高炉熔渣四辊离心法制取矿渣棉

以调质高炉渣为原料在实验室进行了四辊离心法制备矿渣棉实验.研究高炉渣滴落温度、粘度、离心辊径及转速等工艺参数对矿渣棉成纤效果的影响规律.结果表明,高炉渣滴落温度应控制在1 290~1 420℃之间,高炉渣粘度在1~3 Pa.s;四辊直径分别为1# 213 mm、2# 295 mm、3# 295 mm和4# 295 mm时,转速控制在1# 2 707~3 000 r/min、2# 3 093~4 000 r/min、3# 4 350~4 500 r/min和4# 5 000~5 800 r/min,成纤率较高,成纤效果良好.     

Simulation of substrate degradation in composting of sewage sludge

To simulate the substrate degradation kinetics of the composting process, this paper develops a mathematical model with a first-order reaction assumption and heat/mass balance equations. A pilot-scale composting test with a mixture of sewage sludge and wheat straw was conducted in an insulated reactor. The BVS (biodegradable volatile solids) degradation process, matrix mass, MC (moisture content), DM (dry matter) and VS (volatile solid) were simulated numerically by the model and experimental data. The numerical simulation offered a method for simulating k (the first-order rate constant) and estimating k₂₀ (the first-order rate constant at 20 °C). After comparison with experimental values, the relative error of the simulation value of the mass of the compost at maturity was 0.22%, MC 2.9%, DM 4.9% and VS 5.2%, which mean that the simulation is a good fit. The k of sewage sludge was simulated, and k₂₀, k_20s (first-order rate coefficient of slow fraction of BVS at 20 °C) of the sewage sludge were estimated as 0.082 and 0.015 d^?1, respectively.     

The role of epicuticular waxes on foliar metal transfer and phytotoxicity in edible vegetables: case of Brassica oleracea species exposed to manufactured particles

Environmental Science and Pollution Research - The rapid industrialization and urbanization of intra- and peri-urban areas at the world scale are responsible for the degradation of the quality of...     

Coexistence between People and Elephants in African Savannas

Abstract: The decline in the range and numbers of elephants as a result of expanding human activity in Africa is recognized as one of the continent's more serious conservation problems. Understanding the relationship between human settlement patterns and elephant abundance is fundamental to predicting the viability of elephant populations. The prevailing model of human-elephant interaction predicts a negative linear relationship between rising human density and declining elephant density at a coarse (national or subcontinental) scale. Using observed elephant densities and human population data, we tested this prediction in a study area of 15,000 km² in northwestern Zimbabwe. The results did not fit a linear model. Elephant and human coexistence occurs at various levels of human density, up to a threshold of human density beyond which elephant populations disappear. This threshold seems to be related to a particular stage in the process of agriculturally transformed land becoming spatially dominant over the natural woodland that constitutes elephant habitat. Within the contexts of conservation and sustainable development in African savannas, investigating spatial relationships between elephant and human abundance should be a priority topic for future research.     

环评中锅炉房大气污染源强的确定

在环境评价中,污染源强的确定对环境影响因素评价的分析结果有重要作用。对锅炉房污染物排放的分析表明,影响锅炉房大气污染物的主要因素有燃料的构成、发热量和燃烧方式等。确定锅炉房大气污染物的方法主要有物料衡算法、实测法和经验系数法。在这三种方法中,物料衡算法被普遍采用。在确定锅炉房大气污染物的排放量时,也可以采用物料衡算法和实测法相结合的方法。     

工业污水水质在线监测系统研究与推广应用

为了加强对污染源的监控,准确地掌握污染物排放情况,中国石油天然气股份有限公司组织开展了水质在线监测系统研究,并逐步建立了污染源在线监测系统。文章介绍了有关水质在线监测系统的研究现状以及研究成果应用和推广情况。     

应用模糊聚类方法进行四川国土分区研究

本文介绍采用模糊聚类方法进行四川省国土综合分区研究的情况和主要结果。提出将全省划分为8个国土区的结论,论述了各区的前景,探讨了定性与定量分区方法的先进性。     

炼化企业大检修作业的环保管理

以克拉玛依石化公司为例,对检修作业前环境危害因素进行了辨识,提出了检修前、检修期间环保管理的措施,从废气、废水、噪声、固废四个方面详细介绍了大检修期间进行污染控制的具体措施,分析了大型炼化企业在停工大检修作业期间存在的环境影响因素,提出了大检修作业期间的环保管理内容及污染控制措施。     

Evaluation of a Watershed Model for Estimating Daily Flow Using Limited Flow Measurements1

Abstract: The Soil and Water Assessment Tool (SWAT) model was evaluated for estimation of continuous daily flow based on limited flow measurements in the Upper Oyster Creek (UOC) watershed. SWAT was calibrated against limited measured flow data and then validated. The Nash‐Sutcliffe model Efficiency (NSE) and mean relative error values of daily flow estimations were 0.66 and 15% for calibration, and 0.56 and 4% for validation, respectively. Also, further evaluation of the model’s estimation of flow at multiple locations was conducted with parametric paired t‐test and nonparametric sign test at a 95% confidence level. Among the five main stem stations, four stations were statistically shown to have good agreement between predicted and measured flows. SWAT underestimated the flow of the fifth main stem station possibly because of the existence of complex flood control measures near to the station. SWAT estimated the daily flow at one tributary station well, but with relatively large errors for the other two tributaries. The spatial pattern of predicted flows matched the measured ones well. Overall, it was concluded from the graphical comparisons and statistical analyses of the model results that SWAT was capable of reproducing continuous daily flows based on limited flow data as is the case in the UOC watershed.     

活性炭吸附和脱附-等离子体氧化净化有机废气的研究

根据滑动弧放电等离子体适于降解高浓度有机物废气的特性,结合活性炭吸附法,提出了吸附器的吸附浓缩和热脱附-等离子体氧化净化有机废气的方法。在活性炭吸附过程中,最初2 h内甲苯净化率达到100%,随着时间的增加净化率下降;在热脱附滑动弧放电等离子体净化过程中,甲苯降解效率最高为97.3%。将滑动弧放电等离子体反应器出口气相产物收集进行FT-IR检测,发现放电后有CO2、CO、H2O和NO2产生,并分析了甲苯的降解机理。