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691.
China has put great efforts into air pollution control over the past years and recently committed to its most ambitious climate target. Cost and benefit analysis has been widely used to evaluate the control policies in terms of past performance, future reduction potential,and direct and indirect impacts. To understand the cost and benefit analysis for air pollution control in China, we conducted a bibliometric review of more than 100 studies published over the past two decades, including the cur...  相似文献   
692.
Interactions between anions and cations are important for understanding the behaviors of chemical pollutants and their potential risks in the environment. Here we prepared soil aggregates of a yellow paddy soil from the Taihu Lake region, and investigated the effects of phosphate (P) pretreatment on adsorption-desorption of Cu2+ of soil aggregates, free iron oxyhydrates-removed soil aggregates, goethite, and kaolinite with batch adsorption method. The results showed that Cu2+ adsorption was reduced on the aggregates pretreated with low concentrations of P, and promoted with high concentrations of P, showing a V-shaped change. Compared with the untreated aggregates, the adsorption capacity of Cu2+ was reduced when P application rates were lower than 260, 220, 130 and 110 mg/kg for coarse, clay, silt and fine sand fractions, respectively. On the contrary, the adsorption capacity of Cu2+ was higher on P-pretreated soil aggregates than on the control ones when P application rates were greater than those values. However, the desorption of Cu2+ was enhanced at low levels of P, but suppressed at high levels of P, displaying an inverted V-shaped change over P adsorption. The Cu2+ adsorption by the aggregate particles with and without P pretreatments was well described by the Freundlich equation. Similar results were obtained on P-pretreated goethite. However, such P effects on Cu2+ adsorption-desorption were not observed on kaolinite and free iron oxyhydrates-removed soil aggregates. The present results indicate that goethite is one of the main soil substances responsible for the P-induced promotion and inhibition of Cu2+ adsorption.  相似文献   
693.
• PA layer properties tune the primary nanochannels in MIL-101(Cr) TFN NF membranes. • The dense PA layer induced transition of primary nanochannels of TFN NF membranes. • Nanochannels around MOF contributed to the improved flux with a loose PA structure. • Nanochannels in MOFs dominated the separation performance with a dense PA structure. Metal organic framework (MOF) incorporated thin-film nanocomposite (TFN) membranes have the potential to enhance the removal of endocrine disrupting compounds (EDCs). In MOF-TFN membranes, water transport nanochannels include (i) pores of polyamide layer, (ii) pores in MOFs and (iii) channels around MOFs (polyamide-MOF interface). However, information on how to tune the nanochannels to enhance EDCs rejection is scarce, impeding the refinement of TFN membranes toward efficient removal of EDCs. In this study, by changing the polyamide properties, the water transport nanochannels could be confined primarily in pores of MOFs when the polyamide layer became dense. Interestingly, the improved rejection of EDCs was dependent on the water transport channels of the TFN membrane. At low monomer concentration (i.e., loose polyamide structure), the hydrophilic nanochannels of MIL-101(Cr) in the polyamide layer could not dominate the membrane separation performance, and hence the extent of improvement in EDCs rejection was relatively low. In contrast, at high monomer concentration (i.e., dense polyamide structure), the hydrophilic nanochannels of MIL-101(Cr) were responsible for the selective removal of hydrophobic EDCs, demonstrating that the manipulation of water transport nanochannels in the TFN membrane could successfully overcome the permeability and EDCs rejection trade-off. Our results highlight the potential of tuning primary selective nanochannels of MOF-TFN membranes for the efficient removal of EDCs.  相似文献   
694.
Environmental Science and Pollution Research - Metal-free biochar to activate persulfate and degrade organic contaminants has attracted great attention in advanced oxidation processes, while the...  相似文献   
695.
The effects of different electrode on Solanum nigrum L.seed germination were determined.The result showe d that germination percentage(GP) of seeds in treatment T2(titanium electrode) was 26.6% higher than in control(CK,without electric field).High potassium and calcium concentrations were beneficial for seed enzymatic activity in treatment T2,which could partly explain the increase in GP.Cd accumulation(μg/pot) in S.nigrum treated with any electric field was significantly higher(p<0.05) than...  相似文献   
696.
戴宝均 《安全》2009,30(5):23-24
当前,举国上下都在为构建和谐社会而不懈努力,特别是北京市提出了“人文北京、科技北京、绿色北京”的举措,城市建设得到了快速发展。与此同时,高、大、深、新的建筑工程愈来愈多,施工难度日益增大,生产安全事故的发生也呈上升的趋势,特别是高处坠落事故愈来愈严重。  相似文献   
697.
Cities based on mining are distinctive from other cities in China. Their heavy dependence on minerals, a relatively undiversified industrial structure, seriously damaged ecological environment and the rather low degree of openness have all reduced their competitiveness, and severely constrained and hindered their sustainable development. In this paper the authors will study mining-based cities from the perspective of sustainable development, first by having a critical review of their features, and then by researching into strategic options to support their sustainable development.  相似文献   
698.
Land use changes induced by the Conversion of Cropland to Forest and Grassland Program are found to provide farm households sampled in four counties from Shaanxi and Qinghai Provinces with increased net profits. This result is found to be robust for a range of discount rates and output price projections. The net present value of the difference in farm profits with and without the Program is found to be positive even when payments made under the Program are subtracted from with Program profits. Variations in the impact of the Program on farm household net profits were observed across the county samples. These results suggest that reversion to pre-Program land uses is unlikely as long as farmer's rights over converted land are well defined and defended.  相似文献   
699.
选择中国典型的废弃化工污染场地为研究对象,开展第一阶段的场地环境调查,通过资料收集与文献审核、现场踏勘、相关人员的访谈,开展场地和生产设施环境污染初步分析,调查目的是识别可能存在的污染源和污染物,初步确定场地和生产设施存在的环境风险。调查结果表明:N,N-二乙基羟胺生产车间构筑物和车间内的反应釜、蒸馏釜、陶瓷罐等生产设备已经受到污染;场地潜在污染区域为N,N-二乙基羟胺生产车间区域、剧毒品库、废水收集池及管线所在区域。  相似文献   
700.
鄂尔多斯块体周缘地震活动特征分析   总被引:1,自引:0,他引:1  
分析了鄂尔多斯块体周缘的地震活动特征,结果表明块体的东缘、南缘、西缘均发生过8级强震或多次7级以上地震,而北缘历史上仅发生过1次7级地震,可见块体周缘的强震活动水平存在显著差异,中强地震活动的时间、空间差异也较为显著,1929年以前,块体北缘没有中强地震记录,而块体东缘、南缘、西缘却是中强地震的丛集区域,1929年以后,块体周缘的地震活动格局发生了显著变化。2008年5月12日汶川8.0级地震后,多种迹象表明,鄂尔多斯块体北缘特别是西北缘的地震危险趋势将进一步加剧。b值空间扫描结果显示该区域也是低b值高应力积累区域,鄂尔多斯块体北缘的历史中强地震均发生在这些高应力积累的区域。在关注鄂尔多斯块体西北缘的同时,也应特别关注超长平静区内蒙古临河至晋冀蒙交界地区发生强震的可能性。  相似文献   
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