十溴联苯醚降解菌的特性及功能蛋白初步分析

筛选获得了1株对十溴联苯醚(BDE-209)有较好降解效率的菌株,经16S rRNA基因序列分析,初步鉴定为铅黄肠球菌(Enterococcus casseliflavus).该株菌最适培养条件为培养基初始pH 7,培养时间48 h.E.casseliflavus对BDE-209有较好的降解效果,在含有5 mg·L-1葡萄糖的降解体系中,1 g·L-1菌体处理1 mg·L-1BDE-209,4 d时降解率达到最大(56.7%).SDS-聚丙烯酰胺凝胶电泳实验结果表明,在E.casseliflavus降解BDE-209的过程中,2 mg·L-1与5 mg·L-1的BDE-209可诱导菌体生成某类新的胞外蛋白,而胞内蛋白则随着BDE-209含量的增加,表现为蛋白表达量的增减以及受BDE-209抑制而不表达某些蛋白质.双向电泳实验结果检测到31个差异点,表明在降解时菌体中与降解相关的蛋白构象发生了变化,导致蛋白种类和含量变化.     

多级联合处理二甲基二硫醚生产废气

对二甲基二硫醚生产过程中产生的含硫有机恶臭气体采用冷冻回收、氧化吸收、吸附净化等方法进行联合处理 ,该废气处理方法建设周期短 ,投资小 ,见效快 ,具有较好的经济效益 ,两年内即可收回全部投资。实施运行后 ,大大改善了厂内及其周边大气环境。     

生物滤池-接触氧化工艺处理醇醚表面活性剂废水

介绍抚顺醇醚化学厂醇醚生产废水的排放与水质特点 ,结合工艺流程介绍处理工艺设计和技术参数。几年来的运行结果表明 ,采用生物滤池 生物接触氧化 纤维球过滤三级工艺处理醇醚表面活性剂废水 ,处理效果良好 ,出水CODCr<10 0mg/L ,SS <15mg/L ,滤后水可用于厂区绿化。     

Biotic and abiotic transformations of methyl tertiary butyl ether (MTBE)

Background Methyl tertiary butyl ether (MTBE) is a fuel additive which is used all over the world. In recent years it has often been found in groundwater, mainly in the USA, but also in Europe. Although MTBE seems to be a minor toxic, it affects the taste and odour of water at concentrations of < 30 μg/L. Although MTBE is often a recalcitrant compound, it is known that many ethers can be degraded by abiotic means. The aim of this study was to examine biotic and abiotic transformations of MTBE with respect to the particular conditions of a contaminated site (former refinery) in Leuna, Germany. Methods Groundwater samples from wells of a contaminated site were used for aerobic and anaerobic degradation experiments. The abiotic degradation experiment (hydrolysis) was conducted employing an ion-exchange resin and MTBE solutions in distilled water. MTBE, tertiary butyl formate (TBF) and tertiary butyl alcohol (TBA) were measured by a gas chromatograph with flame ionisation detector (FID). Aldehydes and organic acids were respectively analysed by a gas chromatograph with electron capture detector (ECD) and high-performance ion chromatography (HPIC). Results and Discussion Under aerobic conditions, MTBE was degraded in laboratory experiments. Only 4 of a total of 30 anaerobic experiments exhibited degradation, and the process was very slow. In no cases were metabolites detected, but a few degradation products (TBF, TBA and formic acid) were found on the site, possibly due to the lower temperatures in groundwater. The abiotic degradation of MTBE with an ion-exchange resin as a catalyst at pH 3.5 was much faster than hydrolysis in diluted hydrochloric acid (pH 1.0). Conclusion Although the aerobic degradation of MTBE in the environment seems to be possible, the specific conditions responsible are widely unknown. Successful aerobic degradation only seems to take place if there is a lack of other utilisable compounds. However, MTBE is often accompanied by other fuel compounds on contaminated sites and anaerobic conditions prevail. MTBE is often recalcitrant under anaerobic conditions, at least in the presence of other carbon sources. The abiotic hydrolysis of MTBE seems to be of secondary importance (on site), but it might be possible to enhance it with catalysts. Recommendation and Outlook MTBE only seems to be recalcitrant under particular conditions. In some cases, the degradation of MTBE on contaminated sites could be supported by oxygen. Enhanced hydrolysis could also be an alternative. - * The basis of this peer-reviewed paper is a presentation at the 9th FECS Conference on 'Chemistry and Environment', 29 August to 1 September 2004, Bordeaux, France.     

DMMP对二甲醚层流预混火焰的影响研究

二甲醚(DME)作为可再生的清洁燃料,因为其优越的性能而越来越受关注,但与此同时其燃烧的安全性却容易被忽视。自蒙特利尔议定书以后,含磷化合物成为抑制碳氢化合物火焰最理想的卤代烷替代物,选取甲基磷酸二甲酯(DMMP)应用于二甲醚火焰,基于分层结构首次构筑了DME/DMMP详细化学反应机理。通过模拟研究发现,DMMP对DME层流预混火焰表现出与碳氢火焰同样明显的抑制作用。进一步进行火焰抑制机理分析,结果显示DMMP对DME层流火焰的抑制主要是因为PO_2和HOPO的循环反应促进了H和OH重组,同时得出DMMP对DME富燃火焰抑制更有效的结论。     

Synthesis and biological activities of new azacrown ether Schiff bases and spectrophotometric studies of their complexation with [60]fullerene

A series of novel azacrown ether Schiff bases 1–3 have been synthesized in good yield and in a simple way. Their host–guest interaction with [60]fullerene has been studied in toluene by absorption spectroscopic method. All the complexes are found to be stable with 1:1 stoichiometry. Because of their potential applications in industry, agriculture and medicine, they were investigated for their mutagenic and antimutagenic activities using the spot test and the plate incorporation assay of Ames. Compounds 1, 2 and 3 were found to be nonmutagenic in the Ames test using strains TA 1535, TA100 and TA97a of Salmonella typhimurium. However, using strain TA102 revealed that, although both compounds 1 and 2 were nonmutagenic, compound 2 gave a positive response indicating that it acts as an oxidative mutagen. The structure-activity relationship may throw some light on the biological activity of such series of compounds.     

Diffusion of polybrominated diphenyl ether (PBDE) from an e-waste recycling area to the surrounding regions in Southeast China

Using Cinnamomum camphora (C. camphora) leaves as biomonitors, we investigated that the diffusion of polybrominated diphenyl ethers (PBDEs) from an e-waste recycling area to the surrounding regions. Variance in ∑₃₂PBDEs concentrations (0.46–399.93 ng g⁻¹ dry weight) in the leaves showed that PBDEs from the e-waste recycling area diffused into the surrounding regions, and resulted in a halo of PBDEs contamination, at least 74 km in radius. The attenuation of ∑₃₂PBDEs in the diffusing process fitted in log-linear regression. The difference in the attenuating slopes of linear equations among different directions can be explained by terrain and wind direction. The attenuation of PBDE congeners also fitted well in log-linear regression. The findings that similar attenuating slopes and characteristic travel distance among congeners suggest that the transport behavior of lower brominated congeners might not differ from that of higher brominated congeners in short-range scale.     

An exposure study with polybrominated diphenyl ethers (PBDEs) in female European starlings (Sturnus vulgaris): toxicokinetics and reproductive effects

We exposed female European starlings to a pentabromodiphenyl ether (Penta-BDE) mixture through subcutaneous implants, and examined levels and profiles of polybrominated diphenyl ethers (PBDEs) together with reproductive effects. Sum PBDE levels increased significantly in the serum of the exposed females from 218 ± 43 to 23,400 ± 2035 pg/ml. Sum PBDE concentrations in the eggs of the exposed group ranged from 130 ± 12 to 220 ± 37 ng/g wet weight (ww). The profile in serum after egg laying was very similar to that in eggs. There were no detectable levels of HO-PBDEs in both serum and eggs. Fewer females of the exposed group initiated egg laying compared to the control group, although the difference was not significant. In addition, egg weight and volume were significantly higher in the exposed group. These results suggest that, at the investigated exposure levels (150 μg sum PBDEs/bird), PBDEs may have a negative effect on reproductive performance.     

Polybrominated diphenyl ethers in sediments of the Daliao River Estuary, China: levels, distribution and their influencing factors

The concentrations, compositional profiles, possible sources of polybrominated diphenyl ethers (PBDEs) in sediments of the Daliao River Estuary as well as the factors influencing the distribution of PBDEs were investigated. The total concentrations of PBDEs ranged from 0.13 to 1.98 ng g⁻¹ d.w. BDE209 was the dominating congener in all sediment samples, indicating the pollution of PBDEs in the Daliao River Estuary mainly came from the use of deca-BDE commercial mixtures. The intrusion of sea waters promoted the deposition of the colloid-associated PBDEs in the estuary. There were significantly negative correlations between PBDE concentration in sediment with pH value and salinity in the bottom water. The higher river flow in the flood season (summer) obviously accelerated the transport of PBDEs, and thereby increased the risk of PBDE contamination to the deep ocean. Moreover, a positive correlation between TOC and PBDE distributions was observed, suggesting that TOC regulated the distributions of PBDEs in sediments of Daliao River Estuary.     

高级氧化法处理甲基叔丁基醚的研究进展

综述了采用常规氧化、光强化氧化以及超声波辅助氧化等高级氧化技术降解甲基叔丁基醚（MTBE）的降解机理及研究进展。并介绍了MTBE与醚类、苯系物以及可吸附卤化物共存的复合污染物的氧化降解研究进展。指出今后研究的重点是利用光、声、电能量的摄入来降低氧化剂加入量,提高矿化程度以减少毒性较大的叔丁基团的含量,研发更易于固液分离、稳定性更高和寿命更长的高效催化剂及共存体系将是持续热点。