UV/Fenton氧化降解水溶液中甲基叔丁基醚的试验研究

采用UV／Fenton技术对污染水体中的甲基叔丁基醚（MTBE）进行了氧化降解试验。结果表明，在室温条件下，当H2O2为10mmol／L，FC＋为2mmol／L，pH为2．4时，起始摩尔浓度为1mmol／L的MTBE在30min内可去除99％；结果还显示了MTBE的降解分两个阶段，第一阶段是在UV／Fe^2＋／H2O2下的快速降解，第二阶段由于Fe^2＋的大量消耗而降解相对较慢。     

MTBE的降解研究进展

论述了目前国外进行MTBE污染物降解性能基础研究的进展,包括生物法、物理化学法、膜方法,并对它们做出了一定的评价,以期它们对国内研究起到指导作用。     

MTBE环境行为研究

综合评估了MTBE的环境行为,对MTBE的污染源、污染途径进行分析。MTBE在土壤中的不吸附性和极高的水溶性,使其正在成为一种持久的蔓延性地下水污染物。MTBE的污染源有点源和非点源。人体对MTBE的主要暴露途径为大气途径和水途径。     

Tools for an enhanced solvent properties screening in the early stages of pharmaceutical process development

The objective of this research was the implementation of tools for the evaluation of solvents trough property screening in the early stages of process development. An important feature of the tools is that the implementation of indexes, scores, or weights is avoided. Information already available from the literature was stored in a database in order to turn raw data into decision making information. As a result, a solvent radar chart, a solvent representation table, and a solvent telescopying tool were developed in an ASP.NET application. The synthesis of Propranolol was used as study case in order to explore the selection of solvents in the early stages of process development. The replacement of diethyl ether was possible in the extraction step, while solvent choices were detected for potential telescoping for extraction and crystallisation steps. Solubility was found as a critical parameter in telescoping analysis. The methodology proposed enhanced the view towards a more holistic perspective and a more robust solvent screening process. As a consequence, the next steps into solvent evaluation and process development can be reduced.     

吸附法处理甲基叔丁基醚污染物的研究进展

MTBE对地表水和地下水的污染已日益引起国内外的高度重视。对MTBE的性质、污染现状、处理技术及近年来国内外应用吸附法处理MTBE的研究进展作了一般综述,对分子筛、活性炭及吸附树脂这三种吸附剂对MTBE的吸附效果作了评述,对影响MTBE吸附效果的主要因素进行了讨论,并对吸附法处理MTBE的应用前景作了展望。     

MTBE与雌二醇对螺旋鱼腥藻的联合毒性

以螺旋鱼腥藻(Anabaena spiroides)为实验材料,采用每天测定数据,连续跟踪10d的方法,研究了甲基叔丁基醚(Methyl tert-buty1 ether,MTBE)与雌二醇对螺旋鱼腥藻的单一毒性以及在不同毒性单位配比下的联合毒性,选用毒性单位(TU)、相加指数(AI)、混合毒性指数(MTI)和毒性增大指数(TEI)进行联合毒性评价.结果表明,MTBE与雌二醇共存时,在实验周期(10d)内,其联合作用方式基本表现为协同作用.此外,MTBE和雌二醇的单一毒性和联合毒性数据随着培养时间的变化而产生剧烈变化,毒性数据在培养时间3～7d比较平稳,在4～5d最佳.     

甲基叔丁基醚（MTBE）降解菌株的分离鉴定及降解动力学研究

从银杏根部土壤中分离驯化出1株能以MTBE为唯一碳源生长的菌株A1,经过16S rDNA序列分析后,初步鉴定该菌株为睾酮丛毛单胞菌（Comamonas testosterone）;进一步试验研究了微生物接种量、pH值、温度、MTBE初始浓度等环境因素对MTBE降解的影响.结果表明,菌A1降解MTBE的最佳条件为：pH值7.0,温度25℃,接种量2　mL（D₆₀₀=2.523 A）,初始MTBE浓度50 mg/L.在此降解条件下,7　d后MTBE去除率最高可达98.89%（与空白实验对比,MTBE挥发量占46.55%）.菌A1降解MTBE符合高浓度底物抑制的酶促反应类型,其基本降解动力学参数rmax=0.872　d^－1,Km=7.832 mg·L^－１,Ks=130.75 mg·L^－１.     

Effect of methyl tert-butyl ether on adipogenesis and glucose metabolism in vitro and in vivo

Methyl tert-butyl ether(MTBE), as a widely used gasoline additive, is suspected of being environmentally toxic. MTBE accumulates mainly in adipose tissue, but its effect on obesity or obesity-related metabolic disorders has not been well understood yet. Therefore, we examined the effect of MTBE on the adipose function and the related metabolic processes with both 3T3-L1 cell line and C57 BL/6 J mice model. We found that exposure to MTBE at the environmental relevant concentration(100 μmol/L) could significantly induce differentiation of preadipocyte and disturb insulin-stimulated glucose uptake of mature adipocyte.The in vivo observation in male mice showed a positive correlation of visceral white adipose tissue(vWAT) expansion and cell size increase with MTBE treatment in 14 weeks. Glucose tolerance and insulin sensitivity tests demonstrated that MTBE at 1000 μg/(kg·day)disturbed the systemic glucose metabolism in a gender-specific manner, which might be partly attributed to the alterations of gut microbiota community at genus level with respect to Akkermansia, Clostridium XlVb, and Megamonas. In summary, our study characterized the effect of MTBE on adipose tissue function and glucose homeostasis in vitro and in vivo, and revealed that systemic disorders of the glucose metabolism might be modulated by the related gut microbiota.     

甲基叔丁基醚(MTBE)的环境毒理学研究进展

甲基叔丁基醚(MTBE)作为一种新型的无铅汽油添加剂被广泛应用以减少含铅汽油对空气的污染。简要介绍了MTBE的理化性质和MTBE的急性毒性、代谢、生殖、遗传毒性,就其对环境的污染以及其防治作了综述,指出了我国开展MTBE有关研究的重要性。     

珠江三角洲大气中甲基叔丁基醚的污染特征研究

应用先进的大气采样罐、大气样品预浓缩技术和气相色谱/质谱联用仪器,采取长期观测和加强观测方法详细地研究了珠江三角洲大气环境中MTBE的污染浓度水平及其时空分布特征.结果表明,①目前该地区的工业区、交通区以及居住、商业和交通混合区等大气环境中普遍能够检测出MTBE污染物,长期观测的小时浓度均值变化范围从0～1.250 μg·m^-3,夏季污染较冬季更为严重,高浓度的MTBE污染物主要集中在城区,郊区显著受到上风向城市和周边城市污染源排放的影响.②夏季加强观测期间,广州市区的日均浓度为(1.520±0.370) μg·m^-3,约为其下风向郊区花都测点的7倍和清洁区从化监测点的100倍.城区呈现早晚2个污染物浓度峰值,夜间为平均浓度最低值时段,而郊区夜间反而出现高浓度峰值.③冬季加强观测期间,广州市城区的日均浓度为(0.950±0.240) μg·m^-3,为其下风向郊区新垦测点的3.6倍,出现多个峰谷,城区在18:00～22:00点均具有较高的污染物浓度,郊区则在次日的04:00～10:00点具有相对较高的污染物浓度.④在光照比较弱的时段市区交通干线附近的大气MTBE浓度随着距地面高度增加而降低,而在光照比较强的时段则随着距地面高度增加反而有所上升,反映出市区近地面大气MTBE污染物除了主要来自机动车尾气排放之外,还有明显的大气光化学反应生成的二次污染物来源.