外来物种入侵及其环境法律调控准则

随着世界经济、贸易和交通高度发达的影响，外来物种入侵活动且益加剧，已尼成为威胁我国生物多样性与生态环境的重要因素之一，对我国的一些地区造成了巨大的生态和经济损失。有关外来入侵物种管理的立法应贯彻风险预防原则。     

基于全产业链视角实施生态资产管理

生态资产是人类赖以生存的基本条件,当前研究尚未充分关注人类活动对生态资产的影响。本文从社会经济系统的全产业链视角出发,探讨产业链不同环节的生产消费活动对生态资产的影响以及所对应的不同政策内涵。分析结果表明,产业链的不同环节对应不同政策内涵,识别不同环节上的关键区域/行业能够为不同类型的政策决策指出着力点。初始投入环节的核算服务于人力资本投入行为的调控;初始生产环节的核算服务于末端控制手段,包括资源节约与污染物减排;中间生产环节和末端生产环节的核算服务于提升生产效率的政策手段;最终消费环节的核算服务于消费行为优化。最终得出应该从全产业链视角实施多环节生态资产管理的结论,并提出,为了从全产业链视角实施生态资产管理,应考虑建立一套标准化、全产业链视角的生态资产需求核算框架,建设支持全产业链视角核算生态资产需求的基础数据库,将全产业链视角管理生态资产的思维融入政策决策等建议。     

磁混凝预处理小城镇混合污水的效能与混凝机制研究

针对某小城镇污水处理厂混合进水浓度高的问题,本研究探讨了磁混凝技术在典型小城镇混合污水处理厂提质增效与技术升级改造中的适用性,结果表明,优化的混凝条件为：pH=7,PAC和PAM投加量分别为600 mg·L^-1和4 mg·L^-1,慢搅速率为30 r·min^-1.三维荧光光谱耦合区域面积积分法(FRI)和平行因子法(PARAFAC)的分析结果表明,污水中溶解性有机物(DOM)以色氨酸类、酪氨酸类及富里酸类3种组分为主,内源性特征明显.磁种可显著提升混凝效果,优化的磁种投加量为400 mg·L^-1,浊度和COD去除率分别为99.7%和82%.在磁混凝过程中,磁种作为絮体形成的核心并促进絮体生长,可显著提升絮体的比重、密实度与沉降性能,进而强化固液分离效率,沉降时间缩短为1/6.同时,密实度的增加和微磁场的作用可进一步提升絮体颗粒间的结合力,强化水力冲击下混凝过程的稳定性.因此,与传统混凝工艺相比,磁混凝技术在典型小城镇污水处理提质增效中具有较高的应用潜能.     

ASM No.2d模型模拟SBR工艺同步脱氮除磷效能

SBR工艺由于处理上的高效性和操作上的灵活性在世界范围的污水处理领域得到广泛应用.采用国际水质协会1999年提出的ASM No.2d模型,利用matlab作为程序开发工具编制计算模型,并利用该模型对一实验室规模SBR系统进行模拟.模拟过程中动力学和化学计量参数采用ASM No.2d给出的典型参数值,并结合实际SBR系统进行了修正.结果表明,该模型能够较好模拟SBR工艺同步脱氮除磷效能,说明应用ASM No.2d进行SBR系统的模拟能够对SBR系统的优化和控制起辅助作用.     

卫河新乡市区段春季溶解CH4与N2O浓度特征

对卫河新乡市区段春季CH_4与N_2O浓度进行调查分析,初步探讨了城市河流中典型温室气体的溶存量空间变化及其影响因素.结果表明,受到水中污染物质浓度及人类活动影响,春季卫河表层水中CH_4与N_2O浓度处于超饱和状态,饱和度分别为147.59~2 667.85和4.06~188.25.影响市区内N_2O浓度的主要环境因素为NH~+_4-N(P0.01),而新区污水处理厂排水输入显著提高了N_2O的溶存量,说明污染物类型影响温室气体的产生和积累,NH~+_4-N的硝化过程是城市河流N_2O产生的主要来源.逐步回归分析表明CH_4浓度是NH~+_4-N浓度与水温的相关函数,其中CH_4浓度与NH~+_4-N极显著相关(R2=0.70,P0.01),说明春季卫河中NH~+_4-N浓度是影响卫河春季CH_4溶存的关键因素.此外研究结果显示在NO~-_3-N浓度较低并且NH~+_4-N浓度高时水中CH_4与N_2O浓度具有显著正相关关系,表明有效态氮浓度差异影响CH_4与N_2O产生过程的耦合机制.     

Effects of halobenzoquinone and haloacetic acid water disinfection byproducts on human neural stem cells

Human neural stem cells(h NSCs) are a useful tool to assess the developmental effects of various environmental contaminants; however, the application of h NSCs to evaluate water disinfection byproducts(DBPs) is scarce. Comprehensive toxicological results are essential to the prioritization of DBPs for further testing and regulation. Therefore, this study examines the effects of DBPs on the proliferation and differentiation of h NSCs. Prior to DBP treatment, characteristic protein markers of h NSCs from passages 3 to 6 were carefully examined and it was determined that h NSCs passaged 3 or 4 times maintained stem cell characteristics and can be used for DBP analysis. Two regulated DBPs, monobromoacetic acid(BAA) and monochloroacetic acid(CAA), and two emerging DBPs, 2,6-dibromo-1,4-benzoquinone(2,6-DBBQ) and 2,6-dichloro-1,4-benzoquinone(2,6-DCBQ), were chosen for h NSC treatment. Both 2,6-DBBQ and 2,6-DCBQ induced cell cycle arrest at S-phase at concentrations up to 1 μmol/L. Comparatively, BAA and CAA at 0.5 μmol/L affected neural differentiation. These results suggest DBP-dependent effects on h NSC proliferation and differentiation. The DBP-induced cell cycle arrest and inhibition of normal h NSC differentiation demonstrate the need to assess the developmental neurotoxicity of DBPs.     

氮化碳增强Ag/AgI/γ-Al2O3的可见光催化性能及其机理

通过热聚合的方法使氮化碳(CN)与Ag/AgI/γ-Al_2O_3发生耦合作用,制备出CN-Ag/AgI/γ-Al_2O_3可见光催化剂.采用X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)和紫外可见漫反射光谱(UV-vis DRS)等方法对合成的样品进行了表征,并通过可见光下甲基橙(MO)的降解实验探究了CN对Ag/AgI/γ-Al_2O_3光催化活性及稳定性的影响.结果表明,CN的掺杂改变了Ag纳米颗粒的形状与粒径,且Ag、AgI与CN之间形成强相互作用.与Ag/AgI/γ-Al_2O_3相比较,在可见光波长分别为λ420、450和510 nm时,CN-Ag/AgI/γ-Al_2O_3对MO具有更高的催化降解效率,光反应30 min后,MO的去除率分别为97%、97%和93%.同时,CN的加入显著地增加了Ag/AgI/γ-Al_2O_3的稳定性,抑制了反应过程中Ag~+的释放量,而且反应前后CN-Ag/AgI/γ-Al_2O_3样品的结构没有明显的变化.其活性和稳定性提高的主要原因是CN加速了电子由MO传递至Ag纳米颗粒的过程,同时Ag颗粒等离子体共振(plasmon)效应的增强也有利于MO的催化降解.不同自由基捕获剂的影响实验表明,O_2~(·-)和h~+是反应体系的主要活性物种.     

氯霉素对菲律宾蛤仔的急性和亚急性毒性作用

研究了氯霉素对菲律宾蛤仔的急性和亚急性毒性作用.结果表明,菲律宾蛤仔的48,96h LD50值分别为1803,1161mg/dm3,安全浓度为58.05mg/dm3.氯霉素明显抑制菲律宾蛤仔内脏团溶菌酶活性;氯霉素明显抑制内脏团碱性磷酸酶活性,在高浓度时抑制更为明显;氯霉素可激活肌肉组织的碱性磷酸酶活性;氯霉素在高浓度时明显抑制菲律宾蛤仔内脏团及肌肉组织的过氧化氢酶活性,低浓度时抑制不明显.     

环境中挥发性有机物监测及分析方法

挥发性有机物(VOCs)是一类重要的环境污染物,严重威胁着环境和人类健康。随着VOCs问题的日趋突出,关于VOCs监测技术的研究也越来越多,检测技术逐渐完善。本文对大气中VOCs的监测技术进行了详细的综述,重点介绍了气相色谱-质谱、高效液相色谱等离线检测方法和质子转移反应质谱法在线监测方法。此外,本文分析了各种采样方法及仪器检测技术的优势与不足,旨在为大气VOCs的监测与研究起到一定的指导作用。     

Gaseous and particulate polycyclic aromatic hydrocarbons (PAHs) emissions from commercial restaurants in Hong Kong

Commercial cooking emissions are important air pollution sources in a heavily urbanized city. Exhaust samples were collected in six representative commercial kitchens including Chinese restaurants, Western restaurants, and Western fast-food restaurants in Hong Kong during peak lunch hours. Both gaseous and particulate emissions were evaluated. Eight gaseous and twenty-two particulate polycyclic aromatic hydrocarbons (PAHs) were quantified in this study. In the gaseous phase, naphthalene (67-89%) was the most abundant PAH in all of the exhaust samples. The contribution of acenaphthylene in the gaseous phase was significantly higher in emissions from the Chinese restaurants, whereas fluorene was higher in emissions from the Western cooking style restaurants (i.e., Western restaurants and Western fast-food restaurants). Pyrene is the most abundant particulate PAH in the Chinese restaurants (14-49%) while its contribution was much lower in the Western cooking style restaurants (10-22%). Controlled cooking conditions were monitored in a staff canteen to compare the emissions from several different local cooking styles, including deep frying, steaming, and mixed cooking styles (combination of steaming and frying). Deep frying produced the highest amount of total gaseous PAHs, 6 times higher than the steaming. However, steaming produced the highest particulate emissions. The estimated annual gaseous PAH emissions for the Chinese restaurants, Western restaurants, and Western fast-food restaurants were 255, 173, and 20.2 t y(-1) whereas 252, 1.9, and 0.4 t y(-1) were estimated for particulate phase PAH emissions. The study provides useful information and estimates for PAH emissions from commercial cooking exhaust in Hong Kong.