A 1-dodecanethiol-based phase transfer protocol for the highly efficient extraction of noble metal ions from aqueous phase

A 1-dodecanethiol-based phase-transfer protocol is developed for the extraction of noble metal ions from aqueous solution to a hydrocarbon phase, which calls for first mixing the aqueous metal ion solution with an ethanolic solution of 1-dodecanethiol, and then extracting the coordination compounds formed between noble metal ions and 1-dodecanethiol into a non-polar organic solvent. A number of characterization techniques, including inductively coupled plasma atomic emission spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis demonstrate that this protocol could be applied to extract a wide variety of noble metal ions from water to dichloromethane with an efficiency of >96%, and has high selectivity for the separation of the noble metal ions from other transition metals. It is therefore an attractive alternative for the extraction of noble metals from water, soil, or waste printed circuit boards.     

城市安全供水综合指数研究-以太原为例

采集太原市不同区住户的自来水和12种瓶装水,分析了水中无机离子和挥发性有机物( VOCs)成分.结果表明,无机离子和VOCs的总浓度范围分别为1.08~354.18 mg/L和0.43~13.98 μg/L;自来水中的无机离子与VOCs 含量最高,约是瓶装水中浓度的三倍.加热与过滤处理措施均可改善自来水水质,对水中无机离子和VOCs的去除效果均可达19%~100%,其中过滤可能会引发VOCs的二次污染 .根据饮用水标准,使用饮用水水质指数( DWQI)模型对水质评价结果显示,太原市饮用水水质总体较好.     

苏州市连续重污染过程中可溶性离子组分分析研究

文章利用苏州南门空气质量监测站点的可溶性离子组分的数据,结合2013年连续重污染过程细颗粒物中可溶性离子组分.结果表明,重污染过程是在不利气象条件下一次污染过程,从后向轨迹分析,空气团裹挟大量污染物到达苏州,使本地污染和区域污染相互叠加;可溶性离子组分占到细颗粒物组分的一半,可溶性离子又以硫酸盐、硝酸盐和铵盐为主要成分,其中硫酸盐主要来自于二氧化硫的转换.     

Review of the application of quantum dots in the heavy-metal detection

Heavy-metal contamination is a major concern, as excessive heavy metals produce environmental pollution, and the cumulative effects of heavy metals in vivo pose a major threat to human health. There is an urgent need for a rapid, sensitive, and efficient method for detecting heavy metals. Quantum dots (QDs) are in the category of semiconductor nanocrystals whose radii are less than or close to the exciton Bohr radius. QDs possess a potential in the biological and medical fields to function as a new type of fluorescent marker, because of their unique and tunable photophysical properties, which include broad excitation spectrum, narrow emission spectrum, tunable emission wavelengths, and negligible photobleaching. In recent years, QDs made significant progress in quantitative analysis by providing a new approach for determination of chemical content analysis. The aim of this study was to review the research progress of QD detection of heavy metals in water and consider the challenges and future outlook for QD-based sensors for heavy-metal ions.     

纳米氧化锌对大型溞肠道组织毒性效应及机理研究

研究了不同浓度纳米氧化锌（ZnONP）及其在水中释放的对应浓度的Zn²⁺溶液对大型溞（Daphnia magna）肠道组织显微和亚显微结构的影响,探讨了ZnONP对大型溞的肠道组织毒性效应特征和作用机理.结果表明,0.3 mg·L^-1-Zn²⁺组（Zn²⁺浓度0.170 mg·L^-1）和0.3 mg·L^-1 ZnONP溶液皆对大型溞的肠道造成损伤,主要导致大型溞中肠与直肠之间的连接处发生扭曲,其中ZnONP对肠道组织结构弯曲影响最为明显,0.3 mg·L^-1 ZnONP组引起大型溞个体最大肠道弯曲率高达42%.大型溞肠道组织HE染色结果显示,ZnONP暴露会造成大型溞肠道上皮组织断裂、胞间连接空泡化、纹状缘模糊及杯状细胞脱落等,而相对应浓度Zn²⁺组的毒性较弱.电子显微镜下对大型溞肠道组织亚显微结构观察发现,0.3 mg·L^-1 ZnONP处理组大型溞肠道上皮细胞组织出现微绒毛排列紊乱、脱落、溶解,上皮细胞松散,线粒体双层膜结构不完整,嵴溶解消失,核糖体增多等现象.0.3 mg·L^-1-Zn²⁺组大型溞肠道组织上皮细胞有损伤,但整体结构基本完整.从ZnONP和对应的Zn²⁺所产生的毒性效应特征和各组大型溞机体中Zn元素含量的测定分析,ZnONP对大型溞造成的肠道组织损伤不仅与其释放的Zn²⁺引起的毒性有关,更可能与大型溞对颗粒物摄取的方式或ZnONP在体内的积累量、排泄速率和作用的细胞器等有关.因此,ZnONP对肠道组织毒性效应产生的分子机制还需要 进一步研究.     

Novel eco-friendly spherical porous adsorbent fabricated from Pickering middle internal phase emulsions for removal of Pb(II) and Cd (II)

Spherical porous materials prepared from the emulsion template used in the water treat-ment have displayed a vast prospect,as the high surface area,abundant porous structure,convenient operation and excellent adsorption performance.But the tedious fabrication process,high consumption of organic solvent and surfactant limited the application widely.Herein,a facile and eco-friendly spherical porous adsorbent (SPA) is fabricated from the green surfactant-free (corn oil)-in-water Pickering medium internal phase emulsions (Pick-ering MIPEs) via the convenient ion crosslinking procedure.The Pickering MIPEs synergis-tically stabilized with the semi-coke (SC),which is the natural particle produced from the shale oil distillation,and sodium alginate (SA) has excellent storage and anti-coalescence stability.The as-prepared porous adsorbent possessed the abundant pore structure,which provided favorable conditions for effective mass transfer in adsorption,and could be tuned by varying the SA dosage.The saturation adsorption capacities of Pb(Ⅱ) and Cd(Ⅱ) can be achieved with 460.54 and 278.77 mg/g within 45 min at 25℃,respectively.Overall,this study supplied a viable and eco-friendly route for fabricating the spherical porous adsorbent with a tunable porous structure for heavy metal ion wastewater.     

高能重离子辐照下国产RPV钢A508-3的硬化行为

目的 研究在563 K的温度条件下,高能重离子辐照导致国产RPV钢A508-3的硬化行为。方法 使用回旋加速器提供的352.8 MeV Fe²¹⁺对A508-3钢试样进行辐照,使其依次达到0.15、0.30、1.50 dpa的损伤水平。借助辐照终端的梯度减能装置,在样品表面至25 μm的深度范围内产生一个准均匀分布的原子离位损伤坪区,并使用纳米压痕仪和维氏显微硬度计测量了试样的硬度。结果 考虑到压痕尺寸效应的影响,采用Nix-Gao模型对硬度数据进行拟合,由于高能Fe离子产生了较厚的损伤区,辐照试样中的软基效应明显减弱。辐照后的试样出现明显的硬化现象,且随着辐照剂量的增大,硬化增量有饱和趋势。通过辐照前和辐照至0.15 dpa试样的微硬度数据,得出其与纳米硬度之间的线性关系(Hv0=0.85 H0)。结论 借助A508-3辐照前后的硬度数据,计算发现试样的屈服强度增量与辐照剂量之间存在一种幂函数关系,这为A508-3钢中子-离子辐照硬化的映射关系研究提供了基础数据。     

Ion movements in the nervous system of the American cockroach,periplaneta Americana (L.), influenced by toxaphene

Abstract

The effect of toxaphene upon ion fluxes of the central nervous system (CNS) of the cockroach, Periplaneta americana (L.), was studied in vitro. The CNS, divided into three sections (brain, thoracic, and abdominal), was exposed to 10 M toxaphene in saline containing ²⁴Na⁺, ⁴²K⁺, ³⁶Cl^‐, or ⁴⁵Ca⁺⁺. Uptake and efflux of these ions were evaluated. Toxaphene was responsible for significant increases in the internal levels of ⁴²K⁺ and ⁴⁵Ca⁺⁺, but had little affect upon Na or ³⁶Cl^‐ movements. The resulting concentration changes of the ions may be involved in the neural activity observed with toxaphene poisoning. Of the three CNS sections, significant changes were more numerous and occurred earlier in abdominal sections.     

发酵稻壳对亚铁离子和硫离子的吸附-解吸附特性

为了解发酵稻壳对Fe2+和S2-离子的固定潜力,采用静态批式法研究了发酵稻壳对Fe2+和S2-离子的吸附行为,探讨了反应时间、溶液中Fe2+和S2-浓度、溶液p H、吸附反应环境温度及溶液离子强度对发酵稻壳吸附Fe2+和S2-特性的影响,并进一步通过解吸附试验了解发酵稻壳吸附态Fe2+和S2-的稳定性.结果表明,发酵稻壳吸附Fe2+(r=0.912 1)和S2-(r=0.901 1)的动力学过程均符合Elovich动力学模型,且Fe2+(R2=0.965 1)和S2-(R2=0.936 6)的等温吸附特征可较好地用Freundlich等温吸附模型描述.发酵稻壳对Fe2+和S2-的吸附为非优惠型吸附,其中对Fe2+的吸附为非自发反应,对S2-的吸附为自发反应.发酵稻壳对Fe2+和S2-的吸附过程是一吸热过程,升温有利于吸附作用的进行,发酵稻壳对Fe2+的吸附主要为配位吸附,而对S2-的吸附主要为阴离子交换吸附.一定p H范围内(1.50~11.50)发酵稻壳吸附Fe2+和S2-具有较强的适应性.同时随着离子强度的增加发酵稻壳对Fe2+的吸附量有所增加,而对S2-的吸附量略有减少,进一步证明发酵稻壳对Fe2+的吸附以内层配位为主,对S2-的吸附以外层络合为主.此外,不同p H条件及离子强度下发酵稻壳吸附的Fe2+和S2-解吸率很低,解吸率均小于10.00%.上述结果说明,发酵稻壳对Fe2+和S2-具有较好的吸附能力和环境适应性,吸附态Fe2+和S2-稳定性好,不易再释放.     

铜胁迫对黄芪幼苗的生理学毒性与凹凸棒黏土的缓解作用

为探究黄芪幼苗对铜离子（Cu²⁺）胁迫的耐性机理以及凹凸棒黏土对Cu²⁺污染的缓解作用,研究了不同浓度CuSO₄（2~20mmol/L）胁迫对黄芪幼苗的生理学毒性与凹凸棒黏土的缓解作用.结果表明,2mmol/L CuSO₄胁迫使得根系Cu²⁺含量、H₂O₂（过氧化氢）含量、MDA（丙二醛）含量分别较对照显著上升1.82倍、1.04倍、2.14倍.CuSO₄胁迫浓度达8mmol/L时,根系SOD（超氧化物歧化酶）活性、根尖膜损伤程度和叶片Cu²⁺含量分别较对照显著上升1.13倍、1.12倍和2.62倍;同时,叶片PS Ⅱ（光系统II）实际光化学效率[Y（II）]、光化学淬灭系数（qP）、PSⅡ电子传递速率（ETR）和叶绿素含量较对照分别显著降低22.88%、24.44%、21.49%和28.31%,而NPQ和qN（非光化学荧光猝灭系数）则较对照分别显著上升2.35倍和1.58倍.根系POD（过氧化物酶）和CAT（过氧化氢酶）活性、可溶性糖和可溶性蛋白含量在8mmol/L CuSO₄处理下达到最高值后呈下降趋势.CuSO₄浓度为15~20mmol/L时,根系APX活性和叶片光适应下PS II潜在最大光化学效率（F_v'/F_m'）,以及幼苗全株鲜重、全株干重、地下部鲜重、地下部干重较对照显著下降.在非CuSO₄胁迫条件下,基质中凹凸棒黏土的存在使得幼苗根系MDA含量较对照显著降低15.93%,但未对其它所测生理学指标产生显著影响;在20mmol/L CuSO₄胁迫条件下,基质中凹凸棒黏土的存在使得幼苗根系和叶片中Cu²⁺含量分别显著下降30.78%和23.12%;同时显著缓解了20mmol/L CuSO₄胁迫对根系活性氧水平、抗氧化酶活性、膜脂质过氧化程度、根尖膜损伤程度、可溶性蛋白和可溶性糖含量,叶片PS II光化学活性和叶绿素含量的不良影响,以及对幼苗生长的抑制作用.研究结果表明,培养基质中凹凸棒黏土的存在能够显著降低幼苗组织中Cu²⁺的生物有效性,继而缓解CuSO₄胁迫对黄芪幼苗的生理学毒性作用.