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701.
Concentration levels of six natural and anthropogenic origin steroid estrogens, namely, diethylstilbestrol (DES), estrone
(E1), estradiol (E2), estriol (E3), ethinylestradiol (EE2), and estradiol-17-valerate (Ev), from different effluents in Beijing
were assessed. Sampling sites include two wastewater treatment plants (WWTPs), a chemical plant, a hospital, a pharmaceutical
factory, a hennery, and a fish pool. In general, concentrations of estrogens in the effluents varied from no detection (nd)
to 11.1 ng/l, 0.7 to 1.2 × 103 ng/l, nd to 67.4 ng/l, nd to 4.1 × 103 ng/l, nd to 1.2 × 103 ng/l, and nd to 11.2 ng/l for DES, E1, E2, EE2, E3, and Ev, respectively. The concentration levels of steroid estrogens from
different effluents decreased in the order of pharmaceutical factory and WWTP inlets > hospital > hennery > chemical factory
> fish pool. This study indicated that natural estrogens E1, E2, and E3 and synthetic estrogen EE2 are the dominant steroid
estrogens found in the different Beijing effluents. For source identification, an indicator (hE = E3/(E1 + E2 + E3)) was used
to trace human estrogen excretion. Accordingly, hE in effluents from the hospital and WWTP inlets exceeded 0.4, while much
smaller values were obtained for the other effluents. Human excretions were the major contributor of natural estrogens in
municipal wastewater. Estimation results demonstrated that direct discharge was the major contributor of steroid estrogen
pollution in receiving waters. 相似文献
702.
703.
Polycyclic aromatic hydrocarbons in soils along the coastal and estuarine areas of the northern Bohai and Yellow Seas, China 总被引:1,自引:0,他引:1
Wentao Jiao Tieyu Wang Jong Seong Khim Wei Luo Wenyou Hu Jonathan E. Naile John P. Giesy Yonglong Lu 《Environmental monitoring and assessment》2013,185(10):8185-8195
Polycyclic aromatic hydrocarbons (PAHs) and their health risks in surface soils (n?=?31) collected from coastal and estuarine areas of the northern Bohai and Yellow Seas (CEANBYS), China, were investigated. Total concentrations of PAHs ranged from 6.6?×?101 to 9.2?×?102?ng?g?1 dry weight, with an average of 3.1?×?102?ng?g?1 dw. The locations where greater concentrations of PAHs were observed were all near factories emitting black smoke or on the edge of the urban areas. These observations are consistent with concentrations of PAHs in soils being influenced by human activities, especially industrialization and urbanization. Concentrations of PAHs were significantly correlated with concentrations of organic carbon in soils. The patterns of relative concentrations and types of PAHs observed as well as knowledge of the potential sources were consistent with the primary sources of PAHs in soils of the CEANBYS being derived from the pyrolytic processes such as combustion of fossil fuel. The incremental lifetime cancer risks of exposing to PAHs for child, youth, and adult were 1.6?×?10?6, 1.2?×?10?6, and 1.9?×?10?6. 相似文献
704.
依据田间实测资料,运用水流的电模拟原理,定且分析了南亚热带丘陵赤红壤-果树(荔枝、芒果和龙眼)-大气连续体中水流阻力各分量的大小、变化规律及其相对重要性.结果表明,连续体中的水流阻力主要分布于从叶气孔腔到大气的扩散过程,荔枝、芒果、龙眼叶-气系统的水流阻力Rla占连续体水流总阻力Rsa的比例分别为93.65%~98.03、95.68%~99.03%、90.13%~98.71%;果树植株体的水流阻力Rp居其次,占Rsa的比例分别为1.97%~6.35%、0.97%~4.32%、0.08%~9.87%:土壤阻力Rs最小,占Rsa的比例小到可忽略不计,故叶-气系统的水流阻力是决定连缤体中水流速率的重要因素. 相似文献
705.
根据定位系统观测资料,阐述了南亚热带山地常绿森林区、丘陵旱作区和平原水稻区多种土壤的温度变化与气温的关系。观测研究结果表明:低山常绿森林区温度的三维空间差异比丘陵区、平原区大,丘陵区又比平原区大;南亚热带林区的气温、地表温、30cm土温比中亚热带的高,比热带的低:南亚热带林区的谷地气温高于针叶林、混交林和阔叶林,谷地地表温低于针叶林而高于混交林和阔叶林,谷地20m土温低于针叶林、混交林而高于阔叶林;在气温一致的丘陵区栽植植物不同,其地表温、土温略有差异;在平原水稻土区,年气温、地表温、20cm土温差异不大,但30cm以下土温渐显差异;不同地貌单元的气温、地表温和土温的年际差异、年平均温度、各月及0~12~24时的温度动态变化各具特征。根据气温与植物生长的关系,拟把气温>22℃的4~10月称热季、气温<22℃的1~3月及11~12月称作凉季。可因地制宜,根据气温和土温的变化特征与土壤水分和作物生长的关系,采取措施调节温度,以利于作物生长。 相似文献
706.
Koopmans GF Römkens PF Fokkema MJ Song J Luo YM Japenga J Zhao FJ 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):905-914
A Cd and Zn contaminated soil was mixed and equilibrated with an uncontaminated, but otherwise similar soil to establish a gradient in soil contamination levels. Growth of Thlaspi caerulescens (Ganges ecotype) significantly decreased the metal concentrations in soil solution. Plant uptake of Cd and Zn exceeded the decrease of the soluble metal concentrations by several orders of magnitude. Hence, desorption of metals must have occurred to maintain the soil solution concentrations. A coupled regression model was developed to describe the transfer of metals from soil to solution and plant shoots. This model was applied to estimate the phytoextraction duration required to decrease the soil Cd concentration from 10 to 0.5 mg kg−1. A biomass production of 1 and 5 t dm ha−1 yr−1 yields a duration of 42 and 11 yr, respectively. Successful phytoextraction operations based on T. caerulescens require an increased biomass production. 相似文献
707.
Luo Y Zhang X Liu X Ficklin D Zhang M 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):1171-1181
The hydrology, sediment, and pesticide transport components of the Soil and Water Assessment Tool (SWAT) were evaluated on the northern San Joaquin Valley watershed of California. The Nash-Sutcliffe coefficients for monthly stream flow and sediment load ranged from 0.49 to 0.99 over the watershed during the study period of 1992-2005. The calibrated SWAT model was applied to simulate fate and transport processes of two organophosphate pesticides of diazinon and chlorpyrifos at watershed scale. The model generated satisfactory predictions of dissolved pesticide loads relative to the monitoring data. The model also showed great success in capturing spatial patterns of dissolved diazinon and chlorpyrifos loads according to the soil properties and landscape morphology over the large agricultural watershed. This study indicated that curve number was the major factor influencing the hydrology while pesticide fate and transport were mainly affected by surface runoff and pesticide application and in the study area. 相似文献
708.
709.
710.