HY1141和HY241菌产生的絮凝剂絮凝性能及水处理应用研究

从土壤中分离筛选得到絮凝剂产生菌HY1141和HY241，对高岭土悬浊液进行絮凝性能试验研究。试验结果表明：HY1141絮凝荆在ptt值为3．0时，絮凝率达到97．2％，HY241絮凝剂在pH值为4．0-7．0时，絮凝率在90％以上；絮凝剂的最佳投加量均为4mL／L，此时絮凝率分别达到98．2％和96．5％；HY1141和HY241絮凝剂所需CaCl2，最佳浓度分剐为0．5％和1．0％，此时絮凝率分刺为97．6％和96．8％；絮凝荆最佳静置时间分别为5min和10min。此外，两株菌所产絮凝刘对洪水和选矿废水都有一定的处理效果，且HY1141絮凝剂处理洪水效果较好，絮凝率为71．7％，COD去除率为81．8％；混合絮凝刺处理选矿废水效果较好，絮凝率为92．8％，COD去除率为96．0％。     

采油污水中聚丙烯酰胺的去除方法

采用实验室合成的絮凝剂和助凝剂,对聚合物驱采油污水进行了聚丙烯酰胺絮凝实验。通过絮凝效果的比较,筛选出两种絮凝效果较好的絮凝剂XN-Ⅲ和XN-Ⅳ。实验确定了絮凝剂的最佳加入量、沉降时间、pH值和温度条件。在此基础上,对采油污水中聚丙烯酰胺的不同去除方法进行了比较,得到最优去除方法,为现场采油污水中聚丙烯酰胺的脱除提供了依据。     

絮凝- 电气浮法处理乳化油废水

含乳化油废水由于表面活性剂的存在处理难度较大。通过絮凝——电气浮方法处理乳化油废水,确定絮凝及絮凝——电气浮所需的最佳絮凝剂用量;通过正交试验考察了pH值、电流密度、电极间距及气浮时间等操作参数的影响,得到絮凝一电气浮的最优操作条件为电流密度为20．83A／m^2,电极间距为1cm,pH值为7．4。在聚合硫酸铁投加量为50mg／L,电气浮30min时COD去除率可达95．2％。此方法对轴承厂废水的COD去除率可达75％,出水COD可降至91．9mg／L。结果表明用这种方法处理乳化油废水是可行的。     

一株微生物絮凝剂产生菌的絮凝特性及处理气田废水研究

从土壤中分离、筛选得到一株稳定高效的微生物絮凝剂产生菌,命名为B—27。考察了碳源、氮源、pH、温度、培养时间等多种因素对絮凝剂(命名MBF—27)絮凝效果的影响。实验结果表明,当碳源为葡萄糖、氮源为酵母膏、pH为7.0、温度为35℃、培养时间为72h时,絮凝剂MBF—27对高岭土悬浊液的絮凝率可达93.8%。红外光谱扫描分析表明,该絮凝剂的主要成分为多糖类物质。同时,生物絮凝剂MBF—27对气田废水的COD和色度去除率分别达到60.77%和86.1%,优于传统的絮凝剂聚乙烯丙胺(PAM)和三氯化铁(FeCl3)。     

微生物絮凝剂MBF TS-1的表征

对筛选的一株絮凝剂产生菌Bacillus TS-1所产絮凝剂MBF TS-1采用UV- vis吸收光谱、FT-IR光谱、糖类颜色反应、动物急性毒性实验等进行了化学组成分析、表征和理化性质检测.结果证实,该絮凝剂为安全无毒、分子量为105-106的弱酸性多糖类物质,属环境友好型微生物絮凝剂.     

絮凝-酸析-NaClO-Fenton联合处理页岩气产出水研究

以涪陵页岩气田产出水为研究对象，研究絮凝、酸析、Fenton氧化和NaClO氧化相互协同作用下，采出水COD去除率的变化程度及规律。比较了不同组合方式下水样COD去除效果及变化规律，考察了絮凝剂、次氯酸钠和Fenton试剂的加量以及体系pH值对去除率的影响，结果表明：（1）单一絮凝或酸析条件下，最高COD去除率＜25%，在絮凝剂加量80mg/L、酸析pH为4时，絮凝-酸析协同处理COD去除率达到＞40%；（2）原始水样直接进行次氯酸钠氧化，COD最高去除率为75.01%，絮凝-酸析后进行次氯酸钠氧化，最高COD去除率为80.34%，与原始水样相比提高了5.33%，且达到相同的COD去除效果，絮凝-酸析后水样对次氯酸钠的需求量低于原始水样；（3）絮凝-酸析后水样进行Fenton氧化与原始水样直接进行Fenton氧化相比，COD去除率提高了6.07%；（4）絮凝-酸析-NaClO- Fenton协同处理，水样COD去除率达到＞90%，其中最高去除为94.17%，与絮凝-酸析-NaClO和絮凝-酸析-Fenton处理相比分别提高了13.83%和5.27%。水样首先经过絮凝-酸析预处理，达到削减后续次氯酸钠和Fenton氧化负荷、降低药剂用量目的，然后经过Fenton试剂和次氯酸钠对不同类型特征污染物选择性去除的协同作用，可达到较高的COD去除率。     

新型自来水复合絮凝剂的研制与应用

研究用壳聚糖、聚铝和助剂A复合制备出一种成本低、絮凝效果好、出水Al3 含量少的新型自来水处理絮凝剂,并确定其最佳配比(体积比)为:0.1%壳聚糖:2%聚合氯化铝:0.1%助剂A=1:6:5.与传统聚铝类絮凝剂相比,其出水浊度和Al3 含量分别下降了2.97%和10.7%,并且药剂成本下降6.25%,有明显的经济和环境效益.     

一株纤维素分解菌利用枳实废渣产酶条件的研究

以枳实废渣为碳源,对产纤维素酶G2菌进行固体发酵,通过测定FPA、CMC、C1酶活的大小,对其产酶条件进行优化研究.结果表明产酶最适条件为:枳实在发酵前需进行酸处理;氮源为硫酸铵;含水率为70%;初始pH为5～6;发酵周期为6天.在以上最适条件下,G2菌酶活力为FPA:31.8 IU/ml,CMC:11.86 IU/ml,C1:15.79 IU/ml.     

油田措施废液絮凝剂优化与应用

文章以油田措施废液为研究对象,开展絮凝处理实验,筛选出最佳絮凝剂体系,并对絮凝工艺参数进行优化。现场应用结果表明,筛选出的絮凝剂体系H3+X5最佳工艺条件为:H3+X5用量(300+100)mg/L、pH值7.4~8.2、温度25~35℃、混合强度1 300~1 500s~(-1)、混合时间20~30s,优化后斜板直接出水SS由34.71mg/L降至1.77mg/L,去除效果明显,同时药剂加量减少60%,处理成本降低20.5%。     

含硅无机高分子絮凝剂的研究进展

含活性硅酸的无机高分子絮凝剂(Si-IPF)是近几年发展迅速的新型、高效无机高分子絮凝剂的代表。文章对国内外si-IPF的研制开发情况进行了分析评述，为今后发展提出了几点建议：(1)加强制备新工艺研究，积极探索制备高浓度si-IPF的最佳工艺条件，提高产品的稳定性和絮凝效果。(2)加强絮凝作用机理研究。找出提高Si-IPF稳定性及提高Si-IPF中对絮凝效果起实际作用的有效成分含量的具体方法。(3)开展应用研究，开发满足不同水质的多功能新产品，并确定其最佳应用条件和适用范围。     

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.     

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.     

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.     

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.     

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.     

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.     

Effect of Light on Biodegradation of Estrone, 17β‐Estradiol,and 17α‐Ethinylestradiol in Stream Sediment

Biodegradation of [A‐ring ¹⁴C] Estrone (E1), 17β‐estradiol (E2), and 17α‐ethinylestradiol (EE2) to ¹⁴CO₂ was investigated under light and dark conditions in microcosms containing epilithon or sediment collected from Boulder Creek, Colorado. Mineralization of the estrogen A‐ring was observed in all sediment treatments, but not epilithon treatments. No difference in net mineralization between light and dark treatments was observed for ¹⁴C‐E2. Net mineralization of ¹⁴C‐E1 and ¹⁴C‐EE2 was enhanced in light treatments. Extents of ¹⁴CO₂ accumulation and rates of mineralization were significantly greater for E2 than E1 under dark conditions, but were comparable under light conditions. These results indicate substantial differences in the uptake and metabolism of E1 and E2 in the environment and suggest biorecalcitrance of E1 relative to E2 in light‐limited environments. The extent of ¹⁴CO₂ accumulation and rate of mineralization for EE2 in dark treatments were less than half of that observed for E2 and generally lower than for E1, consistent with previous reports of EE2 biorecalcitrance. However, ¹⁴CO₂ accumulation and rates of mineralization were comparable for EE2, E2, and E1 under light conditions. These results indicate photoactivation and/or phototransformation/photodegradation processes can substantially enhance heterotrophic biodegradation of estrogens in sunlit environments and may play an important role in estrogen transport and attenuation.