高温高压高含CO2环境下两种氟橡胶密封可靠性评价

目的 研究两种氟橡胶O型圈在总压为25 MPa,CO2体积分数为5%,温度为120 ℃,液相介质Cl^?质量浓度为7000 mg/L的高温高压高含CO2工况下的密封可靠性。方法 通过高温高压釜模拟井下实际工况,采用自研橡胶O型圈密封装置实现试样的承压状态,以物理性能、腐蚀形貌和抗渗透性能为考察指标,对两种氟橡胶O型圈的耐蚀性能和密封性能进行测试评价。结果 氟硅橡胶O型圈在承压状态下腐蚀后,拉伸强度由18.1 MPa下降为13.4 MPa,拉断伸长率由172.8%下降为151.9%。AFLAS橡胶O型圈在承压状态下腐蚀后,拉伸强度由21 MPa下降为14.6 MPa,拉断伸长率由277%下降为212.3%,硬度从84HA下降为75.5HA,表面破损严重。两种橡胶O型圈抗渗透性能随压差增大、温度上升而减弱。结论 承压状态下,两种橡胶O型圈性能衰减程度低于自由状态,氟硅橡胶O型圈在承压状态下表现出更好的密封可靠性。     

Estimation of primary drainage three-phase relative permeability for organic liquid transport in the vadose zone

The modeling of transport of organic liquid contaminants through the vadose zone often requires three-phase relative permeabilities. Since these are difficult to measure, predictive models are usually used. The objective of this study is to assess the ability of eight common models to predict the drainage relative permeability to oil in a three-phase system (water-oil-air). A comparison of the models' estimates using data set from Oak [Oak, M.J., 1990. Three-phase relative permeability of water-wet Berea. In: Seventh Symposium on Enhanced Oil Recovery, Paper SPE/Doe 20183. Tulsa, OK, April 22-25] showed that they provide very different predictions for the same system. The goodness of the models does not increase with the amount of data or computation that the models require. Also, the calculations showed how different interpretations of the models and of the terminology associated with them can significantly impact the predictions. Thus, considerable error may be introduced into the simulations of organic liquid transport in the vadose zone depending on the selection and interpretation of the three-phase relative permeability model.     

电子去离子净水技术

概述了EDI净水技术的发展历程、原理、组件型式与性能     

超声振动强化膜分离过程机理的研究

膜分离过程中的浓差极化现象是影响膜分离效果的主要因素之一 ,本文探索了利用超声振动的方法来强化膜分离反应过程。首先建立了其动力学模型 ,然后通过试验对其强化机理进行了深入的探讨 ,以达到经济、高效地提高膜分离效果的目的。     

How accurately do semi-permeable membrane devices measure the bioavailability of polycyclic aromatic hydrocarbons to Daphnia magna?

Semi-permeable membrane devices (SPMDs) are passive samplers that have been designed to sample the bioavailable fractions of hydrophobic organic compounds in aquatic ecosystems. This study aims at evaluating the ability for SPMD to sample polycyclic aromatic hydrocarbons (fluoranthene, pyrene and benzo[a]pyrene) that are actually bioavailable to Daphnia magna. For that purpose, the SPMD-available fraction and the bioavailable fraction to D. magna are compared in controlled media with Dissolved Organic Matters (DOMs) from various origins and at different concentrations. The presence of all but one DOM reduces the accumulation of PAHs in SPMD or in D. magna. Moreover, this comparative laboratory study shows that in 10 cases on 13, the SPMD-available fraction is close to the available fraction to D. magna. When significant differences are observed between SPMD-available and bioavailable fractions, they remain less than 50% at DOM concentrations below 10 mg/l DOC, which corresponds to a maximum DOC concentration usually found in temperate rivers. This study confirms the suitability of the SPMD technique to monitor readily bioavailable hydrophobic contaminants in aquatic environments containing DOM from various origins and characteristics.     

Lipophilicity and Metabolic Route Prediction of Imidazolium Ionic Liquids * (6 pp)

- Aims and Background. Ionic liquid application in industry will offer several excellent solutions, but it also means that they will enter the environment sooner or later. Responsible product design should always take into consideration not only technological demands, but also the risks arising out of possible toxicity and ecotoxicity. In our strategy we are aiming to understand the fate of these entities through their life cycle in the environment as a complimentary element of their design. This paper presents results on the lipophilicity of selected imidazolium ionic liquids, a parameter that plays a key role in environmental and biological distribution. Additionally, the prediction of the most stable metabolite of a 1-butyl-3-methylimidazolium (BMIM) cation – a congener representative of this group of compounds is presented. Materials and Methods Lipophilicity was evaluated by means of reversed phase and immobilized artificial membrane chromatography and further compared to calculated data. Theoretical prediction of lipophilicity was undertaken using fragmental methodology combined with manual calculations of the geometric bond factor for quaternary ammonium and the electronic bond factor due to the presence of a charge. Results and Discussion All the substances studied are characterized by very low partition coefficients, and lipophilicity varies linearly with elongation of the n-alkyl chain. Prediction of metabolic routes was based solely on thermodynamic data of the radical intermediates formed during the reaction with the cytochrome P450 system. The energetically most stable radical structure is generated by hydrogen abstraction from the gamma position of the BMIM cation. Conclusions and Recommendations. The experimentally measured and theoretically estimated lipophilicity coefficients obtained for all the compounds studied generally indicate a relatively low lipophilicity and thus preferable partition to the aqueous phase. By means of thermodynamic data, it was also confirmed that the energetically most stable radical structure is generated by hydrogen abstraction from the gamma position on the alkyl chain in the 1-alkyl-3-methylimidazolium cation, as a result of which the C1 atom is preferentially oxidized. - * 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.     

生物膜/悬浮生长强化处理城市污水研究

采用生物膜与悬浮生长强化处理工艺,提高了高负荷生物滤池后续活性污泥的抗冲击负荷和可生化性.综合了生物滤池与活性污泥法各自的优越性,提高了处理效果.     

膜生物反应器处理高氨氮废水

试验采用MBR处理高氨氮废水,重点分析了氨氮、有机物的去除以及膜比通量变化等。结果表明,工艺运行稳定,出水氨氮平均浓度低于3mg/L,MBR能够抵抗有机物冲击负荷,氨氮容积负荷可以达到1.11kgNH3-N/(m3·d)。在整个运行期间膜比通量下降比较缓慢,分析认为是高曝气量、低碳氮比以及自养菌的优势生长起了主要作用。     

植物酶膜萃取-气相色谱分析水体中痕量有机磷农药

建立了植物酶膜萃取 气相色谱分析水体中痕量有机磷农药的方法 .实验表明 ,选用精面粉作为酶源并用纯水萃取所得的植物酶最为合适 .乐果、对硫磷和甲基对硫磷三种有机磷农药的检测限为 0 1 μg·l- 1;多次测定三种农药的加标回收率均达70 %以上 .