山东省平度市农村黑臭水体DOM三维荧光光谱的平行因子分析

运用三维荧光光谱联合平行因子法及相关性分析,以山东省平度市农村黑臭水体为研究对象,探讨其溶解性有机质（DOM）组成、腐殖化程度及来源。结果表明：该市农村黑臭水体DOM包含5类6个荧光组分,分别为类色氨酸荧光组分（C1和C6）、类腐殖质荧光组分（C2）、浮游生物活动产生荧光组分（C3）、类胡敏酸荧光组分（C4）、类富里酸荧光组分（C5）;荧光指数、自生源指数、腐殖化指数和新鲜度指数分别为1.6～1.9、0.8～1.0、0.6～3.0和0.80~0.95的水体占90%,表明该市农村黑臭水体DOM具有外源与内源双重特性,同时具有弱腐殖质特征;结合相关性分析得出,C1、C2、C3、C4之间均呈正相关,其中C2与C4呈极显著正相关（R²=0.98,P<0.01）,C5、C6与其他组分之间均不相关,表明该市农村黑臭水体DOM组分来源具有多样性。

     

冻融作用对土壤中溶解性有机物的光谱学特性的影响

以受季节性冻融过程影响显著的辽宁省棕壤和暗棕壤为研究对象,考察了冻结温度、融化温度、冻结时间和冻融次数对土壤中溶解性有机物(DOM)的光谱学特性的影响.结果表明:冻融处理条件下土壤中的溶解性有机碳(DOC)含量、波长254 nm处的紫外吸光度(UV-254)和单位浓度DOC的紫外吸收值(SUVA)的变化规律相似,均随冷冻和融化温度的升高而增大,随冷冻时间的延长先减小后增大,随冻融次数的增多而减小.冻融作用使DOM的腐殖化程度提高,分子量减小.随着冷冻时间的延长,DOM中类富里酸荧光物质和类腐殖酸荧光物质的含量先减少后增多;随着冻融次数的增多,DOM中荧光物质的含量逐渐减少.研究成果对于准确掌握冻融条件下土壤中DOM的变化规律,以及实施有效的土壤生态环境和地表水流域环境管理具有重要的理论意义和实用价值.     

一种船舶用钢预膜缓蚀剂的研究

目的研究CP-CI021海水介质预膜缓蚀剂的缓蚀行为及复配工艺。方法主要采用失重法和电化学阻抗谱(EIS)研究CP-CI021对Q235碳钢在海水介质中的缓蚀行为,并优化出预膜缓蚀剂最佳复配工艺。结果 CP-CI021预膜缓蚀剂具有优异的缓蚀性能,经预膜处理的Q235碳钢测试的EIS阻抗模值增大了2个数量级。结论得到了预膜缓蚀剂的最佳复配工艺,有机膦PHA质量浓度为7.3 g/L,助剂A质量浓度为3 g/L,助剂B质量浓度为5 g/L,缓蚀效率高达98.4%。     

盐度变化对厌氧污泥胞外聚合物的影响

为探讨盐度变化对厌氧污泥胞外聚合物的影响,采用三维荧光(3D-EEM)和傅里叶变换红外(FTIR)技术,研究了不同盐度下升流式厌氧污泥流化床(UASB)中污泥的松散结合型胞外聚合物(LB-EPS)与紧密结合型胞外聚合物(TB-EPS)的变化规律,并分析了LB-EPS和TB-EPS与污泥沉降性间的关系.结果表明,进水盐度由0逐渐增加至8%,厌氧污泥LB-EPS和TB-EPS含量分别由4.94和12.25 mg·g~(-1)(以VSS计)增加至41.47和43.04 mg·g~(-1)(以VSS计);LB-EPS和TB-EPS中蛋白(PN)和多糖(PS)含量的比值分别由3.2和3.8降低至1.8和2.3;污泥容积指数(SVI)与LB-EPS、TB-EPS均正相关;3D-EEM光谱显示,色氨酸蛋白和芳环蛋白荧光峰存在于不同盐度下LB-EPS和TB-EPS中,类胡敏酸荧光峰仅存在于盐度高于4%的TB-EPS中;FTIR分析表明,进水盐度的增加导致LB-EPS和TB-EPS中PS的C—O组分相对含量增加.     

太湖草、藻湖区沉积物WSOM组成和分子结构分析

草型湖泊（区）和藻型湖泊（区）是浅水湖泊的两种典型状态,两种湖泊中有机质（OM）的来源和转化存在明显差异.有机质在沉积物上的埋藏是湖泊碳汇功能的重要体现.沉积物中的有机质可能发生后续的转化,影响湖泊碳汇功能;其转化过程与其固有的性质密切相关.目前为止,有关草型和藻型湖泊沉积物中有机质的组成,特别是分子结构差异的信息较少.为此,采集太湖草型湖区（东太湖）和藻型湖区（梅梁湾）沉积物,提取和纯化沉积物中的水溶性有机质（分别记为M-WSOM和A-WSOM）,并采用紫外-可见吸收光谱、三维荧光光谱、傅立叶红外光谱和傅里叶变换-离子回旋共振-质谱（FT-ICR MS）对WSOM性质组成和分子结构进行详尽的表征与分析.结果表明：①M-WSOM的相对分子质量比A-WSOM的（E₂ ：E₃指标）稍大;FT-ICR MS的数据显示,M-WSOM和A-WSOM的相对分子质量分别为388.9和379.9.②M-WSOM的芳香性略高于A-WSOM的（SUVA₂₅₄和HIX指标）;同样地,FT-ICR MS的结果显示,M-WSOM中稠环芳烃（6.3%,强度加权平均占比,下同）、芳香类物质（7.7%）的含量高于A-WSOM （分别为1.1%和4.4%）;③荧光组分结果表明A-WSOM中类蛋白质组分的含量大于M-WSOM;FT-ICR MS的结果与之对应,A-WSOM的多肽含量（35.5%）高于M-WSOM的（15.6%）;④质谱数据显示了高分辨的分子信息：M-WSOM和A-WSOM中,沉积物中含杂原子的分子分别占82.9%和91.7%;其中含氮元素的分子占比高达53.5%和78.5%;含磷元素分子占30.4%和41.4%,M-WSOM磷元素主要分布在脂肪烃和高度不饱和低氧物质中,而A-WSOM则主要分布在多肽中.揭示了浅水湖泊两种典型状态沉积物OM的组成和分子结构;有助于研究湖泊沉积物的温室气体排放,及碳、氮、磷元素的生物地球化学过程.     

Zinc and lead sequestration in an impacted wetland system

The fate and bioavailability of pollutant metals is important to the long-term health of freshwater wetland systems, particularly in areas with elevated background levels of trace metals. Precipitation of some authigenic mineral phases in wetland sediments can potentially limit metal bioavailability through sequestration in low-solubility compounds, such as metal sulfides. Zinc and Pb concentrations were analyzed in water, plant and sediment samples taken from a metal-contaminated wetland in Chicago, IL, USA in order to assess metal fate and bioavailability, while X-ray absorption spectroscopy (XAS) studies were conducted to determine zinc speciation in the wetland sediments. The results showed sequestration of metal into the pond sediments, most likely in iron precipitate phases. In surface sediments, re-release of Zn and Pb into pore waters was correlated with microbial iron reduction, while the presence of sulfide in anoxic pore waters corresponded to decreased dissolved concentrations of both elements. Analysis of extended X-ray absorption fine structure (EXAFS) data confirmed that sulfide compounds dominated zinc speciation throughout the sediment. Uptake of trace metals in Phragmites plants was limited primarily to plant roots, while concentrations of both Pb and Zn in aquatic vegetation were significantly elevated, representing a potential bioaccumulation hazard.     

基于液相31P核磁共振分析的沉积物样品制备方法研究

液相31↑P核磁共振（phosphorus-31 nuclear magnetic resonance,31↑P-NMR）是近年来用于分析沉积物有机磷组成的新技术.本研究围绕31↑P-NMR分析沉积物样品的制备过程（包括样品前处理方法、提取时间、提取剂比例、样品浓缩等）进行探讨.结果表明,采用风干的沉积物样品进行提取,...     

络合物吸附波法测定废水中微量铜

本文介绍了Cu-CNS-HSCH_2COOH底液测定废水中微量铜的新方法,该法灵敏度较高,选择性较好,抗干扰强,简便、快速,与8羟基喹啉-铜络合物吸附波法对照,结果满意.     

Monitoring and assessment of toxic metals in Gulf War oil spill contaminated soil using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was applied for the detection of toxic metals in oil spill contaminated soil (OSCS). The OSCS samples were collected from Khursania Saudi Arabia along the coast of Persian Gulf exposed to oil spills in 1991 Gulf war. Environmentally important elements like Aluminum Magnesium, Calcium, Chromium, Titanium, Strontium, Iron, Barium, Sodium, potassium, Zirconium and Vanadium from the contaminated soil have been detected. Optimal experimental conditions for analysis were investigated. The LIBS system was calibrated using standard samples containing these trace elements. The results obtained using Laser-Induced Breakdown Spectroscopy (LIBS) were compared with the results obtained using Inductively Coupled Plasma Emission Spectroscopy (ICP). The concentrations of some elements (Ba and Cr) were found higher than permissible safe limits. Health risks associated with exposure to such toxic elements are also discussed.     

荧光光谱法研究木栓酮与牛血清白蛋白的相互作用

为了解三萜类化合物在体内的结合转运机制,采用荧光光谱法结合紫外吸收光谱研究从中药爵床中分离的有效成分木栓酮(Friedelin,FDL)与牛血清白蛋白(Bovine serum albumin,BSA)的结合反应.通过研究木栓酮对牛血清白蛋白内源性荧光的淬灭作用,发现木栓酮可以与牛血清白蛋白相互结合,且其作用是一个静态猝灭的过程.通过计算木栓酮与牛血清白蛋白的结合常数和结合位点,发现在生理弱碱性溶液中二者具有较强的结合作用,且以1:1结合.根据热力学参数推测木栓酮与牛血清白蛋白的作用力类型为氢键和范德华力.根据F rster非辐射能量转移机理,计算出木栓酮与牛血清白蛋白结合距离为2.86 nm.研究表明木栓酮在体内可以通过血清白蛋白进行结合和转运.