Investigation of indoor environmental quality in Shanghai metro stations, China

A field study was carried out in Shanghai metro stations to gather and evaluate information about the real environment. The thermal environment and particulate matter levels were monitored in this study. The mean thermal sensation vote in metro stations was 0.91, and the mean thermal neutral temperature was 20.6°C. Although 92.1% of subjects voted that the thermal environment was acceptable, the condition of air quality in Shanghai metro stations was not good. The mean levels of PM1.0, PM2.5, and PM10 were 0.231 ± 0.152, 0.287 ± 0.177, and 0.366 ± 0.193 mg/m³, respectively. The contribution of PM1.0 to PM2.5 and PM2.5 to PM10 was up to 79% and 76%, respectively. This means that fine particles or ultrafine particles constituted the preponderant part of metro station particulate matter.     

阴离子表面活性剂测量因素的探讨

针对亚甲蓝分光光度法测定阴离子表面活性剂较难处理的乳化现象,采用破乳剂－异丙醇消除,方法回收率良好,准确度为95％－105％。     

Characteristics of slag, fly ash and deposited particles during melting of dewatered sewage sludge in a pilot plant

This study examines slag, fly ash, and deposited particles during melting of dewatered sewage sludge in a pilot plant. In addition, the chemical composition of particles in flue gas was simulated using a thermodynamics program, namely FACTSage 5.2. The results showed that the main components of slag were Al, Fe, Ca, P and Si; the minor components were Na, K, Mg, Cu, and Zn. The main chemical compound of slag was Ca4(Mg,Fe)5(PO4)6. For fly ash particles, heavy metals with the highest concentrations were in the order of Zn and As, Pb, Cu, and Cd, respectively. For non-heavy metals, Al, Fe and P were also found in significant amounts. The majority of deposited particles were composed of elements of Zn, P, S, Na, Fe, Al, Si, and Ca and such chemical compounds as Zn3(PO4)2, AlPO4, FePO4 and Fe(OH)3 while the minority consisted of elements of As, Cu, and Pb. Moreover, the compositions of deposited particles in each chamber differed due to different flue gas temperatures inside. In the secondary chamber at 760 degrees C, the amounts of Fe and Al were higher than Zn, whereas, in the other chambers (600-400 degrees C), the amount of Zn was higher. In other words, at the lower temperature the deposition of Zn was higher than the deposition of Fe and Al. In the water cooling section, volatile elements (i.e. Zn, As, Cu, Pb) were found in the highest concentrations due to a big difference in temperature between the wall surface and flue gas. From the simulation results, most of the elements in the gas phase were found to be chloride compounds, whereas those in the solid phase were in the form of oxide, sulfate, and phosphate compounds.     

金沙江中下游特有鱼类的生物学、生态学特征及其保护对策

基于2012～2017年在金沙江中下游干流两个区域江段(攀枝花和巧家)的渔获物调查,对两个区域内长江上游特有鱼类的生物学和生态学特征进行了研究,并在此基础上,探讨了适用于金沙江中下游特有鱼类的保护措施.结果显示:2012～2017年间,共采集到特有鱼类25种,隶属于4科17属;向家坝和溪洛渡蓄水后,各调查区域主要特有鱼类的资源丰度均明显下降;除西昌白鱼外,24种鱼类均为适应流水、砾石生境的种类.基于生物学和生态学特征的分析,认为金沙江中下游干支流的梯级开发以及持续的过度捕捞是影响该区域特有鱼类资源变动的主要因素,因此建议在尽量延长各干流水库回水变动区流水生境江段长度的同时,应在流域规划层面上,保证重要支流生境的自然化;此外,应在重要生境区域加强渔业管理,并同时加快特有鱼类的全人工繁殖工作.     

不同竖井送排风方式下半横向通风隧道火灾特性与烟气发展规律研究

通过三维数值模拟方法,用连续方程、动量方程和能量方程描述隧道内火灾发生时气流的流动状态.采用Reynold时均方程法的k-ξluent软件,模拟研究3种工况下,竖井送、排风方式对某越江公路隧道火灾中热烟气排出状况的影响.即开启下游竖井内轴流风机和射流风机,分别采取上游竖井送风、上游竖井风机关闭和上游竖井排风3种方案.分析隧道行车道和排烟道内热烟气的速度场和温度场.结果表明,前两种方案阻碍火源处热烟气自顶部风口进入排烟道,风口横向排烟不具备及时、有效的特点,从而使整个隧道内温度较高;上下游竖井同时排风时,气流以较快速度进入排烟道,且隧道内几乎未留下热烟气,因此共同排烟是合理方案.通过本文研究可较全面地了解半横向通风隧道火灾的特性和烟气发展规律,从而为火灾烟气的控制提供优化通风方案.     

生物过滤法处理挥发性有机物的模型

介绍了生物过滤法处理挥发性有机物模型的研究现状,论述了过滤机理、污染物传递、生物膜增长与脱落、填料和生物膜表面形态学等方面的模型情况,指出了生物过滤法处理挥发性有机物模型的研究趋势,有助于理解生物过滤过程的内在规律和指导优化生物过滤系统的设计与运行。     

膜基活化溶液中活化剂在回收温室气体CO2过程中的作用

将AMP和PZ作为活化剂添加于MDEA溶液中,形成活化溶液,研究了膜基活化溶液回收温室气体CO₂性能,着重考察活化剂的活化作用和对膜接触器传质加强的影响,提出一个活化机理来解释活化现象,建立了阻力层方程模型, 并模拟膜基活化溶液回收CO₂的传质过程。结果表明,活化剂对膜接触器传质的加强起到重要作用,具有双氨基环状结构的PZ对传质的加强作用高于具有空间位阻结构的AMP;活化溶液的CO2回收率和传质通量明显高于未活化的MDEA溶液,活化性能PZ＞AMP;活化剂的活化效应与分子结构有关;流体力学的改变对传质的影响有限,活化剂的反应动力学对传质的加强起主导作用;阻力层方程模型能较好地模拟膜基活化溶液回收CO₂传质过程,传质通量和总传质系数的模型值与实验值符合较好。     

TiO2/NiFe2O2磁性纳米光催化剂的制备及其光催化性能研究

先用水热法制备了纳米级NiFe2O2磁核,然后采用均匀沉淀法在NiFe2O2磁核表面包覆TiO2,制备了一种新型磁性纳米光催化剂TiO2/NiFe2O2通过实验确定了制备TiO2/NiFe2O2的最佳Ti/Ni(摩尔比)为30/1,用X射线衍射(XRD)、透射电子显微镜(TEM)、紫外-可见(UV-Vis)漫反射、热重-差示扫描量热分析(TG-DSC)、磁力学测试等手段对其进行了表征.以甲基橙的水溶液为模拟污染物,评价了TiO2/NiFe2O2的光催化性能,在光照2 h后,甲基橙的脱色率可达98.5%.研究结果表明,TiO2/NiFe2O2是一种可重复使用的高效光催化剂.     

Construction of ternary CuO/CuFe2O4/g-C3N4 composite and its enhanced photocatalytic degradation of tetracycline hydrochloride with persulfate under simulated sunlight

In this study, a graphitic carbon nitride（g-C₃N₄） based ternary catalyst Cu O/Cu Fe₂O₄/gC₃N₄（CCCN） is successfully prepared thorough calcination method. After confirming the structure and composition of CCCN, the as-synthesized composites are utilized to activate persulfate（PS） for the degradation of organic contaminant. While using tetracycline hydrochloride（TC） as pollutant surrogate, the effects of initial p H, PS and catalyst ...     

固态发酵过程中微生物总DNA提取方法比较

为了分析固态发酵过程中微生物群落的多样性及演替情况,对比研究了从固态发酵中提取细菌和真菌DNA的3种方法--溶壁酶法、超声波法、液氮研磨 CTAB法.使用紫外分光光度计测定了由不同提取方法得到的DNA的产量与纯度;使用细菌16S rDNA基因通用引物(341F和907R)和真菌18S rDNA基因通用引物(NU-SSU-0817和NU-SSU-119)对DNA进行了PCR扩增;采用DGGE(变性梯度凝胶电泳)法对固态发酵中细菌和真菌的多样性进行了分析.结果显示,3种方法得到的粗提和纯化DNA长度均约为23 kb;细菌和真菌PCR产物长度分别约为586 bp和422 bp.细菌和真菌PCR产物的DGGE分析表明,3种方法提取的DNA所反映的微生物多样性比较一致;但紫外分光光度计测定结果表明溶壁酶法提取固态发酵中微生物总DNA产量最高,超声波法次之,液氮研磨 CTAB法最低.