改性活性焦的制备及吸附性能研究

研制出了以普通煤为主要原料的活性焦,并对其机械强度和碘吸附率进行了测试.为了考察活性焦对烟气中SO2和NOx的脱除性能,在自行设计组装的吸附塔上,进行了模拟烟气脱硫脱氮的实验.结果表明: 1) 改性活性焦碘吸附率能达到59%,转鼓强度达到98%; 2) 在一定条件下,脱硫率达到98%,脱氮率达到86%; 3) 改性活性焦可用水蒸气进行再生,且再生效果较好.4) 金属氧化物的加入在一定程度上可以提高活性焦的脱硫脱氮性能及再生性能.     

培养基对大型溞(Daphnia magna)生长、繁殖和子代的影响

大型溞(Daphnia magna)急性活动抑制试验和繁殖试验是研究和评价新化学物质对水生生物危害性的重要手段之一。由于经济合作与发展组织(Organization for Economic Co-operation and Development, OECD)测试导则推荐的Elendt M4培养基中含有的乙二胺四乙酸(EDTA)可能会影响金属离子的活性,不适合用于含有金属离子样品的毒理学测试。为选出合适的替代培养基,采用Elendt M4培养基、美国材料与试验协会(American Society for Testing and Materials, ASTM)推荐的ASTM培养基和国际标准化组织(International Organization for Standardization, ISO)推荐的ISO培养基进行大型溞繁殖试验,并收集繁殖试验中亲溞产下的非头胎幼溞进行重铬酸钾的急性活动抑制试验。结果表明,3种培养基对大型溞的生长、存活均无抑制作用,ASTM培养基和ISO培养基中大型溞的繁殖量分别为111±10和70±13,显著低于Elendt M4培养基的132±4 (P 0.05)。3种培养基中大型溞的繁殖量均能满足OECD 211-2012大型溞繁殖试验标准中繁殖量大于60的要求,但在ISO培养基中有死胎出现。重铬酸钾对Elendt M4培养基、ASTM培养基和ISO培养基中繁殖幼溞的24 h半数效应浓度(24 h-EC_(50))值分别为1.29、1.84和0.772 mg·L~(-1),均在OECD 202-2004大型溞急性活动抑制试验标准要求的0.6～2.1 mg·L~(-1)范围内,说明3种培养基中繁殖的大型溞均能用于大型溞急性活动抑制试验的标准测试中。综上所述,进行含有金属离子样品的毒理测试时,ASTM培养基和ISO培养基均可用于大型溞的短期驯养和急性活动抑制试验,ASTM培养基还可以用于长期驯养和繁殖试验。以上结果为大型溞毒性试验中试验培养基的选择提供理论依据。     

The generative power of metaphor: long‐term action research on disaster recovery in a small Japanese village

Disaster recovery is a dynamic process of creating, maintaining, and changing the meaningful context of survivors. It is completed when they redevelop their self‐reliance and resume managing their social relations with a sense of community. This study employed action research to examine how researchers and survivors collaborated to change disaster recovery through the generative power of metaphor in a small village in Japan that experienced the Niigata–Chuetsu earthquake on 23 October 2004. It outlines long‐term collaborative practices as survivors undertook new activities owing to the power of the metaphor of ‘school’. Once ‘school’ was adopted as the metaphor for where survivors learnt new skills and passed on traditional knowledge, they created new metaphors and performed new activities independently, which is critical for recovery as it demonstrates self‐reliance. The paper assesses the reasons why generative metaphors worked effectively in this case and highlights some academic and practical implications for disaster recovery.     

Modelling of a downdraft gasifier fed by agricultural residues

A non-stoichiometric model for a downdraft gasifier was developed in order to simulate the overall gasification process. Mass and energy balances of the gasifier were calculated and the composition of produced syngas was predicted. The capacity of the modeled gasifier was assumed to be 0.5 MW, with an Equivalence Ratio (EQ) of 0.45. The model incorporates the chemical reactions and species involved, while it starts by selecting all species containing C, H, and O, or any other dominant elements. Olive wood, miscanthus and cardoon were tested in the formulated model for a temperature range of 800-1200 °C, in order to examine the syngas composition and the moisture impact on the supplied fuel. Model results were then used in order to design an olive wood gasification reactor.     

Assessing Public Perceptions of Computer-Based Models

Although there is a solid body of research on both collaborative decision-making and on processes using models, there is little research on general public attitudes about models and their use in making policy decisions. This project assessed opinions about computer models in general and attitudes about a specific model being used in water planning in the Middle Rio Grande Region of New Mexico, United States. More than 1000 individuals were surveyed about their perceptions of computer-based models in general. Additionally, more than 150 attendees at public meetings related to the Middle Rio Grande planning effort were surveyed about their perceptions of the specific Rio Grande-based model. The results reveal that the majority of respondents are confident in their ability to understand models and most believe that models are appropriate tools for education and for making policy decisions. Responses also reveal that trust in who develops a model is a key issue related to public support. Regarding the specific model highlighted in this project, the public revealed tremendous support for its usefulness as a public engagement tool as well as a tool to assist decision-makers in regional water planning. Although indicating broad support for models, the results do raise questions about the role of trust in using models in contentious decisions.     

EQUILIBRIUM AND TRANSIENT GLOBAL WARMING SCENARIO IMPLICATIONS FOR WATER RESOURCES IN WALES1

ABSTRACT: A methodology has been developed to predict the responses of a range of water supply sources in Wales to global warming scenarios. Hydrologically effective rainfall is predicted from temperature and precipitation for each season based on site specific formulae developed using the Meteorological Office Rainfall and Evaporation Calculation System (MORECS) and UK Surface Water Archive databases. Comparisons are then made between the effects predicted for the scenarios established from equilibrium simulations and the new Hadley Centre High Resolution Model (UKHI) transient mode results. Though very different, both suggest increased stress on water resources late in the hydrological year.     

Survival,reproduction, and recruitment of woody plants after 14 years on a reforested landfill

With the advent of modern sanitary landfill closure techniques, the opportunity exists for transforming municipal landfills into urban woodlands. While costs of fullscale reforestation are generally prohibitive, a modest planting of clusters of trees and shrubs could initiate or accelerate population expansions and natural plant succession from open field to diverse forest. However, among woody species that have been screened for use on landfills, these ecological potentials have not yet been investigated. We examined a 14-yr-old landfill plantation in New Jersey, USA, established to test tolerance of 19 species of trees and shrubs to landfill environments. We measured survivorship, reproduction, and recruitment within and around the experimental installation. Half of the original 190 plants were present, although survival and growth rates varied widely among species. An additional 752 trees and shrubs had colonized the plantation and its perimeter, as well as 2955 stems of vines. However, the great majority (>95%) of woody plants that had colonized were not progeny of the planted cohort, but instead belonged to 18 invading species, mostly native, bird-dispersed, and associated with intermediate stages of secondary plant succession. Based on this evidence, we recommend that several ecological criteria be applied to choices of woody species for the restoration of municipal landfills and similar degraded sites, in order to maximize rapid and economical establishment of diverse, productive woodlands.     

SAMPLING FREQUENCY SELECTION FOR REGULATORY WATER QUALITY MONITORING1

ABSTRACT: The selection of sampling frequencies in order to achieve reasonably small and uniform confidence interval widths about annual sample means or sample geometric means of water quality constituents is suggested as a rational approach to regulatory monitoring network design. Methods are presented for predicting confidence interval widths at specified sampling frequencies while considering both seasonal variation and serial correlation of the quality time series. Deterministic annual cycles are isolated and serial dependence structures of the autoregressive, moving average type are identified through time series analysis of historic water quality records. The methods are applied to records for five quality constituents from a nine-station network in Illinois. Confidence interval widths about annual geometric means are computed over a range of sampling frequencies appropriate in regulatory monitoring. Results are compared with those obtained when a less rigorous approach, ignoring seasonal variation and serial correlation, is used. For a monthly sampling frequency the error created by ignoring both seasonal variation and serial correlation is approximately 8 percent. Finally, a simpler technique for evaluating serial correlation effects based on the assumption of AR(1) type dependence is examined. It is suggested that values of the parameter p₁, in the AR(1) model should range from 0.75 to 0.90 for the constituents and region studied.     

RUNOFF,EROSION, AND SOLUTES IN THE LOWER TRUCKEE RIVER,NEVADA, DURING 19691

The Truckee River heads in the Sierra Nevada at Lake Tahoe, and terminates in Pyramid Lake. During the 1969 water year, flow about 9 miles upstream from the mouth (974,000 acre-ft) was almost four times the long-term average, due mainly to heavy winter rains and spring snowmelt. A short period of low-altitude rainfall produced the highest concentrations of suspended sediment, whereas a much longer subsequent period of snowmelt yielded a much greater total quantity of material. The upper 90 percent of the basin yielded about 260 acre-feet (630,000 tons) of sediment at the Nixon gage, whereas an estimated 2,800 acre-feet (6.8 million tons) was contributed by erosion of about 200 acres of river bank below the gage. Solute content at the gage ranged from 80 to 450 mg/l, dominated by calcium, sodium, and bicarbonate, plus silica in the most dilute snowmelt and chloride in the most concentrated low flows. Solute load totaled about 130,000 tons, of which the principal constituents in Pyramid Lake-sodium plus equivalent bicarbonate and chloride-amounted to almost 40,000 tons. The total solute load during a year of average flow may be 45,000-55,000 tons, including 18,000-22,000 tons of principal lake constituents.     

Intercomparison of Numerical Urban Dispersion Models – Part I: Street Canyon and Single Building Configurations

Microscale Computational Fluid Dynamics (CFD) models havebecome an efficient and common simulation tool forassessment and prediction of air quality in urban areas.The proper validation of such a model is a crucialprerequisite for its practical application. Within theframework of the European research network TRAPOS a workinggroup on computational fluid dynamics modelling wasestablished and model intercomparison exercises werelaunched. Different Computational Fluid Dynamics Codes wereapplied for simulating the wind flow and pollutantconcentration patterns in several test cases. The aim ofthe present model intercomparison is (1) to assess andallocate the source of differences that appear whendifferent CFD codes using the same turbulence model areapplied to well defined test cases and (2) to improve theknowledge base for model development and application.Throughout the series of model applications coveringmanifold urban configurations, the overall agreementbetween the various models and experimental data is fair.In spite of quantitative differences between the variousnumerical results, the models are capable of reproducingthe flow patterns and dispersion characteristics observedin urban areas but they show significant differences forthe turbulent kinetic energy field that controls thedispersion of pollutants.