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1.
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.  相似文献   

2.
The increasing application of engineered nanoparticles (NPs) has posed an emerging challenge to constructed wetland wastewater treatment. The performance, microbial community and toxic mechanism of anammox-based unplanted subsurface-flow constructed wetlands (USFCWs) were investigated under the long-term exposure of different graphene oxides (GOs) and Ag NP concentrations. Results showed that the addition of GO could promote TN removal, manifesting as function anammox bacteria C. Anammoxoglobus having a relative high abundance, for GO did not cause significant damage to the cell integrity though there was an increase in ROS concentrations. TN removal would not be obviously affected under exposure of 1?mg/L Ag NPs, for the function gene related to cell biogenesis and repair was up-regulated; while the addition of 10?mg/L Ag NPs would have an inhibiting effect on TN removal in the USFCWs, for the disappearance of some species having anammox ability. Key enzymes of anammox process (NIR and HDH) decreased to some extent under GO and Ag NP exposure, and function gene of defense mechanisms had an increase trend in samples.  相似文献   

3.
人工纳米颗粒对水生生物的毒性效应及其机制研究进展   总被引:7,自引:2,他引:5  
随着纳米科技的飞速发展和纳米产品的普及,人工纳米颗粒(NPs)的生物毒性效应研究逐渐成为国内外关注的热点.以水环境和水生生物为对象,综述了近几年来NPs对水生生物的毒性效应、毒性机制等方面的研究进展.文中按NPs的分类总结了NPs对微生物、藻类、原生动物和鱼类等水生生物的毒性效应,着重论述了NPs的可能毒性机制及其与NPs的独特物理化学性质之间的关系,并在细胞和分子水平上探讨了NPs的摄取、跨膜运输等方面的可能机制.在自然水体中,NPs因其化学行为受水化学条件等影响而表现出不同于实验室研究中的生物毒性效应,本文也对这方面的研究进行了讨论和总结.最后分析了目前水生生物纳米毒性研究中的瓶颈和方法、技术方面的问题,并对以后应注重开展的研究进行了展望.  相似文献   

4.
氧化铜纳米颗粒对水稻幼苗根系代谢毒性的研究   总被引:3,自引:1,他引:2  
王淑玲  张玉喜  刘汉柱  辛华 《环境科学》2014,35(5):1968-1973
为阐明氧化铜纳米颗粒(CuO NPs)暴露对植物生长的影响,分别用CuO NPs悬浮液、氧化铜大颗粒(CuO BPs)悬浮液和硫酸铜(CuSO4·5H2O)溶液进行处理,以蒸馏水(d H2O)作为对照,水培水稻幼苗,研究了CuO NPs对水稻幼苗根系相关生理生化行为的影响.结果表明,不同处理对水稻幼苗根系的影响有很大差异,经CuO NPs悬浮液处理后,水稻幼根受损较严重,根系活力明显降低,根内丙二醛(MDA)含量和过氧化氢(H2O2)含量显著升高,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性明显增强.不同处理对水稻幼苗根的影响依次为:CuO NPs>CuSO4·5H2O>CuO BPs>d H2O.说明氧化铜纳米颗粒对水稻根的毒害作用不仅是由于释放离子引起的,纳米颗粒本身也起着重要作用,氧化损伤可能是CuO NPs的主要致毒机制之一.  相似文献   

5.
纳米氧化锌(Zn O NPs)对呼吸道的毒性损伤作用备受关注,但有关其对呼吸道上皮细胞动态变化的影响机理还有待深入研究.因此,本研究通过将大鼠气管上皮细胞(RTE)暴露于不同浓度(1和10 mg·L~(-1))和不同粒径(50和200 nm)的Zn O NPs中,利用细胞电阻抗检测技术(ECIS)检测细胞动态变化,采用CCK8法检测细胞生长抑制效应,并通过胞内ROS和MDA含量变化探讨其影响机制.ECIS检测结果显示,Zn O NPs暴露下,RTE细胞生长和增殖受到明显抑制,且具有浓度依赖效应.当暴露浓度为1 mg·L~(-1)时,与对照组相比,50 nm暴露组细胞电阻抗值的下调幅度为18%,为200 nm暴露组的1.2倍.Zn O NPs诱导的RTE细胞增殖抑制率具有浓度依赖效应,当暴露浓度为10 mg·L~(-1)时,50和200 nm暴露组细胞增殖抑制率分别为暴露浓度为1 mg·L~(-1)时的2.9和1.4倍.Zn O NPs诱导的RTE细胞氧化应激结果显示,胞内ROS和MDA含量随着纳米颗粒暴露浓度的增加而增加,随着纳米颗粒粒径的减小而增加,具有显著的浓度-和剂量-依赖效应.当Zn O NPs浓度分别为1和10 mg·L~(-1)时,ROS含量分别是对照组的2.8和3.7倍;当暴露浓度为10 mg·L~(-1)时,50 nm暴露组细胞内ROS含量是200 nm暴露组的1.7倍;暴露浓度为1和10 mg·L~(-1)时,50 nm氧化锌处理组诱导的细胞内MDA含量分别是对照组的5.4和7.9倍.Zn O NPs能够影响呼吸道上皮细胞动态变化,从而破环RTE细胞屏障并进入细胞,诱导胞内ROS和MDA水平升高,进而抑制细胞的生长与增殖.研究表明,影响Zn O NPs诱导的RTE细胞动态变化和氧化应激的关键因素是颗粒粒径与暴露浓度.  相似文献   

6.
Engineered oxide nanoparticles (NPs) are widely applied in insulators, catalyzers, paints, cosmetic products, textiles and semiconductors. Their attachment on cell membrane may lead to cytotoxicity. The effects of Al2O3, Fe2O3, SiO2, TiO2 and ZnO NPs on membrane integrity and fluidity were studied using giant or small unilamellar vesicles in this study. Al2O3 and SiO2 NPs disrupted the oppositely charged membrane, indicating the important role of electrostatic attraction. However, Fe2O3, TiO2 and ZnO NPs did not cause serious membrane disruption as Al2O3 and SiO2 NPs. Membrane fluidity was evaluated by the generalized polarity (GP) values of Laurdan fluorescent emission. SiO2 NPs induce the membrane gelation of both positively and negatively charged membrane. Al2O3 and ZnO NPs induced the gelation of the oppositely charged membrane, but did not cause obvious membrane gelation to the like charged membrane. The phospholipid molecular structural changes after NP exposure were analyzed by Fourier transform infrared (FT-IR) spectroscopy. FT-IR spectra revealed the hydrogen bond formation between NPs and the carbonyl/phosphate groups of phospholipids. Al2O3 and SiO2 NPs showed strongest evidence of hydrogen bonding on their FT-IR spectra. It was consistent with the microscopic observation and fluorescent data that Al2O3 and SiO2 NPs caused more serious membrane disruption and gelation. This study on membrane damage provides further knowledge on the cytotoxicity of nanomaterials and the safety of NP application.  相似文献   

7.
对比研究了3种典型纳米金属氧化物颗粒(NPs,包括纳米TiO2(n-TiO2),纳米CeO2(n-CeO2)和纳米ZnO(n-ZnO))在不同作用浓度下(0,0.1,1,10,50mg/L)对污水生物脱氮系统中代表性氨氧化菌─ Nitrosomonas europaea连续作用6h的毒性效应及作用规律.结果表明,3种NPs对N.europaea的生物胁迫效应与其投加浓度均呈正相关.其中,50mg/L的n-CeO2, n-ZnO与对照组相比,可显著降低N.europaea细菌浓度,破坏细胞膜完整性,抑制氨氧化速率.相同浓度条件下, n-ZnO对N.europaea的毒性影响最大, n-TiO2影响最小.虽然n-ZnO释放的Zn2+对N.europaea具有明显的毒性效应,但n-ZnO及其产生的尺寸效应仍是其生物胁迫产生的重要来源.  相似文献   

8.
The objective of this study was to understand toxicity of mixture of nanoparticles (NPs) (ZnO and TiO2) and their ions to Escherichia coli. Results indicated the decrease in percentage growth of E. coli with the increase in concentration of NPs both in single and mixture setups. Even a small concentration of 1 mg/L was observed to be significantly toxic to E. coli in binary mixture setup (exposure concentration: 1 mg/L ZnO and 1 mg/L TiO2; 21.15% decrease in plate count concentration with respect to control). Exposure of E. coli to mixture of NPs at 1000 mg/L (i.e., 1000 mg/L ZnO and 1000 mg/L TiO2) resulted in 99.63% decrease in plate count concentration with respect to control. Toxic effects of ions to E. coli were found to be lesser than their corresponding NPs. The percentage growth reduction was found to be 36% for binary mixture of zinc and titanium ions at the highest concentration (i.e., 803.0 mg/L Zn and 593.3 mg/L Ti where ion concentrations are equal to the Zn ions present in 1000 mg/L ZnO NP solution and Ti+ 4 ions present in 1000 mg/L TiO2 NP solution). Nature of mixture toxicity of the two NPs to E. coli was found to be antagonistic. The alkaline phosphatase (Alp) assay indicated that the maximum damage was observed when E. coli was exposed to 1000 mg/L of mixture of NPs. This study tries to fill the knowledge gap on information of toxicity of mixture of NPs to bacteria which has not been reported earlier.  相似文献   

9.
以半滑舌鳎肝脏细胞(HTLC)为研究对象,利用噻唑蓝比色法(MTT)、乳酸脱氢酶(LDH)、活性氧自由基(ROS)和超氧化物歧化酶(SOD)等方法分析细胞活性、细胞膜完整程度以及氧化应激反应相关指标,探究海洋环境中放射性核素137Cs、90Sr的生物毒性效应。HTLC细胞活性随137Cs、90Sr活度升高呈先增加后降低的趋势,且在低活度核素作用下,细胞活性增加极其显著(p < 0.01),137Cs对细胞膜无损伤,90Sr则使细胞膜损伤显著(p < 0.05),但二者均能使ROS含量和SOD活性显著性增加(p < 0.05)。高活度核素作用下SOD活性均显著增加(p < 0.05),但137Cs作用时ROS无显著变化,90Sr则使ROS显著增加(p < 0.05)。研究表明,在本实验活度条件下,137Cs和90Sr对海洋鱼类细胞无显著的生物毒性,细胞能够通过自我调节维持正常功能。90Sr能产生氧化应激反应,对膜系统造成损伤,可能影响细胞多种代谢途径,对生物体具有潜在的毒性效应。  相似文献   

10.
With the increase in silver(Ag)-based products in our lives, it is essential to test the potential toxicity of silver nanoparticles(Ag NPs) and silver ions(Ag ions) on living organisms under various conditions. Here, we investigated the toxicity of Ag NPs with Ag ions to Escherichia coli K-12 strain under various conditions. We observed that both Ag NPs and Ag ions display antibacterial activities, and that Ag ions had higher toxicity to E. coli K-12 strain than Ag NPs under the same concentrations. To understand the toxicity of Ag NPs at a cellular level, reactive oxygen species(ROS) enzymes were detected for use as antioxidant enzymatic biomarkers. We have also studied the toxicity of Ag NPs and Ag ions under various coexistence conditions including: fixed total concentration, with a varied the ratio of Ag NPs to Ag ions; fixed the Ag NPs concentration and then increased the Ag ions concentration; fixed Ag ions concentration and then increasing the Ag NPs concentration.Exposure to Ag NPs and Ag ions clearly had synergistic toxicity; however, decreased toxicity(for a fixed Ag NPs concentration of 5 mg/L, after increasing the Ag ions concentration) to E. coli K-12 strain. Ag NPs and Ag ions in the presence of L-cysteine accelerated the bacterial cell growth rate, thereby reducing the bioavailability of Ag ions released from Ag NPs under the single and coexistence conditions. Further works are needed to consider this potential for Ag NPs and Ag ions toxicity across a range of environmental conditions.Environmental Significance Statement: As silver nanoparticles(Ag NPs)-based products are being broadly used in commercial industries, an ecotoxicological understanding of the Ag NPs being released into the environment should be further considered. Here, we investigate the comparative toxicity of Ag NPs and silver ions(Ag ions) to Escherichia coli K-12 strain, a representative ecotoxicological bioreporter. This study showed that toxicities of Ag NPs and Ag ions to E. coli K-12 strain display different relationships when existing individually or when coexisting, and in the presence of L-cysteine materials. These findings suggest that the toxicology research of nanomaterials should consider conditions when NPs coexist with and without their bioavailable ions.  相似文献   

11.
为揭示邻苯二甲酸二丁酯(dibutyl phthalate,DBP)对短裸甲藻(Gymnodinium breve)的抑制机制,采用荧光探针法和比色法研究了DBP对短裸甲藻活性氧(reactive oxygen species,ROS)、羟自由基.OH和过氧化氢H2O2含量以及超氧阴离子自由基O.2-产生速率的影响,同时观察了电子传递链抑制剂对DBP诱导ROS能力的影响.结果表明DBP诱导了短裸甲藻ROS的积累.随浓度的增大,DBP促进了.OH、H2O2的积累,如3 mg.L-1的DBP处理组,培养至48 h时.OH出现一个极大峰值33U.mL-1,约为对照组的2.4倍;H2 O2含量培养至72 h出现最大值,约为250 nmol.(107 cells)-1,约为对照组的5倍;但是DBP对O.2-产生速率的影响并没有显示出规律性.电子传递链选择性抑制实验表明DBP可能影响了藻细胞线粒体和细胞膜2个位点上电子传递,使.OH、H2O2含量和O.2-产生速率受到了不同的影响,最终诱导了短裸甲藻总ROS的积累.可见,DBP导致ROS的过量积累是其抑制藻细胞生长的主要机制.本研究结果对揭示化感物质抑制藻类的机制提供了科学依据.  相似文献   

12.
采用水热合成法制备了纳米级CuO颗粒粉末,XRD表征显示所制备的CuO催化剂晶型为单斜晶体。采用浸渍法制备CTS/CuO/ACF聚酯功能复合膜,研究了膜中不同组分对5mg/LNP吸附所起的作用,并研究了pH值、温度对复合膜吸附NP的影响以及不同CuO负载量对复合膜光催化性能的影响。研究显示,酸性条件、提高温度均有利于复合膜对NP的吸附去除,氧化铜负载量增加有利于光催化净化能力提高。此外,多次连续吸附实验证明,CTS/CuO/ACF复合膜可重复利用性高,并且如果经过光催化再生其吸附去除壬基酚能力仍然能达到75%以上。  相似文献   

13.
The toxic effects of gold nanoparticles surface-functionalized with the antimicrobial peptide indolicidin(Au NPs-indolicidin) towards the yeast Saccharomyces cerevisiae, one of the major eukaryotic model organisms, have been evaluated. Growth and survival,genotoxicity, as measured by comet assay, and expression of the YCA1, an apoptosis indicating gene, following 72 hr exposure of yeast to Au NPs-indolicidin, and to Au NPs and indolicidin alone have been examined. The gold nanoparticles exerted toxicity with DNA damage, accompanied by reactive oxygen species production(ROS), but they do not inhibit yeast growth and viability. Genotoxicity was less pronounced for surface-functionalized nanoparticles, showing that S. cerevisiae is quite resistant to the complex Au NPs-indolicidin.A progressive reduction of the genotoxic effect was observed along 72 hr exposure,presumably due to the activation of DNA repair mechanisms. These findings suggest the occurrence of a physiological protective response of S. cerevisiae towards nanoparticles,thereby providing useful information to the assessment of the environmental impact of metal nanoparticles.  相似文献   

14.
氧化铜纳米颗粒(CuO NPs)可以通过农药和肥料施用、意外泄露或污水灌溉进入As污染农田土壤,从而对土壤环境因子和As生物有效性产生影响.本试验选取两种不同类型土壤(安徽宿松黄棕壤和黑龙江海伦黑土)进行人工As污染,添加不同浓度的CuO NPs,探究90 d淹水-落干过程中CuO NPs对As污染农田环境因子和As生物有效态的影响.结果表明,CuO NPs进入土壤后12 h内快速溶解产生Cu2+,且在黄棕壤中的溶解速度较黑土迅速.CuO NPs可在短时间内降低土壤pH,提高土壤氧化还原电位(Eh),降低土壤电导率(EC),但随着培养时间增加土壤EC逐渐提高.一定时间内CuO NPs在两种类型土壤中可降低51.0%~82.5%土壤浸出液中的As和15.7%~66.5%的As生物有效性,减少淹水时Fe (II)的含量.但在土壤落干时期产生一定的“纳米效应”从而促进了Fe (II)的产生.研究表明,CuO NPs进入As污染农田改变了土壤环境因子,一定时间内降低了土壤As生物有效性.  相似文献   

15.
TiO_2 nanoparticles(NPs) could adversely impact aquatic ecosystems. However, the aggregation of these NPs could attenuate this effect. In this work, the biological effects of TiO_2 NPs on a marine microalgae Isochrysis galbana were investigated. The aggregation kinetics of TiO_2 NPs under different conditions was also investigated to determine and understand these effects. Results showed that, though TiO_2 NPs had no obvious impact on the size and reproducibility of algal cells under testing conditions, they caused a negative effect on algal chlorophyll, which led to a reduction in photosynthesis. Furthermore, fast aggregation of TiO_2 NPs occurred under all conditions, especially at the pH close to the p Hzpc. Increasing ionic strength and NP concentration also enhanced the aggregation rate.The aggregation and the following sedimentation of TiO_2 NPs reduced their adverse effects on I. galbana.  相似文献   

16.
Titanium dioxide nanoparticles(TiO_2 NPs) are among the most widely manufactured nanomaterials on a global scale. However, prudent and vigilant surveillance, incumbent upon the scientific community with the advent of new technologies, has revealed potentially undesirable effects of TiO_2 NPs on biological systems and the natural environment during their application and discharge. Such effects are likely best evaluated by first assessing the fate of the TiO_2 NPs in natural environments. In this study, the effects of terrestrial humic acid(HA) and tannic acid(TA), two major members of the collective:dissolved organic matter(DOM), on the cytotoxicity of TiO_2 NPs to Escherichia coli were investigated in the presence and absence of natural sunlight. Qualitative(transmission electron microscopy(TEM)) and quantitative(LC50) analyses were employed in this study. In addition, the production of reactive oxygen species(ROS) in the form of UOH was further assessed—as HA or TA increased the production of ROS decreased. The inhibition of bacterial viability in the light treatment groups, with respective treatment organics at concentrations of 10 ppm, was less in TA than in terrestrial HA. SAS was used to analyze the treatment effect of individual factors of light irradiation, DOM, and concentration of TiO_2 NPs.  相似文献   

17.
黑磷纳米片(Black Phosphorus nanosheets,BPNSs)具有广泛的应用前景,而关于BPNSs的安全性研究还十分匮乏.为探究BPNSs对水生生物的毒性作用,本研究通过液相剥离法制备得到厚度为(58.05±36.48) nm,横向尺寸为(541.25±176.22) nm的BPNSs,选择初级生产者斜生栅藻(Scenedesmus obliquus)为受试生物开展了毒性效应研究.将斜生栅藻暴露于0、10、50、100 mg·L-1 BPNSs中,结果表明:各浓度的BPNSs均抑制斜生栅藻的生长,120 h时的EC50为74.86 mg·L-1;与对照组相比,各处理组叶绿素a (Chlorophyll a)含量降低且呈剂量-效应关系,表明BPNSs对斜生栅藻光合系统产生了损害;暴露48 h后3个处理组的活性氧(Reactive oxygen species,ROS)含量显著升高,表明BPNSs对斜生栅藻造成了氧化损伤;显微观测(100×)发现处理组的藻细胞被BPNSs包裹,表明BPNSs可能通过吸附作用团聚在斜生栅藻表面;场发射电子扫描显微镜(FE-SEM)观测发现处理组的藻细胞形态受到显著破坏,表明BPNSs对斜生栅藻产生了物理损伤.本实验结果能够为后续BPNSs在水环境食物链中的潜在富集风险相关研究提供理论支撑.  相似文献   

18.
贺凡  谢磊  徐晓娇  江天久 《海洋环境科学》2019,38(4):489-493, 502
在室内以翡翠贻贝(Perna viridis)为对象,研究单种抑食金球藻(Aureocuccos anophagefferens)及其与亚心形四爿藻(Tetraselmis subcordiformis)混合藻液条件下抑食金球藻对贻贝的生长和摄食的影响。结果表明,抑食金球藻对翡翠贻贝的生长和摄食均有显著的负面影响。单种高、中浓度抑食金球藻组贻贝的鲜重、干重及无灰分干重均显著低于混合藻组,贻贝的个体生长条件指数(CI)下降明显,其下降率甚至高于饥饿组。混合藻组中贻贝的CI、软组织的鲜重、干重、无灰分干重等均显著低于对照组,其抑制程度与混合藻组中抑食金球藻浓度有关,当混合藻组中抑食金球藻浓度较大时(≥ 4×105 cells/mL),贻贝的上述指标更低。四组混合藻中贻贝的摄食率也均显著低于对照组,抑食金球藻对贻贝的抑食作用也与其藻细胞密度有关,混有较高密度抑食金球藻组中贻贝的摄食率更低,说明抑食金球藻并非因其个体太小而不能被贝类正常摄食,可能产生了某种生物活性物质抑制了贻贝的摄食和生长,亚心形四爿藻能在一定程度上可以缓解抑食金球藻对贝类摄食和生长的抑制作用。  相似文献   

19.
利用硼氢化钠还原硝酸银,并使用聚乙烯醇(PVA)作为分散剂,制备出分散良好、粒径为(14±3)nm的纳米银颗粒,考察了其对聚磷菌(Microlunatus phosphovorus)好氧吸磷和厌氧释磷的影响,以及产生的毒性效应.结果表明,在好氧状态下,7mg/L的纳米银能够完全抑制聚磷菌的生长(P <0.01),达到10mg/L时才能完全抑制聚磷菌的吸磷能力(P=0.01);在厌氧状态下,大于20mg/L的纳米银才使聚磷菌释磷能力受到部分抑制(P <0.05).活性氧簇(ROS)和扫描电子显微镜(SEM)的检测结果表明,纳米银使细菌体内ROS水平降低,部分细菌菌体表面塌陷,这说明,纳米银不但可以毒害聚磷菌菌体表面,还可以降低菌内ROS水平.  相似文献   

20.
在静态暴露的条件下,利用流式细胞术等检测技术,考察了不同浓度的溴酸盐对普通小球藻的生长以及生理特性的影响,并对溴酸盐的毒性作用机制进行了初步的探索.结果表明,当溴酸盐浓度达到8 mmol·L~(-1),持续暴露96 h时,能够引起普通小球藻比生长率显著降低、细胞膜完整性显著降低、酯酶活性显著升高、线粒体膜电位显著升高、活性氧水平显著增加.扫描电镜可直观表明细胞膜受到损伤.由此说明,由于溴酸盐毒性的持续作用,使得活性氧在藻细胞内积累,普通小球藻自身的调节功能不能及时消除过多的活性氧,从而引起细胞膜完整性、酯酶活性和线粒体膜电位出现异常情况,藻细胞生理功能出现紊乱,藻细胞结构遭到破坏,最终导致普通小球藻生长受到抑制或死亡.  相似文献   

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