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241.
Yilei Yu Xianfang Song Yinghua Zhang Fandong Zheng Ji Liang Dongmei Han Ying M Hongmei Bu 《环境科学学报(英文版)》2013,25(9):1754-1763
Reclaimed water was successfully used to recover the dry Chaobai River in Northern China, but groundwater may be polluted. To ensure groundwater protection, it is therefore critical to identify the governing factors of groundwater chemistry. Samples of reclaimed water, river and groundwater were collected monthly at Chaobai River from January to September in 2010. Fifteen water parameters were analyzed. Two kinds of reclaimed water were different in type (Na-Ca-Mg-Cl-HCO3 or Na-Ca-Cl-HCO3 ) and concentration of nitrogen. The ionic concentration and type in river were similar to reclaimed water. Some shallow wells near the river bed had the same type (Na-Ca-Mg-Cl-HCO3 ) and high concentration as reclaimed water, but others were consistent with the deep wells (Ca-Mg-HCO3 ). Using cluster analysis, the 9 months were divided into two periods (dry and wet seasons), and all samples were grouped into several spatial clusters, indicating different controlling mechanisms. Principal component analysis and conventional ionic plots showed that calcium, magnesium and bicarbonate were controlled by water-rock interaction in all deep and some shallow wells. This included the dissolution of calcite and carbonate weathering. Sodium, potassium, chloride and sulfate in river and some shallow wells recharged by river were governed by evaporation crystallization and mixing of reclaimed water. But groundwater chemistry was not controlled by precipitation. During the infiltration of reclaimed water, cation exchange took place between (sodium, potassium) and (calcium, magnesium). Nitrification and denitrification both happened in most shallow groundwater, but only denitrification in deep groundwater. 相似文献
242.
Optimization of bio-drying of kitchen waste: inoculation,initial moisture content and bulking agents
Song Xiao Ma Jiao Gao Jiandong Liu Yanbo Hao Yongce Li Wei Hu Ruhai Li Aimin Zhang Lei 《Journal of Material Cycles and Waste Management》2017,19(1):496-504
Journal of Material Cycles and Waste Management - Bio-drying has been proved to be a promising method for treatment of MSW (municipal solid waste) and sewage sludge due to its high energy... 相似文献
243.
近年来,随着全球各地城市化和工业化进程的不断加快,以及人类对河流水生态系统资源的不合理、掠夺式利用,河流水生态系统遭到严重破坏,各地河流相继出现水质恶化、水文条件改变、物种多样性退化、生境条件恶劣等诸多问题。文章对辽河主要支流清河水生态系统的水质状况进行了研究,并于2012年6月,对清河流域22个监测断面水质状况进行了实地调查,对其水质状况进行了评价,结果表明:22个监测断面中,达到Ⅲ类水质断面的有8个,Ⅳ类7个,Ⅴ类1个,劣Ⅴ类6个。其中6个劣Ⅴ类断面分别因氟化物、氨氮、总磷浓度超标而为劣Ⅴ类。 相似文献
244.
本文结合儋州市第二期农业综合开发的实践,客观地总结了该市所取得的成绩,较详细地剖析了成功的原因,并提出了综合开发儋州市农业的建议. 相似文献
245.
Chinese brake fern (Pteris vittata L.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well-documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg(-1)) and P (0, 25, and 50 mg kg(-1)) and with and without Chinese brake fern colonized by a community of AM fungi from an As-contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As-contaminated soils, the mycorrhizal status of ferns needs to be taken into account. 相似文献
246.
采集了 4个不同地区花岗岩石英、热液脉石英 ,分析其中包裹体分子水与结构羟基水的含量、包裹体分子水的δDinclusion、结构羟基水的δDOH,计算了结构羟基水 包裹体分子水之间的D/H分馏系数αOH inclusion。考查了混合水 (结构羟基水 +包裹体分子水 )δDwhole water与单独包裹体水δDinclusion之间的差别 ,分析了这种差别与分馏系数αOH inclusion的关系。结果表明 :花岗岩样品中两种水之间的分馏系数小 ,分馏程度大 ,在常规分析中 ,若采用测定混合水δDwhole water值代表实际流体 (包裹体水 )δDinclusion值时 ,二者间有较大的差异。热液石英脉样品总体来说分馏系数接近于 1,分馏程度小 ,常规分析中引起的二者之间差异小。常规的分析方法用于分馏程度小的热液脉石英是可行的 ,但进行花岗岩石英水的氢同位素分析时有必要区分出包裹体水与羟基水。 相似文献
247.
248.
类二噁英多氯联苯生殖毒性的研究进展 总被引:1,自引:0,他引:1
类二噁英多氯联苯(DlPCBs)作为典型的环境内分泌干扰物,会干扰接触个体或其后代的内分泌功能,破坏机体的神经系统、免疫系统,尤其对生殖系统的影响最为明显,比如对生殖器官的形态与功能、生殖内分泌、原始生殖细胞及其受精和早期胚胎发育等产生严重影响,最终导致各种生殖系统疾病的发生。DlPCBs的蓄积性及半挥发性使其在环境中分布广泛,半衰期长的特点使其将对动物及人类的生存和健康造成难以想象的影响。本文综述了DlPCBs的分类与构成、一般性质、生殖毒性以及其可能的致病机理,并对DlPCBs生殖毒性机理研究的重点方向进行了展望。 相似文献
249.
马莲鞍的化学成分研究 总被引:1,自引:0,他引:1
从马莲鞍根的乙醇提取物中分离得到3个具有细胞毒活性的化合物杠柳苷元(1)、杠柳苷元-3β-乙酸酯(2)和periplogenin3-O-β-D-glucopyranoside(3),此外,还得到了乌沙苷元(4)、α-香树脂醇乙酸酯(5)、α-香树脂醇十三酸酯(6)、乌苏酸(7)、9,19-环阿尔廷-25-烯-3β,24R-二醇(8)、9,19-环阿尔廷-25-烯-3β,24S-二醇(9)、环桉烯醇(10)、9,19-环阿尔廷-23E-烯-3β,25-二醇(11)、25-甲氧基-9,19-环阿尔廷-23E-烯-3β-醇(12)、11α,12α-epoxytaraxer-14-en-3β-ace-tate(13)、齐墩果酸(14)、β-谷甾醇(15)和β-胡萝卜苷(16).通过波谱学方法鉴定了它们的结构.通过X单晶衍射确证了13的结构.化合物1、2和3抗MDA-MB-231细胞株的GI50值分别为2.13×10-5molL-1,2.04×10-5molL-1和2.30×10-6molL-1.图2表5参17 相似文献
250.