Isolation and identification of 3-bromocarbazole-degrading bacteria

In this study, a bacterial strain, CH-1, capable of degrading 3-bromocarbazole (3-BCZ) was isolated from a polluted soil. Based on its physio-biochemical characteristics and 16S rRNA genes, strain CH-1 was identified as a Stenotrophomonas sp. Strain CH-1 was able to degrade 70% of 50 mg/L 3-BCZ within 8 d at pH 7.0 and 30°C in mineral salt medium (MSM). During the process, the main intermediate metabolite was identified as (2E, 4Z)-6-(2-amino-5-bromophenyl)-2-hydroxy-6-oxhexa-2, 4-dienoic by gas (2E, 4Z)-6-(2-amino-5-bromophenyl)-2-hydroxy-6-oxhexa-2,4-dienoic via gas chromatograph-mass spectrometry (GC-MS) analysis. The metabolite disappeared after 14 d, suggesting that the metabolite can also be degraded by strain CH-1. 3-BCZ is a new persistent organic pollutant. This is the first report of the biodegradation of 3-BCZ. The results indicated that strain CH-1 may be a promising bacterial candidate for the bioremediation of environments polluted with polyhalogenated carbazoles (PHCs).     

超声萃取气相色谱法测定植物样中邻苯二甲酸酯

建立了二氯甲烷超声萃取、氧化铝柱层析分离、带电子捕获毛细管气相色谱测定植物样品中痕量邻苯二甲酸酯(PAEs)的方法.方法具有较好的精密度(RSD≤10%)、较低的检测限(MDLDBP=0.4ng·g-1,MDLDEHP=0.5ng·g-1)和较高的回收率(RDBP=87.3%,RDEHP=92.1%).用该法测定了太湖沉水植物中的PAEs含量,其中DBP在0.009-0.013μg·g-1,DEHP在0.026-0.106μg·g-1.     

玄武湖菹草种群的发生与水环境变化

于2005年11月-2006年4月对玄武湖菹草种群进行了采样分析,并对其发生过程中的水环境质量进行了跟踪监测.结果表明,玄武湖菹草种群发生过程中,湖区水质有明显改善,湖水透明度增加,主要监测指标TN、TP质量浓度值下降.指出,在湖区维持一定量的菹草,对湖泊在冬春季的水环境质量的改善以及生态系统的平衡与健康方面具有重要意义.提出解决湖泊环境问题的根本途径是修复重建健康水生态系统.     

空气质量监测中现场空白测定方法探讨

探讨了空气质量监测中现场空白的测定方法,通过对封口的现场空白与实验室对白比对及采样过程现场空白吸收管开口与封口对照试验,认为采样时应对现场空白吸收管作封口处理,才能体现现场空白的真实性。     

Chlorinated, brominated, and perfluorinated compounds, polycyclic aromatic hydrocarbons and trace elements in livers of sea otters from California, Washington, and Alaska (USA), and Kamchatka (Russia)

Concentrations of organochlorine pesticides (DDTs, HCHs, and chlordanes), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), perfluorinated compounds (PFCs), and 20 trace elements were determined in livers of 3- to 5-year old stranded sea otters collected from the coastal waters of California, Washington, and Alaska (USA) and from Kamchatka (Russia). Concentrations of organochlorine pesticides, PCBs, and PBDEs were high in sea otters collected from the California coast. Concentrations of DDTs were 10-fold higher in California sea otters than in otters from other locations; PCB concentrations were 5-fold higher, and PBDE concentrations were 2-fold higher, in California sea otters than in otters from other locations. Concentrations of PAHs were higher in sea otters from Prince William Sound than in sea otters from other locations. Concentrations of several trace elements were elevated in sea otters collected from California and Prince William Sound. Elevated concentrations of Mn and Zn in sea otters from California and Prince William Sound were indicative of oxidative stress-related injuries in these two populations. Concentrations of all of the target compounds, including trace elements, that were analyzed in sea otters from Kamchatka were lower than those found from the US coastal locations.     

环保-气象深度联合开展环境空气质量预报的探索

简述了湖南省环保-气象合作联合开展环境空气质量预报的方向和具体内容,提出了两部门合作的原则和路径。认识方面——统一认识,合作共享;业务方面——发挥优势,做好接力;保障方面——夯实基础,同步推进;服务方面——引导公众,服务决策。两部门合作,有利于提高预报结果的准确率。     

8-羟基喹哪啶固相萃取光度法测定生物样品中的钴

研究了8-羟基喹哪啶与钴的显色反应,在pH为8.0的氯化铵—氨水缓冲介质中,乳化剂-OP存在下,8-羟基喹哪啶与钴反应生成3∶1稳定的蓝紫色配合物,该配合物可被Waters Plus-C18固相萃取小柱萃取富集,小柱上富集的配合物用乙醇为洗脱剂洗脱后用光度法测定,在乙醇介质中,配合物最大吸收波长λmax为595 nm,ε为7.82×103L.mol-1.cm-1。钴含量在0.1~5.0 mg/L内符合比耳定律,方法用于生物样品中痕量钴的测定,结果令人满意。     

Kinetic and isotherms studies of phosphorus adsorption onto natural riparian wetland sediments: linear and non-linear methods

Riparian wetlands provide critical functions for the improvement of surface water quality and storage of nutrients. Correspondingly, investigation of the adsorption characteristic and capacity of nutrients onto its sediments is benefit for utilizing and protecting the ecosystem services provided by riparian areas. The Langmuir and Freundlich isotherms and pseudo-second-order kinetic model were applied by using both linear least-squares and trial-and-error non-linear regression methods based on the batch experiments data. The results indicated that the transformations of non-linear isotherms to linear forms would affect the determination process significantly, but the non-linear regression method could prevent such errors. Non-linear Langmuir and Freundlich isotherms both fitted well with the phosphorus adsorption process (r ²?>?0.94). Moreover, the influences of temperature and ionic strength on the adsorption of phosphorus onto natural riparian wetland sediments were also studied. Higher temperatures were suitable for phosphorus uptake from aqueous solution using the present riparian wetland sediments. The adsorption capacity increased with the enhancement of ionic strength in agreement with the formation of inner-sphere complexes. The quick adsorption of phosphorus by the sediments mainly occurred within 10 min. The adsorption kinetic was well-fitted by pseudo-second-order kinetic model (r ²?>?0.99). The scanning electron microscopy (SEM) and Fourier transformation infrared (FT-IR) spectra analyses before and after phosphorus adsorption revealed the main adsorption mechanisms in the present system.     

膨胀石墨在环境污染治理中的应用

膨胀石墨是一种新型的多孔碳质吸附材料.它具有发达的孔结构,对于大分子的物质具有超大的吸附能力.膨胀石墨作为新型纳米功能材料,广泛应用于石油、化工、冶金、机械和环保等领域.在概述膨胀石墨的吸附性能和机理的基础上,介绍了其在海洋溢油污染、水中微量油污染、印染废水和有毒气体治理等方面的应用,并对膨胀石墨的最新合成方法和应用发展趋势进行了展望和预测.     

氮肥、磷肥、粉煤灰和CaCO3对As(Ⅲ)胁迫下小麦幼苗生物效应及成熟期籽粒As含量的影响

采用盆栽的方法,研究了在As污染土壤中施加氮肥、磷肥、粉煤灰和CaCO3对小麦籽粒萌发、幼苗生理及成熟期籽粒w(As)的影响,并探讨了4种改良剂对在As污染土壤上种植小麦的有效改良方法.结果表明:适量的氮肥、磷肥、粉煤灰和CaCO3对As污染土壤的小麦萌发和幼苗生长具有明显的促进作用,能有效缓解As对小麦的毒害,并降低成熟期籽粒的w(As).表现为出苗率、幼苗株高、植株鲜重增大,w(叶绿素a)升高,丙二醛(MDA)含量和w(游离脯氨酸)下降,成熟期籽粒的w(As)降低.