京津冀区域燃煤发电行业大气污染物排放时空变化特征研究

为了科学评估京津冀区域燃煤发电行业特别排放限值和超低排放相关要求实施后的大气污染物减排效果,以行业调查数据为基础,建立了2013年和2015年京津冀区域燃煤发电行业大气污染物排放清单,分析了装机容量与SO_2、NO_x和烟尘排放量的时空耦合关系,讨论了国家相关政策和标准的实施效果。结果显示:区域内2015年燃煤机组装机容量与2013年相比略有下降,SO_2、NO_x和烟尘排放量分别下降75.95%、83.09%和71.20%,减排效果明显。2015年100 MW以下等级机组3种污染物排放总量位居各机组首位,建议通过多种合理方式压减小型燃煤发电机组数量和排放浓度。     

Oxidation inhibition of sulfite in dual alkali FGD system

A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and 4）.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.     

东莞市蔬菜基地土壤中喹诺酮类抗生素的污染特征研究

抗生素作为新兴环境污染物在区域农业土壤污染特征研究中鲜见报道.本文利用固相萃取-高效液相色谱-串联质谱分析方法,调查了东莞市18个区镇24个代表性蔬菜基地土壤中喹诺酮类抗生素(QNs)的含量与分布特征.结果表明,4种喹诺酮类化合物的检出率均在90%以上,以环丙沙星(平均含量24.93μg·kg-1)和恩诺沙星(平均含量...     

外加淀粉酶预处理污泥厌氧发酵产氢研究

通过外加淀粉酶预处理剩余污泥,考察了淀粉酶对污泥的破解效果,研究了接种产氢菌(Enterococcus sp.LG1)和未接种产氢菌两种状况下,污泥厌氧发酵产氢效果,并与相应温度(60℃)热预处理污泥的发酵产氢效果进行对比,同时分析探讨了污泥发酵产氢过程中底物和pH值的变化.结果表明,淀粉酶预处理污泥4h后水解效果最佳...     

Application of ICP-QMS for the determination of plutonium in environmental samples for safeguards purposes

Aiming to determine the plutonium amount as well as its isotopic composition, in particular, in swipe samples for safeguards purposes, an analytical method was developed with a plutonium separation step based on extraction chromatography using 2 cm TEVA columns and detection with quadrupole ICP-MS applying an ultra-sonic nebulizer coupled with membrane desolvation system. The method was successfully applied to New Brunswick plutonium certified reference materials as well as to Lawrence Livermore National Laboratory round robin samples, based on the round robin samples provided by the Institute for Reference Materials and Measurements (Belgium), as part of the Regular European Interlaboratory Measurement Evaluation Programme (REIMEP), campaign 16 (isotopic abundances of plutonium in plutonium nitrate samples), with a total plutonium amount between 1 and 0.25 ng per sample. After the introduction of an additional separation step, it was also possible to carry out precise and accurate total plutonium, (240)Pu/(239)Pu, (241)Pu/(239)Pu and (242)Pu/(239)Pu atom ratios determination in sediment sample showing its applicability to environmental samples in general, reaching a detection limit equivalent to 5 mBq(239)Pu kg(-1).     

一款用于无线通信系统的小型滤波器天线

目的设计一款适用于现代无线通信系统小型的滤波器天线。方法由一微带开口环谐振器、一段耦合线和一个Г型天线组成一款滤波器天线。这个Г型天线由耦合线激励,在设计中起着导纳变换器的作用。Г型天线不仅起着辐射的作用,同时也是滤波器最后一个谐振器,使滤波器和天线之间基本没有损耗,在仿真调试后,加工成实物进行测试。结果该滤波器天线在反射系数S11<-10 dB的阻抗带宽有12.7%(2.36~2.68 GHz),滤波器天线具有平坦的通带,通带内的最大差异为0.84 dB。滤波器天线通带外增益不到-15 dBi,这说明滤波器天线具有很好的带外抑制性。结论设计的滤波器天线通带内天线增益较为平坦,且拥有良好的带外抑制特性、滤波与辐射特性,并且损耗很低,很适合用于现代无线通信系统的射频前端。     

H2O2胁同三维电极法处理罗丹明B废水的研究

为了了解过氧化氢与三维电极的协同作用,以罗丹明B模拟废水进行了实验研究,探索了填料配比、外加电压、过氧化氢投加量、初始废水pH值、染料初始浓度等单因子对降解罗丹明B的影响,并通过正交试验研究各因素对该法处理罗丹明B模拟废水的效应.结果表明,过氧化氢与三维电极在处理罗丹明B模拟废水时具有明显的协同作用;外加电压=20v,...     

模拟烹饪油烟的粒径分布与扩散

烹饪油烟颗粒物粒径分布与扩散特性研究有助于解析其对室内空气质量和居民健康的影响,采用电子低压撞击器(ELPI)实时监测了油烟机开启和关闭状态下,模拟烹饪油烟发生处和3 m外位置处,0.03~10μm范围内油烟颗粒数浓度和质量浓度随粒径分布.油烟颗粒主要以655 nm以下的细颗粒为主.油烟机能够显著降低室内油烟浓度,开启油烟机后,油烟发生处颗粒数浓度从2.8×106个·cm-3降低到2.3×105个·cm-3,PM2.5(空气动力学直径≤2.5μm的颗粒)质量浓度从85.9 mg·m-3降低到6.2 mg·m-3.油烟机对PM10的净化效率高于PM2.5.油烟迅速从发生处扩散到3 m外,无通风状态下,总颗粒数浓度衰减达65%,PM2.5质量浓度衰减达75%.计算流体动力学(CFD)模拟了油烟机对油烟PM2.5质量浓度场扩散分布影响.红外摄像仪监测了油烟温度场分布扩散,以扇形向外扩散,伴随着油烟温度梯度降低.     

利用3 nm~20 μm颗粒物粒径分布测量仪对南宁市大气颗粒物粒径分布特征进行研究

利用颗粒物粒径分布测量仪(particle size distribution system,PSD)对南宁市2016年11月15日—12月4日大气颗粒物进行实时监测,分析颗粒物数浓度、粒径分布特征及其与颗粒物质量浓度的关系.结果表明,南宁市3 nm~20μm颗粒物平均数浓度为3269个·cm-3,粒径呈双峰分布,主峰值出现在28 nm左右,次峰值出现在100 nm左右.颗粒物数浓度随时间变化呈现一定规律,即早上8:00—10:00和晚上18:00—20:00左右出现浓度高值,这与早晚高峰有关.新粒子一般在16:00~18:00左右开始生成,18:00—20:00左右逐渐长大,并在夜间至凌晨保持较高的浓度.南宁市监测期间新粒子生成与机动车尾气排放有关.颗粒物质量浓度越大对应的数浓度也相应较高,较大粒径颗粒物对质量浓度贡献较大.降雨和风速加大过程对颗粒物数浓度下降有影响;温度和湿度对颗粒物数浓度影响不明显.     

Production of new concrete with leather tannery waste used as partial replacement of the natural sand

Journal of Material Cycles and Waste Management - Leather production is a technology that boosts the economy because of its versatility and durability. However, the wastes generated throughout the...