Chemical characteristics of precipitation at metropolitan Newark in the US East Coast

To investigate the chemical characteristics of precipitation in the polluted coastal atmosphere, a total of 46 event-based precipitation samples were collected using a wet-only automatic precipitation collector from September 2006 to October 2007 at metropolitan Newark, New Jersey in the US East Coast. Samples were analyzed by ion chromatography for the concentrations of major inorganic ions (Cl⁻, NO₃⁻, SO₄²⁻, F⁻, NH₄⁺, Ca²⁺, Mg²⁺, Na⁺, K⁺) and organic acid species (CH₃COO⁻, HCOO⁻, CH₂(COO)₂²⁻, C₂O₄²⁻). Selected trace metals (Sb, Pb, Al, V, Fe, Cr, Co, Ni, Cu, Zn, Cd) in samples were determined by ICPMS. Mass concentration results show that SO₄²⁻ was the most dominant anion accounting for 51% of the total anions, controlling the acidity of the precipitation. NH₄⁺ accounted for 48.6% of the total cations, dominating the precipitation neutralization. CH₃COO⁻ and HCOO⁻ were the two dominant water-soluble organic acid species, accounting for 42% and 40% of the total organic acids analyzed, respectively. Al, Zn and Fe were the three major trace metals in precipitation, accounting for 34%, 27%, and 25% of the total mass of metals analyzed. The pH values in precipitation ranged from 4.4 to 4.9, indicating an acidic nature. Enrichment Factor (EF) Analysis showed that Na⁺, Cl⁻, Mg²⁺ and K⁺ in the precipitation were primarily of marine origin, while most of the Fe, Co and Al were from crust sources. Pb, V, Cr, Ni were moderately enriched with EFs ranging 43–410, while Zn, Sb, Cu, Cd and F⁻ were highly enriched with EFs > 700, indicating significant anthropogenic influences. Factor analysis suggests 6 major sources contributing to the observed composition of precipitation at this location: (1) nitrogen-enriched soil, (2) secondary pollution processes, (3) marine sources, (4) incinerations, (5) oil combustions, and (6) malonate–vanadium enriched sources. To further explore the source–precipitation event relationships and seasonality, cluster analysis was performed for all precipitation events. Results show that about half of the precipitation events were characterized by mixed sources. Significant influences of nitrogen-enriched soil and marine sources were associated with precipitation events in spring and autumn, while secondary pollution processes, incineration and oil combustion contributed greatly in summer.     

废水处理用聚乙烯生物填料表面改性与表征研究

采用化学氧化-铁离子覆盖和化学氧化-表面接枝2种方法对聚乙烯生物填料进行表面改性,并使用接触角、扫描电镜及X射线光电子能谱等手段对改性前后的填料表面进行表征,同时还考察其在废水处理中的挂膜速度和处理效果。结果表明,2种改性方法都能使填料表面形成腐蚀坑而增加了表面粗糙度,并引入基团使填料表面呈正电性,使得填料的亲水性与生物亲和性增强,有利于微生物的粘附。2种改性方法可将挂膜时间分别缩短37.5%和60%,挂膜量分别提高54.8%和76.1%,COD的去除率也分别提高10.63%和8.64%。     

怀化城市形态的演变特征及形成机制

根据城市规划土地利用现状图、怀化市1〖DK1〗∶10 000地形图、遥感影像图、社会经济统计数据以及其他相关资料,借助ArcGIS 92平台和统计分析软件(SPSS 115),采用空间形态分析、地统计分析、等扇分析、景观测度及分形理论等研究方法,对我国中部铁路枢纽城市怀化的城市形态演变特征及形成机制展开研究。结果表明：城市形态的紧凑度、分维数偏低,形状指数偏大,城市以正东、西南、正北方位的扩展为主,演化轨迹为“据点型”-“散点组团型”-“团城型”-“枝状放射型”-“‘T’字型”;城市形态演变是经济发展、交通设施发展、自然地理条件限制等多重驱动力共同作用的结果.     

废弃地的内涵、分类及成因探析

废弃地作为我国后备土地资源的一种特殊类型,对它的防治以及再开发利用已成为实现土地资源可持续发展的有力保障。目前国内已有一些介绍有关废弃地景观更新案例的文献,但是对于废弃地的概念、分类等至今仍缺乏深入系统的分析研究。在分析国内外废弃地概念的起源、发展过程的基础上,结合现阶段我国社会经济的发展特征,提出了废弃地的概念和判别模型;结合土地分类标准,根据4种不同层面的分类依据对现有的废弃地进行了归并分类;同时综合不同类型废弃地形成的原因,从两个方面对废弃地的成因进行了系统的阐述,并在此基础上对我国废弃地的防治以及恢复利用提出了建立健全废弃地管理机构、完善政策法规、加强基础研究以及促进废弃地开发利用等的政策建议.     

基于能值改进生态足迹的长株潭城市群可持续发展研究

为衡量和评价区域发展的可持续状况,针对传统生态足迹模型的不足,利用从系统论出发并具有基于流量算法优点的能值分析理论,建立基于能值改进的生态足迹模型,该模型增加了水消费、污染等生态足迹,用输入输出能值对生态足迹进行调整,同时生态承载力扩展为自然生态承载力、基于净初级生产力的生态承载力、生态服务价值承载力和人类劳务生态承载力等,并综合评价系统可持续发展度,充分考虑了城市生态系统的开放性,物质、能量、信息的流通性,以及人类作用的主观能动性等,较为全面地反映城市生态经济复合系统的结构、功能和发展的持续性。采用该模型计算了长株潭城市群2000～2008年人均生态足迹和生态承载力的演变,结果显示生态足迹不断增加,生态承载力波动发展,略有下降,而生态赤字增加明显,可持续发展评价指数高于05且趋近于1,城市群可持续性发展状况堪忧,采取必要的措施刻不容缓     

油气资源产业集群竞争力形成机理实证研究

旨在揭示油气产业集群竞争力形成机理,据此展开讨论。首先基于成熟的资源整合观RIBV(Resource and Integration-BasedView)和价值链理论在产业集群层面的拓展,通过融合形成集群资源价值链整合VBCRI(Value chain-Based Cluster ResourceIntegration)思想,表明产业集群资源以产业集群价值链为基本格架实施整合,从而培育产业集群竞争力;然后,从VBCRI出发,基于油气集群资源及其竞争力构成,以及油气集群资源价值链整合能力的分析,构建了油气产业集群竞争力形成机理概念模型,并运用结构方程模型,以我国油气产业为例加以验证。结果表明:基础资源、人力资源、社会关系资源均通过油气集群资源价值链整合(能力)的完全中介作用间接地对油气集群竞争力形成产生正向影响,资本资源则通过油气集群资源价值链整合(能力)的部分中介作用对油气集群竞争力形成产生影响,从而显示了油气集群资源价值链整合(能力)在油气产业集群资源作用于油气产业集群竞争力形成中的充分中介作用,揭示了油气产业集群竞争力形成机理。     

AOAB工艺处理难降解混合化工污水的挂膜启动

采用AOAB(水解酸化A1+生物接触氧化O+深度水解酸化A2+曝气生物滤池BAF)工艺处理难降解混合化工污水,重点研究工艺挂膜方式和生物膜的驯化。结果表明,采用分段连续式挂膜法进行反应器挂膜,20 d即可完成快速挂膜启动;采用分阶段同步培养驯化法驯化生物膜,30 d内可完成高浓度多组分混合化工污水进水的驯化,最终进水COD 1 456 mg/L,出水COD 324 mg/L,总去除率76.85%,驯化效果显著;整个工艺对COD的降解主要集中在生物接触氧化池和曝气生物滤池,驯化期间生物接触氧化池去除率稳定在40%左右,曝气生物滤池去除率稳定在50%以上。同时,通过对比一段水解酸化和深度水解酸化的VFA(挥发性脂肪酸)产出,表明在高有机负荷进水时,一段水解酸化降解大分子有机物的能力有限,但这些有机物可通过二段水解酸化再次降解,由此体现了AOAB工艺在处理多组分混合型的难降解化工污水的优势。     

Experience in establishing a natural standard for analyzing the dynamics of taiga ecosystems

Experience in organizing a natural reference area (standard) for studies on the functional dynamics of ecosystems in connection with paludification and forest-bog relationships is described. The essence of studies on ecosystem dynamics with the aid of natural standards and key plots is described using an example of the Yenisei region of Western Siberia. Arguments are presented for the necessity of using a differential approach to studies on the dynamics of nature and taking into account local ecological conditions while extrapolating the results of these studies to other geographic regions.     

The detection of dioxin- and estrogen-like pollutants in marine and freshwater fishes cultivated in Pearl River Delta, China

In this study we aimed to assess the dioxin- and estrogen-like activities of contaminants extracted from twenty species of freshwater and seawater fishes, using luciferase reporter assays. Transfected MCF7 cells were treated with sample extracts and luciferase activities were then measured at 24-h of post-treatment. The mean values of the detected dioxin- and estrogen-like activities in the freshwater fishes were 25.3 pg TEQ/g ww and 102.3 pM EEQ/g ww whereas in the seawater fishes, the values were 46.2 pg TEQ/g ww and 118.8 pM EEQ/g ww. Using sample-relevant dosage of estrogen, inductions of cell proliferation markers (i.e. retinoblastoma, cyclin D) and stimulations of cell growth were revealed by Western blotting, colony formation and BrdU uptake assays. A cotreatment with TCDD significantly reduced these effects. Using the sample extracts with different dioxin- and estrogen-like activities, similar observation was revealed. The data highlighted the mixture effect of food contaminants on human health.     

武汉城市热岛特征及其影响因素分析

正确理解城市热岛效应的形成机制及其影响因素是制定热岛效应缓解政策和研究城市生态问题的前提和基础。选用1987年9月26日的Landsat-5和2013年9月17日的Landsat-8遥感影像进行地表温度反演,分析武汉市城市热岛效应的时空演变特征;对热岛效应明显的武汉市主城区进行格网划分,提取格网内地表温度及所选影响因子指标值,运用主成分回归方法进行地表温度多因子综合分析,探讨城市热岛形成的主要影响因素。结果表明:(1)武汉市地表温度空间分布表现出典型的热岛特征,1987年和2013年分别有27.7%和39.1%的范围被"热岛"覆盖;(2)影响武汉城市热岛效应的主要因素有不透水面指数、水体面积比例、归一化建筑指数、归一化植被指数及绿地面积比例;(3)当其他影响因素稳定时,不透水面指数每增加1%,可使地表温度增温0.04℃~0.10℃;水体面积每增加1%,可降低地表温度0.03℃。