Titanium dioxide mediated photocatalytic degradation of 17beta-estradiol in aqueous solution

Photocatalytic degradation of 17beta-estradiol (E2) in aqueous medium mediated with titanium dioxide (TiO(2)) was studied. Moreover, effect of TiO(2) dosage on the degradation efficiency was investigated. Particular attention was paid to the identification of intermediates and analysis of photocatalytic degradation mechanism of E2 under neutral and alkaline conditions. The degradation efficiency of E2 increased with increasing concentration of TiO(2) but decreased due to light scattering as TiO(2) concentration was greater than 0.5mgml(-1). Several intermediates were formed during photocatalytic degradation of E2. However, only a few of the compounds could be identified and confirmed by LC-MS and LC-MS/MS. Six intermediates were observed by photocatalytic oxidation under alkaline conditions, namely 2-hydroxyestradiol, 10epsilon-17beta-dihydroxy-1,4-estradien-3-one (DEO), 10epsilon-hydroperoxide-17beta-hydroxy-1,4-estradien-3-one and three kinds of dicarboxylic acids formed by the opening of aromatic ring. In addition to the six intermediates mentioned above, 17beta-hydroxy-1,4-estradien-3-one (EO) was observed under neutral conditions and in the presence of methanol. Based on these intermediates, which were hardly degraded even after E2 was fully degraded, the mechanism of E2 degradation by TiO(2) photocatalysis was elucidated.     

柴油在土壤中迁移的试验模拟研究

通过土柱模拟试验研究了0#柴油在不同类型的土壤(壤土、砂土)中分别以连续和间歇方式入渗的渗流特征.结果表明:柴油在壤土中的入渗速率小于砂土;相同类型的土壤中,连续入渗的速率大于间歇入渗;柴油饱和溶液入渗条件下,绝大部分的柴油集中在深度小于25 cm的土层里,只有在连续入渗砂土情况下,大量的柴油迁移到了35 cm深度的土层;柴油以无水液流态(NAPL)间歇入渗条件下,壤土和砂土中各土层的柴油质量比与土层深度服从相应的负指数关系.通过对比静态吸附的结果,发现迁移过程中存在吸附、截留和生物降解作用等.     

石油化工储罐特性重要度的确定及应用研究

在计算石油化工储罐火灾扑救所需的消防力量时,引入储罐特性重要度的概念。通过分析影响石油化工储罐特性重要度的各个因素以及因素间的相互联系,构建了较合理的储罐特性重要度评价指标体系,并利用层次分析和多级模糊评价相结合的方法,确定储罐特性重要度系数。应用研究表明,在计算石油化工储罐火灾所需消防资源时,应考虑到储罐特性重要度对资源需求的影响。储罐特性重要度越大,对消防资源的需求就越大,在储罐发生火灾时调集的消防力量就越多。储罐特性重要度的确定为消防指挥员在扑救石油化工储罐火灾时调集合理的消防力量,提供了科学的决策依据。     

基于复杂性认识的安全木桶模型探讨

认为安全系统是一个复杂的社会技术系统,描述了安全系统的复杂性特征:安全系统特别复杂,由相互依赖多个子系统组成,具有非线性、高度动态性、开放性和相互作用性,安全系统涉及多重反馈过程,包含软硬数据信息,并对安全政策和措施具有抵制性。借鉴传统木桶理论,利用耗散结构理论中安全熵的有关概念,探索性地建立安全木桶模型,分析了安全木桶的组成部件和功能效用。进而结合本质安全型煤矿建设,从员工素质、技术装备、作业环境和安全管理4个方面讨论了该模型的适用性,并针对本质安全型煤矿建设给出了相应建议。     

Adsorption of Acid Red 73 on copper dithiocarbamate precipitate-type solid wastes

Three solid wastes, copper N,N'-bis(dithiocarboxy)piperazine ([CuBDP](n)), copper diethyldithiocarbamate (Cu(DDTC)(2)) and copper dimethyldithiocarbamate (Cu(DMTC)(2)), were prepared and tested as adsorbents to remove Acid Red 73 from wastewater. It was found that the three precipitates all could effectively adsorb the dye but their adsorption abilities were rather different. The maximum adsorption amounts of the coordination polymer precipitate [CuBDP](n) reached as high as 364mg g(-1), much greater than those of Cu(DDTC)(2) and Cu(DMTC)(2) (42.9 and 37.8mg g(-1), respectively). The investigation of adsorption models showed these adsorption processes followed the pseudo-second-order kinetic equation and the adsorption balances could be described with both Langmuir and Freundlich isotherms, but the latter seemed to be more suitable. Their adsorption nature was inferred to be physical adsorption and mainly depended on the hydrophobic interaction between these precipitates and Acid Red 73. This is the first example for the reutilization of metal dithiocarbamate precipitates as solid wastes to date.     

中国循环经济基本法立法架构研究

循环经济基本法立法架构的好与坏，不仅关系循环经济基本法的制定与出台，而且影响循环经济基本法的理解和执行。基于此。就循环经济基本法立法架构展开了综合研究，以期有助于中国循环经济基本法的制定与执行。在比较研究国外循环经济基本法立法架构与综合分析中国循环经济基本法立法架构研究现状的基础上，深入探讨中国循环经济的基本内涵以及中国循环经济基本法的基本定位与基本内容，进而提出一种新的中国循环经济基本法立法架构。从目前实践看，中国特色循环经济的内涵可以概括为是对生产和消费活动中物质能量流动方式的管理经济。中国循环经济建设应该从适度生产系统、适度消费系统和回收利用系统三个环节着手。根据经济基础决定上层建筑的基本原理，中国循环经济基本法作为一部环境友好型经济法以及具有一定强制性与制裁性的促进法，应当按照适度生产-适度消费-回收利用这条主线进行立法架构。     

An accelerated solvent extraction and gas chromatography-flame ionization detector method to rapidly determining and assessing total petroleum hydrocarbon contamination in soil from Fushan oilfield,China

Environmental Science and Pollution Research - A high-efficient method for determining the total petroleum hydrocarbon (TPH) was established by gas chromatography-flame ionization detection,...     

公钥基础设施(PKI)应用中的信任问题与安全解决方案

详细论述受信证书链的替换原理、方法和过程,及其引发的用户错误受信问题。通过分析得到安全证书链的长度为小于3,但由于实际应用的业务需要和安全性需要,证书链的长度通常至少为3。最后针对上述问题给出了一种安全解决方案,通过结合存储用户个人证书的USBKEY硬件设备,采用物理信任点代替逻辑信任点来防止受信证书的替换,为用户构建安全可靠的网络信任环境。     

中小城市污水处理厂设计中应注意的几个问题

针对当前中小城市污水处理厂设计中存在的厂址选择不合理、处理工艺盲目求新求变、设备选择不切合实际等问题进行探讨，结合已建成污水处理厂运行实际进行分析，提出优化厂址选择、结合当地实际选择处理工艺、根据需要选择设备等解决问题的办法。     

枣庄市水体污染现状及治理对策研究

对枣庄市水体环境污染现状进行了简要分析，对7条主要河流水质现状进行比较，运用指数平滑预测模型、灰色预测模型以及组合预测模型等三种预测分析方法对2010年枣庄市水环境污染状况进行了预测，在借鉴国外水污染治理成功经验的基础上，根据枣庄市水污染现状和成因，按照系统性、可持续发展、统一规划、分期实施的原则，研究了枣庄市水环境污染综合治理对策，提出从观念技术创新（发展循环经济等）、体制机制改革（进行水资源管理体制改革等）、公共财政投入（工程设施、资金保障等）等方面进行枣庄市的城市水环境污染的治理工作。