最后利用藻细胞浓度、叶绿素a、透明度、总磷和总氮5个参数制定出水华程度评价等级。     

Gone with the wind? Newspaper discourse of eutrophication and blue‐green algae blooms in Finland

The mass media shape the public and policy agenda by giving prominence to certain ecosystem changes and risks, as well as by framing some policy measures as the preferred ones. Based on longitudinal analysis of the leading Finnish newspaper, this study considers the media coverage of eutrophication. The results show an increase of reporting in the late 1990s as a result of intertwined ecological and social factors – i.e. intense algal occurrences and establishment of a national communication system. The news coverage has highlighted the harmful algal blooms and health risks of algal toxins and has framed short‐term weather conditions as the key factor regulating algal occurrences. This creates a challenge for environmental management aimed at reduction in the nutrient discharges that influence the state of the environment in the long term.     

Reduction of germination frequency in Anabaena akinetes by sediment drying: a possible method by which to inhibit bloom formation

The effect of desiccation on germination frequency of Anabaena akinetes was investigated to evaluate the practical usefulness of sediment drying in reservoirs as a measure of inhibition of Anabaena bloom formation. Sediment samples taken from a small reservoir, where an abundance of Anabaena blooms occur every summer were desiccated in the outdoors and in an incubator at 5, 10, 15, and 25 °C. As a result, the germination frequency of Anabaena akinetes was strongly inhibited in comparison with that of Anabaena akinetes preserved in a refrigerator without desiccation as a control. Greater inhibition of Anabaena germination found at a higher temperature was examined, and almost all akinetes lost the ability of germination at 25 °C after 3 days of the desiccation treatment. Therefore, sediment drying is considered to be a useful measure to reduce periods and scales of Anabaena blooms, and its effect will be enhanced by performance during the warmer seasons.     

影响分光光度法检测藻类叶绿素a的因素

目的为检测藻类叶绿素a提供可借鉴的依据.方法采用玻璃离心管与塑料离心管,待测液样在分光光度计中稳定不同时间,在叶绿素a提取过程中对液样加以冷藏的方法,进行对比试验.结果塑料离心管测得的水样叶绿素a值,比用玻璃离心管测得的值平均高30.1%.液样在分光光度计中稳定时间0~5 min内,叶绿素a值随稳定时间延长而提高,5 min以后提高速度减缓.冷藏时间在6 h以内,叶绿素a值平均增加1.92μg.(L.h)-1,6 h以后,叶绿素a值增加速度减缓.结论塑料材料对叶绿素a值测定有干扰作用,采用塑料离心管测得的水样叶绿素a值偏高,建议用玻璃离心管.待测液样在分光光度计中的稳定时间对藻类叶绿素a值的测定有影响,如果稳定时间过短,会使测定结果偏低.适合的稳定时间为10~20 min,在叶绿素a提取过程中,将液样适当进行冷藏,可使叶绿素a充分溶解于溶液中,适合的冷藏时间为6~8 h,供分光光度法检测藻类叶绿素a参考.     

水体富营养化预警模型研究现状和发展趋势

水体富营养化及修复是我国当前水环境保护的研究热点,有害藻华的预测预警模型是预测水体富营养化的重要工具,并为修复水体提供技术支撑。从有害藻华运动的预测预警、数据驱动和藻类生长模型3个方面,介绍国内外水体富营养化预警模型的研究进展和应用现状,并比较不同模型之间的优缺点,为模型准确度的提高和进一步发展提供参考。     

Mapping Chlorophyll-a Concentrations in West Lake,China using Landsat 7 ETM+

Eutrophication is a persistent problem that affects the ecological health of many shallow lakes in China. An indicator used to monitor trophic status is chlorophyll-a; however, collection and analysis can be spatially limiting and time consuming. In this study we utilized Landsat 7 ETM+ (Path/Row 119/39) imagery for West Lake, Hangzhou, to map chlorophyll-a concentrations. An optimal linear regression model with the band ratio ETM+3/ETM+1 (independent) and concurrent field-collected water quality measurements (dependant) was developed. The resulting model, lnChl.= 5.009 (ETM+3/ETM+1)-1.855, showed a strong (R² = 0.815) ability to accurately map the distribution of chlorophyll-a. The straightforward approach carried out to assess this fresh-water lake in a rapidly developing region increased the level of information required to combat aquatic ecosystem degradation.     

Oxygen microprofiles of trickling filter biofilms

Oxygen microprofiles of photosynthetic and non-photosynthetic biofilms of trickling filters from a sewage treatment plant were studied with Clark type oxygen microelectrodes. The oxygen profiles in photosynthetic biofilms exhibited pronounced changes with changing light conditions, and the profiles of both types of biofilm were affected by addition of nutrients. The existence of a 100–500 μm thick diffusive boundary layer in the water just above the biofilm was evident from all recordings. The O₂ gradient in this boundary layer was used to calculate diffusive fluxes of oxygen exchanged between the biofilms and the overlying water phase. The calculated fluxes were compared to the overall oxygen consumption rates measured experimentally and to the photosynthetic activity as measured with the microelectrodes. Approximately 60–70% of the oxygen produced in the algal films during photosynthesis was consumed within the films. At least one third of this consumption may be due to photorespiration. Dark/light and light/dark shifts demonstrated a very dynamic nature of the O₂ status of the algal films, showing an increase from anaerobic conditions to 500% air saturation and vice versa within 25 min. In the same regime, pH profiles showed a similar dynamic change, whereby pH varied between 8.1 and 9.7 in the same period.

The data obtained with the non-photosynthetic biofilms show that the oxygen respiration and oxygen penetration are mostly limited by diffusive oxygen transport through the boundary layer. The overall oxygen consumption of the heterotrophic biofilms equalled within ± 10% the estimates made from flux calculations.     

河湖水华预测方法研究

以水华预测研究方法的发展为主线,着重从机理生态建模和智能方法建模两方面对水华预测方法进行总结。通过对国内外常用预测模型的建立思路和应用实例进行分析和描述,比较了机理模型和智能模型的优缺点和使用范围。最后,针对目前水华预测存在的问题进行了分析,指出机理建模和智能方法的有机结合将为准确预测水华提供有效的途径。