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911.
采用共沉淀水热合成和离子交换的方法,制备了钛与铜离子共掺杂的羟基磷灰石(Ca10(PO4)6(OH)2:HAP)(HAPTiCu),以大肠杆菌为目标物,研究了不同材料负载的多孔镍网薄膜在弱紫外光下的杀菌活性.结果表明,HAPTiCu在弱紫外光下具有高效杀菌效率,并远远高于HAPTi和P25 TiO2薄膜.这主要是铜离子的抗菌与光催化分解细菌的协同作用的结果.电子自旋共振(ESR)研究表明杀菌反应的主要活性物种是O2-.HAPTiCu薄膜释放的铜离子在光催化杀菌反应过程中,被光催化还原沉积在表面,导致了较低的铜离子溶出,从而保证了材料的稳定性. 相似文献
912.
灰色系统模型在总悬浮物预测中的应用 总被引:1,自引:0,他引:1
以1986-1994年东北某城市总悬浮物统计资料为依据,应用灰色系统理论GM(1,1)模型对总量浮物数值进行预测分析。 相似文献
913.
Effect of temperature on single and competitive adsorptions of Cu(II) and Zn(II) onto natural clays 总被引:2,自引:0,他引:2
This study conducted a combined adsorption-sequential extractionanalysis (CASA), by which five phases (i.e., exchangeable, carbonate, Mn-Oxide, organic, and Fe-Oxide phases) of adsorbed heavy metals were analyzed, to investigate temperature effects on single and competitive adsorptions of Zn(II) and Cu(II) ontonatural clays. In the case of single adsorption of Zn, the exchangeable phase adsorption decreased from 65 to 40%, but thecarbonate phase adsorption increased from 30 to 40%, with an increase in temperature from 15 to 55 °C. However, in itscompetitive adsorption with Cu, Zn was mostly present in the exchangeable phase (over 90%), and with an increase in temperature, the exchangeable phase adsorption decreased only 10%. In the case of Cu, over 50% among the total amount of adsorption was present in the carbonate phase in both cases ofsingle and competitive adsorptions. The carbonate phaseadsorption of Cu increased from 56 to 61% and from 60 to 66% in single and competitive adsorptions, respectively, with atemperature increase. These results show that in the case of Zn,the major mechanism of retention in natural clay soils might beexchangeable phase adsorption, especially in the case of competitive adsorption with Cu. However, in the case of Cu, the major mechanism might be carbonate phase adsorption, which is known to be a more immobile phase than exchangeable phase adsorption. It seems that the adsorption of Zn and Cu onto natural clays is an endothermic reaction, which represents thatthe adsorption equilibrium constants and capacities increase with a temperature increase, with the exception of exchangeablephase adsorption. 相似文献
914.
915.
Kostanjsek R Lapanje A Drobne D Perović S Perović A Zidar P Strus J Hollert H Karaman G 《Environmental science and pollution research international》2005,12(6):361-368
- Goal, Scope, Background. Lake Skadar is the largest lake in Balkan Peninsula, located on the Montenegro-Albanian border. The
unique features of the lake and wide range of endemic and rare or endangered plant and animal species resulted in the classification
of the Skadar as a wetland site of international significance. In spite of its importance the Lake is influenced by inflowing
waters from river Morača and other regional rivers contaminated by the industry, municipal and agricultural activities in
the area. Therefore, the Lake has been subject of various physical, chemical, biological and toxicological examinations. However,
community-level analyses are most relevant to assess the effect of stressors on aquatic ecosystems. In the present study bacterial
community structure among differently polluted sites of the lake was compared by genetic fingerprinting technique.
Methods Water and sediment samples were collected from five differently polluted sampling sites on the Lake Skadar in spring and
autumn of the same year. The bacterial community structure in the samples was characterized and compared by temporal temperature
gel electrophoresis (TTGE) analysis of polymerase chain reaction-amplified bacterial 16S rRNA genes.
Results and Discussion The TTGE analysis resulted in many distinguishable and reproducible band patterns, allowing reliable comparison of bacterial
communities among sampling sites. Results on the bacterial community structure revealed that three of the selected locations
can be considered as sites that have not shown any pollution degradation determined by our method, due to similar structure
of bacterial community in the sediment samples. On the other hand, significant shifts in bacterial community structure in
the mouth of the river Morača and Plavnica were shown. Since the results coincide with some of the bioassays and chemical
analysis performed previously, the changes in bacterial community structure are explained as an effect of antropogenic pollution
on the lake ecosystem by waters of river Morača and stream Plavnica.
Conclusion The TTGE has proven to be an efficient and reliable method to monitor bacterial dynamics and community shifts in aquatic
environment, especially in the sediments. Within the variety of environmental quality assessments the use of TTGE analyses
of bacterial community is strongly recommended, particularly as an initial investigation. However, in any conclusion on the
state of the environment, the TTGE results should be combined to some other biological, chemical and hydrological data.
Recommendation and Outlook Since prokaryotes are a crucial group of organisms in the biosphere, the ecosystem function studies are largely based on
bacterial communities. Therefore, bacterial community structure analysis should be a part of an integrated weight of evidence
approach in pollution assessment. In case of Triad approach, consisting of chemical analyses, bioassays, and community studies
in the field, the TTGE bacterial community structure analyses should be placed in the later Triad leg. In comparison to other
community studies, based on various biotic indices, the TTGE bacterial community analysis has proven to be very sensitive,
reliable and less time consuming. 相似文献
916.
四平市二龙湖底泥磷释放研究 总被引:6,自引:0,他引:6
采用室内实验模拟法对四平市二龙湖富营养化限制因子磷的底泥释放速率及释放量进行了研究,并研究在种环境因子(温度、pH、DO和扰动因素)影响下底泥磷的释放规律。结果表明,(1)二龙湖年平均底泥释磷量为208·78g,最大释磷率为0·889μg/g(T=20℃,pH=8,DO为4·68mg/L);(2)自然和人为的扰动因素会促进底泥的磷释放;(3)H在弱酸至中性范围内底泥释磷量最小,酸性和碱性条件都有利于磷的释放;(4)随着温度的升高底泥释磷量增大;(5)厌条件比好氧条件更有利于磷的释放。 相似文献
917.
对2005年7月至2006年2月采集到的南京市气溶胶Pm2.5 进行季节性初步分析,并对其中的15种优控多环芳烃(PAHs)进行分析研究,通过比值法判断南京市PAHs夏季主要来源于柴油型燃烧,冬季主要来源于柴油和煤型相结合的燃烧.对15种优控PAHs两两之间的相关性分析,发现各化合物之间显著相关,表明各化合物的来源有相似之处. 相似文献
918.
采用颗粒动态分析仪(PDA)对倒伞形表面曝气机曝气的Carrousel小试氧化沟进行测试,得出了氧化沟内较系统的流动特性参数.比较了固液两相在氧化沟内流动的差别,发现固液两相流动速度差别较小,由于惯性的影响,固相的沉降速度略大于液相.考察了表曝机的转速、表曝机相对于液面的位置、氧化沟的深度等因素对氧化沟内流动的影响,随着表曝机转速的增大和表曝机浸入液面深度的增加,流动速度和沉降速度均会增大,而氧化沟深度增加时,距离液面同一深度处的速度则会减小.实验结果与污水处理厂的实际情形进行比较发现,二者变化趋势一致,说明本实验结果可用于指导工程实际,为氧化沟的优化设计提供依据. 相似文献
919.
用超细玻璃纤维滤膜采集杭州市某道路上机动车排放的苯并(a)芘,经超声萃取,高速离心后直接进HPLC分析。在选定的色谱条件下,苯并(a)芘与其他多环芳烃完全分离,绝对进样量在0.8~0.02 ng时线性良好,相关系数为0.99979,最小检出量0.8 pg,加标回收率87.5%~93.8%。 相似文献
920.