云南洱海沉积物中硫酸盐还原菌的时空分布特征

利用PCR扩增和荧光原位杂交方法分析了云南洱海沉积物中硫酸盐还原菌(Sulfate-reducing bacteria,SRB)类群和数量的时空分布特征。结果表明,秋季沉积物中检测出四个SRB类群(脱硫肠菌属、脱硫叶菌属、脱硫球菌属-脱硫线菌属-脱硫八叠菌属和脱硫弧菌属-脱硫微菌属),而春季沉积物中只检测出三个类群(脱硫肠菌属、脱硫叶菌属和脱硫球菌属-脱硫线菌属-脱硫八叠菌属)。相比春季,秋季沉积物检测出来的SRB类群具有更大的分布范围,同时,检测出的SRB类群主要分布在沉积物上部;从数量上来看,秋季沉积物SRB数量高于春季沉积物。上述结果指示秋季沉积物环境条件更适于SRB群落。此外,相比洱海秋季,洱海春季沉积环境溶解氧含量较高,且温度较低,这可能导致脱硫弧菌属-脱硫微菌属在洱海春季沉积物中处于不可育状态,由于其活性低而无法检测。     

高校食堂清洁生产行动方案的研究

高校食堂是高校建设的重要环节之一,清洁生产能更加有效的管理高校食堂.文章以南京某高校食堂为例,通过问卷调查和实地考察的形式,分析高校食堂各个过程能耗比例和污染物产生的原因,并且对高校食堂电消耗、一次性消耗品和固体废物提出具体措施.结果显示:清洁生产每年平均节约电费1.25万元;减少一次性用品并且每年平均增加收益2 058元;平均减少剩饭剩菜14.83％.     

南宁市区交通环境空气颗粒物中碳组分的污染特征分析研究

含碳颗粒物是大气颗粒物的重要组成部分,对人体健康产生很大的威胁.分别于2012年夏季及2013年冬季在南宁市选取六条主要交通干道采集了PM10、PM2.5样品,分析测定了其中的碳组分.结果表明,碳组分浓度季节变化明显.碳组分在细颗粒物中占有比重比在可吸入颗粒物中大.存在二次有机碳污染.对8种碳组分丰度分析说明南宁市大气颗粒物中碳组分的主要来源是燃煤、机动车尾气及生物质样品燃烧.     

Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis

In this study, a novel scaled-up hybrid acidogenic bioreactor(HAB) was designed and adopted to evaluate the performance of azo dye(acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time(HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD(chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis(AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3% ± 2.5%, 86.2% ± 3.8% and 93.5% ± 1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS(61.1% ± 4.7%,75.4% ± 5.0% and 82.1% ± 2.1%, respectively). Moreover, larger TCV/TV(total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2% ± 3.7% and 28.30 ± 1.48 m A,respectively. They were significantly increased to 62.1% ± 2.0% and 34.55 ± 0.83 m A at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater.     

Process analysis of characteristics of the boundary layer during a heavy haze pollution episode in an inland megacity, China

Ground observation data from 8 meteorological stations in Xi'an, air mass concentration data from 13 environmental quality monitoring sites in Xi'an, as well as radiosonde observation and wind profile radar data, were used in this study. Thereby, the process, causes and boundary layer meteorological characteristics of a heavy haze episode occurring from 16 to 25 December 2013 in Xi'an were analyzed. Principal component analysis showed that this haze pollution was mainly caused by the high-intensity emission and formation of gaseous pollutants (NO₂, CO and SO₂) and atmospheric particles (PM_2.5 (fine particles) and PM₁₀ (respirable suspended particle). The second cause was the relative humidity and continuous low temperature. The third cause was the allocation of the surface pressure field. The presence of a near-surface temperature inversion at the boundary layer formed favorable stratification conditions for the formation and maintenance of heavy haze pollution. The persistent thick haze layer weakened the solar radiation. Meanwhile, a warming effect in the urban canopy layer and in the transition zone from the urban friction sublayer to the urban canopy was indicated. All these conditions facilitated the maintenance and reinforcement of temperature inversion. The stable atmospheric stratification finally acted on the wind field in the boundary layer, and further weakened the exchange capacity of vertical turbulence. The superposition of a wind field with the horizontal gentle wind induced the typical air stagnation and finally caused the deterioration of air quality during this haze event.     

人工湿地在污水处理中的应用及展望

本文综述了人工湿地去除有机物、氮、磷和重金属的影响因素,同时对人工湿地处理污水的前景进行了展望．     

基于虚拟水的江苏省2009年水足迹分析

水足迹是基于消费基础的水资源利用情况的指示器,通过虚拟水贸易获得最大利益是水足迹分析方法的重要发展方向。在基于虚拟水计算方法的基础上对江苏省2009年水足迹进行了计算和评价,结果表明：2009年江苏省水足迹为866．75×10^8m^3,人均水足迹为1829m^3／人·年,水匮乏度为217％,水资源消费自给率为86．33％,较高的水资源自给率和水足迹给江苏省生态环境造成了巨大压力。实施虚拟水战略、改变消费模式、提高水资源利用率,已经成为缓解江苏省水资源短缺现状,实现水资源可持续利用的有效途径。     

海上石油平台消防泵细节设计

以有关规范标准为基础,结合国内海上平台消防泵设计,从细节方面对海上平台消防泵设计进行了研究讨论,主要包括海上平台消防泵性能选择、驱动时间、超压保护、最小流量保护、计量等。     

高密度沉淀池技术概述

高密度沉淀池(Densadeg)以其结构紧凑、处理效率高、出水水质稳定等特点,越来越多地被应用于城市污水一级强化处理和深度处理。本文主要介绍了高密度沉淀池的三种基本类型,重点阐述了RL型高密度沉淀池的工作原理及组成,以及污泥外部循环系统、高效斜板设置的特点;同时介绍了Densadeg的另一种运行方式:超高速沉淀池(ACTIFLO工艺),展望了高密度沉淀池的应用前景。     

基于DEM地表水文特征和汇水子流域的提取研究

文章以天津于桥水库上游流域为研究对象,以DEM(数字高程模型)为基础数据,对DEM生成方法、DEM精度、流域地形地貌特征及阈值的选取三个方面分别作了详细研究。试验结果表明,从于桥水库上游流域的水文特征所提取的河网分布与河流与实际分布情况基本吻合,淋河、沙河、黎河三大流域的面积误差范围分别为-3.44%、2.28%和7.63%。