藻菌共生体系对镇江市金山湖湖水的异位修复模拟研究

根据镇江市金山湖湖水的水质配制了模拟湖水,考察了小球藻、栅藻、铜绿微囊藻和聚球藻对模拟湖水中总氮(TN)、总磷(TP)和化学需氧量(COD)的去除效果,筛选出小球藻作为优势藻种.文中研究了小球藻的初始密度对模拟湖水中TN、TP和COD去除效果的影响.结果表明:小球藻初始密度为5×106个/m L时对TN、TP和COD的去除效果相对较好,在72 h内去除率分别可达55.1%,96.2%和55%.文中还对藻菌共生体系修复模拟湖水的效果进行了研究,确定了最佳藻菌体积比为1∶2时,TN,TP和COD的去除率分别达到62.4%,97.2%和96.2%.结果表明:藻菌共生体系可有效地对富营养化湖水进行异位修复.     

纳米TiO2光催化和紫外线辐照法相结合杀灭压载水中藻类模拟实验研究

为了验证紫外线处理器内部附着纳米TiO2薄膜,在压载水处理过程中的灭藻效果,设计了一套杀灭压载水中藻类的模拟实验系统。分别用单一紫外线辐照法和纳米TiO2光催化-紫外线辐照相结合法对鱼腥藻进行杀灭实验研究对比。结果表明,两种方法均可完全杀灭压载水中藻类,且在相同实验条件下,利用纳米TiO2光催化-紫外线辐照结合法,只需要4根低压高强紫外线灯管就能达到单一紫外线辐照法6根低压高强紫外线灯管对海藻的灭活效果。在不影响灭活效果的前提下,降低了处理器的功率,可以起到节能的作用。     

Union examination of AFP, AFU, AFPL3 and γ-GT in early diagnosis of primary liver cancer

Objective To explore the significance of union examination of blood serum liver cancer tracers in the early diagnosis of liver cancer. Methods We observed and compared the level of blood serum liver cancer tracers armor embryo protein (AFP), crag algae glycosidase (AFU), armor embryo protein heteroplasmon (AFPL3) andγ-Gu Anxian transferase (γ-GT) in early time for primary liver cancer patients and hepatitis liver cirrhosis patients and those chronic hepatitis B patients who had liver cancer family history. Results Finally among the 30 patients in the early liver cancer group, 23 were positive with AFP, 20 with AFU, 15 with AFPL3 and 21 with γ-GT. Five were found positive with blood serum AFP, AFPL3, AFU and γ-GT at the same time; 5 with AFP, AFPL3 and γ-GT; 5 with AFP, AFU and AFPL3; 7 with AFP, AFU andγ-GT. By contrast, in the control group, among the 30 hepatitis liver cirrhosis patients and those chronic hepatitis B patients with liver cancer family history, 11 were found positive with AFP, 3 with AFPL3, 12 with AFU and 14 with γ-GT. None of the patients were found positive with union examination of AFP, AFPL3, AFU and γ-GT in the blood serum at the same time. Conclusion The union examination of AFP, AFU, AFPL3 and γ-GT is significant to the early diagnosis of primary liver cancer.     

The influence of upwelling and entrainment on the algal bloom in the Baltic Sea

Hydrodynamic processes control many geochemical and ecological processes in the sea. In this paper, the influence of up- and downwelling and entrainment on the ecosystem components are studied. The ecohydrodynamic model was initially used to simulate the whole Baltic Sea to get the boundary conditions for the Gulf of Riga. Then, to study the influence of different hydrodynamic conditions on the algal bloom, three simulations were made for the Gulf of Riga using different boundary and entrainment conditions. It appears that upwelling in the gulf was strongly dependent on open boundary conditions between the Baltic Proper and the gulf. The vertical transport in the Gulf of Riga was many times more intensive in the calculation system Baltic Proper and Gulf of Riga, than in the case where only the Gulf of Riga was simulated. The blue–green algal bloom was influenced by the vertical transport due to different nutrients' limitation mechanism.     

Eradication of algae in ships'' ballast water by electrolyzing

In order to verify the effectiveness of electrolytic treatment on ships' ballast water,experiments are carried out by a pilot system in laboratory. The raw seawater and seawater with different concentrations of different algae are simulated as ships' ballast water. The algae in the raw seawater can be killed if it is treated by electrolysis with an initial residual chlorine concentration of 5 mg/L. If the seawater with one kind of algae (Nitzschia closterum, Dicrateria spp., or Pyramidomonnas sp.105cells/mL) is treated by electrolysis with an initial residual chlorine concentration of 5 mg/L, the alga can be sterilized. If the seawater with one kind of algae (Dunaliella sp., Platymonas or Chlorella spp.)is directly treated by electrolyzing with an initial residual chlorine concentration of 4 mg/L, the instant mortality changes with the concentration of different algae. However, after 72 hours, in all treated samples, there are no live algal cells found.     

Eradication of algae in ships＇ ballast water by electrolyzing

In order to verify the effectiveness of electrolytic treatment on ships＇ ballast water, experiments are carried out by a pilot system in laboratory. The raw seawater and seawater with different concentrations of different algae are simulated as ships＇ ballast water. The algae in the raw seawater can be killed if it is treated by electrolysis with an initial residual chlorine concentration of 5 mg/L. If the seawater with one kind of algae （Nitzschia closterum, Dicrateria spp., or Pyramidomonnas sp.105cells/mL） is treated by electrolysis with an initial residual chlorine concentration of 5 mg/L the alga can be sterilized, If the seawater with one kind of algae （Dunaliella sp., Platymonas or Chlorella spp.） is directly treated by electrolyzing with an initial residual chlorine concentration of 4 mg/L, the instant mortality changes with the concentration of different algae. However, after 72 hours, in all treated samples, there are no live algal cells found.     

藻类生物燃料的研究进展

该文介绍了当前日益紧迫的能源危机和藻类生物燃料在国内外的研究现状,指出了利用藻类固定二氧化碳的优势及在选种、提高二氧化碳转化率方面存在的问题。藻类具有繁殖快、易培养和含油高的特性,用藻类固定二氧化碳,不仅有利于环境保护,而且还能满足能源需求,因此具有广阔的发展前景。     

Winter–spring dynamics in sea-ice carbon cycling in the coastal Arctic Ocean

An understanding of microbial interactions in first-year sea ice on Arctic shelves is essential for identifying potential responses of the Arctic Ocean carbon cycle to changing sea-ice conditions. This study assessed dissolved and particulate organic carbon (DOC, POC), exopolymeric substances (EPS), chlorophyll a, bacteria and protists, in a seasonal (24 February to 20 June 2004) investigation of first-year sea ice and associated surface waters on the Mackenzie Shelf. The dynamics of and relationships between different sea-ice carbon pools were investigated for the periods prior to, during and following the sea-ice-algal bloom, under high and low snow cover. A predominantly heterotrophic sea-ice community was observed prior to the ice-algal bloom under high snow cover only. However, the heterotrophic community persisted throughout the study with bacteria accounting for, on average, 44% of the non-diatom particulate carbon biomass overall the study period. There was an extensive accumulation of sea-ice organic carbon following the onset of the ice-algal bloom, with diatoms driving seasonal and spatial trends in particulate sea-ice biomass. DOC and EPS were also significant sea-ice carbon contributors such that sea-ice DOC concentrations were higher than, or equivalent to, sea-ice-algal carbon concentrations prior to and following the algal bloom, respectively. Sea-ice-algal carbon, DOC and EPS-carbon concentrations were significantly interrelated under high and low snow cover during the algal bloom (r values ≥ 0.74, p < 0.01). These relationships suggest that algae are primarily responsible for the large pools of DOC and EPS-carbon and that similar stressors and/or processes could be involved in regulating their release. This study demonstrates that DOC can play a major role in organic carbon cycling on Arctic shelves.     

Biological control of harmful algal blooms: A modelling study

A multispecies dynamic simulation model (ERSEM) was used to examine the influence of allelopathic and trophic interactions causing feeding avoidance by predators, on the formation of harmful algal blooms, under environmental scenarios typical of a Mediterranean harbour (Barcelona). The biological state variables of the model included four functional groups of phytoplankton (diatoms, toxic and non-toxic flagellates and picophytoplankton), heterotrophic flagellates, micro- and mesozooplankton and bacteria. The physical–chemical forcing (irradiance, temperature and major nutrient concentrations) was based on an actual series of measurements taken along a year cycle in the Barcelona harbour. In order to evaluate potential effects of advection, some runs were repeated after introducing a biomass loss term. Numerical simulations showed that allelopathic effects of a toxic alga on a non-toxic but otherwise similar competitor did not have appreciable influence on the dynamics of the system. However, induction of avoidance of the toxic alga by predators, which resulted on increased predation pressure on other algal groups had a significant effect on the development of algal and predator populations. The presence of advection overrided the effect of these interactions and only allowed organisms with sufficiently high potential growth rates to thrive.     

Variability of snow and ice thermal, physical and optical properties pertinent to sea ice algae biomass during spring

Changes in the thermal, physical and optical properties of the snow–sea ice system and feedbacks between various temporal and spatial scales affect accumulation of microalgae at the sea ice bottom and are the focus of this research. During the spring transition period, May 4 to June 9, 2002, we closely monitored atmospheric conditions and properties of the snow–sea ice system, including thermal, physical and optical properties of the snow cover (e.g., temperature, grain size, light attenuation), ice thickness and salinity, and biomass of bottom ice algae. Results show that snowdrift size averaged 31.2 by 10.6 m with a depth range of 2 to 45 cm. Snowpacks also varied in age, distinguished by coincident peaks of snow salinity and grain size and a lower PAR extinction coefficient. Spatial variability of the snowpack was superimposed by temporal variability associated with seasonal snow–ice melt and wind redistribution of snow. Maximum biomass of ice algae was observed under intermediate snow covers. Under thin snow covers, algae biomass declined steadily coincident with seasonal warming and desalination of the ice cover. Under thick snow covers, algae biomass was negatively correlated with snow depth. These results suggest that thin snow covers were associated with a thermal effect causing sloughing of algae, whereas under deep snow, algae were still light limited and thermally insulated from the warming atmosphere. Our results highlight the importance of snow cover history on the sea ice system operating below. Furthermore, in the context of current climate change scenarios, shifts in snow depth would result in decreases of ice algae biomass.