曝气池中曝气器布置方式改进的研究

在生物反应池中,通过改变曝气器的布置方式和水平流速,进行曝气充氧检测后得出结论:对于一定数量的曝气器,增加反应池的水平流速将会提高曝气器的充氧能力和氧利用率。同时,在供气量和其它条件不变的情况下,如果把曝气器相对集中布置,将会增加充氧能力,提高氧利用率。     

Tailoring of surface oxygen‐containing functional groups and their effect on adsorptive denitrogenation of liquid hydrocarbons over activated carbon

The objective of this study is to get a fundamental understanding of role of surface oxygen‐contained functional groups (OCFG) in adsorptive denitrogenation (ADN) of liquid hydrocarbons over activated carbon, and thus to improve the ADN performance of activated carbon through modification of surface chemistry of activated carbon. A set of activated carbon samples with different amount and distribution of OCFG was prepared by oxidative modification and thermal treatment of a commercial activated carbon. The prepared activated carbons were characterized by the temperature‐programmed desorption coupled with mass spectrometry for the concentration of various OCFG, and evaluated in a fixed‐bed adsorption system using a model fuel containing aniline, indole, quinoline, carbazole, and ethyl‐carbazole. The results indicate that OCFG, especially the strong carboxyls, weak carboxyls and anhydrides, play a crucial role in determining the adsorptive performance of activated carbon for selective removal of nitrogen compounds from liquid hydrocarbons. The adsorption mechanism of the nitrogen compounds over activated carbon was discussed on the basis of the structure‐performance correlation and the molecular simulation. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1236–1244, 2013     

Oxy‐fuel combustion for CO2 capture using a CO2‐tolerant oxygen transporting membrane

CO₂ capture via an oxy‐fuel route through the U‐shaped (Pr_0.9La_0.1)₂(Ni_0.74Cu_0.21Ga_0.05)O_4+δ (PLNCG) hollow fiber membrane with 100% CH₄ conversion and 100% CO₂ selectivity for 450 h has been explored for the first time. X‐ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy characterizations of the spent hollow fiber membrane have also been investigated. All these results indicate that PLNCG hollow fiber membrane shows excellent reaction performance and good stability under oxy‐fuel reaction conditions, which will be a potential rounte for reducing CO₂ emissions worldwide. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3856–3862, 2013     

A novel porous‐dense dual‐layer composite membrane reactor with long‐term stability

A porous‐dense dual‐layer composite membrane reactor was proposed. The dual‐layer composite membrane composed of dense 0.5 wt % Nb₂O₅‐doped SrCo_0.8Fe_0.2O_3‐δ (SCFNb) layer and porous Ba_0.3Sr_0.7Fe_0.9Mo_0.1O_3‐δ (BSFM) layer was prepared. The stability of SCFNb membrane reactor was improved significantly by the porous‐dense dual‐layer design philosophy. The porous BSFM surface‐coating layer can effectively reduce the corrosion of the reducing atmosphere to the membrane, whereas the dense SCFNb layer permeated oxygen effectively. Compared with single‐layer dense SCFNb membrane reactor, no degradation of performance was observed in the dual‐layer membrane reactor under partial oxidation of methane during continuously operating for 1500 h at 850°C. At 900°C, oxygen flux of 18.6 mL (STP: Standard Temperature and Pressure) cm^?2 min^?1, hydrogen production of 53.67 mL (STP) cm^?2 min^?1, CH₄ conversion of 99.34% and CO selectivity of about 94% were achieved. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4355–4363, 2013     

Extraction of Cadmium from Phosphoric Acid Media by Di(2‐ethylhexyl) Dithiophosphoric Acid

Di(2‐ethylhexyl) dithiophosphoric acid (D₂EHDTPA) was examined for cadmium removal from phosphoric acid solutions. High extraction performance was achieved. By means of slope and saturation methods, the stoichiometry of the complex was postulated. Both methods indicated the presence of anhydrous CdR₂ as being the metallic extracted complex, HR denoting the D₂EHDTPA molecule. The stripping of cadmium from the organic phase was ensured by aqueous solutions of HCl; quantitative stripping was achieved with either HCl (4 M) or an HCl‐NaCl mixture.     

Synthesis and characterization of NIR-responsive Aurod@pNIPAAm-PEGMA nanogels as vehicles for delivery of photodynamic therapy agents

A near-infrared (NIR)-responsive Au_rod@pNIPAAm-PEGMA nanogel was synthesized in two steps, growing a PEGMA monolayer on the surface of gold nanorods (AuNRs), followed by in situ polymerization and cross-linking of N-iso-propylacrylamide (NIPAAm) and poly-(ethylene glycol)-methacrylate (PEGMA). The AuNRs and Au_rod@pNIPAAm-PEGMA nanogel were characterized by UV–vis spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy, respectively. The lower critical solution temperature of the Au_rod@pNIPAAm-PEGMA nanogel could be tuned by changing the molar ratio of NIPAAm/PEGMA. The NIR-mediated drug release behavior of the Au_rod@pNIPAAm-PEGMA nanogel was studied with zinc phthalocyanines (ZnPc₄) as a drug model. It was also demonstrated that the loaded ZnPc₄ could keep the capability of generating singlet oxygen, and the in vitro study showed a great photodynamic therapy (PDT) effect on Hela cells. It thus indicated the potential of this Au_rod@pNIPAAm-PEGMA nanogel for application as a drug carrier in PDT, which might make contributions to oncotherapy.     

基于SOM-RBF神经网络的COD软测量方法

污水处理是一个复杂的非线性过程,化学需氧量（chemical oxygen demand,COD）是评价污水处理效果的关键指标之一。COD的传统测量方法耗时长、成本高,基于传统神经网络的软测量方法提高了COD参数的测量速度但精度较差。针对这些问题,设计一种结合自组织特征映射 (self-organizing map, SOM)和径向基函数(radial basis function, RBF)神经网络的COD参数软测量方法。该方法利用SOM网络聚类数据样本,根据所得聚类结果确定RBF网络的隐层节点数及节点的数据中心,综合提高RBF网络的收敛速度和拟合精度。利用污水处理厂部分水样数据建立COD软测量模型,模型仿真和硬件在线测试结果表明,相对于传统的BP、RBF等网络,基于SOM-RBF神经网络的COD软测量方法测量时间短、预测精度较高,具有较为广阔的应用前景。     

MnFeO3和MnFe2O4氧载体在稻草化学链气化中的应用

通过溶胶凝胶燃烧法合成了MnFeO₃和MnFe₂O₄两种锰铁复合氧载体。通过原位红外实验探究其与稻草的化学链气化过程,发现其加速了稻草热解产物的析出,并通过气化反应促进CO和CO₂的产生,提高了碳转化率。固定床实验结果表明MnFeO₃和MnFe₂O₄在与水蒸气耦合气化的条件下大幅提高了合成气中H₂和CO的产率,气化效率分别达到94.49%和92.76%。并通过XRD分析,发现MnFeO₃和MnFe₂O₄在气化过程主要还原为(Fe,Mn)O,且在氧化反应后能回到初始晶相。在固定床的10次循环实验以及SEM的结果表明,MnFeO₃在循环反应中逐渐形成的颗粒状多孔结构有利于维持稳定的气化效率,而MnFe₂O₄由于团聚和烧结作用形成了块状结构,气化效率呈缓慢下降趋势。因此,认为MnFeO₃在生物质化学链气化中具有更好的适用性。     

高铝耐火砖负载CuO氧载体的化学链氧解耦特性实验

耐火砖常用作高温炉膛材料,具有较高的破碎强度和较强的抗烧结性能。以耐火砖颗粒为惰性载体,采用连续浸渍法制备CuO质量分数为10%～30%的Cu10RefBri、Cu25RefBri和Cu30RefBri氧载体样品,并在热重分析仪（TGA）和批次进料流化床反应器中900～950℃下进行了化学链氧解耦燃烧过程氧载体的释氧-吸氧循环实验测试。结果显示,在上述氧载体样品中Cu25RefBri的释氧速率最高,可达9×10^-5kgO₂/(s?kgOC),流化床中稳定的O₂体积分数可达1.1%。然而,随着循环次数增加,Cu25RefBri的释氧速率逐渐降低至2.0×10^-5kgO₂/(s?kgOC),同时流化床尾气中O₂体积分数降低至0.7%,该值远低于对应温度下的平衡O₂浓度值。氧浓度和释氧速率降低的主要原因在于：循环过程氧载体中形成的低释氧活性的CuAl₂O₄尖晶石含量逐渐增加,导致氧载体总体活性下降。此外,在950℃流化床实验过程,还检测到氧载体颗粒的烧结现象。     

游离氨耦联溶解氧调控高氮豆制品废水脱氮探究

为了实现高氮豆制品废水短程硝化的快速启动与稳定运行,采用了游离氨(FA)耦联溶解氧(DO)的策略进行调控。结果表明,当ρ(DO)在0.2~1.2 mg/L时,豆制品废水均能成功启动亚硝化,并且随着ρ(DO)的增加,达到完全亚硝化的周期数增加。ρ(DO)的升高促进硝化速率,并且当ρ(DO)在1.2~1.5 mg/L时,初始硝化速度为8.5 mg/(g·h),显著高于其他实验组。在FA耦联DO控制豆制品废水短程硝化过程中,而当ρ(FA)控制在6.5~7.0 mg/L时,豆制品废水短程硝化进入稳定期,Nitrosomonas europaea和Nitrosomonas stercoris增加至30.5%和21.3%。