Effects of Light Zenith Angle Variation on Spectral Responses of a Water Body’s Environmental Quality

The effect of light source zenith angle (θ_z) variation on the spectral reflectance measurement from sediment-laden water was studied in the laboratory using a spectroradiometer. Light source zenith angle in addition to sediment characteristics and concentration play a dominant role in affecting the reflectance characteristics of a suspension. With an increase in θ_z values, an increase in spectral reflectance is observed. The spectral reflectance characteristics of a water body also increase with the sediment concentration for all soil types and at all wavelengths. Empirical relationships between the spectral reflectance, suspended sediment concentration, and the light source zenith angle have been developed. Such a remote sensing technique for monitoring the concentration of the suspended sediment and their characteristics is a useful tool for economical estimation of a large water body’s quality related parameters vis-a-vis its environmental quality.Retd. Professor of Environmental Engineering & Pollution Control, Presently Residing at Makkhan Kutir, Bhargava Lane, Devpura, Haridwar-249401, India.Former Ph.D. student.     

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.     

不同碳源及光照对小球藻生长和产油脂的影响

考察了3种碳源(葡萄糖、NaHCO3和乙酸钠)在不同初始质量浓度和光照条件下对小球藻(Chlorella vulgaris)生长和产油脂的影响。采用OD680和生物量来评价小球藻的生长情况;以溶剂浸提法提取生物油脂,并以油脂质量分数和油脂产量来描述产油脂特性。结果表明,经过9 d的培养,3种碳源中葡萄糖是最佳有机碳源。由其培养的小球藻生长速率最快,由NaHCO3培养的小球藻的生长效果不如葡萄糖,而乙酸钠不利于小球藻的生长。随着光照的增强,小球藻光合效率提高,生物量逐渐提高,5 000 lx最利于小球藻的生长,而1 600 lx最利于小球藻油脂的积累。研究表明,光照5 000 lx下,初始质量浓度为15 g/L的葡萄糖作为碳源是小球藻适宜的生长和产油条件,获得了3.17 g/L的最大生物量和1.025 g/L的最大油脂产量。     

Quantifying the erosion of natural darkness in the global protected area system

The nighttime light environment of much of the earth has been transformed by the introduction of electric lighting. This impact continues to spread with growth in the human population and extent of urbanization. This has profound consequences for organismal physiology and behavior and affects abundances and distributions of species, community structure, and likely ecosystem functions and processes. Protected areas play key roles in buffering biodiversity from a wide range of anthropogenic pressures. We used a calibration of a global satellite data set of nighttime lights to determine how well they are fulfilling this role with regard to artificial nighttime lighting. Globally, areas that are protected tend to be darker at night than those that are not, and, with the exception of Europe, recent regional declines in the proportion of the area that is protected and remains dark have been small. However, much of these effects result from the major contribution to overall protected area coverage by the small proportion of individual protected areas that are very large. Thus, in Europe and North America high proportions of individual protected areas (>17%) have exhibited high levels of nighttime lighting in all recent years, and in several regions (Europe, Asia, South and Central America) high proportions of protected areas (32–42%) have had recent significant increases in nighttime lighting. Limiting and reversing the erosion of nighttime darkness in protected areas will require routine consideration of nighttime conditions when designating and establishing new protected areas; establishment of appropriate buffer zones around protected areas where lighting is prohibited; and landscape level reductions in artificial nighttime lighting, which is being called for in general to reduce energy use and economic costs.     

驾驶机舱LED灯光色温与人员警觉度关系仿真实验研究

为了探讨驾驶机舱内LED灯光色温与人员警觉度的联系,在A320模拟驾驶舱内设置2 500～2 700 K,3 000～3 200 K,6 000～6 500 K 3种不同色温的LED灯光环境,采用卡斯罗林嗜睡量表（KSS）、闪光融合临界频率仪（CFF）、视觉舒适度评分量表（VCS）,对5名被试人员在不同灯光环境的疲劳程度和视觉舒适度进行实时测量。针对测量结果,采用方差分析及描述性统计的数据分析方法,评价被试人员于不同灯光环境下的疲劳程度、视觉舒适度的差异性及变化情况。研究结果表明:高色温LED灯光环境下,人员的主观嗜睡感受及客观疲劳感受较低,且有着较低的疲劳感受增长率;高色温LED光源下人员的视觉舒适度也较高;增高LED灯光色温可一定程度上提升人员的警觉性。     

紫外-Fenton试剂的作用机理及在废水处理中的应用

本文研究了紫外光、铁离子对过氧化氢的催化分解作用.证实了紫外光和铁离子对过氧化氢的催化分解存在协同效应,并通过研究三价铁离子与紫外光的相互作用,探讨了协同效应产生的机理.UV-Fenton试剂对硝基苯、十二烷基苯磺酸钠(DBS)模拟废水的处理结果表明:将紫外光引入Fenton试剂可大大提高Fen-ton试剂的氧化性能,对生物难降解或难化学氧化的有机污染物具有良好的处理效果.     

附生假单胞菌存在下不同光照时间对铜绿微囊藻生长与磷代谢的影响

通过设置8/16、12/12、16/8不同光暗比,分析了附生细菌存在下不同光照时间对铜绿微囊藻(M icrocystis aeruginosa)生长及其与附生假单胞菌(Pseudom onassp.)磷代谢之间关系的影响。结果表明:光照时间越长,铜绿微囊藻生长越快,16 h光照下的比增长速率为8 h光照下的1.6倍。铜绿微囊藻的快速生长促进了附生细菌中磷的释放;藻细胞增殖越快,附生细菌释放的磷越多。铜绿微囊藻对数生长期末,8、12、16 h光照下附生细菌磷含量分别降至对数生长初期的87.8%、78.6%和64.9%。铜绿微囊藻对附生细菌磷释放的促进作用是由藻细胞生长对磷的消耗再吸收导致的。     

可见光下氮掺杂二氧化钛对巯基苯并噻唑的降解

光降解反应中为了有效地利用可见光,以氨水为氮源,采用溶胶凝胶法在温和条件下制备出黄色氮掺杂二氧化钛。分别采用XRD、TEM、XPS和UV-Vis漫反射光谱对样品进行了表征。结果表明,所制备的样品均为锐钛矿相,晶粒随N/Ti配比的增加而增大;氮掺杂进入二氧化钛晶格中使可见光吸收增强。为控制水处理过程中的气味问题,以巯基苯并噻唑为探针,考察了氮掺杂二氧化钛的可见光活性。结果显示氮掺杂二氧化钛在可见光照射下可使巯基苯并噻唑的降解率为商用二氧化钛DegussaP-25的3倍。此外,存在一个最佳N/Ti配比显示出最高的可见光活性。