降解菌JQL4-5甲氰菊酯水解酶的提取及酶学特性研究

Sphingomonas sp.JQL4-5是一株甲氰菊酯降解菌。提取该菌株的甲氰菊酯水解酶,对其酶学特性进行了初步研究。该酶水解甲氰菊酯的最适pH值为7.0,最适温度为30℃,供试的金属离子均对酶活性有一定的抑制作用,抑制率与金属离子的浓度呈正相关,其中Ag+的抑制作用最强烈,几乎可以导致酶活性完全丧失。该酶在极性有机溶剂中比在非极性的有机溶剂中稳定。     

Study of 4-t-octylphenol degradation and microbial community in granular sludge

In this study, the authors have investigated the effects of various factors on both aerobic and anaerobic degradation of 4-t-octylphenol （4-t-OP） in granular sludge. In comparison, the aerobic degradation rate was much higher than that of anaerobic degradation. The optimal pH values for 4-t-OP degradation in granular sludge were 9 and 7 under aerobic and anaerobic conditions, respectively. And the degradation rate decreased with an increase in the initial 4-t-OP concentration. Addition of yeast extract or homologous compounds such as phenol also enhanced the 4-t-OP degradation, especially under the aerobic condition. To investigate the bacterial community in this study, the denaturing gradient gel electrophoresis （DGGE） method was applied, based on the primers, for the 16S rDNA V3 region of bacteria, γ-proteobacteria and bacillus were identified as the major species of sludge.     

Photocatalytic Production of Methane and Hydrogen Through Reduction of Carbon Dioxide with Water Using Titania Pellets

This paper presents an experimental study on employing a pellet form of catalyst in photo-reduction of carbon dioxide with water. Water was first absorbed into titania pellets. Highly purified carbon dioxide gas was then discharged into a reactor containing the wet pellets, which were then illuminated continuously for 65 hours using UVC lamps. Analysing the products accumulated in the reactor confirmed that methane and hydrogen were produced through photo-reduction of carbon dioxide with water. No other hydrocarbons were detected. Increasing the temperature in the reactor has showed little change on the amount of methane produced.     

固相微萃取-气相色谱法测定洗涤制品中二噁烷

本文采用顶空-固相微萃取-毛细管气相色谱联用技术测定了洗涤制品中二噁烷量,使用50μmPEG/树脂萃取头。顶空平衡温度为80℃,萃取时间为40min。使用石英毛细管柱:30m×0.32mm×0.4μmi.d.内壁涂有5%二苯基(95%)二甲基硅氧烷固定液。外标法定量,二噁烷测定结果的相对标准偏差(RSD)为9.33%;在0.35μg/g～120μg/g范围,色谱峰面积与质量浓度之间呈良好线性关系,线性相关系数(R)为0.9998;回收率为98.7%～102%。     

纺织品中有毒有害物质检测技术的研究现状

纺织品中有毒有害物质超标是纺织品顺利进出口的主要限制因素,而目前中国的检测技术在具体实施中仍存在许多问题。本文阐述了国内纺织品中主要的三类物质检测技术的发展现状,并针对常用检测方法提出一些建议。     

环境激素对叔辛基酚降解菌的筛选、鉴定及降解特性

为了研究环境激素4-t-OP(对叔辛基酚)的生物降解,从扬州市汤汪生活污水处理厂二沉池污泥中筛选得到1株能以4-t-OP为唯一碳源进行生长的降解菌株,标示为TW30,16S rRNA测试其为不动杆菌属(Acinetobacter sp.),通过摇瓶试验测试其降解活性.结果表明:在40℃、初始pH为6.0、ρ(4-t-OP)为5 mg/L的无机盐培养基中,5 d后降解率可达99.03%;降解过程满足一级反应模型,降解速率常数(k)为0.875 d-1,半衰期(t1/2)为0.8 d.这说明TW30是一株高效的4-t-OP降解菌.此外,培养温度的升高和额外Ca2+、Mn2+的加入可以提高TW30降解4-t-OP的效率,而在5～25 mg/L范围内提高初始ρ(4-t-OP)以及额外加入磷酸盐、NH4+、Mg2+、Fe2+、Na+、Zn2+、Cu2+等无机盐和葡萄糖、CH3COO-等碳源则会降低降解率.      

Effects of temperature on UV-B-induced DNA damage and photorepair in Arabidopsis thaliana

DNA damage in the form of cyclobutane pyrimidine dimers(CPDs) and (6-4) photopreducts(6-4PPs) induced by UV-B radiation in Arabidopsis thaliana at different temperatures was investigated using ELISA with specific monoclonal antibodies. CPDs and 6-4PPs increased during 3 h UV-B exposure, but further exposure led to decreases. Contrary to the commonly accepted view that DNA damage induced by UV-B radiation is temperature-independent because of its photochemical nature, we found UV-B-induction of CPDs and 6-4PPs in Arabidopsis to be slower at a low than at a high temperature. Photorepair of CPDs at 24℃ was much faster than that at 0℃ and 12℃,with 50% CPDs removal during 1 h exposure to white light. Photorepair of 6-4PPs at 12℃ was very slow as compared with that at 24℃,and almost no removal of 6-4PPs was detected after 4 h exposure to white light at 0℃. There was evidence to suggest that temperaturedependent DNA damage and photorepair could have important ecological implications.     

中国垃圾填埋场2012年甲烷排放特征研究

垃圾填埋场是全球重要的CH_4排放源。基于中国1955个垃圾填埋场基础数据和排放因子数据库,核算了中国2012年垃圾填埋场CH_4排放水平,同时分区域和分规模推荐了基于已填容量的计算模型。2012年中国垃圾填埋场的CH_4排放量为148.12万t,广东排放量最高,西藏排放量最低。华东地区的垃圾填埋场CH_4排放在7个区域中占全国排放比例最高,达到33.00%,西北地区排放占比最低,为8.76%;大型填埋场(I类)CH_4排放占总排放比例达45.88%。中国垃圾填埋场CH_4排放在空间分布上具有较强的集聚性,北京-天津,上海-绍兴-宁波,广州-东莞-深圳-清远构成了中国垃圾填埋场CH_4排放的三大核心区域。垃圾填埋场单位已填容量的CH_4排放水平在0.86~1.83 kg/m~3。     

超临界水氧化处理分散染料废水中含氮有机物的实验研究

采用H2O2为氧化剂,在连续蒸发壁式反应器中进行了超临界水氧化降解分散染料废水的实验.结果表明:超临界水氧化技术处理分散染料废水时,TOC的去除效果优于TN的去除效果.在25 MPa,380～460℃的条件下,短短30s的时间内,TOC去除率可达到90%以上,而TN去除率却只有45%～60%.随着温度和压力的升高以及氧化剂用量的增加,废水中TN浓度随之下降而NH3-N浓度却随之升高.     

天然水中痕量磷酸根、亚砷酸根和砷酸根的浮膜分光光度法测定

本文研究了孔雀绿与磷（砷）酸钼的离子对膜的形成条件。并依此与共存元素分离，进行痕量磷酸根、亚砷酸根和砷酸根的浮膜分光光度法测定。选用硫酸为介质，考察了25种共存离子对测定的影响。拟定了天然水中痕量磷酸根、亚砷酸根和砷酸根的分析方法．操作简便，结果令人满意。