平衡分配法在土壤环境质量基准推导中的相关问题研究

为了促进土壤环境质量标准的修订进程,势必要全面系统地开展土壤环境质量基准的研究工作。理论上,水、土之间是一个相互联系、互相依赖和关系密切的系统;同时,水生态毒理及其质量基准研究起步早,研究方法相对成熟。因此,从水质基准来推导土壤环境质量基准具有一定的科学依据与实践意义。本文首先从土-水系统中污染物分布的影响因素及其环境行为两方面简要阐述污染物在土-水系统中的分布规律;然后,扼要介绍了平衡分配(Eq P)理论及其在环境质量基准研究中的应用;之后,从Eq P方法的不确定性、毒理数据选用的争议性、Koc的局限性和分配系数的确定方法选择性等方面,探讨了平衡分配法在土壤环境质量基准研究中应用的瓶颈问题;最后,对此项研究进行了总结与展望。     

Effects of UV-A LED light irradiation on growth of cultured RAW 264.7 cells

The aim of this study was to examine the effects of ultraviolet A (UV-A) irradiation-induced damage on cultured macrophage RAW 264.7 cells and determine which components produced these manifestations. RAW 264.7 cells were irradiated with 365 nm UV-A using a light-emitting diode (LED). Cell viability and damage were determined using a calcein-AM and propidium iodide dual-staining assay and lactate dehydrogenase leakage, respectively. Intracellular reactive oxygen species (ROS) were measured by H₂DCF-DA. The components of ROS in each medium were measured using an electron paramagnetic resonance (EPR) spectrometer in the presence of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and 2,2,5,5-tetramethyl-3-pyrroline-3-carboxamide (TPC). While UV-A irradiation for 2 min significantly suppressed cell growth, LDH leakage did not occur. Addition of N-acetyl cysteine restored inhibition of cell proliferation, and reduced intracellular ROS levels. The EPR signal in the presence of TPC increased with time but was decreased by sodium azide. In addition, a typical EPR spectrum was obtained in the presence of DMPO, indicating the presence of a hydroxyradical. The spectrum was diminished by L-histidine. Data suggest that ROS generated in cells or culture medium by UV-A irradiation is predominantly singlet oxygen, and this singlet oxygen suppressed cell proliferation.     

Heterogeneous uptake of nitrogen dioxide on Chinese mineral dust

Mineral dust is one of the major aerosols in the atmosphere. To assess its impact on trace atmospheric gases, in this work we present a laboratory study of the effect of temperature on the heterogeneous reaction of NO₂ on the surface of ambient Chinese dust over the temperature range from 258 to 313 K. The results suggest that nitrogen dioxide could mainly be adsorbed on these types of Chinese mineral dust reversibly with little temperature dependence. Similar to a previous study on NO₂ uptake on mineral aerosols, the uptake coefficients are mainly on the order of 10^− 6 for the Chinese dust, when BET areas are taken into account. HONO was observed as a product, and its formation and decomposition on Chinese mineral dust during the uptake processes were also studied. The complete dataset from this study was compiled with previous literature determinations. Atmospheric implications of the heterogeneous reaction between NO₂ and mineral dust are also discussed, in an effort to understand this important heterogeneous process.     

微孔曝气国内外研究进展及趋势分析

分析比较了国内外微孔曝气研究和应用实例,指出了目前微孔曝气技术的研究重点。同时,综合国内外研究人员的研究成果,分别叙述了曝气量、安装水深、安装面积、孔径、水质和气孔堵塞状况对微孔曝气充氧性能的影响,对不同影响因素的作用效果做了总结,并指出目前研究存在的问题。以期对污水处理厂曝气系统的优化提供借鉴,对拟采用微孔曝气法进行生态修复的研究提供参考。     

上海市建筑玻璃幕墙光反射影响案例研究

玻璃幕墙光反射影响评价是建设项目环境影响评价的一项新内容,上海市建筑玻璃幕墙光反射评价的实践工作开展后,不同类型建筑产生的光反射影响的特点渐渐为评价工作者所熟知,然而提出一个可操作性强的防治措施却并非易事。本文介绍了几种典型案例的光反射影响的特点及其防治措施,为在上海进行的建筑玻璃幕墙设计和光反射影响评价工作提供借鉴作用。     

Experimental study on the impact of temperature on the dissipation process of supersaturated total dissolved gas

Water temperature not only affects the solubility of gas in water but can also be an important factor in the dissipation process of supersaturated total dissolved gas （TDG）. The quantitative relationship between the dissipation process and temperature has not been previously described. This relationship affects the accurate evaluation of the dissipation process and the subsequent biological effects. This article experimentally investigates the impact of temperature on supersaturated TDG dissipation in static and turbulent conditions. The results show that the supersaturated TDG dissipation coefficient increases with the temperature and turbulence intensity. The quantitative relationship was verified by straight flume experiments. This study enhances our understanding of the dissipation of supersaturated TDG. Furthermore, it provides a scientific foundation for the accurate prediction of the dissipation process of supersaturated TDG in the downstream area and the negative imp）acts of high dam projects on aquatic ecosystems.     

深圳市光环境功能区监管模式研究

根据深圳市地区特点。首先,划分光环境功能区,针对每个光环境功能区,再分成子区域,并提出区域光环境质量标准制定模式;然后,根据光环境的区域划分,结合具体区域功能,对不同光污染源进行划分和规范。提出光污染防护标准制定模式。通过区域光环境质量标准和光污染防护标准的制定,建立相应光环境监管模式,以达到防治光污染,保护和改善光环境,保障人类健康以及生态平衡,保证光的有效利用,构建一个绿色和谐可持续发展的光环境。     

秩相关系数及其在蒲石河水质分析中的应用

系统介绍了秩相关系数的计算、检验及Excel计算模式,为环境质量报告书的编制及水质趋势变化分析提供了更加方便的方法。     

光透法定量两相流中流体饱和度的模型及其应用

基于光透法定量流体饱和度的原理及其在两相流中的应用,设计了两组密封砂箱实验来研究气体或重非水相流体(DNAPL)在饱和孔隙介质中的迁移,观察了气体或DNAPL在孔隙介质中的迁移规律,应用并验证了2个水/气两相流中的光强-饱和度(LIS)模型,特别是建立并应用了适用于NAPL/水两相流系统的2个新LIS模型.结果表明,气体以不规则的"指状"通道向上迁移直到在砂箱顶部聚集,最终形成连续的气体分布;TCE由于自身重力的影响向下迁移直至砂箱底部,最终在砂箱中形成不规则的污染羽并在砂箱底部形成污染池.利用实验结果应用并验证4个光透法模型得到:2个水/气系统中LIS模型(WG-A和WG-B)整体适用于本实验数据;2个NAPL/水系统的LIS模型(NW-A和NW-B)得到与实测资料较吻合的结果,其中基于单个孔隙水驱替假设的模型NW-A与实验结果更加接近,对量化多孔介质中的NAPL/水系统各相饱和度具有一定的参考意义.     

珠江三角洲表层水中多环芳烃的季节分布、来源和原位分配

分别于2011年4月(春季)和2011年9月(夏季)采集珠江广州河段及东江东莞河段表层水体样品,对该区域表层水体中优控多环芳烃(PAHs)的时空分布、固液分配及其来源进行了分析和讨论.结果表明,珠江广州河段及东江东莞河段表层水体中多环芳烃浓度春季高于夏季.藻类有机碳是该水环境有机碳的主要成分.溶解有机碳(DOC)、颗粒态有机碳(POC)以及叶绿素a(Chl a)含量是控制水体PAHs浓度的主要因素,说明水环境的富营养化程度可以通过增长的浮游生物量来影响多环芳烃的生物地球化学过程,继而影响其环境行为和归宿.多环芳烃在水/颗粒物间的有机碳归一化分配系数(log Koc)与辛醇/水分配系数(log Kow)间存在明显的线性关系,其斜率是夏季大于春季,可能与多环芳烃的非平衡吸附有关.多环芳烃同系物比值法和主成分分析(PCA)的结果表明,研究区域水体中PAHs主要来源于石化燃料、煤和生物质的混合燃烧,并且PAHs的来源未体现出明显的季节变化.通过本研究我们能够比较全面的了解该流域多环芳烃的时空分布状况,固液分配及其可能的来源,并且为珠江广州河段及东江东莞河段多环芳烃污染的控制和生态风险评价提供科学依据.