The combined toxicity and mechanism of multi-walled carbon nanotubes and nano copper oxide toward freshwater algae: Tetradesmus obliquus

Nanoparticles(NPs) are widely used for their special physical properties and released into the natural environment. When two types of NPs exist in the same environment, the presence of one type of NP may affect the properties of the other type of NP. This study investigated the toxic effects of multi-walled carbon nanotubes(MWCNTs) and copper oxide nanoparticles(Cu O NPs) on Tetradesmus obliquus. Both NPs had toxic effects on algae, and the toxic effects of MWCNTs were significantly stronger tha...     

纳米颗粒物对肺表面活性物质界面性质的影响

以纳米二氧化硅、纳米碳粉、纳米氧化锌、纳米氧化铈、纳米碳化硅和纳米四氧化三铁等纳米颗粒物(NPs)为代表,研究其对肺表面活性物质(PS)界面性质的影响.结果表明,NPs对PS中的磷脂和蛋白组分均有吸附作用,其中纳米二氧化硅和纳米四氧化三铁分别对磷脂和蛋白组分的吸附能力最强,吸附率为89.3%和82.5%.NPs的存在会导致PS溶液的表面张力升高,这当中纳米二氧化硅的效果最为显著.纳米碳化硅和纳米二氧化硅等颗粒物会引起PS膜的π-A等温线的内缩/外扩,且颗粒物浓度越高,表面压力变化越明显.此外,PS也会对NPs的水合动力学直径和Zeta电位产生影响,导致其分散状态变化.由此可见,NPs可通过改变PS的组成和界面性质而具备危害人体健康的潜力.     

基于神经网络模型绿色合成纳米氧化锰及其性能研究

近年来,基于对纳米材料生物毒性和合成成本的考虑,纳米材料的绿色合成和应用在环境领域受到了广泛关注,但迄今仍面临纳米材料的绿色合成机制尚未明确及去除效率不理想两个问题.本研究选择As（III）和As（V）作为目标污染物,通过神经网络模型对纳米氧化锰（MONPs）的合成条件进行优化,发现当污染物浓度和材料投加量分别为0.1 mg?L^-1和5 mg?L^-1时,优化后的MONPs对As（III）和As（V）的去除 效率分别从43.9%、80.0%提高到90.2%、92.2%.从SEM的结果中发现优化后的材料粒径更小,根据EDS和FTIR结果,可以证明优化后材料中的Mn元素比例显著增加.另外,XRD和XPS结果则证明优化后材料从原来的Mn（II）变为Mn（IV）,提高了材料的氧化能力.Zeta电位结果表明优化后材料表面的负电荷减少,进而循环伏安法结果证实了材料电子转移能力的提高,均有利于As的去除.最后,优化后MONPs在经过5次重复利用后仍具高的性能,同时对多种重金属具有一定的吸附能力.显然,基于神经网络模型绿色合成氧化锰纳米材料对砷污染修复具有 较强的针对性和实用性.     

Investigation of mercury (II) adsorption from aqueous solution onto copper oxide nanoparticles: Optimization using response surface methodology

Response surface methodology was practicable to optimize the mercury (II) removal using copper oxide nanoparticles in an aqueous matrice. The copper oxide nanoparticles structure was performed by TEM, SEM, XRD and BET. The experiment reactions were carried out based on a Box–Behnken design (BBD) and evaluated using RSM. Batch mode tests were conducted to prognosticate the adsorption equilibrium. The three parameters influence on the mercury removal was inquired by a response surface methodological approach. In study, influence of adsorbent dose, pH and temperature on the mercury removal unto copper oxide nanoparticles has been performed. The importance of the independent factors and their interactions were investigated by the ANOVA. The optimum pH, adsorbent dose and temperature were obtained to be 9.0, 0.05 g and 278 K, respectively.     

Physiological and antioxidative response of Brassica nigra (L.) to ZnO nanoparticles grown in culture media and soil

Abstract

To investigate metal nanoparticle-induced phytotoxicity, Brassica nigra seeds were exposed to 50–1000?mg L^?1 ZnO nanoparticles in culture media and 100–1000?mg kg^?1 in soil. Plant length and weight were adversely affected in culture conditions, but with soil the effect was not significant. Determination of the radical-scavenging potential revealed that soil grown plants were less stressed than plants grown on culture medium. The total antioxidant and reducing power potential of soil grown plants were less variable compared to plants grown on culture medium. Total phenolic and flavonoid concentrations varied in plants, which changed with the nanoparticle’s concentrations in medium and soil. High performance liquid chromatography analysis showed that rutin was the major antioxidative molecule that significantly increased in nanoparticles-stressed B. nigra plants.     

利用Fe3O4纳米颗粒磁分离去除水中小粒径微塑料

建立了微塑料（Microplastics,MPs）荧光定量分析方法,系统研究了Fe₃O₄纳米颗粒对水中聚苯乙烯MPs的磁性去除效果.结果表明,MPs浓度在本实验范围内（0.2~10.0mg/L）与荧光强度线性关系良好,相关系数均>0.9990,能准确测定不同粒径（100~1000nm）MPs的浓度.MPs初始浓度与Fe₃O₄纳米颗粒投加量对MPs去除效果具有影响.增加Fe₃O₄纳米颗粒的投加量能够有效提升水中MPs的去除率,当Fe₃O₄投加量为12mg/L时,去除率可达90.8%.在低Fe₃O₄投加量时,MPs去除率随着MPs初始浓度增加而显著增加,显著性水平为0.015;但在中、高Fe₃O₄投加量时,初始浓度对去除效果影响很小,显著性水平分别为0.073和0.060.Fe₃O₄纳米颗粒对MPs的附着过程能够在180min内趋于平衡,整个动力学可通过拟一级或拟二级模型进行拟合.     

磁性纳米材料吸附处理工业废水的研究进展

介绍了磁铁矿、磁赤铁矿、MFe₂O₄型铁氧体等几种常见的磁性纳米颗粒及其制备和功能化方法,综述了磁性纳米吸附剂在重金属废水、染料废水、含油废水、含酚废水吸附处理中的新研究进展.根据研究过程中所存在的问题总结并展望了磁性纳米吸附材料的未来发展趋势,在今后的研究可从吸附剂的制备优化、吸附机理、实用性和再生回用等方面展开探究,以期发挥其在实际工业废水处理中的应用潜力.     

Removal of benzotriazole by heterogeneous photoelectro-Fenton like process using ZnFe2O4 nanoparticles as catalyst

ZnFe2O4 nanoparticles(ZFNPs) were developed as catalyst for the degradation of benzotriazole(BTA) by heterogeneous photoelectroFenton(PE-Fenton) like process.ZFNPs were prepared by a co-precipitation process and then characterized with transmission electron microscopy(TEM),X-ray fluorescence(XRF),X-ray diffraction(XRD) and BET surface area.Using such ZFNPs as catalyst,the degradation of BTA was investigated.Due to the high catalytic activity of ZFNPs,PE-Fenton like process showed efficient degradation of BTA.The influencing factors such as pH,dosage of ZFNPs,applied potential and initial concentration of BTA were systematically investigated.Under the optimum conditions,91.2% of BTA was removed after 180 min treatment.     

纳米氧化铜颗粒和环丙沙星对好氧颗粒污泥的协同胁迫效应

纳米颗粒和抗生素在污水处理厂中的共同存在可产生综合毒性.选择纳米氧化铜颗粒(CuO NPs)和环丙沙星(CIP)作为纳米颗粒和抗生素的代表性物质,探究了CuO NPs和CIP共存胁迫对好氧颗粒污泥(AGS)系统的运行性能、污泥特性和微生物群落的长期影响.结果表明:CuO NPs单独胁迫使脱氮性能轻微提高,对碳和磷的去除性能轻微下降.CIP单独胁迫显著抑制了碳、氮和磷的去除性能.CuO NPs和CIP共存时对碳、氮和磷去除表现出明显的协同抑制效应.CuO NPs和CIP共存胁迫使细胞膜完整性下降,乳酸脱氢酶(LDH)释放量增多,胞外聚合物(EPS)分泌增强,且溶解性EPS(S-EPS)的官能团发生显著变化.CuO NPs和CIP共存胁迫改变了微生物群落结构,对生物多样性具有显著的协同抑制效应,对微生物具有较强的毒性作用.     

纳米氧化铜对镉胁迫下小油菜生理生化和重金属累积的影响

为探究纳米氧化铜（CuO NPs）在镉（Cd）胁迫下对作物生长、生理特性和重金属吸收的影响,采用水培实验,以夏绿2号小油菜为供试植物,研究了CuO NPs （0、10、20和50 mg ·L^-1）和Cd （0、1和5 μmol ·L^-1）单一和复配处理下小油菜鲜重、光合色素、丙二醛含量（MDA）、抗氧化酶活性［过氧化氢酶（CAT）、过氧化物酶（POD）、超氧化物歧化酶（SOD）和谷胱甘肽还原酶（GR）］以及Cu和Cd含量.结果表明,在单一CuO NPs处理下,小油菜鲜重以及CAT、POD、GR酶活性总体上受到抑制,叶绿素含量和SOD活性随浓度增加呈现出先增加后降低趋势,而小油菜叶部、根部MDA含量以及亚细胞中Cu含量随投加量增加而增加.1 μmol ·L^-1Cd处理下,添加CuO NPs促进了小油菜生长,鲜重较对照增加了8.70%~44.87%,当Cd浓度达到5 μmol ·L^-1时,低浓度CuO NPs （10 mg ·L^-1）处理表现为促进植物生长,高浓度（50 mg ·L^-1）处理则呈抑制效应.不同Cd处理下添加CuO NPs均提高了小油菜的光合色素和MDA含量,其中小油菜叶部MDA含量较对照增加了4.34%~36.27%,根部MDA含量增加了13.43%~131.04%.Cd浓度为1 μmol ·L^-1处理下施加CuO NPs后,小油菜叶部CAT和GR活性均下降,POD活性上升;当Cd浓度达到5 μmol ·L^-1时,CuO NPs提高了小油菜叶部POD活性,抑制了SOD和GR活性,CAT活性随浓度升高呈现先上升后下降的趋势.CuO NPs与Cd表现出拮抗作用,添加CuO NPs后,1 μmol ·L^-1 Cd处理下小油菜叶部和根部Cd含量最大降幅分别为45.64%和33.39%,5 μmol ·L^-1 Cd处理下叶部和根部Cd含量最大降幅分别为18.25%和25.35%,小油菜亚细胞器中Cu和Cd质量分数下降,可溶性组分质量分数上升.综上所述,低浓度下CuO NPs可以促进Cd胁迫下植物生长,抑制植物对Cd吸收,但会增加植物氧化损伤.