污水处理厂微孔曝气器选型的探讨

曝气器是污水处理厂的核心设备。目前广泛运用的鼓风机微孔曝气是一种高效节能的曝气方式。选择适当的微孔曝气器是非常重要的,不仅保障污水处理效果稳定,运行成本较低,还能节省设备投资和维护费用。结合微孔曝气器在污水处理厂的运用效果,分析了各种微孔曝气器的性能、特点和优劣,并对污水处理厂微孔曝气器的选型进行了探讨。     

改性硅藻土陶瓷生物膜载体的制备及性能研究

主要对硅藻土的烧结改性进行了进一步的研究,并对改性硅藻土用于污水处理系统生物膜的载体制作进行参数研究。通过设置适宜的污水水力学特性、良好的载体挂膜性能表征、实验运行稳定性等多方面进行对比实验,得出最佳生物膜挂膜性能的改性硅藻土陶瓷生物膜载体。     

温拌阻燃沥青混合料阻燃效果评价

通过氧指数、质量损失率及路用性能试验,研究EC130温拌剂、FRMAX型阻燃剂对沥青混合料阻燃效果的影响。试验结果显示,相比普通沥青混合料,阻燃沥青混合料、温拌阻燃沥青混合料氧指数分别增加23.3%、25.6%,质量损失率减小28.0%、32.0%,残留动稳定度增加14.0%、16.1%,残留最大弯拉应变增加14.1%、17.1%,冻融劈裂强度比增加5.3%、9.0%。相比普通沥青路面,阻燃沥青路面、温拌阻燃沥青路面发生火灾时能够减少34.0%、41.1%的毒害气体生成,并减少路面修补所需的混合料质量。其次得出普通沥青路面、阻燃沥青路面及温拌阻燃沥青路面的质量损失率、残留动稳定度、残留最大弯拉应变、残留冻融劈裂强度比与燃烧时间的关系模型。结果表明:阻燃剂对沥青混合料的阻燃效果显著;温拌剂有助于阻燃剂更好地发挥阻燃作用,降低火灾对道路的破坏,降低隧道火灾发生时有害气体的生成,提升隧道安全性。     

计算机模拟警戒作业疲劳与绩效测量实验设计*

为探索警戒作业工间休息机制,设计计算机模拟监控警戒作业实验研究疲劳与绩效之间的关系。通过对9个时间单元绩效数据的两两比较,发现原有实验方案存在不合理性。分析心理厌倦和暂时性注意缺失对作业绩效的干扰,找出问题根源。通过调整任务界面和参数、增加声音警示音、设置时间进度条、加强实验前自我检查和培训环节对实验方案进行改进,并检验改进效果。结果表明:改进后实验方案产生的数据能客观描述监控警戒作业疲劳与绩效之间的关系,实验结论可为设计警戒作业工间休息制度提供理论依据。     

Chlorobenzene degradation by electro-heterogeneous catalysis in aqueous solution: intermediates and reaction mechanism

This study was performed to investigate the variables that influence chlorobenzene (CB) degradation in aqueous solution by electro-heterogeneous catalysis.The effects of current density,pH,and electrolyte concentration on CB degradation were determined.The degradation effciency of CB was almost 100% with an initial CB concentration of 50 mg/L,current density 15 mA/cm2,initial pH 10,electrolyte concentration 0.1 mol/L,and temperature 25°C after 90 min of reaction.Under the same conditions,the degradation eff...     

羧化CTS微球对共存有机污染物的吸附研究

采用反相悬浮法制备交联羧甲基化壳聚糖微球,并用高效液相色谱法-紫外检测研究了改性壳聚糖微球对共存有机污染物的吸附。试验了吸附时间、溶液pH值、有机物的浓度等因素对水中共存有机污染物吸附的影响。结果表明,在有机物浓度相近的情况下,羧化改性壳聚糖微球对水中2,4-二硝基酚的去除量最大。     

电化学法处理苯酚模拟废水的研究

电化学法处理废水中有机污染物,具有效率高、操作简便、与环境兼容等优点,是一种很有潜力的高级氧化技术。实验是以废旧一号干电池中的碳棒作电极,用烧杯作电解池,在室温下,通过改变支持电解质（Na2SO4）浓度、负载电压、pH值和苯酚初始浓度等影响因素,对苯酚模拟废水进行电化学处理,利用高效液相色谱仪对其处理效果进行了分析研究,结果表明：支持电解质（Na2SO4）浓度为20.0g/L、负载电压为5.5V、pH值为8.0是处理苯酚模拟废水的最佳条件。最后对苯酚的降解机理进行了初步探讨。     

Experimental analysis of thermal performance of evacuated tube and flat-plate solar air collectors at different air flow rates

The thermal performances of an evacuated tube collector (ETC) and flat-plate solar air collector (FPC) are experimentally investigated at different air flow rates. To investigate the performance of the ETC and FPC, experimental set-ups were fabricated. Air was used as a working fluid and tested at the same climatic conditions. The ETC had 15 evacuated tubes with a surface area of 1.66 m². The experimental set-up consisted of a header with a hollow pipe (square pipe) in the centre through which the air flowed. The flat-plate collector had a surface area of 1.35 m². The FPC had a black painted absorber sheet which divides the collector into two sections. The air flowed through the upper and the lower sections parallel to the collector to minimize the overall heat loss. The temperature of the outlet air depends on several factors along with the airflow rate and the intensity of the solar radiation. It was found that during the day at high flow rates, the efficiency of the ETC varies from 0.12 to 0.5, and for the flat plate it was from 0.29 to 0.68. The maximum temperature of the air was 56.7°C for the ETC and 25.7°C for the FPC.     

Sustainability assessment of EPS-geofoam in road construction: a case study

ABSTRACT

In the present study, construction procedure and performance assessment of expanded polystyrene EPS-geofoam layer, which is utilized in the repair and rehabilitation of road work, is demonstrated. EPS geo-foam application was suggested after observing excessive settlement and distress of approach roads near Cross drainage (C-D) works constructed on bypass road of an important National Highway Project in India. EPS-geofoam was used as an alternative to earth backfill in approaches of newly constructed culvert on the same bypass road on one side of the C-D work and, for comparison purpose; the other side of the C-D work was retained with existing earth backfill. EPS-Geofoam was convenient to handle, easy to place and executed effeciently in terms of machineries and man power. Also, after 6 months of observation, it was noted that Pavement Quality Concrete (PQC) constructed over earthfill material have shown sign of distress and longitudinal cracks were observed due to excessive settlement; on the other hand PQC constructed over EPS-geofoam was intact with no sign of distress. Outcome of the study suggest the use of EPS-geofoam in similar situations as per the proposed guidelines for construction as well as cross-sectional details and design recommended.     

The effect of environmental regulation on firms' competitive performance: the case of the building & construction sector in some EU regions

There is a considerable debate on the effects of environmental regulation on competitive performance. Based on survey data, this paper analyzesthe two main research questions, derived from literature, on the links between environmental regulation and competitiveness, by focusing on firms operating in the building and construction sector, i.e.: 1) whether environmental policy stringency affects the competitive performance of firms in the building and construction sector 2) and how a specific form of environmental regulation (direct regulation, economic instruments and soft instruments) affects this performance? By applying a regression analysis, we find that a more stringent environmental regulation, measured by inspection frequency, provides a positive impulse for increasing investments in advanced technological equipment and innovative products and on business performance. Moreover, a well-designed “direct regulation” appears to be the most effective policy instrument for prompting the positive impact of environmental policies on innovation and intangible performance while economic instruments do negatively affect business performance.