镧、铈、钕对小鼠肝细胞核的氧化损伤作用

轻稀土元素进入生物体后主要累积于肝脏,进入肝细胞,分布于细胞核上.为探讨轻稀土元素对小鼠肝细胞核的氧化损伤作用,选用5周龄雄性封闭群(ICR)小鼠灌喂10、20和40 mg·kg-1的稀土元素镧(La)、铈(Ce)和钕(Nd),6周后测定小鼠肝细胞核中超氧化物岐化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(...     

Accumulation and remobilization of metals in superficial sediments in Tianjin, China

The concentrations of Cr, Ni, Cu, Zn, Cd, and Pb in superficial sediment samples collected from three representative sites (Yuqiao Reservoir, Haihe River, and Haihe River Estuary) in Tianjin, North China, were analyzed using various single extraction and sequential extraction procedures to determine their remobilization, extractability, and distribution patterns. Sediments from the Haihe River had higher metal concentrations and geo-accumulation indices, especially for Cd and Zn, than sediments from the other two sites, suggesting that the Haihe River has been heavily influenced by anthropogenic activities. In addition, over 31% and 28.2% of the total Cd in the Haihe River and the Yuqiao Reservoir, respectively, and 18.2% of the total Zn in the Haihe River were found to be associated with the exchangeable form, indicating the significant remobilization of Cd and Zn when compared with Cr and Ni. However, over 98% of the Ni and 78% of the Cr were most closely associated with the residue and oxidizable fractions, which resulted in their becoming environmentally immobile. Based on the Environmental Protection Agency method 3050B, Cd and Zn had the greatest extraction efficiency when a single extraction procedure using 0.5-mol L^???1 HCl, 0.43-mol L^???1 HAcO, and 0.05-mol L^???1 ethylene-diamine-tetra-acetic acid was conducted, with extraction yields of up to 72%, 68%, and 56% for Cd and 50%, 49%, and 29% for Zn, respectively, being obtained for the Haihe River sediments. This was followed by the yields of Cu and Pb and, finally, those of unpolluted metals such as Cr and Ni. HCl and acetic acid extraction provided equivalent information for predicting Cd and Zn mobility in the sediments studied and produced suitable results for quick screening.     

解读城考指标新要求,发挥城考工作新作用

通过解读"十一五"末期国家城考新指标,结合城考工作新形势,剖析当今新疆城市环境综合整治定量考核工作中存在的具体问题,提出新疆城市城考工作具有建议性的意见,为"十二五"期间新疆城市有的放失地推动城考工作提供依据.     

Distribution and ecotoxicological significance of trace element contamination in a ~150 yr record of sediments in Lake Chaohu, Eastern China

This paper presents the concentrations, vertical profiles and possible sources of selected major and trace elements in a sediment core covering ～150 years of sedimentation in Lake Chaohu, eastern China. Element concentrations were measured by portable X-ray Fluorescence Spectroscopy (XRF) and were used to evaluate possible environmental consequences of the recent industrialization in China. Statistical analyses identify four groups: (1) organic carbon (OC), total nitrogen (TN), Pb, Zn, and As associated with the use of chemical fertilizers and pesticides; (2) Mn, Cr, Ni and Cu from industrial and mining activities; (3) Fe, Rb, K, Co, Ti and Ca influenced by post-depositional processes and land exploitation; and (4) Zr and Sr from the soil. The vertical profiles of elements placed in the first two groups show distinct increases in concentrations above depths of 20 cm (~1978), coincident with the timing of industrialization in China, and the anthropogenic-derived fluxes are higher than the lithogenic-derived fluxes over the last three decades. With the exception of Zr and Sr, association of the measured metals with organic carbon and nitrogen suggests that organic matter may act as a carrier phase. The geoaccumulation index (I(geo)) reveals increased contamination from elements in the first two groups in recent years. Element concentrations, compared with the Effects Range-Low (ERL) and Effects Range-Median (ERM) levels set by NOAA, suggest that adverse biological effects from Ni contamination are very likely.     

黑龙江省雷暴灾害损失风险评估与区划

利用黑龙江省2001-2005年78个气象站的雷暴资料,采用加权综合评价法和AHP决策分析法首次对黑龙江省雷暴灾害损失风险进行了评估,并与GIS技术耦合进行了雷暴灾害损失风险区划。结果表明:雷暴灾害高损失风险区分布在哈尔滨、绥化及双鸭山的市区,危险性和暴露性因子为主导因子;中等损失风险区集中在哈尔滨以及绥化所辖的大部分县市,还有牡丹江、鸡西、大兴安岭地区的部分县市,以及齐齐哈尔市、黑河市和讷河县等地;轻、低损失风险区分布在齐齐哈尔、黑河的大部分县市及东部平原地区。     

安太堡露天矿复垦地不同人工植被恢复下的土壤酶活性和肥力比较

人工重建植被是露天矿复垦地植被恢复,提高土壤质量的主要途径之一.选择适宜的人工植被对快速恢复土壤质量具有重要意义.本文主要研究了安太堡露天矿复垦地油松-刺槐-柠条混交林、沙棘-刺槐-柠条-沙枣混交林和苜蓿地的土壤养分含量及酶活性,综合评价了这3种不同植被类型对土壤肥力恢复效果.结果表明,随着植被恢复的进行,土壤养分含量均有增加,油松-刺槐-柠条混交林的土壤养分含量显著高于其它样地.从以养分含量和酶活性权重计算的土壤综合肥力指标值(IFI)可知,油松-刺槐-柠条混交林IFI值最高.综合来看,对土壤重建效果最好的为油松-刺槐-柠条混交林,其次是沙棘-刺槐-柠条-沙枣混交林,再次为苜蓿.     

Surfactant-assisted adsorption of uranyl ions in aqueous solution on TiO2/polythiophene nanocomposite

In this work, hexadecyltrimethylammonium-bromide (HTAB)-modified polythiophene (PTh)/TiO₂ nanocomposite (HTAB/PTh/TiO₂) was applied to remove uranyl ions (UO₂²⁺). FT-IR, XRD, ζ potential, TGA, SEM, and XPS were utilized to obtain the chemical and physical properties of HTAB/PTh/TiO₂. The effects of HTAB content, preparation temperature, and adsorption conditions on UO₂²⁺ removal were investigated comprehensively. And the UO₂²⁺ adsorption process on HTAB/PTh/TiO₂ was fitted to the Sips model with a saturated adsorption capacity of 234.74 mg/g, which was 6 times over TiO₂. The results suggested that the surfactant of HTAB can significantly improve the adsorption ability of TiO₂ for UO₂²⁺ ions. This work provides a strategy of surfactant modification for enhancing the separation and recovery ability of adsorbent toward UO₂²⁺ in the radioactive wastewater.

     

Hydrodynamics and water quality of the Hongze Lake in response to human activities

Environmental Science and Pollution Research - The hydrodynamics and water quality of a lake in response to human activities is an important yet poorly understood issue. In this study, the...     

Life cycle and economic assessment of enhanced ecological floating beds applied water purification

Environmental Science and Pollution Research - The ecological floating beds (EFB) are widely used in water quality restoration because of its low cost, high efficiency, and green characteristics....