基于高铁酸钾同步氧化-絮凝技术在污水处理中的研究进展

Fe(Ⅵ)具有较高的氧化还原电位,Fe(OH)3具有良好的絮凝效果,废水处理中高铁酸钾发挥同步氧化和絮凝作用。介绍高铁酸钾处理各种难降解废水的机理,同时分析高铁酸钾投加量、pH、反应温度、反应时间等因素对各种废水去除效果的影响。并提出基于高铁酸钾同步氧化絮凝技术处理污水的局限性和未来的发展方向。     

混合气体直接吸附分离回收过程研究

以精密陶瓷制造过程中排放的甲苯和异丙醇混合气体为目标气体,采用4段活性炭吸附柱串联吸附实验方式研究了混合组分气体直接吸附分离回收的可行性.结果表明,异丙醇和甲苯这2种物性具有一定差异的物质在吸附床的长度方向存在明显的分层吸附现象.在表观气速0.42 m·s-1、异丙醇与甲苯入口浓度分别为477 mg·m-3和746 mg·m-3、吸附柱总长为26cm条件下,通气吸附798 min时,0～10 cm长度段炭层吸附甲苯量为184.5 mg·g-1,吸附异丙醇量为0 mg·g-1,而21～26 cm长度段炭层吸附甲苯量为0.92 mg·g-1,吸附异丙醇量为91.2 mg·g-1,通过分段再生回收分别得到了纯度99%以上的甲苯和异丙醇回收液.弱吸附质异丙醇在吸附过程中存在气相浓度增浓现象,该现象导致实验条件下部分活性炭层区域对异丙醇的吸附量提高了27%以上.通过多段串联吸附、分段再生回收的方式可以实现混合气体的直接吸附分离回收.     

环境因子对胡敏酸介导下SDZ光解行为的影响

研究了在纯水条件及两种不同来源胡敏酸（HA）介导下,磺胺嘧啶（SDZ）和水稻土胡敏酸（SDHA）、泥炭土胡敏酸（NTHA）的不同浓度、pH值、光敏离子（NO₃^-和Fe³⁺）、离子强度（NaCl）以及金属离子（Ca²⁺、Mg²⁺和K⁺）等环境因子对SDZ紫外光降解的影响.结果表明：光照下,pH=7.1对两种体系的SDZ光降解有促进作用且效果最好.低SDZ浓度（2mg/L）以及低HA浓度（15mg/L）条件下使SDZ光解速率较快.光敏离子中NO₃^-通过光生·OH,促进了纯水中SDZ的光解,但在HA体系中,HA具有猝灭·OH的效应造成SDZ的光解速率低于纯水;Fe³⁺在HA体系下均表现为抑制作用,且抑制强度为NTHA>SDHA.在纯水中SDZ的光解速率随NaCl浓度增加而增加,HA介导下,较低浓度NaCl（C_NaCl=50mmol/L）抑制作用较强.金属离子（K⁺、Ca²⁺和Mg²⁺）在纯水中对SDZ的光解影响程度较弱,但在HA体系中均表现为抑制作用,抑制强度为K⁺ > Ca²⁺ > Mg²⁺,单价阳离子对SDZ光降解影响较为明显.     

大型电子设备机架气流分解方法研究

目的研究分析一种分解大型电子设备机架风冷气流条件的方法。方法以温差和Nu数作为描述传热效果的参数,使用相似对流的方法,使分解夹具中模块两侧的气流传热效果等效于大型机架中模块两侧的气流传热效果。结果气流在分解后,其在分解夹具中的冷却效果等效于分解前其在大型机架中的冷却效果。结论该分解方法能够有效地进行风冷气流条件分解,可以应用于实际工程。     

Purification and Properties of a Poly (β-hydroxybutyrate) Depolymerase From Penicillium sp.

An extracellular poly (β-hydroxybutyrate) (PHB) depolymerase was purified from a Penicillium sp. DS9701-09a by centrifugation, ultrafiltration, precipitation and gel filtration chromatography. The specific activity of the purified enzyme was 37.9-folds higher than that of the culture supernatant and the recovery yield was 11.8%. The PHB deploymerase molecular mass was 44.8 kDa from analysis of both Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Matrix-assisted laser desorption-time-of-flight (MALDI-TOF) mass spectrometer. The isoelectric point of 6.7 for the enzyme was determined by a two-dimensional electrophoresis. The optimum enzyme activity was observed at a temperature of 50 °C and pH 5.0. The apparent K _m of the enzyme was found to be 1.35 mg/mL. The PHB depolymerase consisted of 16 kinds of normal amino acids. The secondary structure of the enzyme was determined by CD spectrum. α-helix and β-turn were found to be 66% and 34% for the enzyme without ammonium sulphite. Chemical inhibition on the PHB depolymerase activity was examined and EDTA was found to have a significantly inhibitory effect.     

我国宏观环境决策的若干问题

本文针对国内外宏观环境决策中存在的问题,阐述了以科学研究为基础的宏观环境决策支持系统的作用,分析了决策观点和思维的多样性对宏观环境决策的意义,探讨了宏观环境决策与环境基础学科建设的关系。     

水资源可持续利用支撑体系能力的基本内涵

本文以山东省水资源利用实际为背景 ,探讨了水资源可持续利用的目标函数及其指标内涵 ,定性定量提出了水资源可持续利用支撑体系应具备的五种能力。     

以人为本开拓创新不断提高海淀区的地震应急能力

近一两年来,海淀区地震办公室树立科学的发展观,勇于创新,敢为人先,以《海淀区破坏性地震应急预案》为中心,围绕落实《海淀区破坏性地震应急预案》的物质载体,开展了一系列地震应急工作.在建设《海淀区地震信息应急指挥中心》、开展应急避险场所建设、成立防灾减灾志愿者队伍、开展灾情速报网建设等方面进行了有益的探索,并取得了一定的成效.     

Improvement of rape (Brassica napus) plant growth and cadmium uptake by cadmium-resistant bacteria

This study focuses on the screening of cadmium-resistance bacterial strains from heavy metal-polluted soils to examine their plant growth promotion and cadmium uptake in rape (Brassica napus). A large number of bacteria were isolated from heavy metal-polluted soil in Nanjing, China. Thirty isolates showing cadmium-resistance on Cd-amended medium were selected and evaluated for their potential to solubilize cadmium carbonate in solution culture. Atomic absorption spectrometer analysis showed variable amounts of water-soluble Cd (ranging from 24 to 117 mg l(-1)) released by the cadmium-resistant bacterial strains from cadmium carbonate. Qualitative analysis confirmed the presence of indole acetic acid as the auxin in the culture of these cadmium-resistant bacterial strains. Root elongation assay conducted on rape under gnotobiotic conditions demonstrated increases (up to 31%) in root elongation of inoculated rape seedlings compared to the control plants. Based upon cadmium-resistance, bio-activation of CdCO3 and growth-promoting activity, three isolates were selected for promoting plant growth and uptake of cadmium from cadmium-amended soil in pot experiments. Inoculation with the isolates was found to increase root dry weight (ranging from 8% to 20%) and shoot dry weight (ranging from 6% to 25%) of rape. An increase in cadmium content varying from 16 to 74%, compared to the non-inoculated control, was observed in rape plants cultivated in soil treated with 100 mgCd kg(-1) (as CdCl2) and inoculated with the isolates. The bacterial isolates were also able to colonize and develop in the rhizosphere soil of rape after root inoculation.     

功能基因组学在环境化学品毒性机制研究中的应用

认识化学品的毒性机制是开展化学品健康风险评估的基础。掌握化学品有害效应的遗传易感性机制是开展精准的健康风险评估的前提。传统的毒理基因组学主要分析化学品暴露诱导的组学表达图谱,不能建立生物学表型与特定基因/通路表达的直接关联。功能基因组学通过敲除或者敲降全基因组或者特定的基因集,建立基因-化学品毒性的直接关联,进而研究化学品致毒的过程和机制,同时可以提供与化学品暴露的遗传易感性相关的分子响应信息。本论文综述了功能基因组学技术的原理及其主要发展,介绍了酵母、鸡DT40细胞和RNA干扰等功能基因组学测试方法的优缺点。同时,详述了CRISPR功能基因组学的原理和特点,以及其在化学品毒性机制研究中的应用,展望了联合应用分子流行病学和CRISPR功能基因组学,开展化学品有害效应的易感性机制研究。