管道内甲烷/空气预混火焰加速传播特性研究

搭建了基于可视化燃烧管道的预混火焰精细结构实验台,通过理论分析和实验等手段对预混火焰的瞬态传播过程及加速传播特性进行了研究,分析得出了不同甲烷含量的预混火焰加速传播规律及预混火焰由层流向湍流的转变规律.     

Seasonal variation, source, and regional representativeness of the background aerosol from two remote sites in western China

Using observations from two remote sites during July 2004 to March 2005, we show that at Akdala (AKD, 47° 06′ N, 87° 58′ E, 562 m asl) in northern Xinjiang Province, there were high wintertime loadings of organic carbon (OC), elemental carbon (EC), and water-soluble (WS) ${\rm SO}_{4}^{2-}$ , ${\rm NO}_{3}^{2-}$ , and ${\rm NH}_{4}^{+}$ , which is similar to the general pattern in most areas of China and East Asia. However, at Zhuzhang (ZUZ, 28° 00′ N, 99° 43′ E, 3,583 m asl) in northwestern Yunnan Province, the aerosol concentrations and compositions showed little seasonal variation except for a decreasing trend of OC from August to autumn–winter. Additionally, the OC variations dominated the seasonal variation of PM₁₀ (particles ≤10 μm diameter) level. Chemical characteristics combined with transport information suggested sea salt origin of ionic Na^?+?, Mg^2?+?, and Cl^??? at ZUZ. At AKD, ionic Ca^2?+?, Mg^2?+?, Na^?+?, and Cl^??? primarily originated from salinized soil. Furthermore, the WS Ca^2?+? contributions (5.4–6%) to the PM₁₀ mass during autumn, winter, and early spring reflected a constant dust component. The results of this study indicated that both sites were regionally representative. However, the representative regions and scales of these background sites may vary seasonally as the regional atmospheric transport patterns change. Seasonal variations in the background aerosol levels from these two areas need to be considered when evaluating the regional climate effects of the aerosols.     

加速战略转移推进持续发展

中国是一个发展中国家,经济已进入高速增长阶段,因而应从实际出发,选择一条既发展经济,又保护环境的持续发展道路。《中国21世纪议程》阐述了持续发展的战略思想、总体目标和步骤,是我国推行持续发展战略的有力保证,亦是指导今后中国环境保护工作的行动指南。     

宜兴市莲花荡水系整治工程前后生态健康评价

以入太湖莲花荡水系为研究对象,结合2015年4个季度9个采样点的水质学、生物学共7个指标生态调查数据,采用多指标综合评价法,从生物完整性、化学完整性2个方面评价了莲花荡水系整治工程前后的生态健康状况。结果表明,2015年第1、2季度健康状况较差,健康的样点个数分别为3和1,在2015年6月开展清淤工程及集约化畜禽产业整改后,3、4季度健康状况明显改善,健康样点个数分别达到9和7。影响莲花荡水系化学完整性的主要水质指标是TN、TP,3、4季度TN仍超出地表水Ⅴ类标准,处于严重病态,TP为地表IV类标准,处于病态。影响莲花荡水系生物完整性的主要因子是底栖动物,仅监测到20种耐污能力较高的底栖动物物种,而未发现清洁物种。为了进一步改善莲花荡水系生态健康状况,建议开展沿岸农村生活污水的截污治理、农业面源的生态拦阻等污染源控工程,辅以生态岸带建设及湖滨带生态修复等工程。     

论成都的环境用水和水生态环境建设

本文首次提出环境用水概念，指出水质、水量、水面是环境用水的基本要素。阐述了环境用水对成都城市发展的重要意义。就成都环境用水目前存在的问题提出了解决途径。结合府南河综合整治工程，就成都的水生态环境建设提出建议。     

生物膜反应器脱氮性能及其硝化细菌的研究

采用模拟含氮废水对自行设计制作的A/O生物膜反应器进行脱氮性能研究。研究结果表明：在水温为20～23℃、水力停留时间为18h、进水总氮质量浓度为61～78m g/L、曝气量为25L/min、进水COD分别为110～165m g/L和205～272m g/L的条件下,废水的COD去除率均在90%以上,硝化率分别为98%和95%,总氮去除率分别为50%和78%。采用荧光原位杂交技术对反应器各区域中的硝化细菌进行了检测。结果表明,反应器中的硝化菌主要为亚硝化螺菌属和硝化螺菌属,有少量亚硝化单胞菌属和硝化杆菌属存在。亚硝化菌和硝化菌在好氧区数量相对较多,在缺氧区数量相对较少。     

木炭窑废气治理方法研究

近年来木炭的新用途及作为新材料的研究开发十分活跃,使该行业市场前景被看好.但木炭窑废气造成的环境污染严重的制约了该行业的发展.目前比较多的木炭窑规模较小,布局分散,应尽量选择投资少、运行费用低的治理方法以利于解决实际问题.     

新型喷射鼓泡塔与传统鼓泡塔脱硫的性能比较

以磷矿浆为脱硫剂进行烟气脱硫研究,比较了自主创新研制的中试规模环栅式喷射鼓泡塔与工业规模的日本千代田CT-121脱硫鼓泡塔的性能。结果表明:塔压降和脱硫剂的pH值是影响脱硫效率的关键因素。鼓泡塔采用三塔串联,控制磷矿浆pH值为3.5~4.2、操作压力为7 000~7 800 Pa时,脱硫效率维持在95%左右。环栅式喷射鼓泡塔维持单塔压降约在3 000 Pa左右,磷矿浆pH值在3.7~4.3时脱硫效率可达67%。环栅式喷射鼓泡脱硫工艺以磷矿为脱硫剂,脱硫除尘效果好,系统投资少,运行费用低,并能资源化利用废渣,是适合我国国情的一项脱硫除尘技术。     

Challenges to saving China’s freshwater biodiversity: Fishery exploitation and landscape pressures

China has over 1320 freshwater fish species, 877 of which are endemic. In recent decades, over-exploitation and landscape pressures have threatened them and led to a severe aquatic biodiversity crisis. In response, large-scale fishing bans have been promulgated to protect freshwater biodiversity in major Chinese rivers since the early 1980s. Here, we present the historical background and current challenges to the fishing bans. Implementing large-scale fishing bans may help improve China’s current freshwater biological resources and biodiversity to some extent. But implementing fishing bans alone is not sufficient to solve the crisis because of shortcomings of the current bans and expanding human pressures in most river basins. Thus, we recommend regulating other anthropogenic pressures, expanding duration and extent of current fishing regulations, establishing a comprehensive monitoring program, and initiating basin-scale ecological rehabilitation. These programs are also needed in other developing countries facing similar biodiversity crises and human pressures.     

Environmental impact of irrigation in La Violada District (Spain): II. Nitrogen fertilization and nitrate export patterns in drainage water

Fertilizer leaching affects farm profitability and contributes to nonpoint-source pollution of receiving waters. This work aimed to establish nitrate nitrogen export from La Violada Gully in relation to nitrogen fertilization practices in its basin (La Violada Gully watershed, VGW, 19,637 ha) and especially in La Violada Irrigation District (VID, 5282 ha). Nitrogen (N) fertilization in VID (and VGW) was determined through interviews with local farmers for the hydrologic years 1995 and 1996 and NO3-N load in the gully was monitored from 1995 to 1998. The N fertilizer applied in VGW was 2175 Mg in 1995 and 2795 Mg in 1996. About 43% was applied in VID (945 Mg in 1995 and 1161 Mg in 1996). The most fertilized crop was corn: 398 kg N ha-1 (665 Mg) in 1995 and 453 kg N ha-1 (911 Mg) in 1996. Nitrogen fertilization was higher than N uptake for irrigated crops, especially for corn and rice. Nitrate N load in La Violada Gully averaged 427.4 Mg yr-1. Seventy-five percent of the exports took place during the irrigation season (321.8 Mg). During the non-irrigation season maximum NO3-N loads (3.1 Mg NO3-N d-1) were found after heavy rains following the N side-dressing of wheat in the rain-fed area of VGW (February). During the irrigation season NO3-N load was determined by outflow from the district (caused by irrigation) and to a lesser extent by changes in NO3 concentration (caused by fertilization), showing peaks in April (pre-sowing corn N fertilization and first irrigations) and June to August (highest irrigation months and corn side-dress N applications, maximum 6.3 Mg NO3-N d-1 in July). Adjusting N fertilization to crops' needs, improving irrigation efficiencies, and better scheduling N fertilization and irrigation in corn could reduce N export from VID.