塔河油田含油污泥低温热解研究

为实现塔河油田含油污泥资源化利用及无害化处置而开展实验,以热解残渣的矿物油值为依据对热解过程进行评价,同时考察了热解工艺的油品回收问题,对比分析了回收油和原油的物化性质,确定了塔河油田含油污泥热解的最佳工艺条件为:热解温度500℃,热解时间30 min,此时残渣中矿物油最低值1 764.89 mg/kg,油品回收率62.3%,回收油品质显著改善,热解残渣矿物油含量符合GB 4284—84《农用污泥中污染物控制标准》要求。     

热解装置对含油污泥热解产物的影响

以含油污泥为研究对象,采用三种不同的热解装置(20g格金试验干馏炉,20kg固定床及2 000kg/h神雾无热载体蓄热式旋转床,简称"旋转床"),探讨热解装置的差异对含油污泥热解产物产率和性质的影响。结果表明,与其他两种热解装置相比,旋转床中热解气和热解液产率最高,分别为27.34%和37.19%,但与固定床差异不显著,且热解气热值最高(20.08 MJ/m3),旋转床热解液中热解油的轻质组分含量以及热值最高,分别90.75%和48.01MJ/kg。格金装置中热解固体产率显著高于其他两种装置,且固体中灰分含量最低。因此,旋转床用于含油污泥热解处理工艺,不仅可以最大程度地减少固体残渣的产生,还可获得较高产率和品质的可燃气和热解油,对含油污泥的减量化和资源化效果显著。     

CO变换反应与煤热解耦合反应特性研究

本文在上层为变换催化剂B113下层为新疆伊犁南台子煤粒的固定床反应器中,研究CO变换反应与煤热解的耦合作用。考察了CO变换反应水气比、煤热解温度对耦合反应的影响,研究了耦合热解所得各项产物的特性。结果表明,水气比为1.0、热解反应温度为650℃时耦合热解获得最高的焦油产量,焦油产率为16.36%,比氮气气氛下的焦油产率增加了6.66个百分点,比氢气气氛下增加了4.49个百分点;耦合热解可以得到更低硫的半焦,在终态温度为750℃时耦合热解脱硫率为92.28%;热解气体产物中氢气、甲烷、C2-C4烃类气体含量增加;焦油的羟基数量减少,脂肪烃和芳香烃增多。     

热解含油污泥制备吸附材料浅析

介绍了含油污泥热解技术及热解实验方法,提出热解产生的残渣进行适当处理可成为具有吸附性的材料。进行了含油污泥热解正交实验,得出影响最大的因素分别是热解温度、热解时间、升温速率,并得出最佳的热解温度、热解时间、升温速率等。分析了含油污泥热解的机理,探讨了热解含油污泥制备吸附材料的活化改性,并在此基础上对所制备吸附材料的脱硫性和除油性进行了研究。     

含油污泥热解的影响因素初探＊

以含油污泥"无害化"为目的,考察了温度、升温速率及含水率对热解反应效果的影响。实验结果表明:温度越高,热解剩余残渣率和残渣含油率越低,热解产气率越高;含油污泥中有机质发生热解反应的主要温度为350～500℃和575～625℃,若热解残渣含油率控制在3.0‰以下,热解温度选择600℃较为适宜;升温速率对热解产气率、剩余残渣率和残渣含油率基本无影响,但升温速率越快,热解反应的产气量曲线峰越向前迁移,热解反应的时间缩短;含油污泥含水率越低,则热解产气率及残渣率越高,但含水率对残渣含油率和热解反应时间无影响。     

油田含油污泥与芦苇共热解实验研究

以北方某油田湿地芦苇与油田某污水处理厂剩余污泥为对象,利用同步热分析仪及静态热解炉研究油田含油污泥及含油污泥-芦苇混合物的热解特性,将静态热解过程数据与同步热分析TG(热重分析)、DTG(微分热重分析)、DSC(差示扫描量热分析)曲线结合,计算了终止温度、产物量等。结果表明:不同含油污泥样品其产物生成率差别不大,热解TG、DTG和DSC曲线有较大差别,添加一定比例的芦苇可以使含油污泥热解过程变得匀速缓和,5%(质量比)的芦苇添加量可以使热解残渣恒重温度降低约25℃。混掺芦苇的样品残渣呈分散颗粒状,无聚结现象,对热解结焦将产生一定抑制作用。     

含油污泥热解工艺优化及资源化利用

针对含油污泥危害性大、难处理的环保难题,以实现含油污泥资源化利用为目标,开展了含油污泥热解实验研究,优化了热解工艺,并对热解产物进行了分析。在催化剂加量1.2％、热解温度为420℃、停留时间3.0 h、加热速率12℃/min、N2流速为90 mL/min条件下对含油污泥进行热解,结果表明：热解油回收率 可达72.35％;热解回收油品质有较大的改善,产生的不凝气体组分可用于燃烧供热,热解残渣热值较高,可制成燃料重复利用,实现了含油污泥的资源化利用。     

硫化废气污泥活性炭净化处理技术研究

以污泥厂剩余活性污泥作为原料,采用KOH为活化剂制备污泥活性炭,探讨了活化温度及时间、热解温度、洗涤温度及方式在污泥活性炭制备过程中的最佳工艺条件。以品红吸附量及产率作为污泥活性炭的考察指标,采用单因素实验筛选出了制备污泥活性炭的最佳工艺条件,并对污泥活性炭脱硫剂的脱硫性能进行了实验研究。实验研究结果显示,烟气中O2、水蒸气含量的多少及脱硫温度的高低会影响污泥活性炭脱硫剂的脱硫性能。     

城市污泥磁化低温热解技术

针对目前城市污水处理厂产生大量污泥,二次污染日益严重的状况,介绍了城市污泥磁化低温热解技术的工作原理、技术特点、工艺流程、检测情况。指出污泥磁化低温热解技术是污泥减量化、稳定化、无害化、资源化的有效途径。     

酸洗预处理对稻壳生物油品质的影响

稻壳通过热解能将其中的有机质转为生物油,但是稻壳中含有的金属会降低生物油的产率,且会影响生物油的品质。通过酸洗预处理,能有效脱除金属,抑制金属对稻壳热解的不良影响。利用不同种类无机酸和有机酸对稻壳进行酸洗预处理,并在550℃下进行热解获得生物油,探究酸洗预处理对稻壳热解的影响。结果表明,酸洗预处理能有效脱除稻壳中的金属含量,减少灰分。经过各种酸溶液酸洗后的稻壳热解所得的生物油产率均有提高,并且盐酸预处理获得最高的生物油产率31.18%。此外,酸洗预处理后生物油中糖类含量明显增加,并且无机酸的效果比有机酸更为明显,其中盐酸和硫酸酸洗后糖类含量由2.8%分别增加到48.29%和51.52%。除此之外,酚类物质也明显减少,酸、酮、醛等化合物则轻微减少。酸洗预处理能有效提高生物油产率,且能提高生物油中的糖含量,从而使得生物油品质得以提升。     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Sources and Transport of Phosphorus to Rivers in California and Adjacent States,U.S., as Determined by SPARROW Modeling

The SPARROW (SPAtially Referenced Regression on Watershed attributes) model was used to simulate annual phosphorus loads and concentrations in unmonitored stream reaches in California, U.S., and portions of Nevada and Oregon. The model was calibrated using de‐trended streamflow and phosphorus concentration data at 80 locations. The model explained 91% of the variability in loads and 51% of the variability in yields for a base year of 2002. Point sources, geological background, and cultivated land were significant sources. Variables used to explain delivery of phosphorus from land to water were precipitation and soil clay content. Aquatic loss of phosphorus was significant in streams of all sizes, with the greatest decay predicted in small‐ and intermediate‐sized streams. Geological sources, including volcanic rocks and shales, were the principal control on concentrations and loads in many regions. Some localized formations such as the Monterey shale of southern California are important sources of phosphorus and may contribute to elevated stream concentrations. Many of the larger point source facilities were located in downstream areas, near the ocean, and do not affect inland streams except for a few locations. Large areas of cultivated land result in phosphorus load increases, but do not necessarily increase the loads above those of geological background in some cases because of local hydrology, which limits the potential of phosphorus transport from land to streams.