含磁粉生物反应器处理苯酚废水

采用含磁粉生物反应器对质量浓度为120～350 mg/L的苯酚模拟废水进行强化生物处理.实验结果表明:添加适量磁粉可使废水中DO提高约10%;与不含磁粉生物反应器比较,含磁粉生物反应器工艺使填料挂膜时间缩短1～2 d,填料上附着微生物量增多;质量浓度为350 mg/L的苯酚模拟废水在20 h内的苯酚去除率可达80%,降解时间缩短了10 h.初步分析了添加磁粉提高生物反应器处理废水效率的机理.实验证实了含磁粉生物反应器工艺的合理运用是强化处理含酚废水的有效途径.     

Profibus-DP现场总线在袋式除尘控制系统中的应用

简要介绍Profibus-DP现场总线技术和采用Profibus-DP现场总线技术的袋式除尘自动控制系统,介绍了采用Profibus-DP现场总线技术的袋式除尘自动控制系统网络结构和系统部件,包括主控制站、上位监控计算机HMI和除尘控制系统各远程I/O站,通过具体工程说明了Profibus-DP现场总线技术在袋式除尘自动控制系统中的应用.     

性能设计方法与现行规范方法的比较

在简要介绍性能抗震设计基本概念和内容的基础上,分析了性能抗震设计方法与现行抗震设计规范方法在设防目标、设计方法和抗震构造措施等方面的异同点,并提出了一些建议.     

除尘风机的节能应用

由除尘控制系统根据电炉炼钢工艺各阶段不同的烟气量,实施由调速型液力耦合器构成的除尘风机变转速变风量调节,实现除尘风机电动机的节能应用.介绍了除尘风机变转速变风量调节的控制系统构成和其节能的工程应用.     

环境气体标准样品量值的计算及不确定度分析

依据《气体分析校准气体混合物的制备重量法》（1SO6142—2001）和《气体分析气体标准样品组成的测定和校验比较法》（ISO6143—2001）,阐述了环境气体标准样品不同定值方法的量值计算及不确定度来源,并比较了同一气体标准样品采用不同定值方法得到的不同量值结果及不确定度：     

Spatial variation and toxicity assessment for heavy metals in sediments of intertidal zone in a typical subtropical estuary (Min River) of China

Environmental Science and Pollution Research - Sediment samples were collected in five marshes (C1, Phragmites australis marsh; C2, P. australis and Cyperus malaccensis marsh; C3, C. malaccensis...     

1990~2013年来洞庭湖区鸟类生物多样性热点区时空动态及变动机理

评估与确定生物多样性分布格局与热点区是建立保护区、制定生物保护决策的基础。洞庭湖地区位处长江中游,是我国重要的淡水湖泊湿地生态系统,为中国乃至亚洲较大的鸟类越冬地之一。以洞庭湖地区14种Ⅰ、Ⅱ级重点保护鸟类为指示物种,基于1990~2013年间的多期遥感影像,运用物种生境分布MAXENT模型,选取地形、水系、植被、气候及人类干扰等共35个影响因子,对其进行生境适宜性评价及生物多样性热点区的筛选与制图,并对热点区时空动态特征进行分析。结果表明：（1）鸟类生物多样性热点区的分布范围呈现出组团状特征,1990~2013年来,热点区面积呈下降趋势;（2）鸟类栖息生境景观格局总体上趋于破碎,生境形状向简单且扁平化形态转变,生境格局呈复杂化;（3）经济与社会发展因素对研究区的鸟类生物多样性热点区变化影响显著,而自然因素产生的影响不明显。研究结果在制定区域生物多样性保护规划方案中可体现较好应用价值。     

Organochlorine pesticides in soil profiles from Tianjin, China

Soil cores were collected from soils at five sites in Tianjin area for the determination of hexachlorocyclohexane isomers (HCHs, including alpha-HCH, beta-HCH, gamma-HCH and delta-HCH), dichlorodiphenyltrichloroethane and metabolites (DDXs, including p,p'-DDT, p,p'-DDE and p,p'-DDD) and total organic carbon (TOC). The levels and vertical distributions of HCHs and DDXs are studied. Results show that the application of pesticides in the past years was the major contributor of HCHs and DDXs accumulation in the sampling areas. Significant positive correlations were seen between the residual and application amounts of HCHs and DDXs. Wastewater irrigation did not bring a significant contribution of HCHs or DDXs into the soils. HCHs and DDXs concentrations peak at the surface and decline in soil profile with depth, while fluctuations were observed in the plow layers of some cultivated soils caused by frequent cultivation activities and batch irrigation. Positive correlations were observed between the contents of TOC and HCHs and DDTs. Although the amounts of HCHs application in all sampling sites are larger than DDXs, at surface and near surface layers of most sampling sites, the concentrations of summation operatorHCHs are lower than summation operatorDDXs. The composition of DDXs in the applied pesticides and sampled soils indicates that there is no recent DDT input at the sample areas.     

Quality assured measurements of animal building emissions: gas concentrations

Comprehensive field studies were initiated in 2002 to measure emissions of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), methane (CH4), nonmethane hydrocarbons (NMHC), particulate matter <10 microm in diameter, and total suspended particulate from swine and poultry production buildings in the United States. This paper focuses on the quasicontinuous gas concentration measurement at multiple locations among paired barns in seven states. Documented principles, used in air pollution monitoring at industrial sources, were applied in developing quality assurance (QA) project plans for these studies. Air was sampled from multiple locations with each gas analyzed with one high quality commercial gas analyzer that was located in an environmentally controlled on-farm instrument shelter. A nominal 4 L/min gas sampling system was designed and constructed with Teflon wetted surfaces, bypass pumping, and sample line flow and pressure sensors. Three-way solenoids were used to automatically switch between multiple gas sampling lines with > or =10 min sampling intervals. Inside and outside gas sampling probes were between 10 and 115 m away from the analyzers. Analyzers used chemiluminescence, fluorescence, photoacoustic infrared, and photoionization detectors for NH3, H2S, CO2, CH4, and NMHC, respectively. Data were collected using personal computer-based data acquisition hardware and software. This paper discusses the methodology of gas concentration measurements and the unique challenges that livestock barns pose for achieving desired accuracy and precision, data representativeness, comparability and completeness, and instrument calibration and maintenance.     

超声去除垃圾渗滤液中的氨氮

采用超声辐照技术去除垃圾渗滤液中的氨氮.研究结果表明,超声辐照对垃圾渗滤液中的氨氮有很好的去除效果.渗滤液中氨氮超声去除的机理主要是氨氮以游离氨的形式在空化泡内发生高温热解反应,生成氮气和氢气而排出.