Catalytic oxidation of gaseous PCDD/Fs with ozone over iron oxide catalysts

Catalytic oxidation of PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) with ozone (catalytic ozonation) over nano-sized iron oxides (denoted as FexOy) was carried out at temperature of 120-180 degrees C. The effects of operating temperature, ozone concentration, space velocity (SV) and water vapor contents on PCDD/F removal and destruction efficiencies via catalytic ozonation were investigated. High activity of the iron oxide catalyst towards PCDD/F decomposition was observed even at low temperatures with the aid of ozone. The PCDD/F removal and destruction efficiencies achieved with FexOy/O3 at 180 degrees C reach 94% and 91%, respectively. In the absence of ozone, the destruction efficiencies of all PCDD/F congeners are below 20% and decrease with increasing chlorination level of PCDD/F congener at lower temperature (120 degrees C). However, in the presence of ozone, the destruction efficiencies of all PCDD/F congeners are over 80% on FexOy/O3 at 180 degrees C. Higher temperature and ozone addition increase the activity of iron oxide for the decomposition of PCDD/Fs. Additionally, in the presence of 5% water vapor, the destruction efficiency of the PCDD/Fs is above 90% even at lower operating temperature (150 degrees C). It indicates that the presence of appropriate amount of water vapor enhances the catalytic activity for the decomposition of gas-phase PCDD/Fs.     

钢筋混凝土结构构件局部地震损伤多尺度监测方法

提出一种结构局部地震损伤过程的多尺度监测方法。首先,在混凝土材料尺度上,针对混凝土材料细观随机性影响问题,基于压电智能骨料进行混凝土压应力监测,通过试验方法建立了混凝土损伤全过程中压电智能骨料应力与混凝土宏观应力的概率统计关系;其次,在截面尺度上,基于MEMS倾角仪转动监测方法,提出混凝土压弯构件截面曲率的监测方法,并通过试验验证了该方法的可行性;最后,在构件尺度上,提出基于转动积分的层间变形监测方法并给出了转动监测位置的设计原理,通过构件试验验证了该监测方法的可靠性。     

用自旋捕集技术研究氟化物刺激人多形核白细胞呼吸爆发产生的活性氧自由基

用ESR波谱研究证明,F^-刺激人多形核白细胞（PMN）呼吸爆发产生活性氧自由基（O₂^-和·OH）,同时消耗O₂.用DMPO自旋捕集技术表明,在高浓度F^-刺激下PMN产生DMPO-OOH加合物;在低浓度F^-刺激下则产生DMPO-OH;在适中浓度F^-刺激下PMN先产生DMPO-OOH,随浓度降低变为DMPO-OH.用超氧化物歧化酶和过氧化氢酶的实验确定氧自由基主要来自O₂^-.用CTPO和CrOX的自旋探针测氧法证明,PMN受F^-刺激产生氧自由基时消耗的O₂是细胞外介质中的O₂.     

长江口潮滩含氯有机物的分布及与TOC、粒度的相关性

对长江口潮滩表层沉积物中的含氯有机物进行GC—ECD测试。结果表明,含氯有机物总量在1.159～54.957ng/g之间,平均值为11.204ng/g,其中多氯联苯(PCBs)含量<有机氯农药(OCPs)含量。含量高低分布随采样点位置变化显著,排污口附近出现最大值,离排污口越远,含量越低,总体显示出在近河口区含量远高于沿岸区。同时,PCBs和OCPs相关性分析结果表明,它们很可能具有相似的分布机制和输入来源。另外,长江口潮滩表层沉积物中含氯有机物的含量与TOC、粒度的相关性很低(r2<0.05),显示了研究区的特殊性和复杂性。     

BP网络模型在朝阳地区大气污染预报中的应用

目前,人工神经网络理论发展迅速,并在模式识别和系统辨识中得到广泛应用。而其中采用误差反向传播方法(Back Error Propagation)的BP网络模型是目前应用最为广泛的神经网络模型之一,它是一种简单而又非常有效的算法。本文应用人工神经网络方法,在模拟人脑的思维方式下,建立了大气污染物浓度的神经网络预报模型,并将计算结果与监测值进行了对比验证,计算结果表明,BP模型应用于大气污染物浓度预报具有较高的预报精度。     

Hydroxyl carboxylate based non-phosphorus corrosion inhibition process for reclaimed water pipeline and downstream recirculating cooling water system

A combined process was developed to inhibit the corrosion both in the pipeline of reclaimed water supplies (PRWS) and in downstream recirculating cooling water systems (RCWS) using the reclaimed water as makeup. Hydroxyl carboxylate-based corrosion inhibitors (e.g., gluconate, citrate, tartrate) and zinc sulfate heptahydrate, which provided Zn^2 + as a synergistic corrosion inhibition additive, were added prior to the PRWS when the phosphate (which could be utilized as a corrosion inhibitor) content in the reclaimed water was below 1.7 mg/L, and no additional corrosion inhibitors were required for the downstream RCWS. Satisfactory corrosion inhibition was achieved even if the RCWS was operated under the condition of high numbers of concentration cycles. The corrosion inhibition requirement was also met by the appropriate combination of PO₄^3 − and Zn^2 + when the phosphate content in the reclaimed water was more than 1.7 mg/L. The process integrated not only water reclamation and reuse, and the operation of a highly concentrated RCWS, but also the comprehensive utilization of phosphate in reclaimed water and the application of non-phosphorus corrosion inhibitors. The proposed process reduced the operating cost of the PRWS and the RCWS, and lowered the environmental hazard caused by the excessive discharge of phosphate. Furthermore, larger amounts of water resources could be conserved as a result.     

In situ nitrogen removal processes in intertidal wetlands of the Yangtze Estuary

Estuarine and intertidal wetlands are important sites for nitrogen transformation and elimination. However, the factors controlling nitrogen removal processes remain largely uncertain in the highly dynamic environments. In this study, continuous-flow experiment combined with ¹⁵N isotope pairing technique was used to investigate in situ rates of denitrification and anaerobic ammonium oxidation (anammox) and their coupling with nitrification in intertidal wetlands of the Yangtze Estuary. The measured rates varied from below the detection limit to 152.39 µmol N/(m²·hr) for denitrification and from below the detection limit to 43.06 µmol N/(m²·hr) for anammox. The coupling links of nitrogen removal processes with nitrification were mainly dependent on nitrate, organic carbon, sulfide, dissolved oxygen and ferric iron in the estuarine and intertidal wetlands. Additionally, it was estimated that the actual nitrogen removal processes annually removed approximately 5% of the terrigenous inorganic nitrogen discharged into the Yangtze Estuary. This study gives new insights into nitrogen transformation and fate in the estuarine and intertidal wetlands.     

电厂冷却系统对梭幼鱼和对虾仔虾卷载效应的初步探讨

根据青岛电厂运行观测和模拟实验，分析了卷载效应中机械损伤和高温冲击对梭幼鱼和对虾仔虾的危害。研究表明，电厂冷却系统内流速≥２．０ｍ／ｓ，滤网孔径８ｍｍ时，对体长７－１７ｍｍ和２０－３４ｍｍ仔虾的致死率分别为２８．３％－５５．３％和２８．６％－６６．９％；对体长２０－４０ｍｍ梭幼鱼的致死率为６３．４％－７８．８％。卷载致死率与生物的密度、体长及形态特征有关。模拟实验结果为：０．９－１．０５ｍ／ｓ的流     

有机废弃物氢发酵制备生物氢气的研究

在批式培养实验中以有机废弃物为原料,通过厌氧生物发酵制备生物氢气研究了菌种来源、有机废弃物种类对产氢能力的影响,以及生物氢发酵过程中液相组成的变化以活性污泥为菌种来源,以淀粉为底物,在30L改进的UASB反应器中进行了放大实验,生物气中氢气浓度达40%～51%,CO₂浓度为49%～60%,且没有检测到甲烷气体,生物气经碱液吸收后氢气纯度大于97%持续产氢时间超过120d.     

河流中BOD-DO动态的数学模拟方法

本文讨论了河流中BOD—DO动态的数学模拟方法,并将该方法应用于图们江,利用在图们江上取得的实测数据建立了江中BOD—DO动态的数学模型。在所得到的模型中,耗氧系数κ_1,复氧系数κ_2,BOD沉淀-再悬浮系数κ_3被表达为流量与水温的函数。表达式中的参数通过系统识别与参数估计方法确定,因此能较好地反映河流的地理环境特点。特别是κ_3的表达式,它以流量为自变量,用一个单一的解析函数同时描述了江中的沉淀与再悬浮现象,具有独创性。 本文所提出的BOD—DO动态模型可以做为图们江水质规划与管理的基础。