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91.
Two acrylic adsorbents with different morphological structures and bearing amidoethylenamine and thiol groups were obtained and used for platinum sorption from chloride solution by the batch method. Physico-chemical parameters that influence adsorption such as initial Pt(IV) concentration, stirring time, pH, and adsorbent amount were investigated. The thermodynamic parameters of Pt(IV) sorption on the synthesized adsorbent were also evaluated based on Langmuir and Freundlich isotherms. Thermodynamic parameters estimated from Langmuir constants indicated that the adsorption is spontaneous, exothermic and there is a disordered state at the molecular level. The models used to analyze the sorption rate led to the conclusion that the most important step in the sorption of Pt(IV) could be both particle diffusion and chemical reaction of [PtCl6] with amine functional groups. Thus, both the ion exchange and complex formation mechanisms can occur via nitrogen atoms in the recovery of Pt(IV) on the studied adsorbent.  相似文献   
92.
To evaluate the acid deposition reduction negotiated for 2010 within the UNECE LRTAP Gothenburg Protocol, sulphur and nitrogen deposition time-series (1880–2100) were compared to critical loads of acidity on five French ecosystems: Massif Central basalt (site 1) and granite (2); Paris Bassin tertiary sands (3); Vosges mountains sandstone (4) and Landes eolian sands (5). The SAFE model was used to estimate the response of soil solution pH and ratio to the deposition scenario. Among the five sites, critical loads were exceeded in the past at sites 3, 4 and 5. Sites 3 and 4 were still expected to exceed in 2010, the Protocol year. Further reduction of atmospheric deposition, mainly nitrogen, would be needed to achieve recovery on these ecosystems. At sites 3, 4 and 5, the delay between the critical load exceedance and the violation of the critical chemical criterion was estimated to be 10 to 30 years in the top soil and 50 to 90 years in the deeper soil. At site 5, a recovery was expected in the top soil in 2010 with a time lag of 10 years. Unexpectedly, soil pH continued to decrease after 1980 in the deeper soil at sites 2 and 5. This time lag indicated that acidification moved down the soil profile as a consequence of slow base cation depletion by ion exchange. This delayed response of the soil solution was the result of the combination of weathering rates and vegetation uptake but also of the relative ratio between base cation deposition and acid compounds.  相似文献   
93.
The material flow analysis method can be used to assess the impact of environmental sanitation systems on resource consumption and environmental pollution. However, given the limited access to reliable data, application of this data-intensive method in developing countries may be difficult. This paper presents an approach allowing to develop material flow models despite limited data availability. Application of an iterative procedure is of key importance: model parameter values should first be assessed on the basis of a literature review and by eliciting expert judgement. If model outputs are not plausible, sensitive input parameters should be reassessed more accurately. Moreover, model parameters can be expressed as probability distributions and variable uncertainty estimated by using Monte Carlo simulation. The impact of environmental sanitation systems on the phosphorus load discharged into surface water in Hanoi, Vietnam, is simulated by applying the proposed approach.  相似文献   
94.
The suddenness and scale of the 26 December 2004 tsunami and the challenges posed to affected communities highlighted the benefits of their members having a capacity to confront and adapt to the consequences of such a disaster. Research into adaptive capacity or resilience has been conducted almost exclusively with Western populations. This paper describes an exploratory study of the potential of a measure of collective efficacy developed for Western populations to predict the capacity of members of a collective society, Thai citizens affected by the 2004 tsunami, to confront effectively the recovery demands associated with this disaster. Following a demonstration that this measure could predict adaptive capacity, the role of religious affiliation, ethnicity and place of residence in sustaining collective efficacy is discussed. The implications of the findings for future research on, and intervention to develop, adaptive capacity among Thai citizens in particular and collectivist societies in general are discussed.  相似文献   
95.
城市防震减灾能力评估研究   总被引:31,自引:3,他引:28  
首先论述了目前国内外关于城市地震灾害风险评估的研究,分析了这些研究取得的成果和存在的不足。然后,提出了城市防震减灾能力的概念,采用人员伤亡,经济损失和震后恢复时间作为衡量城市防震减灾能力强弱的3个最基本的要素。围绕这3个基本要素,列举出影响城市防震减灾能力的6大因素,在此基础上,提出了城市防震减灾能力评价指标体系的具体内容。  相似文献   
96.
张晓彤  章骅  吕凡  何品晶 《中国环境科学》2022,42(12):5725-5733
采用Mg-Fe型类水滑石(LDH)吸附剂提纯污泥焚烧飞灰(ISSA)浸出液中的磷,探究了吸附剂煅烧对磷吸附效果的影响及磷吸附和脱附机理.研究发现,在高浓度磷溶液(>1000mg/L)中,未煅烧的类水滑石(LDHu)磷吸附容量高于煅烧后的类水滑石(LDHc).LDHu具有典型的层状结构,磷的吸附与脱附主要通过磷和金属离子沉淀-溶解、静电吸附-排斥、配位作用和离子交换实现.而LDHc层状结构消失,形成双金属氧化物,不存在明显的阴离子交换作用.经LDHu或LDHc吸附和NaOH溶液脱附后,ISSA浸出液均具有良好的磷纯化效果,磷相对纯度从36%分别上升至77%和69%,磷回收率分别为84%和57%.纯化后的溶液适合制备高值含磷产物.  相似文献   
97.
有机废气中VOC的回收方法   总被引:33,自引:1,他引:33  
闫勇 《化工环保》1997,17(6):332-335
介绍了炭吸附法、冷凝法和膜分离法回胥机废报中VOD的原理、工艺流程和工业应用情况,并对这些方法进行了比较,指出了适用范围。  相似文献   
98.
微生物电化学技术能同时实现污染物去除和能量回收,但存在污染物去除种类有限及产能效率低的局限,近几年将可再生的太阳能引入微生物电化学技术的微生物-光-电化学耦合技术应运而生。本文简要介绍了微生物-光-电化学耦合技术的发展背景和研究现状,对该技术现有的耦合形式进行分类,并对各种形式的耦合机理进行详细的阐释,最后对其未来的发展进行了展望。  相似文献   
99.
针对尾气余热能量浪费问题,建立了某直列四缸汽油机尾气余热回收发电的系统模型。通过B.T米特罗欣的数学分析法和涡轮特征曲线快速匹配到适合的涡轮机,然后根据涡轮特征曲线对高速发电机进行了匹配。以满足国Ⅴ标准的NEDC工况为参考,对整个系统进行了仿真分析。结果表明,该系统能够实现尾气余热能量的回收,在市区和市郊平均分别可以回收能量1 k W和1.5 k W,市郊最高可达1.8 k W。  相似文献   
100.
核辐射事故以及随后的应急响应和恢复行动都会产生大量的废物,对这些废物的安全管理至关重要,有必要对核或辐射应急过程中产生的废物管理可能遇到的困难和挑战进行分析,提出在应急准备中需要注意的问题,对我国目前相关的法律条文进行梳理并提出建议。  相似文献   
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