Spatial distribution of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs) in an e-waste dismantling region in Southeast China: Use of apple snail (Ampullariidae) as a bioindicator

Fengjiang is a large e-waste dismantling site located in southeast China. In this paper, apple snail and soil samples were collected from this e-waste dismantling site and 25 vicinal towns to investigate the contamination status, spatial distributions and congener patterns of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs). Total PCB concentrations in apple snails (3.78-1812 ng g⁻¹ dry weight (dw)) were significant higher than that in soil samples (0.48-90.1 ng g⁻¹ dw). PBDE (excluding BDE 209) concentrations in apple snail and soil samples ranged from 0.09 to 27.7 ng g⁻¹ dw and 0.06 to 31.2 ng g⁻¹ dw, respectively. Concentrations of PCBs and PBDEs in snails and soils correlated negatively with the distance from Fengjiang. Both the concentrations and profiles of the pollutants were significantly correlated (p < 0.05) between the snail and soil samples, indicating the suitability of apple snail as a reliable bioindicator for PCBs and PBDEs contamination in this region. Relatively high concentrations of PCBs and PBDEs at locations far from e-waste dismantling sites implied that these pollutants have been transported to surrounding regions.     

2008年低温雨雪冰冻对武汉城市公共交通的影响评估

为了对2008年低温雨雪期间气象条件对城市交通运输的影响给出定量评估,运用天气分析及统计学方法,分析了低温雨雪冰冻期间武汉市主要气候特征,利用2008年初持续低温雨雪期间武汉城市公共交通线路（包括公交车、轮渡、汽渡）逐日停运数据,定义了持续低温雨雪冰冻过程城市公共交通影响度,通过统计分析,找到了关键气象因子、关键期和低温临界指标,建立了气象评估模型。结果表明：在持续低温雨雪冰冻过程中,初发时期是公共交通影响的关键时期之一,影响度与积雪深度关系最密切,在公交车、轮渡、汽渡3种交通工具中,公交车影响度与气象要素的相关最密切,对武汉城市公交车造成明显影响的临界气温是17℃。该结论在实际的气象灾害评估业务工作中进行了运用,效果良好     

Tracing the sources of refractory dissolved organic matter in a large artificial lake using multiple analytical tools

Structural and chemical characteristics of refractory dissolved organic matter (RDOM) from seven different sources (algae, leaf litter, reed, compost, field soil, paddy water, treated sewage) were examined using multiple analytical tools, and they were compared with those of RDOM in a large artificial lake (Lake Paldang, Korea). Treated sewage, paddy water, and field soil were distinguished from the other sources investigated by their relatively low specific UV absorbance (SUVA) values and more pronounced fulvic-like versus humic-like fluorescence of the RDOM samples. Microbial derived RDOM from algae and treated sewage showed relatively low apparent molecular weight and a higher fraction of hydrophilic bases relative to the total hydrophilic fraction. For the biopolymer types, the presence of polyhydroxy aromatics with the high abundance of proteins was observed only for vascular plant-based RDOM (i.e., leaf litter and reed). Molecular weight values exhibited positive correlations with the SUVA and the hydrophobic content among the different RDOM, suggesting that hydrophobic and condensed aromatic structures may be the main components of high molecular weight RDOM. Principal component analysis revealed that approximately 77% of the variance in the RDOM characteristics might be explained by the source difference (i.e., terrestrial and microbial derived) and a tendency of further microbial transformation. Combined results demonstrated that the properties of the lake RDOM were largely affected by the upstream sources of field soil, paddy water, and treated sewage, which are characterized by low molecular weight UV-absorbing and non-aromatic structures with relatively high resistance to further degradation.     

高铁酸钾氧化处理苯酚废水的研究

采用高铁酸钾氧化法处理了具有难生化特性的苯酚废水,以期为该废水提供一种高效经济的处理方法.研究了高铁酸钾加入量、pH值、反应时间、苯酚初始浓度和稳定剂对苯酚废水处理效果的影响.实验结果表明,高铁酸钾投加量为1.2g/L,pH值为4,反应30 min,初始苯酚浓度为100m/L时处理效果最好.所考察的稳定剂包括HAC、N...     

铁盐与铝盐对腈纶废水生化出水混凝特性的对比

针对腈纶废水生化单元出水,对比研究了Al2(SO4)3和Fe2(SO4)3在不同絮凝剂投量和p H时的混凝处理效果,并利用紫外-可见分光光度法(UV-Vis)、三维荧光光谱(EEM)、凝胶渗透色谱(HPSEC)等对混凝特性进行了初步探讨。研究显示,2种混凝剂在投量为63.5 mg/L时可获得30%以上的COD去除率,且最佳p H为中性附近。当投量小于32 mg/L时,Al2(SO4)3较Fe2(SO4)3具有更高的COD去除率,进一步增大混凝剂的投量很难提高Al2(SO4)3对COD的去除率,而Fe2(SO4)3则在有限范围内能持续提高COD去除率。EEM光谱分析显示,与Al2(SO4)3相比,Fe2(SO4)3对有机物具有更广的处理范围和更好的去除效果。HPSEC分析表明,Fe2(SO4)3相对于Al2(SO4)3在去除重均分子量为2 776、1 856和1 325 Da的有机物组分方面具有优势。铁盐或铝盐混凝是深度净化腈纶废水生化单元出水的可行方案之一。     

能源回弹效应的研究进展及其政策涵义

“十二五”期间节能减排的目标是单位GDP能耗下降16％,为实现这一目标,政府采取了以提高能源效率为核心的节能减排政策,但是能源效率的提高可能产生潜在的“回弹效应”,即可能增加能源的使用从而使得节能减排目标难以实现.本文在文献研究的基础上,分析了回弹效应的类型和产生机理,梳理了国内外文献中关于回弹效应测度的实证结果,指出了当前实证研究中存在的主要问题,并从公共政策制定的角度设计了经济模型和其他社会科学相结合的定性比较分析研究方案,主张从经济主体行为反应、替代品价格、能源补贴以及发展新能源政策等多重视角研究回弹效应发生的内在机理,从而对能源政策产生明确的导向.最后,提出了加强能源回弹效应研究的具体政策建议.     

Emission of dioxins/furans and other U-POPs from test burns of non-POP pesticides in a hazardous waste incinerator

This paper presents the results of test burns for obsolete pesticides (OPs) of the permethrin group in a high temperature incinerator (HTI) in Southeast Asia. Three test burn runs were conducted, a baseline run when no OP was fed to the incinerator, and two test runs with different mixtures of OP compounds (formula 1 and 2, refer to Table 1 for detail) containing chlorine in the feeding wastes. The unintentional formed persistent organic pollutants (U-POPs) including 17 dioxins/furans, 12 dioxin-like PCBs and 12 chlorobenzenes (CBs) were monitored in all input materials and all discharges (flue gas, scrubbing liquid and solid residues). The results show relatively high levels of the U-POPs in the flue gas emission with total dioxins/furans of 4.4, 3.4, and 8.4 ng I-TEQ/m³ in the baseline, test run 1 and test run 2, respectively, which are above international acceptable emission levels. The PCB levels in flue gas were, respectively, 0.01, 0.3 and 0.4 ng I-TEQ/m³. The baseline thus had similar U-POPs levels with the OP test runs.In stack emission, approximately 90% of the U-POPs and 100% of CBs were present in gas phase. The emission factors, mass of pollutants per metric ton (tonne) of input waste, of U-POPs associated with fly ash (from bag house) were the highest, followed by flue gas and bottom ash while those associated with scrubbing liquid were relatively low. Among the waste input material only the black toner power contained U-POPs, but at low levels. The profiles of the dioxins/furans and PCBs in the toner waste were significantly different from that in the discharges. Despite the overall good destruction and removal efficiency of permethrin (better than 90%) the high emission of U-POPs and CBs from the test burn is of another more serious concern. To our best knowledge the findings of this study are the first of this kind for the Southeast Asia. The findings emphasize that if not properly conducted a standard destruction technology of a non-POP chemical can lead to a release of a range of more dangerous U-POPs into the environment.     

提高高职护理学基础教学质量的探讨

护理学基础是护理专业的一门主干课程,学好护理学基础对学生以后从事临床工作至关重要.因此,搞好护理学基础的教学必须从提高教师综合素质入手,结合学生的实际情况,充分做好课前准备工作,运用灵活多样的教学方法,加强实习前的培训,让学生牢固地掌握该课程的基本理论和基本技能,打好临床护理工作的基础.参4.     

河南省自然灾害的地域分界规律

河南省自然灾害的地域空间分异，主要遵循水平地带性规律、非地带性规律与垂直地带性规律。水平地带性主要影响以致控制灾害的不同类型，非地带性与垂直地带性则主要影响各种灾害的成灾强度。它们相互联系与制约，从而形成该省域灾害的三维分异。