城市排水系统在水污染防治中的作用

本文介绍了城市排水系统的组成、分类和功能,通过介绍目前国内外城市的排水体制,对比了合流制和分流制的优缺点,并重点对雨污分流排水系统存在的问题、改造措施以及雨污分流效益分析进行了详细的介绍,最后指出城市排水系统在水污染防治中的作用和发展前景。     

老窿残矿开采技术及安全管理措施

在调查、分析龙山金锑矿老窿残矿赋存特征和开采技术条件的基础上,结合矿山生产实际,采用脉外平巷加穿脉群开采技术,并对现场施工提出具体的安全措施和要求,确保安全、高效地回收老窿残矿.采矿试验研究证明:该项技术采矿效率高、回采作业安全性好、经济效益显著.可供类似矿山借鉴.     

Laser cleaning of historical limestone buildings in Bordeaux appraisal using cathodoluminescence and electron paramagnetic resonance

BACKGROUND: Most historical buildings in Bordeaux city are made of limestone. This yellowish-white rock is rather porous and highly sensitive to pollution. As a consequence of local weathering conditions, these buildings present a dark appearance due to the development of a superficial dark grey to black crust. METHODS: For the last decade, a campaign has been underway to clean these buildings. Eleven techniques of surface treatment have been used, including laser beam technology. As a contribution to the study of laser beam effects on stone buildings, two analytical methods have been used on clean versus unclean surfaces: Cathodoluminescence (CL) and Electron Paramagnetic Resonance (EPR), in addition to SEM-EDX and XRD. RESULTS: The black crust is composed of different types of particles: carbon porous micro-particles of industrial origin, atmospheric dust due to the erosion of soils and rocks, alumino-silicate particles from urban pollution; all these particles being cemented by gypsum. DISCUSSION: As far as heritage conservation is concerned, the laser surface treatment not only preserves the original patina of the stone, but also leaves surface smoothness unaltered. CONCLUSIONS AND PERSPECTIVES: CL and EPR data confirm that lasers--with highly controlled parameters--only get rid of the black crust and, thus, reveal the underneath layer, the so-called patina. This patina shows no luminescence, whereas the limestone on which it has grown shows a bright orange emission of CL. This indicates CL to be a fast and easy way to provide a high quality control for the restoration of polluted ancient stones.     

特殊工况下船舶生活污水处理的试验研究

采用厌氧复合床反应器与接触氧化、接触沉淀相结合的工艺,针对实船条件下可能出现的重启动、倾斜、海水及淡水海水交替冲洗厕所和水力负荷增加等情况,进行了特殊工况下船舶生活污水处理的试验研究.结果表明,该组合工艺在设计条件下(HRT为5 h)重启动速度较快,可用于海水冲厕所产生的高盐度污水处理,耐受淡水海水交替变化的盐度冲击负荷变化能力较强,具有一定的水力负荷增加潜力,并且不受倾斜影响.     

应用钙法除磷-碱解-微电解组合工艺预处理吡虫啉农药废水

根据吡虫啉农药废水成分复杂,含有大量有毒有害物质的特点,在小试实验研究的基础上,确定了预处理的组合工艺流程为：钙法除磷-碱解-催化微电解。实验结果表明,预处理的适宜参数为：钙法除磷的pH值11,搅拌速度为100 r/min,钙的投加量为理论计算值的1.4倍;碱解反应的温度70℃,pH值11,反应时间2 h;催化微电解反应的pH值3～4,曝气时间3 h,催化剂与铸铁屑的质量比1∶5。组合工艺对COD、色度、磷的总去除率分别达到81%、90%和99.99%,废水的可生化性能得到很大改善。组合工艺不仅适用于预处理高浓度吡虫啉农药废水,也能为其他高浓度、难生物降解农药废水的治理提供有益的参考。     

Interaction of DNA with aromatic hydrocarbons fraction in atmospheric particulates of Xigu District of Lanzhou, China

Voluminously epidemiological studies show that the relationships exist between the air pollution and human health and cancer. Aromatic hydrocarbons(AHs)in air form a large class of organic pollutants,which are widely in environment and many of them are known to be carcinogenic and/or mutagenic and contribute to ambient air pollution.In the past decades,bioassays mainly have been used to evaluate the toxicity of chemical mixtures in atmospheric particulates or aqueous environment.However,it is well known that the covalent complexes formed by carcinogens with DNA may be exert negative results in bioassay.So the main aim of this paper is to develop an evaluation method of toxicity effects of chemical mixtures in atmospheric particulates from chemical standpoint.In this study,the in vitro interaction of the AHs with DNA was investigated by absorption,fluorescence and resonance light scattering (RLS)spectroscopic techniques.The results showed that the AHs in the atmospheric particulates could combine with calf thymus DNA(ctDNA)and herring sperm DNA(hsDNA)without being activated or metabolized by organism,respectively.Intercalation may be present in the mechanism of interaction.The binding constants of the AHs with ctDNA and hsDNA were 2.5×10~2 and 2.0×10~3, respectively,which indicated that the interaction of the AHs with hsDNA is stronger than that with ctDNA.In addition,the relationships of dose-effect between the total mole concentration of chemical components and the ability of binding ctDNA and hsDNA were confirmed.This research made it possible to study the toxicity effects of chemical mixtures in atmospheric particulates by chemical method.It is believed that the composition and contents of unknown AHs and the interaction of DNA with AHs in atmospheric particulates of Xigu District of Lanzhou City,China are first reported in the past twenty years.     

硝基苯在傍河地下水源地迁移转化的模拟实验

以黑龙江省佳木斯市傍河地下水源地为主要模拟对象，进行了硝基苯迁移转化的室内模拟实验。结果表明：吸附与生物降解作用是影响硝基苯在含水屡中迁移转化的主要因素。淤泥介质对硝基苯的除去能力较高，砂砾介质对硝基苯的除去能力相对较弱。实验过程中，从进水口至出水口的各取样点依次出现硝基苯浓度峰值，并且随着硝基苯迁移路径的延长其浓度峰值相应变小。硝基苯的浓度峰值在含水介质中的持续时间并不很长，但由于硝基苯解吸附作用的存在，在此后相当长的一段时间里都存在较为明显的拖尾现象。     

带坞舱船舶尾舱消浪装置消浪性能研究

目的 带坞舱船舶尾部具有与外界连通的自由液面,由于船舶运动会在坞舱内产生波浪,形成有害的波浪砰击,影响舱内装备的正常作业。针对这一问题,系统地对带坞舱船舶尾舱内的消浪方案进行模拟与优化,提出一套具有良好消浪性能的消浪装置方案。方法 以荷兰皇家海军两栖运输船为目标进行三维建模,使用CFD方法对其进行不同波浪下船舶响应模拟和分析,监测船舶的运动响应和舱内多个监测点的波高情况,使用多孔挡板为基础,给出一套消浪装置,并进行带有消浪装置方案的船舶响应模拟,评估该消浪装置方案的消浪性能。结果 对舱内首端和侧壁布置多孔板消浪装置,消浪效果可达40%~50%,验证了该消浪装置的可行性。结论 采用多孔介质区域模型对带有多孔介质消浪装置的整船进行数值模拟,在计算效率远高于对实际物理模型建模的同时,可以得到较好的消浪效果。