Characteristics of emissive spectrum and the removal of nitric oxide in N2/O2/NO plasma with argon additive

Although the approach using non-thermal plasma (NTP) for deNOx has been studied for over 15 years, how to achieve higher removal e ciency with lower cost is still a barrier for its industrial application. In order to investigate the impact of the argon additive on electron density, energy and nitric oxide reduction process in plasma, the spectrum of the dielectric barrier discharge at atmospheric pressure in a coaxial reactor was measured using the monochromater with high resolution. The comparative experiments for NO reduction were carried out simultaneously in N2/O2/NO plasma stream with and without argon, respectively. The nitrogen molecular spectrum which is attributed to the energy level transition (C3 u ! B3 g) was compared in the wavelength range 300–480 nm and the electron density and temperature were determined based on the relative intensities and Stark broadening width of spectral lines. The spectrum results indicated that the argon additive could enhance the intensity of emissive spectrum of plasma, thus the electron concentration as well as the energy was increased, and finally prompted the ionization rate to produce active N, O and O3. The results of NO reduction showed that NO conversion e ciency increased in the range of 10%–30% with 5% addition of argon in stream comparing with the condition without argon additive. This study will play a positive role in the industrial application of dielectric barrier discharge deNOx reactor.     

白石砬子自然保护区几种主要植被类型土壤入渗特性研究

为了深入研究辽东山区森林土壤的水源涵养功能,以白石砬子自然保护区内的6种主要植被类型下土壤为研究对象,采用野外双环试验和室内理化性质分析相结合的方法,研究了不同植被类型下土壤入渗能力及其与理化性质的关系。结果表明,不同植被类型土壤的初渗率、稳渗率、平均入渗率、渗透总量均表现为下层低于上层,最大值是最小值的近3倍;不同植被类型间土壤入渗能力差异较大,其中A层初渗率排列顺序为原生红松阔叶混交林>红松人工林>鱼鳞云杉臭冷杉林>农地>蒙古栎林>杂木林,B层初渗率排列顺序为鱼鳞云杉臭冷杉林>农地>杂木林>红松人工林>原生红松阔叶混交林>蒙古栎林,A层稳渗率排列顺序为红松人工林>鱼鳞云杉臭冷杉林>原生红松阔叶混交林>杂木林>蒙古栎林>农地,B层稳渗率以杂木林最大,为3.8 mm?min-1,原生红松阔叶混交林最小,仅为1.1 mm?min-1,其他4种植被类型土壤稳渗率几乎无差异,A层平均入渗率排列顺序为红松人工林>原生红松阔叶混交林>鱼鳞云杉臭冷杉林>杂木林>蒙古栎林>农地,B层平均入渗率排列顺序为杂木林>鱼鳞云杉臭冷杉林>红松人工林>蒙古栎林>农地>原生红松阔叶混交林,A层的渗透总量以红松阔叶混交林和红松人工林最大,蒙古栎林和农地相对较低,B层的渗透总量以杂木林最大,红松阔叶混交林最小;主成分分析评价的土壤入渗能力排序为红松人工林>鱼鳞云杉臭冷杉林>原生红松阔叶混交林>杂木林>蒙古栎林>农地,初渗率、稳渗率、平均入渗率和渗透总量等4个指标综合起来能够很好的表达土壤入渗能力,其主成分方差的累积贡献率为90.662%;不同层次土壤入渗速率与入渗时间均存在良好的幂函数关系;土壤的稳渗率、平均入渗率、渗透总量与非毛管孔隙度呈显著正相关关系,初渗率与非毛管孔隙存在相关性,但不显著。与容重存在负相关关系,但不显著。     

Speciation and sources of atmospheric aerosols in a highly industrialised emerging mega-city in central China

Monitoring air quality in large urban agglomerations is the key to the prevention of air pollution-related problems in emerging mega-cities. The city of Wuhan is a highly industrialised city with >9 million inhabitants in Central China. Simultaneous PM10 sampling was performed during 1 year at one urban and one industrial site. Mean PM10 daily levels (156 microg m(-3) at the urban site and 197 microg m(-3) at the industrial hotspot) exceed the US-EPA or EU annual limit values by 3-4 times. A detailed study of daily speciation showed that the mean chemical composition of PM10 presents minimal differences between peak and low PM episodes. This implies that PM10 aerosols in the study area result from local emissions, and air quality management and abatement strategies in Wuhan should thus focus on local anthropogenic sources. The levels of some elements of environmental concern are relatively high (409-615 ngPb m(-3), 66-70 ngAs m(-3), 116-227 ngMn m(-3), 10-12 ngCd m(-3)) due to industrial, but also urban emissions. Principal component analysis identified a mineral source (probably cement and steel manufacture) and smelting as the main contributors to PM10 levels at the industrial site (34%), followed by a coal fired power plant (20%) and the anthropogenic regional background (16%). At the urban site the major PM10 source is a mixed coal combustion source (31%), followed by the anthropogenic regional background (28%) and traffic (16%).     

微电解、A/O和膜生物反应器组合工艺处理高浓度有机氮废水

农药百菌清及其中间体生产废水含有大量有机物和无机盐,特别是氰基苯类化合物,对细菌有强抑制和毒害作用,且生物处理中有机氮转化产生大量氨氮,易造成污泥膨胀,废水采用传统生化处理工艺无法运行。而采用微电解、A/O和膜生物反应器组合工艺建设的废水处理工程,运行良好,出水各项指标达到接管排放标准。     

山东省环境空气“‘蓝天白云、繁星闪烁’标准”解析

山东省环保部门提出使用"蓝天白云、繁星闪烁"标准评价空气质量,该标准使用能见度作为主要技术判定指标。为了探讨这种"具象性"标准对空气质量的指示能力,对2013—2014年监测数据进行了深入分析。结果显示,能见度与颗粒物有良好的相关性,与气态污染物的相关性均一般。源于能见度与空气污染物的密切关系,"蓝天白云、繁星闪烁"标准能够将空气污染物水平大致划分为优劣两类,但对各种污染物的指示能力不同。     

高昌故城内城墙墙体土遗址动力响应分析∗

对高昌故城内城墙墙体进行现场脉动测试,获取土建筑遗址的频谱特性及其自振频率,分析高昌故城内城墙不同部位速度放大效应,研究其在地震荷载作用下的动力响应特征,明确墙体薄弱部位已有加固措施的防护效果。结果表明：高昌故城内城墙的速度放大倍数约1.5~2倍,与地脉动测试结果大致吻合;内城墙自底部至顶部,速度、位移响应均逐渐增大,二者在墙体凹陷处的表现不同,前者相对降低、后者量值最大;内城墙凹陷及洞穴处加固前后应力分布变化明显,应力集中部位不再处于墙体薄弱部位,墙体加固效果良好。所得结果可为高昌故城墙体抗震加固防护提供参考依据。     

黑龙江省水稻初霜冻灾害致灾因子危险性分析

根据黑龙江省水稻的生长发育期,以全省77个台站1961-2009年的逐日最低气温资料、霜冻历史灾情数据、社会经济资料、地理信息数据及作物生育期资料为基础,综合运用GIS空间分析和灾害风险评估数学方法,分析了黑龙江省初霜冻灾害的灾情特征,并根据霜冻灾害的形成机制,分别计算水稻生育期初霜冻发生概率及偏早初霜冻发生概率,进而确定了致灾因子,对致灾因子危险性进行分析与评估。结果表明:水稻初霜冻灾害发生的概率随纬度的增加大致呈增大的分布形势,大兴安岭、孙吴、逊克、嘉荫、伊春、嫩江、克山、拜泉、海伦等市县为高危险区,黑河大部、齐齐哈尔东部、绥化北部、尚志、穆棱、富锦为次高危险区,松嫩平原南部、三江平原大部、牡丹江南部为次低及低危险区。     

Inhibition effect of magnetic field on nitrous oxide emission from sequencing batch reactor treating domestic wastewater at low temperature

This study aims to investigate the effect of a magnetic field on nitrous oxide(N_2O) emission from a sequencing batch reactor treating low-strength domestic wastewater at low temperature(10℃).After running for 124 days in parallel,results indicated that the conversion rate of N_2O for a magnetic field-sequencing batch reactor(MF-SBR) decreased by34.3% compared to that of a conventional SBR(C-SBR).Meanwhile,the removal efficiencies for total nitrogen(TN) and ammonia nitrogen(NH4-N) of the MF-SBR were 22.4% and 39.5% higher than those of the C-SBR.High-throughput sequencing revealed that the abundances of AOB(Nitrosomonas),NOB(Nitrospira) and denitrifiers(Zoogloea),which could reduce N_2O to N_2,were promoted significantly in the MF-SBR.Enzyme activities(Nir) and gene abundances(nos Z nir S and nir K) for denitrification in the MF-SBR were also notably higher compared to C-SBR.Our study shows that application of a magnetic field is a useful approach for inhibiting the generation of N_2O and promoting the nitrogen removal efficiency by affecting the microbial characteristics of sludge in an SBR treating domestic wastewater at low temperature.     

复合床生态滤池处理城市污水中试研究

复合床生态滤池(MMEEF)是利用由微生物和蚯蚓为代表的微型动物共同组成的人工生态系统,是对城镇污水中的污染物进行降解处理的新型污水处理技术.滤床由植物性填料层和惰性填料层组成.复合床生态滤池处理初沉池出水,水力负荷为2 0m3·m-2·d-1,出水SS小于5mg·L-1,CODCr去除率为74%～87%,NH 4 N去除率为30%～50%,TN去除率为25%～40%,TP去除率为40%～57%.水力负荷降低,NH 4 N去除率和硝酸根浓度的增加量4 N去除率增加,硝酸根浓度增加,NH 与碱度减少量成正相关.惰性颗粒层在硝化方面起着主要作用,蚯蚓对生态滤池的正常运行有重要作用.     

两相厌氧系统中产甲烷相有机酸转化规律

研究了两相厌氧系统产甲烷相中有机酸转化规律.以产酸相、产甲烷相COD负荷分别为41.5 kg/(m³·d)、6.05kg/(m³·d)的连续流试验装置培养种泥,运行稳定后,进行静态试验采用气相色谱仪(GC-122型)分析有机酸组成及含量结果表明,反应器相同位置的微生物降解转化有机酸速率快慢依次为:乙酸＞乙醇＞丁酸＞丙酸;利用乙醇产乙酸的微生物与产甲烷菌所需最佳pH值范围相近;乙醇型发酵是充分发挥两相厌氧系统功能的最佳发酵类型;在产甲烷反应器中,大部分挥发酸的最终降解都要经历乙酸降解途径才能完成,造成乙酸的降解转化相对缓慢,成为厌氧工艺中的限速步骤.