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111.
112.
Adsorption behaviors of Cd^2+ on Fe2O3/MnO2 and the effects of coexisting ions under alkaline conditions 总被引:2,自引:0,他引:2
This study describes the adsorption features of cadmium on Fe2O3 and MnO2 in alkaline saline conditions. The adsorption reached equilibrium in 6 hours under alkaline conditions. The absorption of cadmium on Fe2O3 and MnO2 was consistent with Freundlich absorption isotherms, and the corresponding adsorption capacities were 16.3 and 16.7 mg·g-1, respectively. Moreover, the adsorption quantity of cadmium on Fe2O3 and MnO2 rose with increasing pH from acidic to neutral, and reached the maximum at pH= 9. The coexisting chlorides reduced the adsorption capacity of Fe2O3 and MnO2. The influence intensities of different cations follow the order of CaCl2>>KCl>NaCl. However, the influence of sodium salts on the capacities of Fe2O3 and MnO2 to adsorb cadmium appeared more complicated: the relatively low concentrations of sodium salts could reduce the adsorption capacity; with increasing concentrations of sodium salts, e.g. NaCl and NaNO3. The adsorption capacity decreased continually. Moreover, due to the competition adsorption and precipitation effects, the adsorption capabilities of Na2CO3, NaH2PO4 and Na2HSO4 could also be reduced and cadmium concentrations in the solution were reduced as well. 相似文献
113.
采用半静态染毒实验研究了菲和Cd2+单一及复合污染下胁迫9 d和清水释放2 d过程中毛蚶体内活性氧(ROS)、谷胱甘肽(GSH)含量和谷胱甘肽硫转移酶(GST)活性的变化。结果表明,菲和Cd2+单独胁迫能诱导毛蚶体内ROS含量的增加及GSH含量、GST活性的降低,且随染毒浓度的增加,对各指标影响愈明显,存在剂量-效应关系。毛蚶体内GSH和GST的变化趋势具有一致性。菲和Cd2+复合污染对毛蚶体内的氧化胁迫效应整体大于二者单独污染。在清水释放阶段,单一及复合污染胁迫组各指标均能恢复至对照组水平。表明毛蚶体内抗氧化系统适合作为监测海洋多环芳烃和重金属复合污染的生物标志物。 相似文献
114.
To assess the toxicity of heavy metal pollution to marine intertidal shellfish, enzymatic responses and lipid peroxidation were investigated in the clam Mactra vereformis exposed to cadmium under laboratory conditions. Three antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPx), two immune defense enzymes (acid phosphatase, ACP; alkaline phosphatase, ALP), and one lipid peroxidation product (malondialdehyde, MDA) were measured in the gills and the hepatopancreas of the ... 相似文献
115.
重金属铅和镉对溪荪生理特性的影响 总被引:2,自引:0,他引:2
采用水培法,研究重金属铅和镉及其复合胁迫对溪荪(Iris sanguine)生理特性的影响。结果表明,在500mg/L铅和500mg/L铅+25 mg/L镉复合胁迫下,溪荪的叶绿素a、叶绿素b和类胡萝卜素含量增加,其中,叶绿素a含量增加显著(p<0.05);在25 mg/L镉胁迫下,溪荪的叶绿素a、叶绿素b和类胡萝卜素含量均减少,其中叶绿素a含量减少显著(p<0.05);25 mg/L镉胁迫增大了溪荪地上部分细胞膜的透性,比对照升高了27%,并使丙二醛含量增加到对照的1.19倍;在500mg/L铅胁迫下,丙二醛含量有所上升,但与对照相比差异不显著,说明在该实验浓度下,溪荪对铅的耐性比对镉的耐性强;在500mg/L铅+25 mg/L镉复合胁迫下,无论溪荪地上部分(叶片)还是地下部分(根茎和根)的丙二醛含量都明显增加,说明复合胁迫给溪荪细胞膜带来很大的伤害;铅和镉胁迫对溪荪过氧化物酶(POD)和超氧化物歧化酶(SOD)活性的影响相似,所有污染处理都对溪荪的地下部分酶活性起明显的促进作用,而对溪荪地上部分的酶活性有明显抑制作用。过氧化物酶和超氧化物歧化酶活性在溪荪耐铅和镉胁迫中起到了非常重要的作用。 相似文献
116.
117.
研究了石墨炉原子吸收测定钛铁矿中微量元素Cd的方法,探索了在高含量的Fe,Ti基体干扰下以NH4H2PO4-H2NCSNH2-EDTA为混合基体改进剂的最佳仪器工作条件。在取样0.200 0g,定容25mL的条件下,方法检出限为0.006μg/g,用国家标准物质验证,其准确度(RE%)10%,12次测定精密度(RSD%)10%,加标回收率90%~110%之间,符合国家相关要求。 相似文献
118.
基于我国海洋生物区系特征的渤海表层水体中镉的概率生态风险评估 总被引:1,自引:0,他引:1
Predicted no-effect concentration(PNEC) is often used in ecological risk assessment to determine low-risk concentrations for chemicals. In the present study, the chronic data from native saltwater species were used to calculated PNEC values using four methods: log-normal distribution(ETX 2.0), log-triangle distribution(US EPA's water quality criteria procedure), burr III distribution(Burrli OZ) and traditional assessment factor(AF). The PNECs that were calculated using four methods ranged from 0.08 μg/L to 1.8 μg/L. Three of the SSD-derived PNECs range from 0.94 to 1.8 μg/L, about a factor of two apart. To demonstrate the use of SSD-based PNEC values and comprehensively estimate the regional ecological risk for cadmium in surface water of the Bohai Sea, in the Liaodong Bay, Bohai Bay, and Laizhou Bay, China, the dissolved cadmium concentrations were measured and obtained 753 valid data covering 190 stations from July 2006 to November 2007. Based on three ecological risk assessment approaches, namely hazard quotient(HQ), probabilistic risk quotient and joint probability curve(JPC), the potential ecological risk of cadmium in surface water of the Liaodong Bay, Bohai Bay, and Laizahou Bay were estimated. Overall, the ecological risk of cadmium to aquatic ecosystem in the whole Bohai Sea was at acceptable ecological risk level, the order of ecological risk was Liaodong BayBohai BayLaizhou Bay. However, more concerns should be paid to aquatic ecological risk in the Liaodong Bay which is the home of many steel, metallurgy and petrochemical industrial in China. 相似文献
119.
Small heat shock proteins encompass a widespread but diverse class of proteins,which play key roles in protecting organisms from various stressors.In the present study,the full-length cDNAs of two small heat shock proteins(MgsHSP22 and MgsHSP24.1)were cloned from Mytilus galloprovincialis,which encoded peptides of 181 and 247 amino acids,respectively.Both MgsHSP22 and MgsHSP24.1 were detected in all tissues examined by real-time PCR,with the highest expression being observed in muscle and gonad tissues.The real-time PCR results revealed that Cd signifi cantly inhibited MgsHSP22 expression at 24 h and MgsHSP24.1 at 24 and 48 h under 5 μg/L Cd 2 + exposure.MgsHSP24.1 expression was also signifi cantly inhibited after 50 μg/L Cd 2+ exposure for 48 h.With regard to antioxidant enzymes,increased GPx and CAT activity were detected under Cd 2+ stress(5 and 50 μg/L),while no signifi cant difference in SOD activity was observed throughout the experiment.Overall,both MgsHsps and antioxidant enzymes revealed their potential as Cd stress biomarkers in M.galloprovincialis. 相似文献
120.
Yin Hanqin Lu Xinzhe Sun Rui Huang Chunlei Kang Zhanjun Xu Mingxing Wei Yingchun Cai ZiHua 《地理学报(英文版)》2023,33(2):413-426
Journal of Geographical Sciences - In recent years, Cadmium (Cd) pollution has been found in many soil geochemical surveys in Northern Zhejiang Plain, a crucial rice production area in East China,... 相似文献