Development trajectory for the temporal and spatial evolution of the resilience of regional tourism environmental systems in 14 cities of Gansu Province,China

Environmental Science and Pollution Research - The rapid development of the urban economy in China and the accompanying income growth experienced by urban residents have increased demand for...     

The effects of polyethersulfone and Nylon 6 micromembrane filters on the pyraclostrobin detection: adsorption performance and mechanism

Environmental Science and Pollution Research - Adsorption of test substances on micromembrane filters during sample pretreatment before qualitative and quantitative analysis has greatly affected...     

Inter-comparisons of VOC oxidation mechanisms based on box model: A focus on OH reactivity

Volatile organic compounds (VOCs) oxidation processes play a very important role in atmospheric chemistry, and the chemical reactions are expressed in various manners in chemical mechanisms. To gain an improved understanding of VOCs evolution during oxidation processes and evaluate the discrepancies of VOCs oxidation schemes among different mechanisms, we used the total VOC reactivity as a diagnostic and evaluated tool to explore the differences for six widely used chemical mechanisms. We compared the total VOC reactivity evolution under high-NO_x conditions for several sets of precursors, including n-pentane, toluene, ethene, isoprene and a mixture of 57 Photochemical Assessment Monitoring Stations (PAMS) species in a 0-D photochemical box model. Inter-comparison of total VOC reactivity of individual precursor simulations showed discrepancies to different extent of the oxidation schemes among the studied mechanisms, which are mainly attributed to the different lumping approaches for organic species. The PAMS simulation showed smaller discrepancy than individual precursor cases in terms of total VOC reactivity. SAPRC07 and RACM2 performances are found to better match the MCM for simulation of total VOC reactivity. Evidences suggest that the performance in simulating secondary organic products, OH concentrations and NO_x concentrations are related to the OH reactivity discrepancies among various chemical mechanisms. Information in this study can be used in selection of chemical mechanisms to better model OH reactivity in different environments. The results in this study also provide directions to further improve the ability in modelling total VOC reactivity with the chemical mechanisms.     

FCC汽油吸附脱硫技术

与常规的加氢脱硫技术相比,吸附脱硫技术具有易于操作,故障率低,超低的硫含量,低辛烷值损耗,低操作成本,几乎不消耗氢气等优点,是解决当代能源、资源和环境问题的重要技术。本文将就吸附脱硫技术的研究现状做简要评述。     

空预器热端传热元件失效的原因分析及措施

针对广州中电荔新电厂 1 号炉空预器热端传热元件损坏失效问题,通过宏观和微观检查分析,找出故障原因,并制定相应的改进措施。改造结果表明:通过优化调整空预器吹灰程序,有效解决了空预器传热元件破损失效问题,保证了锅炉、机组正常运行。     

一种单相接地故障定位新方法的研究与应用

针对 10 kV 架空线路接地故障定位困难的实际问题,分析了现有定位方法的优缺点,提出了一种简捷实用的接地故障定位新方法,并根据该方法研制了单相接地故障巡查助手。应用结果表明:巡查助手可以快速定位接地故障点,尤其对一些外部特征不明显的隐蔽接地故障, 具有较高的实用价值。     

城市小区气象与污染扩散数值模式建立的研究

建立了一个城市小区尺度模式。该模式为三维非静力高分辨，取κ-ε湍流闭合方案。除考虑空气动力学作用外，引入了作为城市特征的街区建筑物布局及其高度、朝向和对短波辐射的遮蔽以及不同地表利用类型等特征影响，用强迫-恢复法计算地面温度，同时加入了污染物平流扩散方程。模式经专门布置的实测资料验证并用其模拟了北京一个小区中的气象条件和污染物扩散特征。结果表明：模式能够较合理的地反映由于建筑物遮蔽造成的温度差异以及不同下垫面上的温度变化；能够较好地模拟实际气象条件下的气象要素场特征和不同建筑物布局和土地利用类型的气象要素场特征，风场与观测比较一致；NOx浓度的模拟基本上反映了小区整体污染物浓度的变化趋势和特征，与观测值有一定的可比性；模式对不同城市小区可有良好的模拟能力。     

天然秸秆纤维素分解菌的分离选育

从土壤、酒糟、腐烂的玉米秸秆及牛粪中共分离到14株能分解纤维素的真菌菌株,外加已保藏的10株共24株菌株。分别对其进行了滤纸分解度、羧甲基纤维素(CMC)酶活和天然纤维素酶活的测定。筛选出6株对天然纤维素有较强的降解能力,酶活力在60mg/mL.d以上的菌株。通过改变其培养基中天然纤维素的含量,发现随着培养基中天然纤维素含量的减少,酶活力也随之降低。     

焦化废水处理中酚、氰降解细菌的分离选育

针对焦化废水为含酚、氰废水的特性，从焦化厂处理焦化废水的活性污泥和油泥中分离出能降解酚的细菌7株，降解氰的细菌8株，并对其降解能力进行了测定，结果表明，当酚浓度为150mg/L，经6h处理后0512菌株对酚的去除率达96．84％，当CN^-浓度为25mg/L经8h处理后，0501菌株对CN^-的去除率达99．96％。     

乙酸钙不动杆菌TS2H对DBP降解特性的研究

邻苯二甲酸酯(PAEs)是一类具有一般毒性和致畸、致突变性的有机化合物,它作为重要的化工原料被大量地用于塑料生产,同时也带来了严重的环境污染问题。文章以邻苯二甲酸二丁酯(DBP)为PAEs生物降解研究的模型物,通过驯化富集培养,分离出1株能降解DBP的乙酸钙不动杆菌(Acinetobacter calcoaceticus)TS2H,研究了TS2H对DBP的生物降解特性。结果表明,该菌可在好氧条件下高效降解DBP,在最佳pH值7时,150r·min-1振荡培养48h对DBP初始质量浓度为40mg·L-1的降解率可达到98.64%;TS2H对100mg·L-1内较高质量浓度的DBP均具有较高的降解效能,但当DBP质量浓度达到300mg·L-1时,降解效能受到一定的抑制;加入营养物蛋白胨能促进菌株TS2H对DBP的降解,而葡萄糖和苯甲酸钠的加入对DBP的降解有延缓作用;菌株TS2H在一定浓度的Zn2 、Cd2 和Cu2 条件下仍可较高效地降解DBP。