煤无烟燃烧锅炉炉内燃烧特性分析

对一台所设计的DZL1.0-0.7-AⅢ煤无烟燃烧锅炉炉内燃烧特性进行了数值模拟.对床层反应,采用了基于热力学平衡法的"黑箱模型",而对于床层上方炉膛空间内的气相湍流燃烧则采用了标准k-ε模型、旋涡消散模型和离散坐标模型.采用非结构化四面体网格生成技术处理复杂炉膛几何空间的网格生成.通过数值模拟,得到炉内速度场,温度场,浓度场等参数的分布特性.结果表明:"多孔分层错列撞击流式"二次风的引入对于改变炉内流动和燃烧特性,加强炉内烟气和空气的混合,强化燃烧及实现炉内消烟除尘具有重要的作用.     

改性TiO_2/浮石光催化去除二级出水中有机物

为了实现城市污水厂二级出水的回用,将La3＋、Fe3＋共掺杂TiO2/浮石光催化用于二级出水中有机物的去除。在优化工艺条件下,该方法对TOC的去除率为49.0%,对UV254的去除率为76.5%;出水BDOC/DOC值大幅度提高,由最初的0.21提高到0.56,增加了出水的可生化性;二级出水中存在着影响光催化去除有机物的因素,其中阴离子对有机物的去除有一定的抑制作用;光催化反应在通过O3强化后对有机物的去除率得到提高,TOC的去除率达到75.0%,光催化和O3氧化对有机物的去除具有协同效应;随着光催化反应次数的增加,催化剂活性有下降趋势,使用10次后TOC去除率下降到第一次使用时的16.7%,再生能够使催化活性恢复到使用前的95%,催化剂在使用15次以内稳定性较好。     

工矿商贸行业较大以上次生衍生事故分析研究

通过对2012~2015年6月全国工矿商贸行业发生的较大以上次生衍生事故行业分布、地域分布、时段分布、空间分布等特征的分析,归纳总结了次生衍生事故发生的规律和特点,根据事故致因理论,对次生衍生事故原因进行了分析,并提出对策措施,为降低工矿商贸次生衍生事故发生率、减少人员伤亡提供理论支撑。     

中国地区黑碳气溶胶的气候效应模拟

RegCM模式对于中国区域气候要素模拟的准确性已得到本地化验证,但系统默认的数据源往往不具备本地化的特征,尤其是气溶胶排放清单设定的生物质源具有季节变化性,人为源为固定值,大大降低了人为源的气溶胶气候效应影响。采用多尺度排放清单模型(MEIC)计算的2013年黑碳气溶胶排放清单,设置不同试验情景,对比分析了人为黑碳气溶胶的气候效应。结果表明:黑碳气溶胶的加入使中国地区的辐射强迫、温度、降水以及黑碳气溶胶柱含量都产生明显变化,且有显著季节变化特征;随着季节变化,气候要素的增减效应范围不同,温度呈由南向北的增长趋势,降水量呈南增北减的趋势,黑碳气溶胶柱含量高值区集中出现在南方工业聚集区。     

北京市不同区域大气气溶胶粒子中水溶性离子的特征

在北京市两个区域同时采集不同粒径的气溶胶粒子,利用离子色谱分析了样品中的水溶性无机离子组分．研究发现,城乡结合带采集的总水溶性离子浓度比郊区高．两地水溶性离子浓度有明显的季节变化趋势,SO4^2-浓度冬季最高,而夏季许多离子浓度普遍较低,NO3^-质量中值直径随季节变化有明显的不同．Na^ 浓度受地表植被影响较大．两地NO3^-,SO4^2-,NH4^ ,K^ 四种离子间的相关系数很好,可能是因为这些离子的来源相似．     

悬挂链曝气工艺应用于中小城镇污水治理

通过对悬挂链曝气工艺特点和应用情况的分析,总结了针对中小城镇污水处理厂的设计与建设经验。结合我国国情,提出悬挂链曝气工艺为中小城镇污水处理厂的建设提供了一个良好的选择。     

大气微生物粒子与飘尘粒子的关系

用ＡＮＤＥＲＳＥＮ生物粒子采样器和光散射气溶胶粒子计数器，在北京西单对大气细菌、真菌和飘尘粒子的浓度、粒度分布及它们之间的关系进行了观测和研究。结果表明，大气细菌的粒度是负偏态分布，大气真菌是对数正态分布，飘尘是正偏态分布。大气细菌浓度与飘尘浓度的比值冬季大，为１１９５３８；夏季小，为２４２１７；年平均比值为６７５１７，＞２．０μｍ的菌尘比值为１５２５３８７，２．０μｍ～８．２μｍ的菌尘比值为３３１８，＞８．２μｍ的菌尘比值为３９４。大气真菌浓度与飘尘浓度的比值冬季大，为２１２７７０；夏季小，为６５５８５；年平均比值为１３５３４４，＜２．０μｍ的菌尘比值为９５２６９８，２．０μｍ～８．２μｍ的菌尘比值为５３４３，＞８．２μｍ的菌尘比值为２６３２。     

Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China

To understand the size-resolved aerosol ionic composition and the factors influencing secondary aerosol formation in the upper boundary layer in South Central China, size-segregated aerosol samples were collected using a micro-orifice uniform deposit irnpactor （MOUDI） in spring 2009 at the summit of Mount Heng （1269 m asl）, followed by subsequent laboratory analyses of 13 inorganic and organic water-soluble ions. During non- dust-storm periods, the average PM1.8 concentration was 41.8 μg·m^-3, contributing to 55% of the PM10. Sulfates, nitrates, and ammonium, the dominant ions in the fine particles, amounted to 46.8% of the PM1.8. Compared with Mount Tai in the North China Plain, the concentrations of both fine and coarse particles and the ions contained therein were substantially lower. When the air masses from Southeast Asia prevailed, intensive biomass burning there led to elevated concentrations of sulfates, nitrates, ammonium, potassium, and chloride in the fine particles at Mount Heng. The air masses originating from the north Gobi brought heavy dust storms that resulted in the remarkable production of sulfates, ammonium, methane sulfonic acid, and oxalates in the coarse particles. Generally, the sulfates were primarily produced in the form of （NH4）2SO4 in the droplet mode via heterogeneous aqueous reactions. Only approximately one-third of the nitrates were distributed in the fine mode, and high humidity facilitated the secondary formation of fine nitrates. The heterogeneous formation of coarse nitrates and ammonium on dry alkaline dust surfaces was found to be less efficient than that on the coarse particles during non-dust-storm periods.     

A comparison study of aerosol emissions sources in two receptor sites in Salvador (Brazil) city

Total suspended particles (TSP) and metal concentrations were determined in Salvador, Bahia, Brazil at two sites: a residential area and a residential‐commercial‐industrial neighborhood. The determined metals associated with atmospheric aerosols include Al, Ca, Cr, Cd, Fe, Mg, Mn, V, Zn and Na. Factor analysis was employed to identify the major atmospheric deposition sources. At one site the data were best represented by two sources: resuspended soil + marine aerosol and vehicular emissions, which represents 93% of the total system variance. In the second one the data were best represented by three sources: resuspended soil, metallurgy and building construction, which represents 79% of the total system variance.     

巷道内粉尘二次飞扬规律的数值模拟研究

针对巷道中沉积粉尘二次飞扬的现象,利用数值模拟的方法对粉尘二次飞扬进行了研究,分析了巷道内粉尘二次飞扬的极限风速与扬尘粒径之间的关系,从而为矿井通风除尘提供一定参考依据,给矿井工人创造良好的工作环境。