微絮凝深床层过滤去除无机营养物及典型金属离子

在分析了微絮凝深床层过滤机理的基础上,实验研究了以煤矸石燃后残渣为滤料的深床层对微污染矿井水中无机营养物及典型金属离子的去除效果。结果表明,对于微污染矿井水中的NH3-N及COD的去除率仅有20%～40%;对可形成微絮凝体的磷的去除率高达80%以上,对于矿井水中的铁、锰离子的去除率可达75%以上,而絮凝剂的适量加入,不会大幅增加出水中铝离子的含量;分析表明,煤矸石燃后残渣滤料具有良好的吸附、截留作用;对溶解性NH3-N及COD的去除以吸附及生物作用,对铁、锰离子的去除则是以形成絮体沉淀为主,同时金属离子的水合作用、溶度积等对其去除有一定的影响。     

Pseudomonas fluorescens Dynamics in the Soil Surface to Subsurface Transect

Microbial displacement in the soil is an important process for bioremediation and dispersal of wastewater pathogens. We evaluated cell movement in surface and subsurface red-yellow podzolic soil driven by advection and microbial motility and also survival of a microbial population at high pressure as is prevalent in deep soil layers. Pseudomonas fluorescens Br 12, resistant to rifampycin and kanamycin, was used as a model organism traceable in non-sterile soil. Our results showed that more than 40% of the P. fluorescens population survived under high pressure, and that microbial motility was not a major factor for its displacement in the soil. Cells were adsorbed in similar amounts to surface and subsurface soils, but more viable cells were present in the leachate of surface than in subsurface soils. The nature of this unexpected cell binding to the subsurface soil was studied by EPR, Mossbauer, NMR, and infrared techniques, suggesting iron had a weak interaction with microbes in soil. P. fluorescens movement in soil resulted mainly from convection forces rather than microbial motility. The transport of this bacterium along the transept toward groundwater encountered restricted viability, although it survived under high pressure conditions simulating those in deep soil layers.     

直物收割频率对水生植物滤床深度处理养猪废水的影响

采用水生植物滤床系统深度处理养猪废水,开展了不同收割频率条件下系统对污水净化效果的对比研究。实验结果表明,当水力负荷为5cm／d时,植物收割频率的增加会降低系统对TN和TP的去除效果,而对COD的去除效果则无明显影响。当不进行植物收割时,系统对养猪废水的净化效果最好,对COD、TN和TP的平均去除率分别为71．26％、34．32％和29．52％。因此,合适的植物收割频率是强化APFB系统处理效果的关键因素。     

植物收割频率对水生植物滤床深度处理养猪废水的影响

采用水生植物滤床系统深度处理养猪废水,开展了不同收割频率条件下系统对污水净化效果的对比研究。实验结果表明,当水力负荷为5 cm/d时,植物收割频率的增加会降低系统对TN和TP的去除效果,而对COD的去除效果则无明显影响。当不进行植物收割时,系统对养猪废水的净化效果最好,对COD、TN和TP的平均去除率分别为71.26%、34.32%和29.52%。因此,合适的植物收割频率是强化APFB系统处理效果的关键因素。     

二氧化氯催化氧化—曝气生物滤池法深度处理造纸废水

采用二氧化氯催化氧化法—BAF法深度处理造纸废水,实验结果表明:在二氧化氯加入量为150mg/L,催化氧化时间为40min时,可生化性BOD5/COD最高达到0.316;二氧化氯氧化后出水经曝气生物滤池深度处理后,BOD5低于20mg/L,COD低于90mg/L,TSS低于30mg/L,处理后水质完全达到国家新的排放标准(GB3544—2008)。     

诱导喷嘴改进滤筒清灰效果的数值模拟

采用计算流体动力学数值模拟方法,对规格为325 mm×660 mm滤筒在采用高效诱导喷嘴(超音速引流喷嘴和气流散射器)喷吹时的内部流场进行研究。通过分析喷吹气流在滤筒内的压力分布云图和喷嘴处的速度分布图,得出模拟结果与脉冲喷吹实验结果基本一致,验证了数值模拟的可靠性和实验的准确性。进而从微观上分析得出采用诱导喷嘴可使气流更加稳定的进入滤筒内部,以此确保滤筒长度方向上内壁清灰压力的均匀性,对滤筒清灰效果有明显的改善作用,为解决滤筒的清灰问题提供了一定的指导。     

Artificially roughened solar air heater: A comparative study

Artificially roughened solar air heater has been topic in research for the last 30 years. Prediction of heat transfer and fluid flow processes of an artificially roughened solar air heater can be obtained by three approaches: theoretical, experimental, and computational fluid dynamics (CFD). This article provides a comprehensive review of the published literature on the investigations of artificially roughened solar air heater. In the present article, an attempt has been made to present holistic view of various roughness geometries used for creating artificial roughness in solar air heater for heat transfer enhancement. This extensive review reveals that quite a lot of work has been reported on design of artificially roughened solar air heater by experimental approach but only a few studies have been done by theoretical and CFD approaches. Finally this article presents a comparative study of thermo-hydraulic performance of 21 different types of artificial roughness geometries attached on the absorber plate of solar air heater in terms of thermo-hydraulic performance parameter. Heat transfer and friction factor correlations developed by various investigators for different types of artificially roughened solar air heaters have also been reported in this article.     

Optimal heat rejection pressure for transcritical CO2 refrigeration cycle with an expander

Heat rejection pressure plays an important role in designing a transcritical CO₂ refrigeration system, and it has an optimal value to maximize the system’s coefficient of performance (COP). With a thermodynamic simulation model, the optimal heat rejection pressure is studied in the paper for an expander cycle, as well as conventional throttle valve cycle. The effects of compressor efficiency, expander efficiency, gas cooler outlet temperature, and evaporation temperature on the optimal heat rejection pressure are analyzed. It is the first time for a transcritical CO₂ expander cycle that the optimal heat rejection pressure is correlated with the gas cooler outlet temperature and the evaporation temperature at given compressor efficiency and expander efficiency. The average deviation from the correlation to simulation results is less than 1.0%. The correlation provides a guideline to system development and performance optimization of a transcritical CO₂ expander cycle.     

中原经济区能源消费视角下的大气环境压力评估

研究以能源消费模式为切入点,分析中原经济区能源消费总量、消费结构和利用效率的现状水平,并分析能源消费引起的大气环境压力状况。基于经济发展速度调控及节能减排力度的不同,设置2020年三种能源消费情景,使用区域能源消费总量优化模型模拟预测不同情景下的能源消费总量,并分析不同情景下的大气环境压力。结果表明,快速发展和适度发展Ⅰ情景下,2020年区域能源消费总量将比2012年增加4.2×10~8tce和2.4×10~8tce,煤炭消费总量将增加3.1×10~8tce和1.2×10~8tce,大气污染物排放压力增加30%和50%;适度发展Ⅱ情景下,能源消费总量将增加0.2×10~8tce,煤炭消费总量将下降0.3×10~8tce,大气污染物排放压力将降低20%。因此,要实现经济发展稳步增长(年均增长率7.7%)和大气污染物排放总量削减10%目标,重中之重是实现煤炭消费总量"零增长"或"负增长",同时力争能源消费总量控制在5×10~8~6×10~8tce,凭借煤炭占比大幅下降(降至65%左右)最大限度发挥能源供给领域节能效应,依靠产业结构升级节能效应和技术节能拓展能源消费领域节能空间,将能效水平提高至0.6tce/万元以下。     

S-K型管式混合器-微絮凝高速过滤的实验研究

基于2种传统管式混合器的特点,研究了苏尔士-凯尼斯（S-K）新型组合管式混合器在预氧化-微絮凝高速过滤技术中的应用,对苏尔士（Sulzer）管式混合器、凯尼斯（Kenics）管式混合器及s-K型管式混合器高速过滤出水水质进行了对比分析,结果表明,S-K型微絮凝方式对浊度、COD及TP的平均去除率比其他2种混合器混合方式的去除效果提高了5％～10％,分别为80．3％、64．76％和51．15％。S-K型混合器过滤形成的絮体能够充分利用深层滤料,延长过滤周期。