基于卫星观测的中三角地区吸收性气溶胶的时空演化解析

基于臭氧检测仪(Ozone Monitoring Instrument,OMI)的遥感数据,利用ArcGIS10.2对2005—2020年中三角地区(湖北省、湖南省、江西省)紫外吸收性气溶胶指数(Ultraviolet Aerosol Index,UVAI)的时空变化进行分析,结合气溶胶颗粒物(PM_2.5、PM₁₀)和气态污染物(CO)数据,利用HYSPLIT(Hybrid Single-Particle Lagrangian Integrated Trajectory model)方法研究主要污染城市气溶胶颗粒物的来源与传输路径,通过核密度估计法、相关性分析、聚类分析,研究其影响因素.结果表明：(1)在空间分布上,中三角地区吸收性气溶胶的高值区集中在襄阳市北部、孝感市东部、武汉市西部;在时间分布上,2008年UVAI最低,2014年达到最大值;季节分布具有明显变化,2005—2020年吸收性气溶胶指数季均值为冬季>春季>秋季>夏季.(2)UVAI与人口增长率、第二产业产值占总产值的比重呈正相关性,与节能环保预算支出呈显著负...     

国家环境监测网质量体系的构建

为适应国家生态环境监测网的统一布局和监测任务事权上收的新形势,强化国家对环境监测的统一管理,创新性构建了以全程序全要素为核心、体现国家管理特征的国家环境监测网质量体系框架,形成了一套规范化的质量体系文件,包括质量手册、程序文件、作业指导书和记录表格等。     

基于PHAST软件的站场冷放空燃爆事故模拟分析

为提高天然气长输管道阀室冷放空作业的安全性,针对冷放空作业中的意外闪燃、爆燃事故现象,基于UDM模型并运用PHAST计算机软件,先模拟了泄放气体发生闪燃事故的影响域,分析冷放空气体闪燃范围随风速、大气稳定度、放空压力及放空速率4种影响因素而变化的趋势;后又讨论了放空速率对爆燃超压伤害范围的影响。结果表明:闪燃范围随风速、大气稳定度、放空压力及放空速率增加而递增,后两者对其影响较大,应重点关注并控制;在模拟工况下,最远轻伤距离达60 m,因此在实际工程中,控制放空速率对减轻意外燃爆事故的后果极为重要,应注重对放空作业参数的调整。     

Optimization and characterization of the formation of oil-in-water diazinon nanoemulsions: Modeling and influence of the oil phase,surfactant and sonication

Nanoemulsions are particularly suitable as a platform in the development of delivery systems for lipophilic functional agents. Current research describes the formation of oil-in-water (O/W) diazinon nanoemulsions using synthetic and natural additives by adopting a high-energy (ultrasound) emulsification method. The diazinon nanoemulsions were spontaneously formed by adding dropwise a mixture of diazinon, solvent and co-solvent in an aqueous solution containing a surfactant (tween or lecithin) with continuous stirring. The nanoemulsions were then formed by ultra-sonication. The effects of three levels of active ingredient, solvent, co-solvent, surfactant, sonication time and sonication cycle and power were performed by Minitab software to design the experiment. Effects of these factors on droplet size, polydispersity index (PDI), viscosity and pH of nanoemulsions were investigated. The results of the modeling showed that the experimental data could be adequately adapted in a second-order polynomial model with a multiple regression coefficient r² of 0.821 for the prediction of particle size, PDI and viscosity. The long-term and thermodynamic stability of the prepared nanoemulsions were tested. The droplet size and morphology of the nanoemulsions were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM). On this basis, a water-insoluble insecticide diazinon was incorporated into 26 optimized nanoemulsion systems to demonstrate potential applications in pest control. The results of DLS and TEM measurements showed that most of prepared nanoemulsions had an almost monodisperse droplet size distribution (PDI < 200 nm). Incorporation of diazinon had no significant effect on the size and stability of the nanoemulsions and the formulated nanoemulsion remained stable after four months of storage.     

城镇污水厂微塑料赋存形态、组分及去除效率全流程分析与归趋行为

微塑料是污水处理厂最难去除的新型污染物之一. 为探究污水厂微塑料颗粒赋存形态、尺寸分布、组分、去除效率、泥水中的迁移规律及归趋行为特征,以呼和浩特市某污水处理厂为例,布置17个采样点,并对水厂按月取样对出水进行全年检测分析,借助LAS X软件对微塑料的形状、丰度和尺寸进行统计,并展开全流程分析. 结果表明,纤维状微塑料丰度最高且分布最广,是主要的存在形态,占总丰度的61.8%;微塑料尺寸主要介于0~1.00 mm之间,4种尺寸中0.25~0.50 mm的微塑料丰度最多,占比32.9%. 检测到的8种塑料成分中,以聚酯类物质（PET、PBT）、纤维素和聚丙烯（PP）成分为主,占比分别为25%、21%和17%. 污水厂进水丰度为（73 ±5）n·L^-1,出水丰度为（14 ±2）n·L^-1,整体去除率为（80.8 ±12.1）%. 污水厂3个处理阶段中,只有一级处理起到了去除作用,微塑料在二级处理中丰度出现了激增. 不同构筑物对微塑料起到主要去除作用的是细格栅（49.2 ±7.4）%和二沉池（92.4 ±13.9）%. 微塑料主要以纤维状、碎片状和薄膜状存在,纤维状占比在70%左右,碎片状尺寸主要集中在0.50~5.00 mm之间,占比从大于0.50 mm以后开始上升,尺寸在1.00~5.00 mm范围内最多,占比为50%,成为超过纤维状存在的主要形态. 薄膜状尺寸多集中在小于0.50 mm范围内,占比在10%以上. 因此,提高小尺寸纤维状与薄膜状微塑料与大尺寸碎片状微塑料颗粒的去除可以有效地降低污水处理厂排水对环境中微塑料的污染风险.     

园林绿化废弃物资源化利用的贡献度研究——基于减轻北京城市生活垃圾处理压力的视角

园林绿化废弃物是城市固体废弃物的重要构成。为了进一步优化当前园林绿化废弃物的处理方式,引起相关部门和社会公众的重视,借助统计分析理论构建贡献度指数公式,结合生命周期评价等方法围绕园林绿化废弃物资源化利用在资源、经济和环境三方面的贡献度展开量化研究。结果显示,北京市2004—2013年的贡献度指数持续增长,对减轻北京城市生活垃圾处理压力的能力逐年增强,且在改善环境方面的贡献占比超过2/3;对缓解酸化、全球变暖、光化学污染和富营养化有积极作用,在节约稀缺资源如土地空间和能源资源方面的贡献次之,约1/3;在经济方面的贡献最小,但也在一定程度上能够对政府在环境治理方面的投资压力减负。     

Determination of etoxazole residues in fruits and vegetables by SPE clean-up and HPLC-DAD

A method for determination of etoxazole residues in apples, strawberries and green beans was developed and validated. The analyte was extracted with acetonitrile from foodstuff and a charcoal-celite cartridge was used for clean-up of raw extracts. Reversed phase high performance liquid chromatography with photodiode array detector (HPLC-DAD) was used for the determination and quantification of etoxazole residues in the studied samples. The calibration graphs of etoxazole in a solvent or three blank matrixes were linear within the tested intervals 0.01–2 mg L^?1, with correlation coefficient of determination >0.999. The combined solid phase extraction (SPE) clean-up and the chromatographic method steps were sensitive and reliable for simultaneous determination of etoxazole residues in the studied samples. The average recoveries of etoxazole in the tested foodstuffs were between 93.4 to 102% at spiking levels of 0.01, 0.10, and 0.50 mg kg^?1, with relative standard deviations ranging from 2.8 to 4.7%, in agreement with directives for method validation in residue analyses. The limit of detection (LOD) of the HPLC-DAD system was 100 pg. The limit of quantification of the entire method was 0.01 mg kg^?1.     

水稻对低磷反应的基因型差异及其生理适应机制的初步研究

选取构建水稻分子连锁图谱的两个亲本ＪＸ１７和ＺＹＱ８为材料,在３低磷胁迫下,对磷营养效率有关指标进行分析,结果表明,ＪＸ１７在与磷吸收效率有关的生理指标,如根干重、根分泌质子、根分泌有机酸等方面,都明显优于ＡＹＱ８,说明ＪＸ１７表现较高的相对干物重,低磷胁迫反应不敏感。     

黄河包头段水环境中稀土元素的形态及分布特征

把干流和接纳工业污水的支流的上覆水、悬浮物及表层沉积物作为整体,利用等离子质谱法,对黄河包头段有关环境要素中稀土元素的形态及分布特征进行了系统研究.结果表明,干流上覆水中稀土元素主要以悬浮态形式存在,溶解态含量极微;接纳工业污水的支流上覆水中稀土元素主要以溶解态为主,且悬浮态∑REE和溶解态∑REE明显高于干流;干流悬浮态∑REE和溶解态∑REE,以及表层沉积物和悬浮物中稀土元素含量沿程变化均表现自对照断面至重点排污河段逐渐升高,于四道沙河入黄河口后的下游D站位达到极值,又至削减断面下降的趋势.包头市工业废水对黄河包头段干流稀土元素,特别是轻稀土元素具有明显的迭加作用.干流颗粒物中稀土元素分布模式均属于轻稀土富集,Eu中度亏损型.四道沙河入黄口后的下游D站位颗粒物中轻稀土元素分布模式曲线形状与中国黄土及其他站位均有一定差别,显示有来自包头市工业废水的外源稀土,特别是轻稀土元素的加入;其他站位稀土元素分布模式曲线形状与中国黄土基本一致.干流和接纳工业污水的支流表层沉积物与悬浮物中稀土元素各形态含量分布的顺序均为残渣态碳酸盐结合态、铁锰氧化物结合态>有机质结合态可交换态;接纳工业污水的支流表层沉积物与悬浮物中稀土元素的可交换态明显高于干流.     

不同陈化烟叶叶面高温微生物多样性

以国内外不同品种、不同陈化时间的10个烟叶样品为材料,对其叶面高温微生物进行了分离纯化、鉴定和多样性研究,以了解表面高温微生物在烟叶陈化发酵中的作用.结果表明:陈化烟叶表面高温菌总量为103~105个/g,高温细菌占绝对优势,真菌很少,未能分离到放线菌和酵母菌;高温细菌主要包括芽孢杆菌属(Bacillus)和地芽孢杆菌属(Geobacillus)两个属,芽孢杆菌属为优势菌属;高温霉菌主要包括青霉属(Penicillium)和曲霉属(Aspergillus),曲霉属为优势菌属.国内外烟叶表面微生物种类和数量有所差异,与陈化时间和烟叶品种等因素有着密切关系.