非均相催化湿式氧化法再生活性炭实验

使用自制的CuO-Al₂O₃催化剂对苯酚饱和活性炭进行非均相催化湿式氧化再生研究,系统观察了反应条件对非均相催化湿式氧化再生活性炭的影响.实验中得到非均相CuO-Al₂O₃催化湿式氧化再生活性炭的最佳条件为:反应温度210℃,反应时间60min,催化剂投加量25mg(以铜离子计),反应氧分压0.6MPa(25℃),投炭量15g(干炭量),加水量300mL.通过对催化剂进行X衍射分析,并对催化剂的稳定性进行实验,可以得出该催化剂在催化湿式氧化再生活性炭的过程中具有较好的稳定性.     

以梭鱼金属硫蛋白基因表达监测海洋重金属污染

分离了梭鱼金属硫蛋白132个碱基对应44个氨基酸的部分基因序列,以此为基础建立了分析梭鱼金属硫蛋白基因表达的实时定量PCR方法,并用于分析渤海南戴河和大神堂近岸海域野生梭鱼金属硫蛋白基因的表达.结果表明,南戴河野生梭鱼金属硫蛋白基因的表达水平(雄鱼:0.012 ± 0.0064 copies/copy β-actin;雌鱼:0.0099 ± 0.0042 copies/copy β-actin)明显高于大神堂野生梭鱼的表达水平(雄鱼:0.0017± 0.0011 copies/copy β-actin;雌鱼:0.0014 ± 0.00095 copies/copy β-actin).该结果与两地野生梭鱼体内重金属残留水平相一致,提示梭鱼金属硫蛋白基因可作为监测海洋重金属污染的敏感标志物之一.     

Design and use of group-specific primers and probes for real-time quantitative PCR

Real-time quantitative polymerase chain reaction (qPCR) has gained popularity as a technique to detect and quantify a specific group of target microorganisms from various environmental samples including soil, water, sediments, and sludge. Although qPCR is a very useful technique for nucleic acid quantification, accurately quantifying the target microbial group strongly depends on the quality of the primer and probe used. Many aspects of conducting qPCR assays have become increasingly routine and automated; however, one of the most important aspects, designing and selecting primer and probe sets, is often a somewhat arcane process. In many cases, failed or non-specific amplification can be attributed to improperly designed primer-probe sets. This paper is intended to provide guidelines and general principles for designing group-specific primers and probes for qPCR assays. We demonstrate the effectiveness of these guidelines by reviewing the use of qPCR to study anaerobic processes and biologic nutrient removal processes. qPCR assays using group-specific primers and probes designed with this method, have been used to successfully quantify 16S ribosomal Ribonucleic Acid (16S rRNA) gene copy numbers from target methanogenic and ammonia-oxidizing bacteria in various laboratory- and full-scale biologic processes. Researchers with a good command of primer and probe design can use qPCR as a valuable tool to study biodiversity and to develop more efficient control strategies for biologic processes.     

A simple and robust method for determination of neem (Azadirachta indica A. Juss) oil in neem oil coated urea

The production of neem oil coated urea (NOCU), a technology developed by the Indian Agricultural Research Institute, has been grown to over 2.0 million tons per year. The estimation of neem oil content in NOCU is important due to its significance in ensuring agronomic efficiency. Therefore, this study was taken up to develop a simple method for the determination of neem oil in NOCU. The procedure involves extraction of neem oil from NOCU; saponification of extracted oil; oxidation of released glycerol to formaldehyde, and subsequent conversion of formaldehyde to a dihydrolutidine derivative. Its concentration was determined spectrophotometrically. The recoveries of neem oil from NOCU with oil load of 500 and 1000?ppm were 87.6?±?3.0% and 90.0?±?4.8% respectively with direct method; and improved to 92.6?±?4.0% and 96.7?±?3.8% after including the in situ purification. A simple method based on the Hantzsch reaction was developed for the determination of neem oil in NOCU. This method is superior to earlier methods in terms of sensitivity, simplicity, and time required.     

Efficiency of mercapto flavor compounds in removing acrylamide under high temperature and low humidity conditions

Acrylamide (AA) is a potential human carcinogen, genotoxicant, and neurotoxicant. Thus, the aim of this study was to examine the ability of mercapto flavor compounds to remove AA released from consumer packaging into food products. Four mercapto flavor compounds including 1,2-ethanedithiol, 1-butanethiol, 2-methyl-3-furanthiol, and 2-furanmethanethiol were employed to extract AA in model system using high temperature and low humidity. Our study showed that mercaptans were effective in eliminating AA in our model system. In order to remove 0.2 μmol AA, the optimal conditions in the reaction system were mercaptan flavor chemicals at 5 μmol, temperature 180 °C, and reaction time 25 min. In the presence of a higher pH, the greater was the amount of AA eliminated. Evidence indicates that employment of mercapto flavor chemicals under certain temperature and pH conditions is a reliable method to remove any unwanted AA from food products.     

低温驯化对自养脱氮颗粒污泥功能活性与菌群结构的影响分析

低温驯化是提高部分亚硝化-厌氧氨氧化（PN/A）组合工艺低温脱氮效能和运行稳定性的有效方法.为探究低温驯化对污泥特性的具体影响,本文从温度敏感性、颗粒外观形态、胞外聚合物（EPS）组成和微生物群落结构等方面,对中高温培养（30℃）和低温驯化（15℃）PN/A颗粒污泥之间的差异性进行了分析.反应热力学的研究结果表明,驯化污泥（G_L）在低温区（10~20℃）的脱氮性能较中高温培养污泥（G_H）有了显著提高,总无机氮去除的表观反应活化能（E_a）降低了28.4%.与G_H相比,G_L的平均粒径减小了25.8%,EPS含量增长了16.6%,颗粒的沉降性能明显下降.由高通量测序结果可知,G_L具有更高的菌群多样性,同时,污泥中好氧氨氧化菌（Nitrosomonas）与厌氧氨氧化菌（Candidatus_Kuenenia）的丰度比值（0.04）远小于G_H的0.34.这意味着颗粒污泥在低温环境中对慢速生长自养菌仍具有较强的截留能力.上述发现为解析PN/A污泥在低温条件下的自适应机制,推动组合工艺的工程化应用提供了重要参考.     

北京奥运会期间奥运村站空气质量的观测与研究

为了跟踪研究北京2008年奥运会期间奥运村大气污染物浓度的变化,2008年6月1日─9月30日,利用符合国际标准的在线观测仪器,对奥运村站大气中主要污染物进行加强观测. 结果表明:奥运会期间奥运村站大气中φ(NO₂),φ(SO₂),ρ(PM_2.5)和ρ(PM₁₀₎分别比奥运会前(7月1日─8月7日)下降了11.2%,46.7%,57.0%和50.0%;比残奥会后时段(9月20─30日)分别下降了41.7%,31.8%,21.6%和28.6%;与2007年同期相比,奥运会时段的φ(NO₂),φ(O₃),ρ(PM_2.5)和ρ(PM₁₀₎分别下降了38.8%,37.2%,42.1%和68.0%;残奥会时段分别下降了17.8%,27.5%,44.0%和64.1%. 除对污染源严格的控制措施取得了良好的效果外,有利的天气过程也是奥运会期间北京空气质量全面达标的重要原因.      

含乐果废水的循环电-Fenton氧化过程及其影响因素

为克服传统Fenton(Conventional Fenton,简称CF)法中存在着Fe2 在反应初始时即被氧化且反应过程中产生大量铁泥(Fe的复杂络合物)的不足,研究了循环电-Fenton(Circulating Electro Fenton,简称CEF-FeRe)法氧化降解自配乐果废水的过程及其各影响因子的作用机制.CEF-FeRe反应所需的H2O2通过蠕动泵缓慢加入到电解池中,而被氧化了的Fe2 又在阴极被还原,使得Fenton反应能持续进行.在乐果浓度为200mg·L-1时,通过多个单因素试验确定最佳CEF-FeRe反应条件为:常温、pH值为3.0、H2O2/Fe2 的摩尔比为10、H2O2的加入量为理论剂量、恒流0.5A.结果表明,在此条件下反应120min后COD去除率为81.67%,乐果在25min内去除率为99.4%.通过测定CEF-FeRe以及CF反应过程中Fe2 和H2O2的变化情况验证了CEF-FeRe反应的机理.动力学研究结果表明.乐果废水的CEF-FeRe反应符合一级动力学反应规律.CEF-FeRe法处理实际乐果废水也可以得到91.16%的乐果去除及68.53%的COD去除,这表明CEF-FeRe法处理乐果废水效率高且运行费用较低的特点.     

应用氢化物发生-原子荧光光谱法测定土壤中砷的方法研究

本文主要讨论应用氢化物发生-原子荧光光谱法,测定土壤中砷的技术。用硝酸-高氯酸分解法对样品进行预处理,探讨了共存离子对测定的影响及干扰的消除,分析了土壤标样Ess-2、Ess-3,进行了方法精密度和回收率试验。在经过优化的试验条件下,砷的检出限:0.02ug/L。回收率在91%~107%之间,相对标准偏差小于或等于7.8%。土壤标样Ess-2、Ess-3测定值与标准值相符,相对标准偏差也低于10%。表明将该法用于土壤中砷的测定操作简便、快速基体干扰少、灵敏度高、分析结果稳定可靠。     

烟气同时脱硫脱硝技术探讨

开发先进的烟气治理技术,控制二氧化硫和氮氧化物排放是国内外脱硫脱硝研究的一大热点。本文简述了同时脱硫脱硝技术的工作机理及其优缺点,从反应机理、技术特点和工程应用等方面,介绍了烟气同时脱硫脱硝技术的研究进展情况,并对其应用前景进行了预测。