菌藻复合体系氮代谢性能及菌群特征

为了城市尾水深度脱氮,控制地表水体富营养化,利用分子生物学等方法,分别对脱氮复合菌群和藻菌共生系统的氮代谢性能进行研究.结果表明,氮代谢复合菌群具有较高氨化和反硝化性能.JZ组对城市尾水中氨氮的去除效果最好,降解率高达95%以上,在实验室模拟污水中JZ组系统总氮去除效果优于J组.高通量测序显示,J组主要优势菌群及占比分别为：厚壁菌门44.53%,变形菌门43.41%,放线菌门5.37%,类杆菌门3.04%,绿弯菌门1.35%;JZ组丰度主要优势菌群和占比分别为：蓝藻门33.89%,绿弯菌门25.34%,变形菌门19.38%,厚壁菌门10.02%,酸杆菌门4.20%;各优势物种在J组和JZ组比例不同,厚壁菌门分别为82%和18%,变形菌门为69%和31%,蓝藻门为1%和99%,绿弯菌门为5.1%和95%,放线菌门分别为73%和27%.表明JZ组在城市尾水中去除氨氮效果较好,J组氮代谢菌群随着微球藻加入和生长,JZ组氮代谢菌群构成随之发生变化,以适应优势藻类形成的环境,与微球藻构成新的菌藻氮代谢体系.研究结果为藻菌共代谢体系应用提供了理论和数据基础.     

外源稀土La在沉积物中的形态及其生物可利用性

将沉积物中的外源稀土La分为可溶解态、酸可提取态、有机质及硫化物结合态,研究了小球藻(Chlorella Vulgaris Beijerinck)对这三种形态La的生物可利用性.研究结果表明:这三种形态的La在沉积物中的含量与其在藻中的含量有很好的相关关系.其中可溶解态La的生物可利用性最大,这说明,沉积物中La的释放对其生物可利用性至关重要.     

Changes in the Biochemical Composition of Tetraselmis Suecia and Isochrysis Galbana During Growth and Decay

The variations of the biochemical composition of Tetraselmis suecica and Isochrysis galbana during growth and decay were determined. the content of chlorophyll a (Chl-a) of the cultures, as expected, slowly degraded into phaeopigments during decay, confirming that chlorophyll measurements do not always provide an accurate estimate of phytoplanktonic biomass and, consequently, may fail if used to measure the food availability of particulate matter for consumers. Measurements of total amounts of proteins, carbohydrates and lipids, related to the nutritional value of particles in terms of caloric content, are shown to provide information on the readily available food for consumers, particularly during the blooms. the protein/carbohydrate, C/N and POC/Chl-a ratios were used to evaluate the differences between these two species during the growth and the decomposition processes. A comparison between experimental and field conditions was undertaken to implement our understanding of the growth and degradation processes of particulate organic matter of phytoplanktonic origin in the sea and its role on natural systems, during and after phytoplankton blooms.     

Ecotoxic Effect of Photocatalytic Active Nanoparticles (TiO2) on Algae and Daphnids (8 pp)

Background, Aim and Scope Due to their large potential for manifold applications, the use of nanoparticles is of increasing importance. As large amounts of nanoparticles may reach the environment voluntarily or by accident, attention should be paid on the potential impacts on the environment. First studies on potential environmental effects of photocatalytic TiO2 nanoparticles have been performed on the basis of widely accepted, standardized test systems which originally had been developed for the characterization of chemicals. The methods were adapted to the special requirements of testing photocatalytic nanoparticles. Materials and Methods: Suspensions of two different nanoparticles were illuminated to induce their photocatalytic activity. For testing, the growth inhibition test with the green alga Desmodesmus subspicatus and the immobilization test with the daphnid Daphnia magna were selected and performed following the relevant guidelines (algae: ISO 8692, OECD 201, DIN 38412-33; daphnids: ISO 6341, OECD 202, DIN 38412-30). The guidelines were adapted to meet the special requirements for testing photocatalytic nanoparticles. Results: The results indicate that it is principally possible to determine the ecotoxicity of nanoparticles. It was shown that nanoparticles may have ecotoxicological effects which depend on the nature of the particles. Both products tested differ in their toxicity. Product 1 shows a clear concentration-effect curve in the test with algae (EC50: 44 mg/L). It could be proven that the observed toxicity was not caused by accompanying contaminants, since the toxic effect was comparable for the cleaned and the commercially available product. For product 2, no toxic effects were determined (maximum concentration: 50 mg/L). In the tests with daphnids, toxicity was observed for both products, although the concentration effect-curves were less pronounced. The two products differed in their toxicity; moreover, there was a difference in the toxicity of illuminated and non-illuminated products. Discussion: Both products differ in size and crystalline form, so that these parameters are assumed to contribute to the different toxicities. The concentration-effect curves for daphnids, which are less-pronounced than the curves obtained for algae, may be due to the different test organisms and/or the differing test designs. The increased toxicity of pre-illuminated particles in the tests with daphnids demonstrates that the photocatalytic activity of nanoparticles lasts for a period of time. Conclusions: The following conclusions can be drawn from the test results: (I) It is principally possible to determine the ecotoxicity of (photocatalytic) nanoparticles. Therefore, they can be assessed using methods comparable to the procedures applied for assessing soluble chemicals. - (II) Nanoparticles may exert ecotoxicological effects, which depend on the specific nanoparticle. - (III) Comparable to traditional chemicals, the ecotoxicity depends on the test organisms and their physiology. - (IV) The photocatalytic activity of nanoparticles lasts for a relevant period of time. Therefore, pre-illumination may be sufficient to detect a photocatalytic activity even by using test organisms which are not suitable for application in the pre-illumination-phase. Recommendations and Perspectives: First results are presented which indicate that the topic 'ecotoxicity and environmental effects of nanoparticles' should not be neglected. In testing photocatalytic nanoparticles, there are still many topics that need clarification or improvement, such as the cause for an observed toxicity, the improvement of the test design, the elaboration of a test battery and an assessment strategy. On the basis of optimized test systems, it will be possible to test nanoparticles systematically. If a potential risk by specific photocatalytic particles is known, a risk-benefit analysis can be performed and, if required, risk reducing measures can be taken.     

磷酸铵盐亚纳米粉体灭火性能实验研究

使用溶剂-非溶剂法制备了粒径达到亚纳米量级（300nm-500mm）的磷酸铵盐灭火剂,建立了1．2m×1．2m×1．2m的小尺度灭火实验平台,开展了灭油池火和木垛火的全淹没灭火实验,对磷酸铵盐亚纳米粉体的灭火性能进行了研究,并与普通磷酸铵盐粉体的灭火性能进行了比较。实验结果显示磷酸铵盐亚纳米粉体的灭火性能要明显高于普通粉体,并且在低压下就可以获得很好的灭火果。工作压力的增加会缩短粉体的灭火时间,但是对于磷酸铵盐亚纳米粉体灭木垛火的情况,由于灭火时间相差示大,反而会导致灭火剂用量增加。     

滇池水体除藻材料的除藻作用试验研究

利用昆明地区的粘土矿制作新型轻质除藻材料,试验研究该材料对滇池湖水中藻类的除藻及净化作用.实验室小试(20 L)结果表明,该除藻材料放入滇池水样实验70 d后,水质明显好转,藻类去除率可达95.8%,CODMn、TN及TP的去除率分别为34.4%、81.5%、28.2%.在滇池湖边300 m2水面围栏扩大试验结果显示,除藻材料放入试验区水体10 d后,水体中藻类含量明显减少,水体透光率从55%增加到80%,水质状况也有很大改善.研究结果表明,该材料具有良好的湖泊水体除藻及净化作用,有必要对其开展进一步的深入研究.     

载铁改性沸石粉体抑制甲烷/空气扩散火焰试验研究

为发展洁净高效新型粉体灭火介质,以沸石粉体为基体,采用盐酸活化和氯化铁溶液浸泡方法制备载铁改性沸石粉体灭火剂。采用X-射线衍射仪(XRD)、扫描电镜(SEM)和X-射线荧光光谱仪(XRF)等仪器对该粉体灭火剂的结构和形貌进行表征。通过小尺度的杯式燃烧器试验研究载铁沸石粉体对甲烷/空气扩散火焰的灭火效果,并和未改性沸石粉体进行对比。试验结果表明,载铁改性沸石粉体灭火剂的灭火效能明显高于未改性沸石粉体。改性沸石灭火效能提高,主要是由于所负载的铁离子在火焰中转化为活性铁原子,参与清除火焰自由基的催化反应。     

气-固复合粉体在高原地区灭火性能的试验研究

为满足高原地区低压低氧环境对火灾防治的特殊需求,在拉萨进行模拟试验,研究由溴氟丙烯和13X沸石所组成的气-固复合粉体灭火剂对汽油火的灭火性能,并与平原地区的合肥的灭火效果进行对比。试验结果表明,在拉萨低压低氧的环境下,复合粉体灭火剂对汽油火具有很好的灭火性能。在同样的试验条件下,其灭火时间和灭火剂用量比合肥减少20%以上,说明该复合粉体灭火剂在高原地区有很好的适用性。     

4种营养元素对水华鱼腥藻和四尾栅藻增殖的影响

以水华鱼腥藻和四尾栅藻分别作为蓝藻,绿藻代表藻种,采用均匀设计实验方法(uniform design experimentation,UDE)设计藻类AGP实验。采用通径分析法(Path Analysis,PA)对氮、磷、铁和锰在不同藻种增殖过程中的影响程度进行分析。结果表明,4种营养元素对水华鱼腥藻增殖影响的决策排序为FeTNTPMn,微量金属元素铁是影响水华鱼腥藻(蓝藻)增殖的主要因素;对四尾栅藻增殖影响的决策排序为TNTPFeMn,常量元素是影响四尾栅藻(绿藻)增殖的主要因素。联合通径分析法和逐步二次方回归分析法(QRA)建立的数学模型,可用于预判藻增殖。     

基于环境卫星CCD数据的黄海浒苔遥感监测

2007年以来,黄海海域每年夏季都发生大面积浒苔绿藻潮,影响沿岸人民的生活、生产。考虑到其分布范围动则几千、上万平方公里,水面监测很难实施,尝试利用遥感技术对其分布和发展变化情况进行监测。基于中国自主产权的环境卫星(HJ1)数据,采用经典植被指数算法和人工辅助判读方法,对2013年黄海浒苔暴发全过程进行了连续遥感监测,分析了此次浒苔过程的分布和漂移路线。监测结果表明,浒苔绿藻潮首发于江苏盐城东部海域,由南向北逐渐漂移,面积逐渐扩大,结束于青岛东北部海域;该期间,浒苔最大覆盖面积达663.54平方公里。