一种异养生物膜(heterogeneous biofilms)活细胞生物量的空间变化

根据文献数据研究了一种正常发育的异养生物膜中活细胞生物量的空间变化特征,运用双自然对数相关分析和分形几何学分析方法发现：异养生物膜中活细胞生物量与生物膜的表面积或面积之间具有显著的双自然对数正相关关系;活细胞生物量在空间上呈现异速生长特性和分形几何学生长特征;活细胞生物量的分维值（D）指示了活细胞生物量在生物膜中空间分布的非均匀程度,并因随生物膜发育阶段变化而能够指示生物膜系统的发育演化进程,将生物膜活细胞生物量和分形几何学结合起来,提供了一种相对目前流行的像素分析法更为简便的认识生物膜空间结构及其变化的新方法。     

粉煤灰-H2O2催化氧化水中对氨基苯酚的试验研究

研究了利用电厂粉煤灰作为非均相催化剂,催化H2O2氧化对氨基苯酚(PAP),讨论了各种因素对PAP去除率的影响.结果表明,在30℃,pH=1.5,H2O2和PAP的起始浓度分别为0.50 mol/L和0.10 mol/L,反应时间为100min,粉煤灰用量为6.0%,搅拌速度为1000r/min的条件下,粉煤灰具有良好的催化活性,能有效地催化H2O2氧化PAP,PAP的去除率可达81%左右.该法可用于预处理含PAP的工业废水.     

Photo-Induced OH reactions of naphthalene and its oxidation products on SiO2

The photo-induced degradation of naphthalene, 1,4-naphthoquinone, 1-naphthol and 1-NO₂ naphthalene, adsorbed on silica gel, and with the addition of nitrogenous air pollutants e.g. NO₂ (as KNO₂) was investigated. Results indicate that compounds adsorbed onto a solid carrier are degraded when irradiated with UV light (λ > 290 nm) in the presence of nitrites. The key species initiating the naphthalene degradation is the OH-radical which is generated through the photolysis of NO₂. Reaction products identified were 2-formyl-cinnamaldehyde, 1,4-naphthoquinone, nitronaphthol, o-phthaldialdehyde, phthalide and nitronaphthalene. A mass balance between 40–50% was achieved. Under the same irradiation conditions, 1-NO₂ naphthalene is mainly degraded by direct photolysis while degradation of 1-naphthol and 1,4-naphthoquinone proceeds via the reaction with OH-radicals. Identified products were hydroxy-nitro-nitroso- and quinones compounds.     

湿式氧化技术的应用现状与发展

湿式氧化技术是上世纪50年代发展起来的一项在高温高压下处理废水的技术。50年来,被广泛地应用于高浓度难降解有机废水和城市污水厂污泥的处理。着重介绍了当今世界上几种主要的湿式氧化工艺的工艺特点及应用现状,为我国湿式氧化技术的工业应用提供参考,并提出了今后的研究重点。     

TiO2及负载Fe(Ⅲ)可见光催化H2O2降解扑草净的协同效应

以TiO2P25(TIO-P25)及Fe(NO3)3为前驱物制备TiO2负载Fe3+多相催化剂Fe/TIO-P25,研究Fe/TIO-P25可见光催化H2O2降解扑草净的协同效应.XRD、XPS、EDS及SEM结果表明,Fe元素以Fe2O3形式高度分散于TiO2表面,负载量约1.5%(wt%),未对TIO-P25的粒径及形貌产生明显影响,Fe/TIO-P25的粒径约20~40nm;光催化结果表明,Fe/TIO-P25能可见光催化H2O2降解扑草净,反应30min降解率达100%,远大于TIO-P25的催化活性,负载Fe与TIO-P25之间存在明显的协同效应;通过对反应体系的荧光光谱分析显示,扑草净的降解涉及较单纯羟基自由基(·OH)过程更为复杂的反应机理.     

The progress of catalytic technologies in water purification： A review

Catalytic technologies have been paid increasing attention in refractory pollutants abatement due to its practical and potential values in water purification. As e ective and e cient approaches for water purification, Fenton’s reagent, ozonation, electrochemical and photocatalytic methods have been widely studied and applied in di erent aspects and have been reviewed by several articles. In recent years, some novel catalytic processes based on above processes have been developed for enhancing the e ciency of removing the organics from water. This review emphasized on the recent development of heterogeneous catalytic ozonation, electrocatalysis in respect of novel electrodes and electro-Fenton method, photoelectrocatalysis process and photoelectron-Fenton in water purification. It was also an attempt to propose general ideas about mechanism and principle enhancing the catalytic e ciency for the degradation and the mineralization of organics in water.     

基于尖点突变的人群拥挤模型研究

近年来的统计分析表明,人群拥挤踩踏事故逐步上升为大型公共聚集场所的主要人为事故灾害类型之一。为了防止这类事故带来的危害,需要从理论高度开展对人群拥挤踩踏事故的承载体人群的运行系统的研究。国内外关于人群拥挤事故的研究方法很多,但至今还未找到较为完善、科学和经济的方法。因此提出将尖点突变理论引入到人群拥挤模型中,建立人群拥挤的尖点突变模型。实证分析表明,用突变模型得出的结论与数据拟合得出的结果大体一致,这说明突变理论应用于此领域是可行的。     

基于回归分析的群集疏散时间模型优化研究

为提高国际上通用的疏散时间模型(简称经验模型)的仿真度,将人员的属性因素(自然属性和社会属性)影响纳入时间模型,采用回归分析方法,以某高校大型大学生艺术中心疏散案例为研究基础,通过调查采样建立185组数据的实测样本。结合影响人员疏散行为和疏散时间相关因素,运用统计软件SPSS17.0对样本进行回归分析,建立疏散时间回归模型。以回归模型为基础,将个体属性综合为群集属性,求取修正系数并对经验模型进行修正、检验。结果表明:利用回归分析和修正系数对疏散时间经验模型进行修正,可有效弥补经验模型缺乏考虑群集属性影响的弱点,提高经验模型的仿真度和应用价值。     

Heterogeneous Fenton-like degradation of 4-chlorophenol using iron/ordered mesoporous carbon catalyst

Ordered mesoporous carbon supported iron catalysts(Fe/OMC) were prepared by the incipient wetness impregnation method and investigated in Fenton-like degradation of 4-chlorophenol(4CP) in this work. XRD and TEM characterization showed that the iron oxides were well dispersed on the OMC support and grew bigger with the increasing calcination temperature. The catalyst prepared with a lower calcination temperature showed higher decomposition efficiency towards 4CP and H2O2, but more metals were leached. The effect of different operational parameters such as initial pH, H2O2 dosage, and reaction temperature on the catalytic activity was evaluated. The results showed that 96.1% of 4CP and 47.4% of TOC was removed after 270 min at 30°C, initial pH of 3 and 6.6 mmol/L H2O2. 88% of 4CP removal efficiency was retained after three successive runs, indicating Fe/OMC a stable catalyst for Fenton reaction. 4CP was degraded predominately by the attack of hydroxyl radical formed on the catalyst surface and in the bulk solution due to iron leaching. Based on the degradation intermediates detected by high performance liquid chromatography, possible oxidation pathways were proposed during the 4CP degradation.     

体育赛场人群疏散过程滞留人数定量模型研究

体育赛场历史事故统计分析表明,出口堵塞为导致人群拥挤踩踏事故发生的主要原因.滞留人群是疏散过程最常见的一种人流形式,同时也是拥挤踩踏事故风险的主要承载体.基于人群流量与人群密度关系建立了体育赛场时间维变量的滞留人数定量模型.体育赛场看台不同宽度出口人群疏散计算结果表明,滞留人数不仅对人群疏散时间有直接影响,而且与事故发生概率之间存在一定的关系.该模型可用于指导体育赛场出口设计,疏散路线选择及应急预案的编制等.