超声波降解苯酚溶液的研究

以20mg/L的苯酚为研究对象,在超声波槽中对超声波作用于苯酚的降解效率和降解规律进行了初步研究。实验表明:单一的超声波对苯酚的降解率是很低的,不超过6.3%;而在苯酚溶液中加入H2O2后,降解率提高了大约3倍;酸性条件利于苯酚的降解,而在碱性条件下苯酚几乎没有降解。     

几种激素对光合细菌生长的影响

提出在培养基中添加一定浓度的动物或植物生长激素可促进光合细茵的生长。泼尼松、地塞米松、三十烷醇、α-萘乙酸的最适添加浓度分别为0．5mg／L，1mg/L，0．5mg/L和0．5mg/L。混和激素促生效果好于单一激素。指出在生产性培养中，添加某些激素促进光合细茵的生长是可行的。     

共基质条件下TNT降解菌的选育及其处理效果

选取SBR弹药销毁废水处理系统中的活性污泥作为菌源,在共基质条件下,经过驯化和筛选,分离出11株可降解TNT的单菌,从中选出生长速度较快的3株菌JT1,JT2,JT3进行了单菌及混菌降解能力测试,结果表明:混合菌JTH降解能力最强,其适宜环境条件为25℃～30℃,pH7.5～9.0,基质中添加2g/L葡萄糖可显著增强混菌JTH生长并可使24h内的TNT降解率达到96 1%;模拟废水的处理实验表明:混菌JTH对COD的去除率>80%,TNT降解率80%～90%;生物强化实验表明:以0.1的菌量污泥比在SBR系统中投加混合菌可使系统的出水COD稳定在100mg/L左右,出水TNT浓度<5mg/L。     

Fe_2O_3/TiO_2芬顿-光催化协同提高处理废水能力

通过高温煅烧制备复合光催化剂Fe_2O_3/TiO_2,加入H_2O_2构建芬顿-光催化协同体系,对有机废水进行深度降解处理。实验结果表明,Fe_2O_3含量为3%的复合光催化剂投加量1.0 g/L,H_2O_2浓度30 mmol/L,紫外光照射3 min,20 mg/kg亚甲基蓝溶液降解率为88.6%,比TiO_2单体活性提高5倍,芬顿体系3 min对MB几乎无降解,芬顿-光催化协同极大地提高了处理有机污染物的降解能力。紫外光照射20 min,能降解98.2%的20 mg/kg苯酚溶液,分别是单体TiO_2和芬顿体系活性的3倍和24.5倍。     

高效降氰菌的筛选及其特性研究

本研究从电镀废水中分离出了三株能够高效降解自由氰根的菌种，并对这三株菌的生长曲线和影响其降解氰化物的因素进行了研究。结果表明，这三株菌分别属于青霉属、木霉属和酵母属，并命名为M3、Mw4和Ms；其最大生长量的时间分别为15、20和18小时；当CN^-初始浓度为80mg／L时，M3菌16h内降解氰化物的最优条件是pH为5-7、温度为20℃～30℃、摇床转速为130rpm、接种量为10％。在此条件下，M3菌将80mg/L CN^-降解到0．22mg/L，降氰率达到98．9％。该研究结果可为微生物在处理含氰废水的实际应用提供依据。     

微生物法处理海上钻井废钻井液

微生物法适用于海上钻井含油废弃物的处理。通过多次对菌株采集、分离、纯化和培养驯化,选育得到了3株对石油烃类有很好降解效果的石油类降解菌;确定了石油类降解菌适宜的生化处理条件:最佳生长及原油降解温度为50℃、最佳生长及原油降解酸碱性环境为pH=6.0、最佳菌株接种量2%、最佳原油初始浓度为500mg/L。处理后的含油废弃钻井液含油量基本稳定在2mg/L以下,降解率达98%以上。     

P-25纳米TiO2在含酚废水处理方面的应用

采用室内模拟研究,以P-25纳米TiO2作为光催化剂进行了苯酚水溶液的光催化降解性能探讨,初步考察了溶液的pH、P-25纳米TiO2用量对光催化降解苯酚过程的影响,以获得P-25纳米TiO2光降解含酚废水的较好反应条件.实验结果表明,当溶液pH=8时,降解水体中苯酚效果最佳,强酸和强碱条件均不利于苯酚的降解;在pH 8的反应体系中,当光催化剂用量为0.4g/L时,催化水体中苯酚降解的效果最好.     

生物流化床处理生活污水的动力学研究

本研究采用颗粒活性炭（Granule Activated Carbon,GAC）为填料,考察了生物流化床（Biological fluidized Bed,BFB）处理生活污水的动力学.研究结果表明,GAC-BFB内生物膜的表现产率YoA为2.3057gVSS/gCOD,微生物细胞衰减常数Kd为0.3056d-1;基质降解动力学中米氏常数Ks为0.2182mg/L,反应速率常数K为13.09 mg/（l·h）.GAC-BFB的微生物生长动力学拟合方程为1/θc=2.3057q-0.3056,R2=0.9549; GAC-BFB的基质降解动力学拟合方程为1/U =0.2182＊1/S ＋0.0764,R2 =0.9972,该微生物生长动力学拟合方程及基质降解动力学拟合方程能较好的反映GAC-BFB系统的出水水质状况,本研究所获得的动力学关系和动力学参数可作为GAC-BFB系统的设计依据.     

醋酸钠和次氯酸钠对高铁酸钾溶液稳定性的影响

基于分光光度法研究了醋酸钠和次氯酸钠对高铁酸钾溶液稳定性的影响。对于1 mmol/L的高铁酸钾溶液，在25℃和pH值12的环境中，醋酸钠能提高其稳定性，当醋酸钠浓度达到10 mmol/L时，高铁酸钾的稳定性最好，静置10h高铁酸钾的留存率约79%;为验证醋酸钠在高铁酸钾分解有机物的反应中是否仍具有稳定高铁酸钾的作用，以降解苯酚为例，当醋酸钠与高铁酸钾摩尔比为5:1时，苯酚的降解率达到最高值88.9%。次氯酸钠对高铁酸钾的稳定性影响实验结果显示，次氯酸钠可以提高高铁酸钾稳定性，次氯酸钠耗尽前，高铁酸钾留存率接近100%。     

纤维素降解真菌的分离鉴定及特性研究

经过实验分离到一株纤维素降解真菌CD-Q1,通过形态及分子生物学鉴定该真菌为匍匐根霉。该菌能够以滤纸、秸秆和脱酯棉为唯一碳源生长,8 d内可将26.5%的秸秆降解,可将7.5%的滤纸糖化。当以滤纸为唯一碳源时,pH=5条件下,滤纸失重及还原糖产生量最高,45 h内可将3%滤纸降解,生成0.845 mg/ml的还原糖(以葡萄糖计)。该纤维素降解真菌的分离为纤维素糖化及进一步利用提供了较好菌源,为纤维素降解性能的基因改良提供了理想的出发菌株。     

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.     

Using Paleo Reconstructions to Improve Streamflow Forecast Lead Time in the Western United States

In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.     

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.     

BIOLOGICAL INDICATORS AND BIOLOGICAL EFFECTS OF ESTUARINE/COASTAL POLLUTION1

ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.     

Journalists' views of advertiser pressures on agricultural news

All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by outside sources. However, much of the previous research on agricultural information has concentrated on what information various media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy. Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work, and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel study.     

Definition Procedures Have Little Effect on Performance of Environmental Classifications of Streams and Rivers

Mapped environmental classifications are defined using various procedures, but there has been little evaluation of the differences in their ability to discriminate variation in independent ecological characteristics. We tested the performance of environmental classifications of the streams and rivers of France that had been defined from the same environmental data using geographic regionalization and numerical classification of individual river valley segments. Test data comprised invertebrate assemblages, water chemistry, and hydrological indexes obtained from sites throughout France. Classification performance was measured by analysis of similarity (ANOSIM). Geometric regions defined by a regular grid and without regard to environmental variables and a posteriori classifications based on clustering the test datasets defined lower and upper bounds of performance for a given number of classes. Differences in classification performances were generally small. The ANOSIM statistics for the a posteriori classifications were around twice that of all environmental classifications, including geometrically defined regions. The hydro-ecoregions performed slightly better for the invertebrate data and the network classification performed slightly better for the chemistry and hydrological data. Our results indicate that environmental classifications that are defined using different procedures can be comparable in terms of their ability to discriminate variation of ecological characteristics and that alleged differences in performance arising from different classification procedures can be small relative to unexplained variation. We conclude that definition procedures might have little effect on the performance of large-scale environmental classifications and decisions over which procedures to use should be based primarily on pragmatic considerations.     

MANGANESE CYCLE IN IMPOUNDMENT WATER

Manganese entering impounded water will undergo a cyclic transformation. Oxidation precipitates manganese from top waters. At the bottom of the lake, biological activity will render manganese soluble by both intracellular as well as extracellular activity. The study was made to demonstrate that biological reduction and transformation, organometallic complexation, together with the presence of carbon dioxide and the lowering of pH all have some effect on the solubility of manganese. Dissolved manganese may be brought back to top waters during the lake overturn and therefore deteriorates the water quality.     

Provincial development plans in Zimbabwe: an analysis of their content,structure and methodology

Zimbabwean provincial plans were instituted to help in the achievement of the national goal of the creation of an egalitarian, socialist and integrated society. The national goal itself was adopted as an antithesis to the dualist society characterised by spatial, economic, social, politican and technological inequalities that Zimbabwe inherited from colonialism. This meant that provincial plans had to play both a functional (or growth allocating/distribution) and a territorial (or redistribution) role.

This paper reviews their role in achieving the national goal by examining their functions, content, structure and methodology. The paper concludes that because of their nature, provincial plans are not suitable tools for the achievement of the national goal.