环境噪声监测的问题及解决对策研究

当今社会,经济飞速发展,噪音污染也随之越来越严重,影响了人们正常的工作和生活。环境噪声监测能够提供准确的噪声数据,为国家和人民群众提供指标性服务。本文结合当前噪声污染的具体情况,分析了环境噪声监测中存在的问题,在发现问题、了解问题的基础上,针对这些问题提出了解决对策。     

臭氧氧化去除吐氏酸溶液COD的动力学研究

研究了臭氧氧化条件下，吐氏酸水溶液在鼓光反应器内的COD去除动力学，考察了pH值、温度、自由基抑制剂及进气口臭氧浓度等因素对反应的影响。结果表明：在pH=8左右时，COD去除效果较好；在17－30℃范围内，温度对反应影响不大；自由基抑制剂明显影响氧化效果，说明氧化过程是分子臭氧和其分解产生的自由基共同参与的结果；氧化降解效果与进气中臭氧浓度与正相关；臭氧氧化明显改善吐氏酸的生物降解性能，BOD5／COD可达0．18。研究表明：吐氏酸臭氧化的COD去除过程符合一级反应动力学。     

全程自养脱氮系统中氨氧化菌关键种群的变迁

全程自养脱氮是在高铵氮低溶氧条件下完全由自养菌群作用而将水中氮素脱除的现象。特异性扩增16SrDNA上的氨氧化菌特异的CTO基因片段,建立克隆文库并进行系统发育学分析,考察全程自养脱氮系统菌群驯化及退化过程中氨氧化菌的结构组成和其中关键种群的变迁,结果表明:在驯化过程中Nitrosospira属细菌和Nitrosomonas oligotropha细菌逐渐被能够耐受高氨氮低溶氧的Nitrosomonas europaea细菌所代替,后者可能是全程自养脱氮系统氨氧化步骤的主要参与者,而氨氧化菌的菌群演变可能并不是后来系统退化的原因。     

基因间隔序列(ITS)在细菌分类鉴定和种群分析中的应用

Use of 16S -23S intergenic transcribed spacer (ITS) variability, as a relatively new method, is becoming an important supplement to the molecular methods based on 16S rRNA for which has a fairly constant size and is not divergent enough to give good separation in close relationships. This paper summarizes the structures and characteristics of ITS regions that are extremely variable in copy number, length and sequence per genome. The ITS region can be amplified easily taking advantage of conserved nucleotide stretches at the 5′of the 16S and 3′of the 23S gene, and the amplicon can contain different amounts of the 16S rDNA by choosing primers at different conserved areas within this gene. These primers are listed and discussed for perfecting the methodology of ITS. Furthermore, some recent progresses on the taxonomy, identification and community analysis of bacteria by means of ITS in epidemiology, ecology and artificial environment are reviewed, as well, the virtues and limitations of that method are discussed. Fig 2, Tab 1, Ref 51