利用发光细菌测试方法评价菲和芘生物降解过程的毒性变化

将发光细菌毒性测试方法应用于典型多环芳烃生物降解过程的毒性评价,研究了菲和芘单独及混合状态下生物降解过程中的毒性变化。结果表明:溶解态的菲和芘在一定浓度范围内对发光细菌均具有毒性,菲和芘对发光细菌的10 min-EC50值分别为1.61×10-5mol·L-1和2.31×10-6mol·L-1。单组分和混合组分的菲和芘经过微生物降解后,其毒性显著降低。混合组分生物降解体系中由于菲和芘分子之间的互相作用,使其对发光细菌的毒性效应与其单独存在时有差异。生物降解的各阶段,混合组分降解体系的毒性均大于单组分菲或芘降解体系的毒性,且在降解完全的后期,培养液的毒性有增加的趋势。这与菲和芘降解中间产物的积累变化有关。     

马尔科夫链模型在铁路春运客流预测中的应用

预测春运客流量是铁路部分的一项重要工作。运用马尔科夫链模型对春运期间一天中的客流量进行预测。首先,介绍了马尔科夫链模型及其预测的基本原理;其次,分析北京西站2007年春运期间每天的客流量,并按照北京西站突发事件三级预警方案将客流量数据处理为三个状态;最后,运用马尔科夫链模型对2007年的春运客流进行预测,结果表明,运用马尔科夫链模型具有良好的预测结果。     

高浓度洗毛废水的生物絮凝处理工艺研究

研究了生物絮凝剂代替化学絮凝剂处理高浓度洗毛废水的絮凝效果 ,试验结果表明 ,微生物絮凝剂的絮凝效果优于化学絮凝剂 ,可以使洗毛废水的COD的去除率达到 85 %。SS去除率达到 88% ,水的颜色由灰黑色变成红褐色液体 ,更为重要的是微生物絮凝剂无二次污染。     

Temporal variations of atmospheric carbonyls in urban ambient air and street canyons of a Mountainous city in Southwest China

Carbonyl compounds in urban ambient air and street canyons were measured from December 2008 to August 2009 in a mountainous city in southwest China (Guiyang). The formaldehyde yield from the photo-oxidation of isoprene emitted by vegetation was estimated to be in the range of 0.63–3.62 μg m^?3 from May to August, which accounted for 28.8–33.4% of ambient formaldehyde. Based on the calculation of photolysis rates and rates of reaction with the OH radical, it was found that photolysis was the predominant sink for formaldehyde and acetone in both summer and winter. For acetaldehyde, photo-oxidation by OH radicals and photolysis were the major sinks in summer while photo-oxidation by OH radicals was the dominant sink in winter. Wet precipitation was found to be an important removal process for the atmospheric carbonyls. In the urban ambient air, the average concentrations of formaldehyde, acetaldehyde, acetone and all carbonyls were 4.8 ± 2.1, 5.7 ± 3.3, 5.1 ± 2.5, and 25.1 ± 9.2 μg m^?3 (n = 139), respectively. The average concentrations of these species in street canyons were 18.8 ± 6.5, 9.4 ± 3.2, 10.9 ± 2.1, and 64.1 ± 16.3 μg m^?3 (n = 62), respectively. The significantly higher carbonyl levels on weekdays (compared to weekends) highlight the contribution of vehicle emissions to carbonyls in the street canyons.     

曝气生态浮床-渗透性反应墙组合工艺水质净化特性研究

通过中试研究,考察了EAFB-PRB组合工艺的动态水质净化特性。结果表明,在3种对比实验工况条件下,组合工艺在HRT为4.2 d时比较适宜,此时TN、TP和COD的平均去除率分别为42.15%、90.48%和61.71%;组合工艺对COD、TP的去除主要发生在浮床区,而PRB区是脱氮的主要单元,组合工艺弥补了单项技术的不足,提高了对污水水质的净化效果。     

曝气充氧和人工造流技术修复河道污染水体

基于模拟河道反应器,考察了曝气充氧及人工造流技术对污染水体的修复效果。结果表明,河道本身具有一定的自净能力,自然运行条件下对COD、TP、NH₃-N和TN的去除率分别为7.44%、4.88%、5.70%和10.60%。通过对模拟河道进行曝气充氧,最佳气水比条件下对COD、TP、NH₃-N和TN的去除率分别为15.33%、10.45%、6.78%和21.18%。在曝气基础上通过设置人工阻流板,对COD、TP、NH₃-N和TN的去除率分别为26.82%、16.07%、9.51%和23.80%。结果初步显示,通过曝气充氧和人工造流技术的集成应用研究,对污染水体具有明显有效的修复作用。     

污泥减量化技术研究进展

针对当前日益突出的污泥处理处置难等问题,分别从物理法、化学法和生物法等方面阐述了当前污泥减量化技术的研究发展现状,介绍了各种工艺的基本原理、特点和存在的问题.结合国内外污泥减量化技术的研究进展,提出了未来污泥减量化技术的发展方向.     

浅谈废弃电路板的回收及资源化利用

介绍了印刷电路板(PCB)的组成及其中的重金属对环境的危害.比较了几种废弃电路板回收处理方法,着重分析了最为常用的机械处理法及其设备和分选技术,并论述了实现我国废弃电路板资源化的途径.     

Evaluation of spatiotemporal differences in suspended sediment concentration derived from remote sensing and numerical simulation for coastal waters

Remote sensing and numerical models are often used to monitor the suspended sediment concentration (SSC) in coastal waters; however, the derived SSC varies between the two methods in both space and time. In this study, a method was proposed to assess the spatiotemporal differences in SSC derived from Moderate Resolution Imaging Spectroradiometer (MODIS) images and numerical simulation for coastal waters, using the Bohai Sea in China as an example. An empirical model for SSC retrieval from remote sensed images was initially established. A comparison of the temporal synchronicity over a single day period was performed between the observed data and the numerically simulated results. The range in the SSC at different observation sites was significantly different. Both the SSC values and their daily variation ranges were larger near the estuary of the Yellow River compared with the open area due to the concurrence of tidal flow and the introduction of fresh river water with high turbidity near the estuary. The areas that exhibited spatial differences were defined according to their differences in remotely sensed and numerically simulated SSC distribution patterns. Finally, the reasons for these spatiotemporal differences were discussed. The results provided understanding into the spatiotemporal differences that were introduced when multi-source data were used, thus improving the accuracy of the results when monitoring coastal environments for the management of coastal conservation.     

水工保护在管道建设中的实践

在管道工程建设中,管道通常在河、沟道地段,田坎、地坎穿越地段,顺坡、横坡敷设地段,山地、冲积平原以及水网地区等地段频繁遭受危害。山东天然气管网的水工保护设计遵循"预防为主、防治结合"的原则,采取合理的综合整治方案和有效的工程措施,结合管道的敷设方式,对沿线地形、地质、地貌、水文、水利、气象等条件进行综合考虑,并符合相关河道、航道管理条例及相关防洪标准。