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171.
随着非甾体抗炎药(NSAIDs)的持续使用与排放,世界各地的地表水、海水、地下水、污水厂进出水中均已频繁检测到该类药物,这对生态系统中各种非靶标生物造成了一定威胁.本研究评价了两种典型的非甾体抗炎药-双氯芬酸(Diclofenac)和醋氨酚(Acetaminophen)对中国特有物种稀有鮈鲫(Gobiocypris rarus)早期生活阶段的毒性效应.实验结果显示,醋氨酚的毒性较弱,当浓度达到48.4 mg·L-1(NOEC)时,稀有鮈鲫的孵化率、死亡率、异常率、全长和干重均未表现出明显的中毒症状;而双氯酚酸的毒性则较强,当浓度达17.8 mg·L-1(LC10)时,即可导致稀有鮈鲫孵化率下降,当浓度达到10.2 mg·L-1(LOEC)时,即可造成幼鱼外观和行为的显著异常,表明双氯芬酸对稀有鮈鲫的孵化和生长均产生了一定的致毒效应.同时,根据稀有鮈鲫和几种常用模式生物之间的孵化率、孵化后存活率、体长和双氯芬酸敏感性的比较结果,可认为稀有鮈鲫适用于污染物对鱼类早期生活阶段毒性效应的评估.  相似文献   
172.
A series of nanaoscale aramid-based adsorbents were prepared by the functionalization of poly (p-phenylene terephthalamide) (PPTA) with different content of ethylenediamine (EDA). Their structures were characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis. Metal ions, including Hg2+, Pb2+, Ag+, Cu2+, Cd2+, and Ni2+ were chosen as the models to explore the binding behaviors of PPTA–ECH–EDA in aqueous medium. Results showed that PPTA–ECH–EDA exhibited higher adsorption capacity for Hg2+ due to their nanoscale structures. In particular, the adsorption rate was so high that equilibrium was achieved within 15 min for Hg2+. The adsorption of Hg2+ on PPTA–ECH–EDA followed the pseudo second-order model well. Langmuir and Freundlich models were employed to fit the isothermal adsorption, and the results revealed that Freundlich isotherm was a better model to predict the experimental data. The adsorption mechanism was revealed by X-ray photoelectron spectroscopy. It is preconceived that PPTA–ECH–EDA could be used as an effective adsorbent for fast removal of heavy ions from wastewater.  相似文献   
173.
In recent history the volume of electronic products purchased by consumers has dramatically escalated. As a result this has produced an ever-increasing electronic waste (E-waste) stream, which has generated concerns regarding the E-waste’s potential for adversely impacting the environment. The leaching of toxic substances from obsolete personal computers (PCs) and cathode ray tubes (CRTs) of televisions and monitors, which are the most significant components in E-waste stream, was studied using landfill simulation in columns. Five columns were employed. One column served as a control which was filled with municipal solid waste (MSW), two columns were filled with a mixture of MSW and CRTs, and the other two were filled with MSW and computer components including printed wire boards, hard disc drives, floppy disc drives, CD/DVD drives, and power supply units. The leachate generated from the columns was monitored for toxic materials throughout the two-year duration of the study. Results indicate that lead (Pb) and various other heavy metals that were of environmental and health concern were not detected in the leachate from the simulators. When the samples of the solids were collected from underneath the E-waste in the columns and were analyzed, significant amount of Pb was detected. This indicates that Pb could readily leach from the E-waste, but was absorbed by the solids around the E-waste materials. While Pb was not observed in the leachate in this study, it is likely that the Pb would eventually enter the leachate after a long term transport.  相似文献   
174.
在地震灾难频发及网络媒体迅速发展的背景下,"青龙奇迹"引起了公众的广泛关注和争议,其社会舆论影响不容忽视.以此为切入点,笔者一行利用2010年暑期社会实践在河北省青龙县、抚宁县进行了实地调研走访,结合学者论述、新闻报道,从灾难社会学和传播学角度,分析"青龙奇迹"传播现象,并对其准确度进行了探讨.  相似文献   
175.
Efficient and reliable removal of polyacrylamide (PAM), which are present in oil extraction waste water, is critically important to prevent toxic discharges to receiving waters. In the present study, two PAM degrading bacterial strains, namely HWBI and HWBIII, were isolated from the activated sludge and soil in an oil field. Two sequencing batch reactors (SBRs) were bioaugmented with either HWBI or HWBIII and the performance of each bacteria for enhancing PAM removal was compared. The effects of bioaugmentation on the performance of the SBRs with different exogenous strains after a single inoculation were investigated under long term operation. Results showed that for the SBR augmented with HWBI, 70% of PAM was removed at the end of the first operation cycle, and the removal remained at approximately 70% in the following eight cycles after a single inoculation. For the SBR augmented with HWBIII, only 45% of the PAM was removed in the first cycle after the inoculation, and PAM removal decreased to 30% after eight cycles. Terminal restriction fragment length polymorphism (T-RFLP), a molecular screening technique, was applied to track the supplemented bacterial strains and to evaluate the effects of bioaugmentation on the microbial communities and to investigate the optimal bioaugmentation strategy.  相似文献   
176.
通过简要概述美国超级基金5年回顾政策的形成与发展、执行约束力、实施内容,分析其实施过程中面临的问题,从环境立法、强化后期风险管理、完善污染场地风险管理链条、公开修复治理信息和提高社会公众参与度等角度,为解决我国因多样性修复技术实施导致的污染场地修复后风险难题提供可借鉴的重要经验,以期为构建适宜我国国情的污染场地修复长期风险管理和污染控制制度提供理论依据,实现污染场地修复后的安全再利用。  相似文献   
177.
针对CO_2驱油封存技术,我国在环境监测、环境影响评价等领域的环境监管能力建设还处于空白,亟待加强。文章从CO_2泄漏路径分析、环境监测方法的筛选以及环境背景值缺失情况下的监测数据分析方法等三个方面阐述了各环节的主要研究思路。其中重点介绍了"过程分析法"在CO_2泄漏识别中的应用,强调环境背景值不仅是注气前的环境状况,在注气过程中,每个时间点之前的监测数据均可以看作是背景值。为我国制定相关的法律法规提供重要信息和参考依据。  相似文献   
178.
以高温活化改性钢渣颗粒为研究对象,对其在机械搅拌条件下对水体中不同种属藻的去除效果和对藻类的光合作用活性的影响进行试验研究,并对其除藻机理进行了初步探讨.结果表明:改性钢渣颗粒对水体中各藻属均有很好的去除效果,对藻类的光合作用活性具有很好的胁迫抑制作用;改性钢渣颗粒在100 r/min的搅拌强度下,对藻类的去除主要以吸附为主,在400 r/min的搅拌强度下,对藻类的去除以吸附和机械损伤为主.  相似文献   
179.
We fabricated and characterized two hybrid adsorbents originated from hydrated ferric oxides(HFOs) using a polymeric anion exchanger D201 and calcite as host. The resultant adsorbents(denoted as HFO-201 and IOCCS) were employed for Sb(V) removal from water. Increasing solution pH from 3 to 9 apparently weakened Sb(V) removal by both composites, while increasing temperature from 293 to 313 K only improved Sb(V) uptake by IOCCS. HFO-201 exhibited much higher capacity for Sb(V) than for IOCCS in the absence of other anions in solution. Increasing ionic strength from 0.01 to 0.1 mol/L NaNO3would result in a significant drop of the capacity of HFO-201 in the studied pH ranges; however, negligible effect was observed for IOCCS under similar conditions. Similarly, the competing chloride and sulfate pose more negative effect on Sb(V) adsorption by HFO-201 than by IOCCS, and the presence of silicate greatly decreased their adsorption simultaneously, while calcium ions were found to promote the adsorption of both adsorbents. XPS analysis further demonstrated that preferable Sb(V) adsorption by both hybrids was attributed to the inner sphere complexation of Sb(V) and HFO, and Ca(II) induced adsorption enhancement possibly resulted from the formation of HFO-Ca-Sb complexes. Column adsorption runs proved that Sb(V) in the synthetic water could be effectively removed from 30 μg/L to below 5 μg/L(the drinking water standard regulated by China), and the effective treatable volume of IOCCS was around 6 times as that of HFO-201, implying that HFO coatings onto calcite might be a more effective approach than immobilization inside D201.  相似文献   
180.
The study on population and the resource-environment by the consumption may contribute to the further cognition about their correlations and provide the policy references for natural resources use and environmental protection. This article has studied the impact status of the consumption level difference of China's 31 provinces or autonomous regions on the resource-environment in 2005 by per capita consumption expenditure and serial statistical data with unit person method and constructed consumption model and hierarchical cluster analysis. We found several trends. To the intensity that population acting on the resource-environment, four sorts of regions might be divided in 2005, furthermore, most of them were at the level of unit person. Provinces or autonomous regions, located in the developed coastal areas in China, generally have the bigger impact intensity on the resource-environment than the others. That is to say, the natural resources mainly flow from west to east and from north to south, but the environmental loads are shared in the whole China and are likely to be aggravated from east to west reversely. The main causes of imbalance of pressure on the resource-environment should be the difference of consumption level, the unmatchable resource exploitation and utilization, the imbalance of discharging pollutants, and the difference of moderate carrying capacity. To the total impact quantities that population acting on the resource-environment, four sorts of regions were divided in 2005 and the difference of them was notable. Provinces or autonomous regions, having the bigger impact quantities on the resource-environment, are generally located in the eastern and central China while the extended western China is still the weak impact area of the resource-environment consumption or terminal pressure. Provinces or autonomous regions are few, where the total impact quantities are more or less; alternately, those are many, where the total impact quantities rank the middle.  相似文献   
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