有机颜料废水的混凝预处理研究

利用絮凝剂阳离子聚丙烯酰胺(CPAM)和混凝剂聚合氯化铝(PAC)对有机颜料废水进行混凝处理,考察了单独使用CPAM、PAC及两者联合使用的处理效果,探讨了初始pH值、混凝剂投加量对处理效果的影响.结果表明,CPAM与PAC复配处理该废水时效果较好,水样pH值为7.0;CPAM与PAC的投药量分别为10mg/L和150mg/L时,浊度去除率可达97.56％.     

Cl^-含量对古油污泥絮凝效果的影响

针对化学混凝处理含油污泥中混凝剂投加量大而混凝效率较低的问题,通过实验研究了Cl^-对混凝剂处理含油污泥絮凝效率的影响。实验中采用抽滤的方法来测定絮凝效率。实验结果表明Cl^-是影响絮凝效率的重要因素,C1^-<10000mg／L时,A12(SO4)3、PAC混凝效果较好,Cl^->20000mg／L时,PAM的混凝效果较好。     

苎麻脱胶废水预处理研究

通过采用自制的苎麻脱胶废水混凝剂、去杂脱色剂对苎麻脱胶废水进行预处理，实现了苎麻脱胶废水COD（mg／L）、BOD（mg／L）、SS（mg／L）下降到生化处理的要求，为废水生化处理打下基础。通过微波处理废水滤渣，使其达到快速干燥、炭化，并能作为自制脱色剂组成成分之一，实现了滤渣的资源化利用并降低了废水的处理成本。     

高含盐钻井废水真空蒸发处理实验

针对钻井过程产生的高含盐废水和反渗透处理产生的高含盐水的特点,采用混凝预处理、过滤、真空蒸发处理工艺对钻井废水进行综合处理,混凝实验探讨了混凝剂(PAC)、助凝剂(PAM)、pH值、静置时间和搅拌速度对CODCr去除率的影响,得出混凝实验最佳方案。并对过滤实验、蒸发实验结果进行分析。实验表明:混凝预处理、过滤后的废水再进行真空旋转蒸发处理,馏出液经冷却收集后能达到GB 8978—1996《污水综合排放标准》一级标准,实验可为高含盐废水处理工艺提供参考。     

强化混凝工艺深度处理含聚采油废水

利用强化混凝工艺对含聚采油废水进行深度处理。在以PFS作为主混凝剂,Potenflo1315和Potenflo1365作为助凝剂的强化混凝实验中,分别考察了pH值、PFS投加浓度以及有机助凝剂Potenflo1365和Potenflo1315的投加浓度对含聚采油废水的处理效果。实验结果表明:在pH值为5.0时,当投加浓度为150 mg/L的PFS与2.5 mg/L的Potenflo1365复配后,对含聚采油废水的处理效果最佳,COD_(Cr)去除率达到88.8%,浊度去除率达到98.1%,经处理后废水主要指标可以达到GB 8978—1996《污水综合排放标准》一级标准。     

钢铁厂废酸对印染前处理废水的混凝沉淀实验

棉纺织印染前处理废水水质成分复杂,污染物含量极高,是印染厂污水处理难以达标的重要原因。实验针对常州某印染厂棉纺织印染前处理车间废水水质特性,选取钢铁厂废酸作为混凝剂对棉纺织印染前处理废水进行了混凝试验研究。得出废酸的最佳投加量为30mL/L;混凝最佳搅拌方式为：以300rpm速度快速搅拌2min,以40rpm搅拌10min;助凝剂阳离子型聚丙烯酰胺（CPAM）以投加4mg/L为宜;最佳沉淀时间为20min。     

混凝-超滤组合工艺处理鱼粉加工废水

鱼粉加工废水COD_Cr很高,需要进行处理后才能排入市政管网。开发了混凝-超滤组合处理鱼粉加工废水的新工艺,确定了混凝剂、助凝剂的最佳投量,以及超滤膜工艺的运行参数。实验结果表明,利用混凝-超滤组合工艺处理鱼粉加工废水,处理后的水COD_Cr为264 mg/L,达到《污水排入城镇下水道水质标准》(CJ343-2010)的排放标准。     

硫酸盐生物还原的限制性生态因子的影响研究

利用厌氧颗粒污泥对烟气中SO2吸收生成的硫酸盐或亚硫酸盐废水进行处理，考察起始SO4^2-质量浓度、初始COD／SO4^2-、初始pH、接种污泥质量、亚铁离子等限制性生态因子对硫酸盐还原的影响。结果表明：在起始SO4^2-质量浓度800mg／L，初始COD／SO4^2-为3．0，pH值为7．0，接种污泥质量为31．10gVSS／L，添加亚铁离子的条件下，进行半连续试验，硫酸根去除率可迭70％。表明在COD／SO4^2-较低的条件下，各生态因子综合作用下，硫酸盐还原可得较好效果。     

微波化学工艺处理烟草行业综合废水工程实践

采用微波化学工艺处理了烟草行业综合废水，工程规模为2500m3／d。处理前废水水质指标平均值为：CODCr1700mg／L，SS475mg，L，氨氮10．1mg/L，P0．72mg／L，pH值8．93；处理后废水水质指标平均值为：CODCr42．1mg／L，SS4mgL，氨氮3．7mg／L，P0．019mg／L。pH值7．91。除氨氮外，废水污染物去除率均达到95％以上，出水水质完全符合GB8978—1996《污水综合排放标准》的一级标准，经过消毒可回用。     

混凝强化COD_Cr减排方案的研究

通过M—BFA、PAFS和PFS三种混凝剂对出水浊度、CODcr和TP的去除效果的研究，分析了混凝强化降低上海市某污水处理厂出水CODcr的效果，给出了混凝强化CODcr减排方案。实验结果表明，采用M—BFA和PAM组合强化混凝，可控制CODcr浓度在120mg／L以内。     

AN APPLICATION RUNOFF MODEL STRATEGY FOR UNGAGED WATERSHEDS1

ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m²) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft³/sec (0.085 to 3.34 m³/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes.     

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.     

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.     

Biodiversity and biotechnology

The maintenance of biodiversity is urged from many quarters and on grounds ranging from aesthetic considerations to its usefulness, particularly for biotechnology. But regardless of the grounds for preserving biodiversity, writers are generally in agreement that it should be preserved. But, in examining the various references biodiversity, such as species diversity, genetic diversity, and habitat diversity, it is apparent that we cannot aim to preserve biodiversityas such, since there are a number of conflicts in any such undertaking. In preserving one aspect of biodiversity, we damage another aspect. Five arguments which attempt to ground our moral concern for biodiversity are reviewed and critiqued, not only for their consistency but also for their power to move us to action. The final section of the paper shows how conflicts in the values of personal and environmental health can impair ethical action and especially policy formation.An earlier version of this paper was read at the conference on Agriculture, Food, and Human Values: Tradition and Change, Orlando, Florida, October 7–9, 1987.     

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.     

A Social Contract for Biotechnology: Shared Visions for Risky Technologies?

Future technological developmentsconcerning food, agriculture, and theenvironment face a gulf of social legitimationfrom a skeptical public and media, in the wakeof the crises of BSE, GM food, and foot andmouth disease in the UK (House of Lords, 2000). Keyethical issues were ignored by the bioindustry,regulators, and the Government, leaving alegacy of distrust. The paper examinesagricultural biotechnology in terms of a socialcontract, whose conditions would have to be fulfilled togain acceptance of novel applications. Variouscurrent and future GM applications areevaluated against these conditions. Successwould depend critically on how far a sharedvision can be found with the public. Tore-establish trust, significant changes areidentified in the planning and pursuit ofbiotechnology.