Application potential of carbon nanotubes in water treatment：A review

Water treatment is the key to coping with the conflict between people’s increasing demand for water and the world-wide water shortage. Owing to their unique and tunable structural, physical, and chemical properties, carbon nanotubes (CNTs) have exhibited great potentials in water treatment. This review makes an attempt to provide an overview of potential solutions to various environmental challenges by using CNTs as adsorbents, catalysts or catalyst support, membranes, and electrodes. The merits of incorporating CNT to conventional water-treatment material are emphasized, and the remaining challenges are discussed.     

贵阳市工业固体废物现状及发展研究

随着贵阳市城市经济的快速发展,工业固体废物的产生量、综合利用处置量也随之增加。调查和分析了近年来贵阳市工业固体废物产生、利用和处置的相关现状,并提出相应的管理对策和建议,对贵阳市工业固体废物的有效管理和循环经济的发展具有一定参考价值。     

Detoxifying PCDD/Fs and heavy metals in fly ash from medical waste incinerators with a DC double arc plasma torch

Medical waste incinerator (MWI) fly ash is regarded as a highly toxic waste because it contains high concentrations of heavy metals anddioxins, including polychlorinateddibenzo-p-dioxins (PCDDs) and polychlorinateddibenzofurans (PCDFs). Therefore fly ash from MWI must be appropriately treated before beingdischarged into the environment. A melting process based on adirect current thermal plasma torch has beendeveloped to convert MWI fly ash into harmless slag. The leaching characteristics of heavy metals in fly ash and vitrified slag were investigated using the toxicity characteristic leaching procedure, while the content of PCDD/Fs in the fly ashes and slags was measured using method 1613 of the US EPA. The experimental results show that thedecomposition rate of PCDD/Fs is over 99% in toxic equivalent quantity value and the leaching of heavy metals in the slag significantlydecreases after the plasma melting process. The produced slag has a compact and homogeneous microstructure withdensity of up to2.8 g/cm3 .     

LncRNA NEAT1 contributes to the acquisition of a tumor like-phenotype induced by PM 2.5 in lung bronchial epithelial cells via HIF-1α activation

Environmental Science and Pollution Research - The hazards of particulate matter (PM2.5) on human respiratory health have been previously reported. However, the molecular mechanisms underlying...     

Assessment of uranium migration and pollution sources in river sediments of the Ili River Basin using multiply statistical techniques

Environmental Science and Pollution Research - Uranium (U) is a highly toxic radioactive element and limited to < 30 μg/L in drinking water by the World Health Organization. In this...     

Prenatal diagnosis of de novo distal 11q deletion associated with sonographic findings of unilateral duplex renal system,pyelectasis and orofacial clefts

In utero diagnosis of de novo distal 11q deletion associated with renal and orofacial malformations has not been previously described. We present a 35-year-old pregnant woman with prenatal sonographic findings of a unilateral duplex renal system, pyelectasis and orofacial clefts at 20 weeks' gestation. Both genetic amniocentesis and postnatal cytogenetic analysis revealed de novo 46,XX,del(11)(q23). After birth, the fetus manifested a dysmorphic phenotype correlated with del(11q) syndrome. Genetic marker analysis showed a paternally derived distal deletion of chromosome 11q and a breakpoint centromeric to D11S1341. The present case represents the earliest prenatal diagnosis of a duplex renal system, pyelectasis and an additional feature of orofacial clefts associated with distal 11q deletion. Prenatal sonographic detection of a duplex renal system, pyelectasis and orofacial clefts should warrant a careful assessment of fetal anatomy and prompt cytogenetic analysis looking for chromosomal aberrations. Copyright © 2001 John Wiley & Sons, Ltd.     

Chromosome doubling of Sedum alfredii Hance: A novel approach for improving phytoremediation efficiency

Sedum alfredii Hance is a cadmium(Cd)/zinc(Zn) hyperaccumulator native to China.However, its relatively low biomass restricted the large-scale application for heavy metal contamination remediation. The chromosome set doubling of S. alfredii in vitro was achieved by 0.1%–0.2%(W/V) colchicine treatment. The plant DNA ploidy was analyzed by flow cytometry and chromosome set doubling plants(CSD) were identified based on the obvious different sharp peak. A tissue culture experiment with different Cd treated levels and a field trial with natural polluted mined soil were conducted to study the effects of chromosome doubling on plant biomass and Cd accumulation in shoots. The results suggested that S.alfredii is a mixoploid. Compared with the wild type plants(WT), CSD exhibited typical"gigas" characteristics in morphology including stem thickness, root hair production,number of leaves and size of stoma guard cell. Fresh weight and dry weight of CSD were increased to 1.62–2.03-fold and 2.26–3.25-fold of WT. And Cd content of CSD showed a17.49%–42.82% increase and 59% increase under tissue culture and field condition,accordingly. In addition, the TF and in BCF of CSD were 2.37-and 1.59-fold of WT,respectively. These results proved that it is feasible to promote phytoextraction efficiency of S. alfredii in Cd contaminated soils through chromosomal engineering, which provides a novel approach for hyperaccumulator application in phytoremediation.     

贵阳市“两湖一库”周边蜘蛛体内镉含量及暴露风险

调查了高镉地质背景区蜘蛛(肖蛸科、园蛛科、蟹蛛科和络新妇科)及其生境水体、土壤和植物中的镉含量,探讨了蜘蛛体内镉的来源、影响因子及存在风险。结果表明,研究区蜘蛛体内的平均镉含量为1. 82±1. 37μg/g(n=130),表现为园蛛科肖蛸科络新妇科≈蟹蛛科。蜘蛛体重与体内镉含量表现出弱的负相关关系(r=-0. 17,p=0. 08),暗示了蜘蛛生长发育过程中的生物稀释效应。狩猎型蟹蛛科和结网型园蛛科蜘蛛体内镉含量与对应土壤镉含量呈显著正相关关系(r=0. 61,0. 97),并且它们对土壤的生物富集因子均大于1,表明这两类蜘蛛可以用来指示土壤镉污染。生物有毒物质残留指数显示,研究区蜘蛛受高镉地质背景影响,体内存在着一定的镉暴露风险。     

Hydrological Variability and Uncertainty of Lower Missouri River Basin Under Changing Climate

The lower Missouri River Basin has experienced increasing streamflow and flooding events, with higher risk of extreme hydrologic impacts under changing climate. The newly available North American Regional Climate Change Assessment Program (NARCCAP) climate projections were used as atmospheric forcing for Soil and Water Assessment Tool (SWAT) model which runs with varying potential evapotranspiration (PET) methods to assess the hydrological change and uncertainty of 2040‐2069 over 1968‐1997. The NARCCAP temperature and precipitation predictions were refined using a bias correction method. The results show that, following the seasonal variability of precipitation, various water fluxes would increase in most seasons except the summer. Expected precipitation tends to increase in intensity with little change in frequency, triggering faster surface water concentration to form floods. The greatest streamflow increase would occur from November to February, increasing by around 10% on average. An increase of 3% occurs in the other months except for July and August in which river discharge decreases by around 2%. The climate predictions contribute more uncertainty annually, but PET algorithms gain more influence in winter or when other weather factors such as wind play a relatively more important role on evapotranspiration flux. This study predicts an even wetter environment compared to the historically very wet period, with the possibility of more flooding.     

不同温度条件下高分子固化剂改良砂土的强度特性∗

近年来城市热岛效应越加明显,温度变化对土体性质的影响程度备受关注。通过一系列无侧限抗压强度试验,对高分子固化剂改良砂土在不同温度条件下的抗压强度特性进行了研究,并结合微观扫描电镜对改良砂土的微观结构和改良机理进行了研究。结果表明：在相同温度条件下,高分子固化剂改良砂土的强度和弹性模量随高分子固化剂含量的增加而增大;随着温度的升高,高分子固化剂改良砂土的强度和弹性模量一直保持增强趋势,且当温度达到 35℃后,加入 3% 和 4% 含量的高分子固化剂改良砂土的强度增幅变缓;高分子固化剂溶液均匀分散在砂土中,随着水分挥发,在砂粒之间形成了空间网状固化膜,使得分散的土体连接成为一体,从而提高砂土强度;且随着温度的增加,形成的固化膜强度增强,使得改良砂土强度进一步增加。高分子固化剂在高温条件下对砂土依然具有较好的加固效果,可为高温地区防风固沙加固提供新途径。