水体各组分吸收系数的测量方法研究

主要综述了水体水色组分吸收系数的测定方法.其中有色可溶性有机物采用0.22 μm聚碳酸酯滤膜过滤后的过滤清液在分光光度计上测定换算得到.总颗粒物吸收系数采用定量滤膜技术得到,并总结了文献中各种光程放大因子β的校正方法.综合分析了甲醇浸泡提取法、次氯酸钠漂白法和数值分离法区分浮游藻类、非藻类颗粒物吸收的原理、操作方法和优缺点.最后对水体组分光谱吸收的典型特征进行了讨论.     

黄土台塬不同土地利用土壤有机碳与颗粒有机碳

为了探讨土地利用方式对土壤有机碳固定的影响,论文以乔木、灌木、草地和农田等不同植被类型,纯林和混交两种栽培模式的黄土台塬为研究对象,进行了土壤有机碳(SOC)和颗粒有机碳(POC)分析。结果表明:不同土地利用方式土壤SOC和POC在0~100 cm土体中均存在差异,尤以0~40 cm深度突出,其中灌木林地和天然草地在整个剖面上可积累更多的SOC和POC;不同土地利用方式土壤细颗粒有机碳(FPOC)含量、分配比例及其在剖面上的分布变化均小于粗颗粒有机碳(CPOC),在0~100 cm土体中,CPOC敏感性指标分别为SOC、FPOC和POC总量的2.66~13.56、3.75~5.99和2.58~4.17倍;不同土地利用方式土壤SOC与POC极显著相关,耕地SOC与POC相关性相对较小,乔灌混交林地和乔木林地最大。因此,CPOC和FPOC均可作为衡量土地利用方式转变对于土壤影响的评价指标之一。     

Characterization of polycyclic aromatic hydrocarbons and gas/particle partitioning in a coastal city, Xiamen, Southeast China

An intensive sampling program had been undertaken in autumn (October, 2008) and winter (December, 2008 and January, 2009) at urban (Xiamen University and Xianyue residential area), suburban (Institute of Urban Environment), industrial area (Lulian Hotel) and background (Tingxi Reservoir) in Xiamen, Fujian Province, to characterize the atmospheric concentration and gas-particle phase partitioning of PAHs. The average concentration of total PAHs in winter was almost 1.7 times higher than those in autumn. The log scale plot of Kp versus sub-cooled liquid vapor pressure (P0 L) for all the data of autumn and winter season samples gave significantly di erent slopes. The slope for the winter samples (–0.72) was steeper than that for the autumn samples (–0.58). The partitioning results indicated that slope values varied depending on characteristics of specific site, source region and meteorological conditions which play important roles in the partitioning of PAHs. In addition, local emission sources had a stronger e ect on partitioning results than long-transported polluted plume. The sources of PAHs in five sampling sites in Xiamen also have been discussed initially. Diagnostic ratios showed that the primary source of PAHs in urban, suburban and industrial area was from vehicle exhausts. While emission from petrochemical factory and power plant was another main contributor to industrial area.     

青岛市大气污染特征分析及防治对策

对青岛的空气质量监测数据进行了分析,分析结果表明：青岛市大气污染物主要是SO2、PM10与NO2,大气污染主要原因是工业废气和机动车尾气。本文还探讨了大气污染防治的新形势,提。出了大气环境质量的改善对策。     

褐煤与烟煤燃烧排放可吸入颗粒物的特性

分别对燃烧褐煤与烟煤两个电厂排放可吸入颗粒物的粒度分布、显微结构及重金属和多环芳烃在可吸入颗粒物中分布特征进行研究。研究表明:不同煤种燃烧排放可吸入颗粒物的形态都以球形颗粒为主,表面比较光滑,同原状飞灰相比,可吸入颗粒物以实心结构为主,多孔和空心结构较少;随着可吸入颗粒物粒径的减小,重金属和多环芳烃含量呈现逐渐增加的趋势;褐煤燃烧排放可吸入颗粒物中重金属总量要高于烟煤燃烧排放重金属总量,尤其是褐煤燃烧排放As含量明显高于烟煤燃烧排放As含量,原因是由于褐煤中As含量大于烟煤中As含量;褐煤燃烧排放可吸入颗粒物中多环芳烃总量要高于烟煤燃烧排放多环芳烃总量与煤种的挥发份有很大的关系。研究旨在为大气颗粒物的源识别、可吸入颗粒物的污染控制与资源综合等方面提供科学的依据。     

西江上游河水悬浮物中稀土元素的地球化学特征

采用改进的BCR逐级提取法和ICP-MS测试技术,对西江上游河流悬浮物中稀土元素进行了研究。结果表明:河流悬浮物稀土元素总量的含量变化范围在188～402mg/kg之间,并主要来源于流域内岩石的风化,反映了源区的物质特征。西江上游河水悬浮物中三种非稳定态(即酸可提取态、铁锰氧化物结合态和有机物硫化物结合态)稀土元素页岩(PAAS)标准化配分模式均显示出中稀土富集的特征。这种配分模式可能是由于流域内广布的海相沉积岩中磷酸盐矿物的风化所造成的。稳定态(即残渣态)的配分曲线较为平直,没有体现出明显的稀土分异。悬浮态稀土各赋存形态含量的顺序为:残渣态有机物硫化物结合态、铁锰氧化物结合态酸可提取态。中稀土元素Sm、Eu、Gd相对于轻、重稀土元素的稳定态所占比例偏低,而相对于三种非稳定态所占比例偏高,反映了其潜在的地球化学活性。     

灵山风景区空气质量分析评价

随着灵山风景区旅游业的蓬勃发展,景区空气质量备受关注。根据灵山风景区景点的水平分布及高度落差,选取了11个具有代表性的采样点,从2010年3月至2011年1月进行空气质量连续监测。结果表明:灵山风景区的空气质量整体较好;焚香点的空气质量明显低于其他景点;客流量是影响景区空气质量的主要因素之一。在环境监测的基础上,采用改进的灰色聚类法对景区内各采样点进行空气质量评价,发现除百子戏弥勒、祥符禅寺、大佛3个采样点的空气质量为国家二级,其余采样点的空气质量均达到国家一级标准。辅以SPSS分析,发现空气质量等级与TSP、PM₁₀、PM_2.5浓度之间显著相关,说明颗粒物对空气质量等级的影响较之SO₂、NO₂更大。     

Effects of continuously regenerating diesel particulate filters on regulated emissions and number-size distribution of particles emitted from a diesel engine

The effects of continuously regenerating diesel particulate filter (CRDPF) systems on regulated gaseous emissions, and number-size distribution and mass of particles emanated from a diesel engine have been investigated in this study. Two CRDPF units (CRDPF-1 and CRDPF-2) with di erent specifications were separately retrofitted to the engine running with European steady-state cycle (ESC). An electrical low pressure impactor (ELPI) was used for particle number-size distribution measurement and mass estimation. The conversion/reduction rate (RCR) of hydrocarbons (HC) and carbon monoxide (CO) across CRDPF-1 was 83% and 96.3%, respectively. Similarly, the RCR of HC and CO and across CRDPF-2 was 91.8% and 99.1%, respectively. The number concentration of particles and their concentration peaks; nuclei mode, accumulation mode and total particles; and particle mass were highly reduced with the CRDPF units. The nuclei mode particles at downstream of CRDPF-1 and CRDPF-2 decreased by 99.9% to 100% and 97.8% to 99.8% respectively; and the particle mass reduced by 73% to 92.2% and 35.3% to 72.4%, respectively, depending on the engine conditions. In addition, nuclei mode particles increased with the increasing of engine speed due to the heterogeneous nucleation initiated by the higher exhaust temperature, while accumulation mode particles were higher at higher loads due to the decrease in the air-to-fuel ratio (A/F) at higher loads.     

“十二五”我国大气颗粒物污染防治对策

颗粒物是影响我国环境空气质量的首要污染物。本文深入分析了当前我国大气颗粒物的污染现状和排放控制现状,总结分析污染分布特征,评估重点行业和主要领域大气颗粒物污染控制情况及存在的不足。以此为基础,从管理体系、控制手段和科学研究等方面,提出"十二五"期间大气颗粒物污染防治的对策、措施和建议。     

武汉军运会前后大气PM2.5化学组分和来源

基于第七届世界军人运动会前后武汉大气细颗粒物(PM_2.5)及其化学组分的在线监测数据,分析了管控前、管控期和管控后PM_2.5的质量浓度和化学组分,并通过PMF结合后向轨迹的聚类分析和浓度权重轨迹开展来源解析.研究揭示了军运会前后武汉市PM_2.5对本地和周边区域管控措施的响应,可为PM_2.5的区域精准防控提供依据.在减排措施影响下,管控期间ρ(PM_2.5)为(31.3±12.0)μg·m^-3,比管控前降低14.7%;而二次组分有明显生成,其中硫酸盐、硝酸盐和铵盐(SNA)质量浓度升高25.6%.管控后由于湿度降低和西北气团的影响,SNA的质量浓度降低36.9%,矿质元素的质量浓度升高4.7倍.源解析表明管控前后机动车尾气的整体贡献率变化不显著(P<0.05).管控期工业排放和燃煤贡献分别较非管控期降低68.1%和43.7%,二次源贡献上升89.5%.由于并未针对机动车尾气采取大规模控制,管控期NO^-₃和NO<...