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1.
Coking wastewater has caused serious health risk in coal-producing areas of China, however its toxic effects have not been well understood. The genotoxicity induced by coking wastewater on mice in vivo and its possible oxidative mechanisms were investigated via observing the induction of micronuclei in polychromatic erythrocytes of mouse bone marrow, and subsequently determining the antioxidative enzyme activities (superoxide dismutase Cu, Zn-SOD, Se-dependent glutathione peroxidase, and catalase), thiobarbituric acid reactive substance contents and protein carbonyl levels in brains and livers of mice. Results showed that the tested coking wastewater caused a significant increase of micronucleus frequencies in a concentration-dependent manner. Also, the sample increased lipid peroxidation and protein oxidation levels, which was accompanied by changes in antioxidative status. Interestingly, pre-treatment with an antioxidant (vitamin C) led to a statistical reduction in the micronucleus frequency caused by coking wastewater. This implies that coking wastewater induces evident genetic damage in mammalian cells, and exposure to polluted areas might pose a potential genotoxic risk to human beings; in the process, oxidative stress played a crucial role.  相似文献   

2.
李洁  肖琳 《环境科学》2016,37(10):3850-3857
本研究合成了一种新型高效的去除铜绿微囊藻(Microcystis aeruginosa)的氧化石墨烯/季铵盐聚乙烯亚胺(GO/QPEI)纳米复合材料.GO/QPEI在pH为4~10的条件下都具有高效去除M.aeruginosa的能力,其去除能力在2 min内可达96%以上.GO/QPEI对微囊藻的吸附更符合Freundlich方程,最大吸附量为5.58×1011cells·mg-1.吸附动力学表明GO/QPEI的假二级吸附反应.GO纳米片和QPEI的协同效应是其高效去除微囊藻的主要机制.  相似文献   

3.
Hepatitis A virus (HAV) is currently recognized as an important human food borne pathogen, and it is one of the most resistant enteric RNA viruses, is highly infectious, and may lead to widespread outbreaks. The aim of this study was to optimize the methods to detect HAV from artificially contaminated food. To this end, strawberry and lettuce were experimentally contaminated with HAV suspension containing 6 × 106 copies/ml. After contamination, HAV persistence and washing procedure were evaluated at 0, 1, 3, 7, and 9 days of storage. Five elution buffers (PBS (pH 7.4)/0.1% Tween80; 50 mM glycine/3% (wt/vol) beef extract (pH 9.5); PBS (pH 7, 4); 25 mM glycine/0.1 Tween80; and 1 M sodium bicarbonate) were used to elute the virus, and qualitative and quantitative PCR were used for HAV detection. HAV was detected by qualitative and quantitative PCR using any of the five elution buffers, but PBS was the most effective. Even after washing, HAV was detected up to 9 days after contamination by quantitative PCR. Quantitative PCR was more sensitive than qualitative PCR since samples containing viral load lower than 1.4 × 103 copies/ml could not be detected by qualitative PCR. Quantitative PCR can be used for rapid detection of food borne viruses and will help in the monitoring and control of food borne disease.  相似文献   

4.
从焦化废水厂的活性污泥中筛选间二甲苯混合降解菌,并研究非离子型表面活性剂吐温80(C_(64)H_(124)O_(26))对混合菌降解间二甲苯的强化作用.研究结果表明:驯化后的间二甲苯混合降解菌以产黄杆菌属(Rhodanobacter sp.)为主,占比41.2%;仅存在吐温80作为单一碳源时,高浓度的吐温80对混合降解菌没有明显的抑制作用;吐温80与间二甲苯共存时,当吐温80浓度为2 CMC,反应72 h后间二甲苯的降解率达到最高,为76%;提前12 h(较混合降解菌)投加浓度为2 CMC的吐温80,最利于菌种的生长繁殖及间二甲苯的降解.  相似文献   

5.
我国流域水环境呈现典型的复合污染特征,亟需发展基于生物效应的生态风险评估方法,以实现环境管理和生态修复的精准化.在野外原位暴露下受试生物受到多种污染物的共同胁迫,可以准确表征研究位点复合污染所产生的生态风险.原位生物测试较传统实验室生物测试具有更高的环境真实性和生态相关性,较野外生物监测对生物体承受的外源污染压力更清晰、可控.综述了基于原位生物测试的水生态风险评估技术,旨在促进该技术在我国水环境监测中的应用,提高生态风险评估的准确度.总结了国内外近年来原位生物测试的研究特色,详细阐述了实施过程中受试生物选择、暴露装置设计和研究位点选择的原则,以及原位生物测试方法在水环境生态风险评估中的应用案例.结果表明:①对原位生物测试实施要素进行规范化形成标准,将有利于该方法在环境管理中的推广应用.②利用原位生物效应、原位生物体内浓度以及二者与环境浓度相结合进行风险评估,是原位生物测试在生态风险评估中的三类应用类型.③原位生物暴露与被动采样的联合应用可同步获取原位生物效应和污染物生物可利用浓度,有利于实现全面准确的风险评估,应用潜力较大.研究表明,选用本土模式生物,采用多层次的毒性终点,设计简单有效的暴露装置,并同时考虑原位生物效应和环境浓度将有利于原位生物测试方法在我国的发展.   相似文献   

6.
表面活性剂Tween80及DOM对土壤中菲、芘解吸的影响   总被引:1,自引:0,他引:1  
王艮梅  孙成  谢学群 《环境科学》2007,28(4):832-837
采用室内序批试验研究了水溶性有机物(DOM)及表面活性剂Tween80对污染土壤中菲、芘解吸行为的影响.结果表明,DOM能够增加土壤中菲、芘的解吸率,且猪粪堆肥的DOM作用效果较好;随着体系中Tween80浓度的增加,土壤中菲、芘的解吸率也明显地增加,当Tween80浓度为150 mg·L-1时,菲、芘的解吸率分别是对照的1.7倍(菲)和6.2倍(芘);DOM与Tween80联合作用时受Tween80浓度的影响,低浓度时联合作用效果不明显,当Tween80为150 mg·L-1时,菲、芘的解吸率显著增加且大于两者单独作用的结果之和.试验结果还表明,同等条件下高相对分子质量DOM组分(>25000)对土壤中菲、芘的解吸作用大于低相对分子质量DOM组分(<1 000).  相似文献   

7.
To attain a better understanding of the effects of surfactants on the metabolic kinetics of hydrophobic organic compounds, the biodegradation of phenanthrene by Citrobacter sp. SA01 was investigated in a batch experiment containing Tween 80, sodium dodecyl benzene sulfonate and liquid mineral salt medium. The Monod model was modified to effectively describe the partition, phenanthrene biodegradation and biopolymer production. The results showed that Tween 80 and sodium dodecyl benzene sulfonate (each at 50 rag/L) enhanced phenanthrene metabolism and poly-β-hydroxybutyrate production as indicated by the increasing amounts of intermediates Coy 17.2% to 47.9%), and percentages of poly-β- hydroxybutyrate (by 107.3% and 33.1%) within the cell dry weight when compared to their absence. The modified Monod model was capable of predicting microbial growth, phenanthrene depletion and biopolymer production. Furthermore, the Monod kinetic coefficients were largely determined by the surfactant-enhanced partition, suggesting that partitioning is a critical process in surfactant-enhanced bioremediation of hydro- phobic organic compounds.  相似文献   

8.
为揭示饮水型砷暴露对机体的毒性,系统研究了砷摄入对实验动物基础生理和多系统脏器的毒性损伤作用.选雄性ICR小鼠为受试动物,以自由饮用含砷10 mg·L-1的水溶液进行染毒,连续染毒60 d后检测发现,饮水砷暴露对小鼠一般体征和体重无显著影响,肝脏脏器系数显著降低,心脏、肺脏、肾脏和睾丸脏器系数降低,但无统计学意义.砷染毒组血清谷丙转氨酶(ALT)和谷草转氨酶(AST)活性显著升高,总胆固醇(TC)和甘油三酯(TG)含量显著升高,高密度脂蛋白胆固醇(HDL-C)含量显著降低,低密度脂蛋白胆固醇(LDL-C)含量显著升高;肝脏、小肠、心脏、肺脏、肾脏和睾丸组织中还原型谷胱甘肽(GSH)含量和超氧化物歧化酶(T-SOD)活性显著降低,过氧化氢(H2O2)和丙二醛(MDA)含量显著升高,并出现程度不同的组织形态结构损伤.研究结果表明,饮水砷暴露可诱发实验小鼠肝脏功能异常、生理代谢紊乱,导致消化系统、循环系统、呼吸系统、泌尿系统与生殖系统等多系统脏器组织的氧化损伤和结构病变,砷暴露对机体的毒性作用存在组织器官差异性,对肝脏的损伤较严重.  相似文献   

9.
陈少毅  张静  汪涵  任源 《环境科学》2014,35(10):3918-3925
增强多氯联苯(PCBs)的水溶性是强化PCBs微生物降解的主要控制因素之一,本研究选取了PCB5(2,3-CB)和PCB31(2,4’,5-CB)作为低氯代PCBs的典型代表,以曲拉通100(TX-100)、吐温80(Tween 80)、鼠李糖脂粗提物(RL crude)3种表面活性剂和β-环糊精(HPCD)联合Burkholderia xenovorans LB400构建PCBs好氧降解体系,测试了它们对PCB5和PCB31的溶出率及微生物生长的影响.结果表明,TX-100(CMC=194 mg·L-1)、Tween 80(CMC=13.1 mg·L-1)、RL crude(CMC=50mg·L-1)浓度在1~7 CMC时和HPCD浓度在500~1500 mg·L-1时对PCB5和PCB31溶出率分别达到54.7%~100%、59.8%~100%;10.5%~40.8%、6.8%~31.6%;10.3%~19.9%、3.3%~11.6%和19.5%~34.2%、4.2%~10.7%.TX-100浓度在1~7 CMC时对B.xenovorans LB400生长的抑制率达到30.3%~45.8%,而Tween 80浓度在0.1~1 CMC时对其生长的抑制率为10.0%~15.4%;RL crude本身能作为底物促进LB400的生长,而HPCD对其生长无明显影响.B.xenovorans LB400对PCB31(5 mg·L-1)的降解效率在添加表面活性剂后有不同程度的提高:TX-100,23.7%~65.5%;Tween80,14.6%~44.3%;RL crude,9.6%~27.2%;HPCD,15.3%~20.7%;而表面活性剂对PCB5(10 mg·L-1)的降解效率则无明显影响.表面活性剂主要通过增大溶液中PCBs-表面活性剂的胶束浓度来提高LB400对PCBs的降解效率,在水溶液培养体系中当设置TX-100和Tween 80浓度分别在1和7 CMC时,PCB31的降解效率达到100%和81.7%,而此时B.xenovorans LB400生长的抑制率为30.3%和5.4%.  相似文献   

10.
研究了铜锈环棱螺对沉积物颗粒的摄取速率、从水和沉积物中摄取BDE-47的效率,以及在BDE-47污染沉积物中添加玉米秸秆生物炭后对这些生理学参数和间隙水中BDE-47平衡浓度的影响.构建了基于铜锈环棱螺摄取和消除BDE-47的相关生理学参数和沉积物地球化学参数的生物动力学预测模型,同时评价了该模型预测BDE-47生物积累的效力.结果显示,铜锈环棱螺对沉积物的摄食率为6.04 g·g-1·d-1,对水中BDE-47的摄取效率为38.41%.在BDE-47污染沉积物中添加4%的玉米秸秆生物炭(CSB)可以显著降低间隙水中BDE-47的平衡浓度,降幅达到81%.铜锈环棱螺对添加CSB的沉积物中BDE-47的生物积累显著低于未添加CSB的沉积物,暴露28 d后,添加CSB的沉积物中BDE-47的生物积累下降了66%.本研究构建的生物动力学模型的预测结果与暴露测试中观察到的铜锈环棱螺对BDE-47的摄取情况基本一致.BDE-47的28 d生物积累对沉积物颗粒摄食率、从沉积物中摄取BDE-47的效率、沉积物中BDE-47的浓度和BDE-47的消除速率常数等4个参数的响应表现出较好的敏感性.根据模型的预测,铜锈环棱螺从沉积物中摄取的BDE-47占总积累量的80%以上.当沉积物中添加CSB后,模型显示出更好的预测效力.因此,在已知沉积物和间隙水中BDE-47浓度的前提下,利用该模型可以有效地预测铜锈环棱螺体内BDE-47的积累量,从而减少沉积物生态毒性风险评价和利用生物炭进行原位修复效果评估的不确定性.  相似文献   

11.
Homogeneous and vertically aligned silicon nanowires (SiNWs) were successfully fabricated using silver assisted chemical etching technique. The prepared samples were characterized using scanning electron microscopy, transmission electron microscopy and atomic force microscopy. Photocatalytic degradation properties of graphene oxide (GO) modified SiNWs have been investigated. We found that the SiNWs morphology depends on etching time and etchant composition. The SiNWs length could be tuned from 1 to 42 µm, respectively when varying the etching time from 5 to 30 min. The etchant concentration was found to accelerate the etching process; doubling the concentrations increases the length of the SiNWs by a factor of two for fixed etching time. Changes in bundle morphology were also studied as function of etching parameters. The SiNWs diameter was found to be independent of etching time or etchant composition while the size of the SiNWs bundle increases with increasing etching time and etchant concentration. The addition of GO was found to improve significantly the photocatalytic activity of SiNWs. A strong correlation between etching parameters and photocatalysis efficiency has been observed, mainly for SiNWs prepared at optimum etching time and etchant concentrations of 10 min and 4:1:8. A degradation of 92% was obtained which further improved to 96% by addition of hydrogen peroxide. Only degradation efficiency of 16% and 31% has been observed for bare Si and GO/bare Si samples respectively. The obtained results demonstrate that the developed SiNWs/GO composite exhibits excellent photocatalytic performance and could be used as potential platform for the degradation of organic pollutants.  相似文献   

12.
为掌握氧化石墨烯(GO)的水环境风险,以斜生栅藻(Scenedesmus obliquus)和湖泊微拟球藻(Nannochloropsis limnetica)为研究对象,探究了GO对淡水微藻生长及其生物活性物质(碳水化合物、总蛋白质、总脂)的影响.结果表明,GO对2种微藻具有中等毒性,72h EC50值分别为25.63和48.44mg/L.透射电镜(TEM)观察发现,GO纳米片层既能附着于藻细胞表面也能进入藻细胞内部,造成藻细胞超微结构明显变化,包括:质壁分离;叶绿体收缩;淀粉粒数量减少甚至消失.较低浓度(10mg/L)GO会促进微藻中光合色素(叶绿素a、叶绿素b、类胡萝卜素)合成;而较高浓度(100mg/L)GO暴露下,2种微藻的类胡萝卜素和斜生栅藻叶绿素a的含量显著降低.2种浓度的GO总体上刺激了藻细胞内生物活性物质的合成,这是污染胁迫下的一种主动防御机制;而较高浓度GO造成碳水化合物含量显著降低,可能原因是细胞中储能物质由淀粉向中性脂转化.  相似文献   

13.
通过TCS(三氯生)亚致死剂量急性暴露斑马鱼胚胎至幼鱼,探究其对斑马鱼胚胎发育和脂质代谢的影响.结果表明,在体视显微镜下统计发现TCS在200μg/L浓度急性暴露延迟了 72hpf胚胎的孵化,孵化率下降13.24%,而畸形率提高80%以上.120hpf(受精后小时)幼鱼畸形表现为能量淤积、卵黄囊肿、吸收障碍而后延,游囊...  相似文献   

14.
为了考察复杂体系的二级处理出水在UV光解及UV/TiO_2光催化反应过程中生物效应的变化,本文探究了反应前后发光细菌的荧光抑制毒性、SOS/umu遗传毒性、小球藻光合抑制效应3种生物效应的变化,并分析了物化指标的变化与生物效应之间的关系.结果表明,UV光降解过程并不能高效削减二级处理出水的荧光抑制毒性,但可以高效削减遗传毒性和光合抑制效应,其削减率分别达到61%和81%;在低辐照强度下,UV/TiO_2光催化过程对3种生物效应的削减率分别为38%、84%和80%.增大辐照强度后,3种生物效应的削减率进一步提高,尤其是荧光抑制毒性,其削减率可提高至62%.在UV光降解条件下,二级处理出水的遗传毒性、光合抑制效应与荧光强度、UV_(254)之间存在很好的线性关系;在UV/TiO_2光催化条件下,二级处理出水的3种生物效应都与荧光强度、UV_(254)之间具有很好的线性关系.这为二级处理出水生物效应的控制及生态安全的保障提供了一定的依据.  相似文献   

15.
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   

16.
徐巍  赵勇胜  李隋  戴宁 《环境科学》2008,29(8):2336-2340
通过静态吸附实验,研究了25℃条件下,表面活性剂冲洗液Tween 80在中砂上的吸附,以及CaCl2、SDS和木质素磺酸盐(木质素磺酸钠和木质素磺酸铵)对其吸附量的影响.结果表明,向Tween 80溶液中加入CaCl2和SDS都可以显著增加其吸附量.投加量越多,吸附量越大,当投加量达到一定程度后,吸附达到饱和,不会继续增大.SDS以预吸附的方式注入同样会导致Tween 80吸附量升高.而木质素磺酸盐与Tween 80共混则可大大降低Tween 80的吸附量.随着投加量的增加,Tween 80吸附量明显下降.在低投加比例(1:10)时,木质索磺酸铵效果较好,可以减少20%-75%的吸附量.而木质素磺酸钠只能减少10%-60%.当投加较高比例(1:2)时,两者都口1以明显降低Tween 80的吸附量,可达70%-90%.而采用木质素磺酸盐预吸附的方式注入的效果较混合注入要好,相同投加最的情况下,所降低Tween 80的吸附量是混合注入时的1.2-1.8倍.因此.在表面活性剂原位冲洗过程中用木质素磺酸盐进行预冲洗,能够减少表面活性剂吸附量,降低冲洗成本,可以作为原位冲洗过程中降低吸附损失的一种手段.  相似文献   

17.
张秋亚  马晓妍  王晓昌  游猛 《环境科学》2017,38(3):1084-1092
为了更加准确评估城市生活污水的综合生物毒性以及处理工艺对污水毒性的削减状况,本研究通过发光菌急性毒性、遗传毒性、雌激素活性检测方法对A~2/O工艺处理前后污水的毒性进行评价,同时通过斑马鱼暴露实验分析污水和回用水对水生生物内分泌干扰效应的作用模式.结果表明,污水厂进水具有较强的急性毒性、遗传毒性以及雌激素活性,水质较差.经二级生物处理后,上述毒性显著性降低,污水厂出水水质提高.但污水出水雌二醇当量为1.89 ng·L-1,仍可能会对受纳水体的水生生物产生潜在危害.浓缩2.5倍的水样导致雄性斑马鱼肝脏的卵黄原蛋白基因(vtg1)和雌激素受体基因(esr1)的表达水平显著上升,由此可以得出污水可通过干扰目的基因的表达来调控水生生物的内分泌活动.而esr1基因在肝脏的表达被抑制说明污水可能具有抗雌激素作用,同时反映进行生物毒性效应分析时应从多个组织或器官考虑,以获得比较全面的信息.  相似文献   

18.
以海洋微藻青岛大扁藻(Platymonas helgolanidica var.tingtaoensis)为受试对象,研究了氧化石墨烯(graphene oxide,GO)与邻苯二甲酸二丁酯(dibutyl phthalate,DBP)单独及共同对青岛大扁藻的急性毒性效应,考察了藻细胞的生长状况,光合色素产量,细胞通透性,氧化应激指标及扫描电镜,以探讨GO的加入对DBP藻毒性的影响.结果表明,低浓度GO(0.1~10 mg·L~(-1))对青岛大扁藻的藻密度和叶绿素产量无明显影响,但藻细胞通透性随GO浓度升高显著增加(P0.05),10mg·L~(-1)时达到空白组的2.2倍.DBP对青岛大扁藻的EC50,96 h为(11.14±0.80)mg·L~(-1),其毒性远大于GO(EC50,96 h大于100mg·L~(-1)).1 mg·L~(-1)GO的加入使DBP的EC50,96 h降低到(4.93±2.14)mg·L~(-1),低浓度GO对DBP藻毒性表现出一定的增强作用.1 mg·L~(-1)的GO加入时,对低浓度DBP组(0.1~2 mg·L~(-1))的藻密度、叶绿素产量、细胞通透性水平没有显著性影响,但加剧了高浓度DBP组(4 mg·L~(-1))对藻密度、叶绿素产量的抑制,使单个藻细胞内ROS和SOD平均增加了21%和7%.扫描电镜结果发现GO对藻细胞具有覆盖,包裹及聚集作用,这些可能是DBP藻毒性增强的主要原因.该结果为揭示新型污染物碳纳米材料对海洋生物的风险提供了数据支持.  相似文献   

19.
研究氧化石墨烯(GO)的水环境行为对于阐明其生态风险具有重要意义。本文将GO分散于不同盐度的水体中,研究了GO在水环境中的分散稳定性及聚沉行为。结果表明,GO能够均匀分散于去离子水中,且降低溶液的pH。随着静置时间的延长,GO产生缓慢聚沉。随分散水体盐度增加,GO溶液的聚沉速率快速增加,聚沉颗粒粒径明显增加;当水体盐度达到8~10后,GO溶液的聚沉速率趋于理想状态下的快速聚沉速率。GO在不同盐度海水中的聚沉服从经典的胶体稳定性理论,其聚集效率随盐度的增加呈现两阶段过程。由此计算出2~100 mg/L的GO溶液的临界团聚盐度为6.79~11.84。由此可见,较稳定分散于淡水水体的GO可能对淡水生物产生较高的生态风险,而在海水中易于聚沉的GO可能对近海底栖生物存在较高的生态风险。  相似文献   

20.
氧化石墨烯强化厌氧氨氧化菌的脱氮性能   总被引:1,自引:0,他引:1  
采用氧化石墨烯(GO)增强厌氧氨氧化菌的脱氮性能.通过批次试验观察GO对厌氧氨氧化菌的影响,结果表明:当GO浓度为0.15g/L时,厌氧氨氧化菌脱氮性能最好,总氮去除率比无GO的空白组提高18.6%;当GO剂量达到0.2g/L时,厌氧氨氧化菌活性受到抑制,总氮去除率比空白组降低了26.0%.通过对照实验研究GO对厌氧氨氧化菌脱氮性能的长期影响,结果表明:添加GO的R2反应器在每个基质浓度阶段的平均总氮去除率分别为85.3%,83.2%,81.1%,80.8%,均高于未添加GO的R1反应器.对R2反应器周期内脱氮性能进行动力学分析发现,修正的Boltzmann模型和修正的Gompertz模型比修正的Logistic模型更适合描述GO作用下周期内基质去除特性,并且通过模型得到了周期内任意t时刻下的出水总氮浓度和总氮去除率预测公式.  相似文献   

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