基于多属性决策方法的太原市冬季街道尘土中潜在有害元素关键来源解析

为解析太原市冬季街道尘土中潜在有害元素(PHEs)的关键污染来源,采集了40个街道尘土样本,使用电感耦合等离子体质谱和原子荧光光谱仪测定了尘土中As、 Cd、 Pb、 Ni、 Cr、 Cu和Zn这7种元素的含量.使用内梅罗综合危害指数法(NIRI)、美国环境保护署推荐的健康风险评估模型分别评价了尘土中PHEs造成的生态和居民健康风险;使用正定矩阵因子分解模型结合主成分分析法分析了尘土中PHEs的来源,并基于此计算了不同来源对尘土PHEs的总含量和PHEs造成风险的贡献程度;使用多属性决策方法(MADM)识别了街道尘土中PHEs的关键来源.结果表明：(1)太原市冬季尘土中ω(As)、ω(Cd)、ω(Pb)、ω(Ni)、ω(Cr)、ω(Cu)和ω(Zn)的平均值分别为17.92、0.32、69.10、30.06、107.74、73.37和268.49 mg·kg^-1,均超过了太原市土壤中相应元素的背景值,说明尘土中PHEs已经出现富集现象,尘土中PHEs的NIRI平均值为63.86,属于中度风险,处在可控状态;(2)尘土中PHEs造成的致癌和非致癌风险均低于阈值,表明...     

土壤气抽提多井方案的数值模拟研究

以存在石油烃污染的北京市某加油站场地为研究对象,设计了土壤气抽提(SVE)原位修复系统,应用AIR3D软件对SVE作用下土壤包气带的气压场进行数值模拟.划定以土壤气压强低于或等于101.122kPa的区域为抽气影响区域.模拟结果显示,单井的抽气影响区域不能满足要求;多井抽气时,井间区域土壤气体真空度受多井共同作用,扩大了抽气的影响区域.抽气井不同布置情况下井间距大小对相互作用效果存在影响.研究发现,井间相互作用随着井间距的增大而减小,井间距存在临界值.井间距临界值与抽气井的布置形式相关.对于本研究中的2眼井、3眼井、4眼井情景,此临界值分别在3~5m、5~8m、8~10m区间.超过此临界值时井间相互作用将显著减弱,并导致抽气影响区域不能覆盖整个井间范围.     

复合菌群产絮凝剂MAC37的特征及其在黏合剂废水中的应用

以利用复活促进因子(Rpf)从土壤和污水处理系统中分离得到的菌种作为筛选絮凝剂产生菌的菌源,采用高岭土悬浊液为活性评价体系,筛选出4株絮凝率高于50%的菌株.经两两菌株复配,构建出产高效絮凝剂的复合菌群M3+M7,该菌群经优化培养后,絮凝率达96.27%.将其产生的絮凝剂进行提纯固化得絮凝剂粗品MAC37,对其主要成分进行定性和定量分析,并将复合菌群的发酵液应用于黏合剂废水的处理.结果表明:MAC37的主要成分为多糖和蛋白质,含量分别为74.5%和20.4%;黏合剂废水经复合菌群发酵液絮凝处理后,浊度、色度及CODCr的去除率分别为92.57%、94.73%和92.12%.      

Proteomics study of Southern Punjab Pakistani cobra (Naja naja: formerly Naja naja karachiensis) venom

Because of the potential of significant geographic variation in the compositions of snake venoms, much insight can be gained by examining individuals originating from diverse locations, and detailed characterization of any species can only be done by including animals from the entire range. Pakistani N. naja (formerly N. naja karachiensis) venom was decomplexed by applying diverse techniques and found a concoction of proteins (a total of 43 venomous proteins comprising 11 super families) from 6 to 200 kilodaltons in size. Among them three finger toxins (58%), phosphoplipses A₂ (19%), snake venom metalloproteinases (5%), l-amino acid oxidases (5%), helvepryns (3%), vespryns (2%), cobra venom factor (2%), 5′-nucleotidases (2%), venom nerve growth factor (2%), and Kunitz type serine protease inhibitor (2%) were included. It is the first report that this venom possesses significantly higher percentage of three finger toxins belonging to the cytotoxins (32% overall) and α‐neurotoxins (32% overall, predominately long chain neurotoxins, 24% overall) compared to N. naja from other geographic locations. Better understanding of intraspecific variations in venom can improve the development of location-specific anti-venoms. Furthermore, this pool of diverse toxins could potentially be a source of novel drug candidates for the treatment of muscarinic acetylcholine receptors mediated nervous disorders.     

金属及其氧化物催化降解多氯联苯的研究进展

催化降解因其高的反应速率和降解彻底性,在氯代有机物的削减中得到广泛应用.目前研究较多的催化剂为零价态和氧化态的碱金属和碱土金属、过渡金属及贵金属,包括单金属和双金属两种.这类催化剂表面活性位点多样,在氯代有机物的降解中显示出优异的活性.多氯联苯(Polychlorinated Biphenyls,简称PCBs)是一类有毒难降解的持久性有机污染物.本文阐述了不同价态的单金属和双金属催化剂催化降解PCBs的反应机理,并介绍了影响反应速率和产物选择性的因素.并对金属及其氧化物催化降解PCBs的应用现状做了评述,对该技术的发展进行展望.     

空区探测方法优选的ANP模型及其应用

目前矿山空区探测方法众多,但缺乏对其进行优化选择的分析模型。为了提高特定条件下空区探测方法选择的科学性、合理性,采用网络分析法(ANP)将决策问题分解成控制层和网络层。就这些层中的元素而言,用一种标度对人的主观判断进行客观量化后,对其实施定性、定量分析。综合考虑空区探测方法的技术、经济、人机设计及环境指标,构建空区探测方法综合评价体系,确定各判断准则间的相互影响关系,建立空区探测方法优选决策问题的ANP结构,借助Super Deci-sions软件计算参选方法基于各影响因素的综合优先权,从而确定适用于特定条件下的空区探测方法。结果表明,该模型能够随着工作环境的改变而计算影响因素优先权,使空区探测方法根据工作环境的改变而调整。     

Relationships of nitrous oxide fluxes with water quality parameters in free water surface constructed wetlands

The effects of chemical oxygen demand (COD) concentration in the influent on nitrous oxide (N₂O) emissions, together with the relationships between N₂O and water quality parameters in free water surface constructed wetlands, were investigated with laboratoryscale systems. N₂O emission and purification performance of wastewater were very strongly dependent on COD concentration in the influent, and the total N₂O emission in the system with middle COD influent concentration was the least. The relationships between N₂O and the chemical and physical water quality variables were studied by using principal component scores in multiple linear regression analysis to predict N₂O flux. The multiple linear regression model against principal components indicated that different water parameters affected N₂O flux with different COD concentrations in the influent, but nitrate nitrogen affected N₂O flux in all systems.     

纳米材料对环境抗生素抗性基因污染扩散影响的研究进展

抗生素抗性基因(antibiotic resistance genes,ARGs)的环境扩散严重威胁了人类健康和生态安全。除抗生素滥用所产生的选择性压力以外,其他环境物质也能影响ARGs的传播。而纳米材料的广泛应用使其不可避免地在环境中扩散并进而影响ARGs的环境分布。因此,笔者综述了近年来纳米材料影响ARGs污染扩散的研究,并探讨了纳米材料对ARGs传播的影响机制,旨在深入理解ARGs的环境扩散行为,为ARGs环境控制及纳米材料非毒性环境效应的评估提供理论和技术支持。     

The values and vulnerabilities of ‘Star Wars Island’: exploring tensions in the sustainable management of the Skellig Michael World Heritage Site

This paper explores challenges in reconciling the cultural, economic and ecological pillars of the sustainable development concept. It does so by examining how conflicts in the management of an island off the Irish coast called Skellig Michael, which has been internationally designated for its significant cultural and ecological attributes, have been intensified by: (a) increasing tourist numbers; (b) a re-framing of the site’s identity and (c) changing visitor motivations. These have resulted from the amplified attention the island has received following the release of Star Wars: The Force Awakens and The Last Jedi in which it features prominently. Following a critical identification and discussion of the fault lines between different stakeholders involved in the conservation and use of the island, the paper advances a roadmap for action to help resolve animosity in the governance of the site and facilitate its sustainable management in the context of changing visitor numbers and profiles.     

太湖水体Chl-a预测模型ARIMA的构建及应用优化

叶绿素a（Chl-a）是湖泊浮游植物生物量的重要指标,其含量能反映水中浮游植物的丰度和变化规律.以1999年12月~2019年8月太湖水体Chl-a和环境因子的逐月监测数据为基础,运用主成分分析方法探讨了Chl-a与环境因子的关系,据此建立了Chl-a与主要环境因素之间的多元线性逐步回归模型及自回归综合移动平均模型（ARIMA）.结果表明：①太湖Chl-a浓度存在着明显的季节变化,且总体处于上升趋势.总磷（TP）、高锰酸盐指数、月均气温（MAT）和月度降雨量（MR）与Chl-a浓度存在较好的变化同步性,总氮（TN）和氨氮（NH₄⁺-N）则表现出明显的滞后性.②主成分分析结果表明,太湖水体藻类暴发条件不仅仅是基于N和P等限制性因素,而是发展为TN、NH₄⁺-N、TP和高锰酸盐指数、MR和MAT等多元因素的综合影响.③两种模型经验证比较,基于1999~2019年逐月资料建立的Chl-a浓度的ARIMA模型模拟效果和预测精度明显优于所建立的多元线性逐步回归模型,特别是在考虑主要环境因素作为自变量及优化自变量取值情况下其预测效果得到进一步提升.建立的ARIMA（0,1,1）（0,1,1）模型将有助于太湖藻类暴发的预报和预警,并为及时有效地安排水资源调度及调控等水环境管理措施提供依据.