谈二级泵冷冻水系统的常见问题

二级泵冷冻水系统在很多高层建筑中央空调系统中得到应用,但实际运行中却经常出现能耗过高的问题。结合某空调技改工程实例,在实测与分析的基础上,深入探讨了典型二级泵冷冻水系统的整体特性和易设计出现的问题:主要包括部分负荷下一次泵与二次泵的额定流量不匹配,引起水泵偏离高效区的问题;二次泵扬程选择过高造成的"混水"效应;末端是通断控制风机盘管的系统,二级泵恒压差控制造成的"大流量小温差"问题等,从而为该类系统的设计和运行管理提供一定的参考。     

居住区水景设计

水景设计对小区整体环境的提升影响重大。文章首先从居住区水景设计的现状入手，针对当前存在的一些误区，提出相应的解决对策。在此基础上介绍了水景设计的一些原则、水景与绿化的搭配、水景相关配套设施建设，以及对今后住区水环境建设的几点思考与展望。     

Chemometrics in monitoring spatial and temporal variations in drinking water quality

This case study reports multivariate techniques applied for the evaluation of temporal/spatial variations and interpretation of monitoring data obtained by the determination of chloro/bromo disinfection by-products in drinking water at 12 locations in the Gdańsk area (Poland), over the period 1993-2000. The complex data matrix (1756 observations) was treated with various multivariate techniques. Cluster analysis (CA) was successful, yielding two different groups of similarity reflecting different types of drinking water supplied (surface and groundwater). The locations supplied in general with groundwater could be further classified into two subgroups, depending on whether the groundwater was mixed with surface water or not. Analysis of variance (ANOVA) was used to classify and thus confirm the groups found by means of cluster analysis and proved the existence of statistically significant differences between the concentration levels of CHCl3, CHBrCl2+C2HCl3, CHBr2Cl, and CH2Cl2 in the samples collected. Of all the variables evaluated, only three were characterized by statistically significant correlations (CHCl3, CHBrCl2+C2HCl3, CHBr2Cl). The analysis of correlation coefficients revealed that chloroform formed as the main chlorinated disinfection by-product and, furthermore, the natural presence of bromide in water (both ground and surface) results in the formation of brominated disinfection by-products (DBPs). Temporal variations of volatile organic chlorinated compounds (VOCls) were also evaluated by multidimensional ANOVA. Observation of temporal changes in the concentration of VOCls at the location supplied with both surface and groundwater reveals a steady improvement in drinking water quality. In general, the study shows the importance of drinking water monitoring in connection with simple but powerful statistical tools to better understand spatial and temporal variations in water quality.     

防水混凝土的结构设计与配合比设计探讨

阐述了防水混凝土设计考虑的重点应是避免混凝土开裂的观点,并重点从造成混凝土开裂的原因入手,从防水混凝土结构设计和配合比设计的角度,探讨了避免和减少混凝土开裂渗漏的措施.即结构设计人员应对防水混凝土不同部位的配筋布置作出相应的调整,在满足荷载的前提下,尽量多使用较细而分布较密的钢筋,并应对混凝土的膨胀率作出要求;而配合比设计人员应选择合理的水泥、掺合料、膨胀剂,配制满足膨胀率要求、施工性能良好的混凝土,满足抗裂防水工程的需要.     

高浓度制药与染料混合废水处理一例

结合某公司制药、染料混合废水处理工程概况，从废水特性、工艺及其流程等方面，详细阐述了处理废水的过程，在调试期运行效果良好，并总结了几点废水处理经验。     

MBR在建筑中水的应用

针对在水资源日益紧张的今天,中水回用已经提上日程的现状,通过对膜生物反应器（MBR）技术的去除效果和膜污染的论述,以及对MBR在中水回用中的经济分析,指出MBR作为污水回用技术将会愈来愈具有经济、技术上的竞争优势。     

水解-好氧工艺在氯丁橡胶废水处理中的应用

结合工程实例，介绍了水解酸化——好氧工艺在处理氯丁橡胶废水中的应用，经实际运行证明，PH等五项主要污染物实现达标排放，COD基本接近排放标准，为橡胶工业废水处理提供了有益的参考和借鉴。     

生物接触氧化/气浮、生物滤地/沉淀处理地表水比较

为筛选出合适的滴水湖补充水的处理工艺,开展了"生物接触氧化+气浮"(工艺1)和"生物滤池+沉淀"(工艺2)两种组合工艺处理地表源水的中试研究(规模为20 m3/h).结果表明,生物接触氧化池对藻类、叶绿素a和氨氮的去除效果比生物滤池好,但二者对浊度、总磷、CODMn的去除效果相差不大;工艺1去除浊度、藻类、叶绿素a、总磷、氨氮和CODMn的效果较工艺2好,且对污染物的去除效果受混凝剂投加量的影响较小.     

Nitrogen gas supersaturation in the recent sediments of lake erie and two polluted harbors

Nitrogen gas distributions in sediment pore water were determined for cores collected in Lake Erie and two nearby harbors. Concentrations of N₂ gas ranged from 11.9 to 37.0 ml l⁻¹ and from 8.9 to 58.3 ml l⁻¹ for open lake and polluted harbor sediments, respectively. Maximum concentrations in the harbor sediments were as high as 3.5 times N₂ saturation calculated for the overlying water. Indirect diffusive flux estimates for nitrogen gas ranged from 20 to 32% of the particulate nitrogen sedimentation rate in Lake Erie. At one location, the amount of nitrogen gas lost by diffusion was calculated to be greater than the nitrogen deposited to the sediments. Nitrogen gas production and diffusive loss from surficial sediments probably represents a major pathway for nitrogen removal from Lake Erie.     

城市集中供热的单独用户供暖与生活热水供应

指出应把供热作为一种商品来考虑。探讨了造成目前供系统中用户用热量无法计量，用户反映供热差，管理部门收不回供暖费等问题的原因，认为对住宅而言每户应设一个独立的供热系统并在每个系统上装热量计；另外，为提高居民生活质量，建议在集中供热系统中，采用一种既能供热又能供应生活热水的每衣单独供热与计量的供热系统。