论有机质在湖泊水环境中的作用

国内外学者在湖泊水环境方面开展了大量的研究,然而主要集中在各种形态氮、磷等营养盐上,对有机质的来源、循环及生态学效应的研究比较缺乏。近期研究表明：有机质是水体及沉积物中的重要组分,沉积物中有机质可经分解、矿化,释放到上覆水体,重新进入营养循环;同时,有机质对重金属及有机污染物的迁移转化有着重要影响。本文简要分析了湖泊有机质已有的研究进展,论述了有机质在湖泊水环境中的重要作用、主要技术突破及难点,指出有机质研究对水环境质量评价、污染控制和生态修复都具有重要意义。研究表明,开展有机质在水环境中循环转化、生物有效性及其与富营养化之间关系的研究,将是湖泊水环境研究领域未来的主要研究方向之一。     

微生物硫酸盐同化的调控及其在提高重金属抗性中的研究进展

硫酸盐同化是微生物将环境中硫元素整合到细胞内的主要途径,在微生物硫代谢中发挥至关重要的作用。近年来,基因组学和转录组学研究发现硫酸盐同化途径参与调控了微生物的重金属抗性。综述了微生物硫酸盐同化途径调控的最新研究进展,分析其在重金属抗性中的作用,旨在为深入揭示微生物硫酸盐同化途径及其与重金属抗性的关系提供参考。     

塔中油田硫酸盐还原菌恶性繁殖机理分析＊

硫酸盐还原菌等的恶性繁殖使油田生产管线设施腐蚀破坏、结垢堵塞,注入地层后对油层造成伤害。研究发现,塔中油田联合站水体可检测SRB菌数高达2.5×104个/mL,注水管垢含FeS高达29.8%,属硫酸盐还原菌恶性繁殖代谢产物。塔中油田水系统各主要环节中硫酸盐还原菌和硫化氢含量与油田水处理工艺特点密切相关,其中塔中油田联合站完全密闭的水处理压力流程是造成该站硫酸盐还原菌恶性繁殖的主要原因。实验表明,前端适度曝氧、添加H2O2等氧化性杀菌剂和300mg/L冲击式加药等都是抑制硫酸盐还原菌的有效方法。     

水体沉积物磷形态及释放风险分析——以苏州工业园水体为例

应用SMT法测定了苏州工业园内水体沉积物各形态磷的含量,并对沉积物磷的释放风险进行了评估。结果表明园区内水体沉积物磷污染较严重,吴淞江沉积物中总磷(TP)含量最高,达到了1 604.59 mg/kg;沉积物中磷主要赋存形态为生物可利用磷,其中金鸡湖沉积物中生物可利用磷占比最高,占总磷含量的59.59%,湖泊水体流动性较弱,存在非常大的释放风险。     

微生物烟气脱硫技术研究进展

通过对微生物烟气脱硫方法的介绍，综述了微生物烟气脱硫原理、工艺和技术。叙述了烟气吸收和吸收尾液的处理工艺所利用的脱硫微生物种类，并阐述了氧化亚轶硫杆菌、硫酸盐还原茵、丝状硫细菌、光合硫细菌、无色硫细菌和脱氮硫杆菌的代谢途径、作用效果和关键影响因素，并且指出其优缺点。文章总结了国内外在微生物烟气脱硫工艺的研究进展，并对我国今后微生物烟气脱硫技术发展趋势进行了简要分析。     

乌鲁木齐东道海子湖岸表层沉积物对氨氮的等温吸附特征研究

乌鲁木齐东道海子是乌鲁木齐河与头屯河下游的尾闾湖泊,东道海子水体氮素主要受放牧和采樵对荒漠植被破坏和农业排碱影响。而湖泊沉积物是湖泊水体污染物源汇关系中的重要介质,这些沉积物可能成为污染物运移转化的载体。本文通过野外采样与实验室模拟的方法,研究东道海子湖岸沉积物对氨氮的吸附特征。在吸附动力学特征中,准二级反应动力学达到极显著水平,沉积物Q_(max)变化范围在179~450mg/kg之间,平均值为238mg/kg,沉积物对氨氮的最终平衡时间在2h,均遵循先快后慢的规律,在前30min的吸附量基本已经与最终的吸附平衡浓度差别不大。在吸附热力学特征中,在低浓度条件下,对吸附浓度与吸附量进行拟合,Henry模型的拟合效果基本达到了显著水平,东道海子沉积物对氨氮吸附规律适用于低浓度吸附氨氮,在低浓度下Langmuir和Freundlich模型对数据没有达到显著水平,拟合效果不如Henry模型。     

硫酸盐废水处理产电过程中的电子分流机制研究

为探讨废水中硫酸盐对微生物燃料电池（MFC）产电效能的影响,采用单室空气阴极MFC反应器处理模拟硫酸盐废水,并对硫酸盐的电子分流过程进行了监测。结果表明,在一定范围内,提高硫酸盐浓度能使MFC的稳定电压上升,电池持续时间延长,MFC输出功率增大。随着进水硫酸盐浓度提高,微生物产生的电子总量中,硫酸盐还原捕获的电子和通过外电路的电子所占的比例均下降,分别由12．54％和31．45％下降至7_32％和8．49％。研究表明,较低浓度硫酸盐能够提高MFC的电能输出功率,但由于硫酸盐的还原将消耗掉大量电子,进而降低MFC的库伦效率。     

内源磷的释放作用及影响因素研究进展

水体的富营养化已成为目前环境研究中的焦点问题,磷在湖泊中的浓度高低是衡量湖泊富营养化水平的重要指标,是水生态系统基本营养盐之一,并且是淡水湖泊的最主要限制性营养因子。在外源磷得到有效的控制之后,内源磷的污染仍然能够保持湖泊的富营养化状态,此时内源磷的控制就成为了难点和重点。在底泥中的结合态磷,主要是以无机磷和有机磷的形式存在,有机磷与微生物活性密切相关,无机磷则主要与底泥存在的环境联系紧密。湖泊底泥内源磷释放受到一系列物理、化学、生物过程的控制,其影响因素主要包括扰动、氧化还原电位、pH值等,是多种因子综合作用的结果,同时,扰动引起的底泥再悬浮对内源磷有吸附固定作用。故底泥内源磷的释放机理有待进一步探索,在多种影响因素作用下,进一步研究底泥再悬浮对磷的吸附释放作用,从而明确内源磷的主要来源及吸附释放过程,为内源磷的控制提供理论依据,进而控制水体富营养化。     

我国煤炭开采和燃烧过程中的硫污染对土壤环境的影响

我国煤炭在开采和燃烧过程中形成的硫污染物主要是酸性矿井水和二氧化硫,由煤炭燃烧造成的硫的干湿沉降以及煤炭开采过程中形成的酸性矿井水使土壤的物理化学性质发生变化,从而对土壤造成严重的破坏。主要表现在造成土壤中可溶性硫酸盐的大幅度升高;引起土壤的pH值下降;植物营养元素特别是K、Na、Ca、Mg等产生淋失;活性铝溶出量增加;有毒重金属活化;抑制土壤酶的活性等方面。可以通过脱硫除尘、加强绿化、建立合理的工业布局、加入土壤改良剂等措施来减少硫污染物的排放量和改善其对土壤环境的影响,但总量控制是关键,是最根本的途径。     

徐州市近年来大气硫酸盐化速率的时空变化研究

硫酸盐化速率反映大气中二氧化硫及硫的化合物的污染状况,文章以徐州市区11年大气中硫酸盐化速率监测数据为依据,分析研究了煤烟型城市环境空气中硫酸盐化速率的变化规律及污染状况。结果表明：徐州市硫酸盐化速率变化有明显的时空特征,与环境空气质量也密切相关。提出削减污染源,加快清洁能源推广步伐,完善城市规划,进行产业结构调整是解决徐州市大气污染的有效途径。     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Neighbourhood characteristics and urban gardens in the Toledo metropolitan area: staffing and voluntarism,food production,infrastructure, and sustainability practices

Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.     

Predicting deer-vehicle collisions in an urban area

Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.     

Surface applied water treatment residuals affect bioavailable phosphorus losses in Florida sands

Water treatment residuals (WTR) can reduce runoff P loss and surface co-application of P-sources and WTR is a practical way of land applying the residuals. In a rainfall simulation study, we evaluated the effects of surface co-applied P-sources and an Al-WTR on runoff and leacheate bioavailable P (BAP) losses from a Florida sand. Four P-sources, namely poultry manure, Boca Raton biosolids (high water-soluble P), Pompano biosolids (moderate water-soluble P), and triple super phosphate (TSP) were surface applied at 56 and 224kgPha(-1) (by weight) to represent low and high soil P loads typical of P- and N-based amendments rates. The treatments further received surface applied WTR at 0 or 10gWTRkg(-1) soil. BAP loss masses were greater in leachate (16.4-536mg) than in runoff (0.91-46mg), but were reduced in runoff and leachate by surface applied WTR. Masses of total BAP lost in the presence of surface applied WTR were less than approximately 75% of BAP losses in the absence of WTR. Total BAP losses from each of the organic sources applied at N-based rates were not greater than P loss from TSP applied at a P-based rate. The BAP loss at the N-based rate of moderate water-soluble P-source (Pompano biosolids) was not greater than BAP losses at the P-based rates of other organic sources tested. The hazards of excess P from applying organic P-sources at N-based rates are not greater than observed at P-based rates of mineral fertilizer. Results suggest that management of the environmental P hazards associated with N-based rates of organic materials in Florida sands is possible by either applying P-sources with WTR or using a moderate water-soluble P-source.     

Animal Consciousness and Ethics in Asia and the Pacific

The interactions between humans, animals and the environment have shaped human values and ethics, not only the genes that we are made of. The animal rights movement challenges human beings to reconsider interactions between humans and other animals, and maybe connected to the environmental movement that begs us to recognize the fact that there are symbiotic relationships between humans and all other organisms. The first part of this paper looks at types of bioethics, the implications of autonomy and the value of being alive. Then the level of consciousness of these relationships are explored in survey results from Asia and the Pacific, especially in the 1993 International Bioethics Survey conducted in Australia, Hong Kong, India, Israel, Japan, New Zealand, The Philippines, Russia, Singapore and Thailand. Very few mentioned animal consciousness in the survey, but there were more biocentric comments in Australia and Japan; and more comments with the idea of harmony including humans in Thailand. Comparisons between questions and surveys will also be made, in an attempt to describe what people imagine animal consciousness to be, and whether this relates to human ethics of the relationships. This revised version was published online in July 2006 with corrections to the Cover Date.     

Rehabilitation and Flood Management Planning in a Steep,Boulder-Bedded Stream

This study demonstrates the integration of rehabilitation and flood management planning in a steep, boulder-bedded stream in a coastal urban catchment on the South Island of New Zealand. The Water of Leith, the primary stream flowing through the city of Dunedin, is used as a case study. The catchment is steep, with a short time of concentration and rapid hydrologic response, and the lower stream reaches are highly channelized with floodplain encroachment, a high potential for debris flows, significant flood risks, and severely degraded aquatic habitat. Because the objectives for rehabilitation and flood management in urban catchments are often conflicting, a number of types of analyses at both the catchment and the reach scales and careful planning with stakeholder consultation were needed for successful rehabilitation efforts. This included modeling and analysis of catchment hydrology, fluvial geomorphologic assessment, analysis of water quality and aquatic ecology, hydraulic modeling and flood risk evaluation, detailed feasibility studies, and preliminary design to optimize multiple rehabilitation and flood management objectives. The study showed that all of these analyses were needed for integrated rehabilitation and flood management and that some incremental improvements in stream ecological health, aesthetics, and public recreational opportunities could be achieved in this challenging environment. These methods should be considered in a range of types of stream rehabilitation projects.     

AN INDEX FOR MEASURING THE PERFORMANCE OF IRRIGATION MANAGEMENT SYSTEMS WITH AN APPLICATION1

ABSTRACT: This paper presents a statistically valid index for measuring the performance of irrigation systems. The index is applied to a sample of 39 farms on a watercourse under the warabandi system of irrigation management in India. It is found that while the farmers in fact irrigated almost exactly the total amount of irrigated area as designed, inter-farm variations were considerable. The index shows that the degree of error of managerial effectiveness of irrigation on this watercourse is 20 percent. Therefore it is concluded that the system is performing at 80 percent effectiveness.     

WATER LOSS EQUATIONS AND COEFFICIENTS TO ESTIMATE RUNOFF FROM RAINFALL1

Infiltration models are based on physical characteristics of the soil and initial soil moisture. For a given soil it is based on the initial soil moisture distribution. A computer simulation model for flood runoff systems (FH-Model) was used to analyze 39 sets of rainfall-runoff data on four small watersheds ranging in size from 17 to 342 square kilometers located in the Yamaska River basin in Quebec. From these analyses, parameters and coefficients have been determined for a water loss (infiltration) equation. A method for determining the loss parameters, using a nonlinear least square curve fitting technique, is presented. Expressions were made to relate the loss parameters to antecedent precipitation. The equations were tested on 11 storm rainfall and runoff events on a watershed located in the same region and close agreements were found.     

Vegetation dynamics in impounded marshes along the Indian River Lagoon,Florida, USA

Data are presented on the vegetation dynamics of two impounded marshes along the Indian River Lagoon, in east-central Florida, USA. Vegetation in one of the marshes (IRC 12) was totally eliminated by overflooding and by hypersaline conditions (salinities over 100 ppt) that developed there in 1979 after the culvert connecting the marsh with the lagoon was closed. Over 20% recovery of the herbaceous halophytesSalicornia virginica, S. bigelovii, andBatis maritima was observed at that site after the culvert was reopened in 1982, but total cover in the marsh remains well below the original 75%. No recovery of mangroves was observed at this site. The second site (SLC 24), while remaining isolated from the lagoon during much of the study, did not suffer the complete elimination of vegetation experienced at the first site. At this location, mangroves increased in cover and frequency with a concomitant decrease in herbaceous halophytes. Considerable damage to the vegetation was evident at IRC 12 when the impoundment was closed and flooded for mosquito control in 1986. Although the damage was temporary, its occurrence emphasizes the need of planning and constant monitoring and adjustment of management details as conditions within particular marshes change. Storms and hurricanes may be important in promoting a replacement of black mangroves by red mangroves in closed impoundments because the former cannot tolerate pneumatophore submergence for long periods of time. University of Florida-IFAS Journal Series R-00521.