土壤环境汞形态及吸附解吸研究进展

汞污染一直是全球备受关注的问题,由于土壤是环境汞的源和汇,因此已经开展了大量相关的研究工作。本论文系统总结了土壤环境汞形态及吸附解吸特征的研究现状,综述了不同类型土壤汞的背景含量,以及汞在土壤中的赋存形态,分析了土壤汞吸附特征及几种典型的土壤吸附剂（粘土矿物、铁锰氧化物、硫化物和土壤有机质）对汞吸附的作用机制。     

水库汞污染研究进展

汞污染是水库环境存在的一个重要问题,本文概述了目前水库汞污染现状、汞的存在形态、汞的迁移转化过程及其动力学模型的研究进展,指出了不足之处,以促进下一步研究。     

亭子口库区水质汞的污染特征及建库后水体中汞的预测

亭子口水利枢纽位于喜陵江平流苍溪县城以上,１５ｋｍ处。本文根据嘉陵江广元段水质监测资料,分析库区地面水体中汞的现状污染特征,并运用沉积物的负指数方程预测库区建坝后水体中汞的浓度。     

MA-2000型测汞仪直接测定环境水体中的汞

介绍了MA-2000型测汞仪测定环境水体中的汞,以氯化亚锡为还原剂,0．001％半胱氨酸为汞固定剂,在一定浓度范围内被测汞蒸汽在波长253．7nm紫外光下的吸收值与汞蒸汽浓度成正比。方法检出限0．006ng,精密度和准确度均满足水质监测实验室质量控制的要求。     

大气汞的时空分布研究进展

大气汞是汞全球循环的组成部分,探索汞在大气中的时空分布对于研究其地球化学循环具有重要意义。本文综述了大气汞时空分布的研究现状,主要包括大气汞的来源,形态分布,空间分布度时间分布。研究表明,大气汞具有扩散范围广,空间变异大,时间变化规律性强的特点,同时还指出扩大时空分布研究范围和建立污染和预测模型是未来的研究重点。     

烟气脱汞技术研究进展

基于现阶段烟气汞的排放情况,介绍当前燃煤电站的几种烟气脱汞技术。主要是先将零价汞氧化为二价汞,再进行脱除。其中利用现有烟气控制设备,活性炭吸附及添加改性物质,有比较好的脱汞效率,电催化、光催化以及等离子体脱汞等新技术处于研发阶段,而烟气中多种污染物协同脱除有较好的应用前景。     

土-气界面汞交换特征研究进展

本文综述了20多年来汞在土壤-大气界面间交换的研究现状,包括汞在大气和土壤中的存在形态、大气汞的干湿沉降、土壤汞释放及影响因素的研究,分析其存在的问题,并提出了未来的研究重点。     

含汞气田汞污染控制技术研究

痕量组分汞可能出现在大多数天然气气藏中。汞及其化合物均是剧毒物质,在含汞天然气处理过程中可能危害操作人员健康、腐蚀管线设备以及污染环境。针对某气田含汞天然气处理工艺,分析汞在天然气处理过程中分布情况,评价汞对天然气处理工艺及环境的影响,提出了含汞气田汞污染的控制技术以及防护措施,对降低含汞气田开发风险、保护人身健康及防止环境污染具有现实意义。     

溶解性有机质对有机污染物环境行为的影响及其环境意义

DOM是陆地及水生生态系统中十分活跃的组分,是土壤圈与相关圈层物质交换的重要形式,对有机污染物质的毒性、迁移转化以及生物降解性等有着重要影响。文章在论述DOM来源、组成及结构特征的基础上,重点阐述了DOM对有机物的环境行为的影响。DOM主要通过氢键、电荷转移、范德华力、配位体交换、疏水分配、共价键结合、螯舍等增强或抑制有机物在土壤的吸附／解吸、生物有效性,阐述了DOM与有机物结合的两重性;同时,DOM不同组分和分子量大小对有机物环境行为的影响有着较大的差别。     

Differences in Dissolved Organic Carbon and Nitrogen Responses to Storm‐Event and Ground‐Water Conditions in a Forested,Glaciated Watershed in Western New York1

Abstract: Differences in the storm‐event responses of dissolved organic carbon (DOC) and nitrogen (DON) in streamflow and ground water were evaluated for a glaciated forested watershed in western New York. Eight to ten storm events with varying rainfall amounts, intensities, and antecedent moisture conditions were studied for three catchments (1.6, 3.4, and 696 ha) over a three‐year period (2003‐2005). Concentrations of DOC in streamflow exiting the catchments were significantly higher for storm events following a dry period, whereas no similar response was observed for DON. Highest DON concentrations in streamflow were typically associated with storm events following wet antecedent moisture conditions. In addition to antecedent moisture conditions, DOC concentrations were also positively correlated with precipitation amounts, while DON did not reveal a consistent pattern. Streamwater and ground‐water concentrations of DOC during storm events were also strongly correlated with riparian ground‐water depths but a similar relationship was not observed for DON. Ground‐water DON concentrations were also more variable than DOC. We hypothesized that the differences in DOC and DON responses stemmed from the differences in catchment sources of these solutes. This study suggests that while DOC and DON are intrinsically linked as components of dissolved organic matter, their dynamics and exports from watersheds may be regulated by a different set of mechanisms and factors. Identifying these differences is critical for developing more reliable and robust models for transport of dissolved organic matter.     

A Review of Water Level Fluctuations on Aquatic Biota With an Emphasis on Fishes in Ice‐Covered Lakes1

Abstract: The effects of water level fluctuations on fish and other aquatic biota, with an emphasis on winter water withdrawal in northern regions is reviewed. Water demands for population growth and development are adding pressure on water reserves, particularly when coupled with changing climatic conditions. Water level fluctuations can have adverse effects on the environment, most notably to hydrologic and biotic processes ranging in magnitude from the micro‐scale to landscape level. Water level management of lakes and reservoirs can affect all forms of aquatic biota. The severity of effect is dependant on the magnitude, duration and timing of the fluctuation, and the species exposed. In northwestern Canada and northern Alaska, water is withdrawn from water bodies to construct ice‐roads and other winter based developments. Biota in small, isolated water bodies are particularly sensitive to reductions in winter water levels. Water withdrawals can reduce the oxygen available to overwintering fish, while reduced water levels can reduce habitat for fish and furbearers, and freeze littoral areas killing plants, invertebrates, and fish eggs. Regulatory winter water withdrawal thresholds have been developed in the Northwest Territories and Alaska and continue to be refined as new data becomes available. The use of thresholds can help minimize or avoid negative impacts to the environment, particularly fish, from winter water withdrawal activities. Many different factors may influence the effect that winter water withdrawal has on a water body, such as basin shape, substrate and location. More research is warranted to better understand the linkages between anthropogenic and natural water level fluctuations and their combined effect on aquatic ecosystems. A general decision support system is proposed for minimizing risk to aquatic life from winter water withdrawal activities.     

Contribution of Wastewater Treatment Plant Effluents to Nutrient Dynamics in Aquatic Systems: A Review

Excessive nutrient loading (considering nitrogen and phosphorus) is a major ongoing threat to water quality and here we review the impact of nutrient discharges from wastewater treatment plants (WWTPs) to United States (U.S.) freshwater systems. While urban and agricultural land uses are significant nonpoint nutrient contributors, effluent from point sources such as WWTPs can overwhelm receiving waters, effectively dominating hydrological characteristics and regulating instream nutrient processes. Population growth, increased wastewater volumes, and sustainability of critical water resources have all been key factors influencing the extent of wastewater treatment. Reducing nutrient concentrations in wastewater is an important aspect of water quality management because excessive nutrient concentrations often prevent water bodies from meeting designated uses. WWTPs employ numerous physical, chemical, and biological methods to improve effluent water quality but nutrient removal requires advanced treatment and infrastructure that may be economically prohibitive. Therefore, effluent nutrient concentrations vary depending on the particular processes used to treat influent wastewater. Increasingly stringent regulations regarding nutrient concentrations in discharged effluent, along with greater freshwater demand in populous areas, have led to the development of extensive water recycling programs within many U.S. regions. Reuse programs provide an opportunity to reduce or eliminate direct nutrient discharges to receiving waters while allowing for the beneficial use of reclaimed water. However, nutrients in reclaimed water can still be a concern for reuse applications, such as agricultural and landscape irrigation.     

The future of water in Australia: The potential effects of climate change and ozone depletion on Australian water quality,quantity and treatability

Water is a resource that is essential for all life on Earth. An exponentially growing human population, in addition to unprecedented industrial and technological development, threaten the availability and quality of this resource. Climate change and ozone depletion are two major environmental problems facing mankind today. These problems have the potential to further strain currently available freshwater resources. Recent research has shown that climate change and ozone depletion are linked phenomena and their interaction exacerbates their impact. Changes in precipitation, surface runoff, solar UV radiation, temperatures, and evaporation are some of the predicted outcomes of climate change and ozone depletion. They influence the biogeochemical cycles and aquatic ecosystems in lakes and rivers, and alter the character of natural organic matter (NOM) and, consequently, they have the potential to affect the quality, quantity and treatability of our water resources. Given these uncertainties, and the need to mitigate the consequences of climate change and ozone depletion, the issues of changing water quality, quantity and treatability cannot be ignored by Australian governments and water utilities.     

土壤有机质测定全程质量控制

质量控制是环境监测赖以生存和发展基础,加强全程质量控制才能确保监测数据的准确性和可靠性。结合环境监测工作实际,应用标准分析方法—重铬酸钾容量法《土壤检测第6部分:土壤有机质的测定》(NY/T 1121.6-2006)对土壤有机质测定进行了全程质量控制技术探讨。简介了方法所需仪器与试剂,深入探讨了运用标准法进行土壤中有机质测定全程质量控制技术问题。指出在标准分析方法基础上,选用有效期内质量合格分析纯以上试剂,全面规范样品采集与保存,有序开展样品制备与称取,严格管控消煮操作与滴定过程,准确进行分析结果数据处理,切实加强结果填报规定程式,能够确保大批量、成分复杂土壤样品有机质测定精密度和准确度。     

内陆水环境风险分析的理论与方法研究

本文对内陆水环境中风险的概念、分类及风险分析的目的作了较为全面的阐述,主要综述了关于水环境风险分析的理论与方法并做了一定的展望,为内陆水环境中风险分析研究工作的进一步展开作了一些基础性的工作。     

捕集阱顶空-气相色谱/质谱法检测地表水中25种挥发性有机物

建立了捕集阱顶空-气相色谱/质谱法检测地表水中25种挥发性有机物的分析方法。采用正交实验设计对捕集阱顶空条件进行了优化,该方法相关系数0.995,加标回收率为90%~110%,方法检出限为0.08~0.39μg/L,相对标准偏差(n=7)为0.7%~4.8%,仪器检出限低于0.04μg/L。方法准确度和灵敏度较好,可以满足对地表水中25种挥发性有机物的检测要求。     

西昌邛海水体污染及其综合整治与保护管理问题研究

本文阐述了邛海水体污染及其生态环境破坏的状况,剖析了污染源及其危害。同时,针对问题提出了全方位综合整治与保护管理具体措施。     

水务企业多元化模式探讨

以在沪深两市上市的22家以涉水业务为主营业务的企业为研究样本,从战略相关多元化与非相关多元化的角度,利用优化的Jacquemin-Berry熵测度模型,定量展现了一幅水务企业多元化发展的图景。并基于核心资源与能力理论,总结了水务企业不同的多元化发展模式。研究发现,在样本企业中,存在三种主要模式:以资本运营为核心的综合多元化扩张、以技术研发为核心的战略相关多元化扩张和以非水务资源为核心的非相关多元化扩张。其中,实行综合多元化扩张的水务企业更倾向于成长为我国本土大型、综合、流域型水务集团。