水热处理泔脚脱油与产物消化性能变化

水热预处理泔脚废物,测定生物化学甲烷势(BMP),研究废物脱油、水解和消化性能的变化.结果表明,预处理加速废物的溶解和有机物的水解.随着反应温度升高,产物pH 降低,SCOD 和VFA浓度显著升高.150℃、 60 min预处理后,可浮油含量增加并达到较好的分离效果,消化过程在4～6 d内完成,降解速率提高1倍.170℃预处理后4 d生物气产量最高,继续提高温度会降低产物甲烷势.能量衡算分析表明,优化预处理能耗合理.     

稀土掺杂钨钼酸盐类荧光粉水热法合成及结构与性能的研究

利用水热法制备了A0.925（MoO4）0.5（WO4）0.5∶Dy03.＋05（A=Ca、Sr、Ba）固溶体微晶。通过X射线衍射（XRD）、扫描电镜（SEM）、荧光分析（FA）等测试手段对微晶结构、形貌和发光性能进行了表征。结果表明A0.925（MoO4）0.5（WO4）0.5∶Dy03＋.05（A=Ca、Sr、Ba）复合钨钼酸盐微晶均呈现典型的四方晶相白钨矿结构。荧光光谱中的480nm处的偶合双峰和575nm处的锐而强的黄发射峰,分别对应于稀土离子Dy3＋的4F9/2→6 H15/2和4F9/2→6 H13/2跃迁。其中具有球状颗粒（尺寸为0.7μm）形貌的Ca0.925（MoO4）0.5（WO4）0.5∶Dy03.＋05微晶的发射峰强度最强,在光学材料中具有潜在应用。     

Material conversion from paper sludge ash in NaOH solution to synthesize adsorbent for removal of Pb^2＋, NH^4＋ and PO4^3- from aqueous solution

Material conversion from paper sludge ash (PSA) in NaOH solution was attempted to synthesize the adsorbent for removal of inorganic pollutants, such as Pb2+, NH4 + and PO4 3?? from aqueous solution. PSA of 0.5 g was added into 10 mL of 3 mol/L NaOH solution, and then heated at 80, 120, and 160°C for 6–48 hr to obtain the product. PSA mainly composed of two crystalline phases, gehlenite (Ca2Al2SiO7) and anorthite (CaAl2Si2O8), and amorphous phase. Hydroxysodalite (Na6Al6Si6O24 8H2O) was formed at 80°C, and anorthite dissolved, whereas gehlenite remained una ected. Katoite (Ca3Al2SiO4(OH)8) was formed over 120°C, and hydroxycancrinite (Na8(OH)2Al6Si6O24 2H2O) was formed at 160°C, due to the dissolution of both gehlenite and anorthite. Specific surface areas of the products were almost same and were higher than that of raw ash. Cation exchange capacities (CECs) of the products were also higher than that of raw ash, and CEC obtained at lower temperature was higher. Removal abilities of products for Pb2+, NH4 +, and PO4 3?? were higher than that of raw ash.With increasing reaction temperature, the removal e ciencies of Pb2+ and NH4 + decreased due to the decrease of CEC of the product, while removal e ciency for PO4 3?? was almost same. The concentrations of Si and Al in the solution and the crystalline phases in the solid during the reaction explain the formation of the product phases at each temperature.     

Co3O4纳米棒的制备及其对气相甲苯的催化氧化

采用低温水热法制备棒状纳米结构的Co3O4,通过加入少量的表面活性剂（聚乙烯吡咯烷酮简称PVP）,在95℃下低温反应,并调控制备过程的老化时间、溶液的pH这2个因素合成了棒状Co3O4纳米结构.X射线衍射（XRD）、透射电镜（TEM）表明制得的是呈立方晶体的Co3O4纳米棒,氢气程序升温还原（H2-TPR）、N2吸附脱附等表征手段表明老化时间和pH会影响Co3 O4纳米棒的尺寸、孔隙结构,进而影响其比表面积大小.采用气相甲苯作为目标物,运用气相色谱（GC）对Co3 O4的催化性能进行研究.结果表明在该实验中,调控老化时间和pH制得的Co3O4纳米棒只影响其低温降解效果,在温度低于260℃,活性最好的是pH=9,老化时间为12 h的催化剂;当温度高于260℃后,其降解曲线基本一致.     

基于高通量测序解析碳化温度对麻秆电极微生物群落影响

采用Solixa高通量测序技术比较了1 000℃和1 800℃碳化麻秆制备电极OCP-1000和OCP-1800在生物电化学系统运行过程中形成的生物膜微生物群落结构差异.测序分别获得OCP-1000和OCP-1800附着生物膜16S rRNA基因V3区优化序列4 231和5 263条,经过97%相似度归并后获得OTUs数量分别为1 187和1 338个.α多样性指数(Chao、Shannon指数)分析表明碳化温度越低,电极生物膜微生物多样性越丰富.电极OCP-1000和OCP-1800生物膜中优势菌群均为Proteobacteria、Firmicutes和Bacteroidetes,这3个门的细菌在OCP-1000生物膜含量分别为66%、10%和9%,但在电极OCP-1800生物膜中含量分别为71%、7%和9%.不同碳化温度制备的麻秆电极在生物电化学系统运行过程形成的生物膜不仅存在共有细菌种类,也含有独特菌种,说明电极制备过程碳化温度影响电极生物膜微生物群落结构.     

大粒径厨余垃圾水热碳化制备炭燃料

开展了不同温度条件（150～300℃）下大粒径（>2 cm）厨余垃圾水热碳化实验,研究了水热炭的理化性质、燃烧特性和关键元素迁移规律.实验结果表明,当水热温度过低,厨余垃圾颗粒尺寸影响水热碳化效果;大粒径厨余垃圾碳化需更高的水热温度;水热温度250～300℃产生的水热炭具有高热值(24.48～26.9 MJ·kg^-1)、高燃料比（0.44～0.56）、高含碳量（59.6%～65.6%）和低含灰量（8.51%～4.35%）的特点.随着水热温度提高,水热炭中碳含量升高、灰含量下降;水热炭的着火温度、燃烬温度、挥发分释放特性指数VI、可燃性指数CI和综合燃烧特性指数CP均上升,提高了燃烧稳定性;同时水热炭中K、Na浓度降低,有利于降低水热炭燃烧结焦;N、S在水热炭中分布比例下降,这将减少水热炭燃烧的烟气污染物排放.因此,水热碳化能实现大粒径厨余垃圾的燃料化利用.     

Green synthesis and characterization of metal ions-mixed titania for application in dye-sensitized solar cells

Abstract

The objective of the present study is to synthesize various metal ions mixed TiO₂ nanoparticles using a continuous hydrothermal synthesis pilot reactor for dye-sensitized solar cells (DSCs). In the pilot plant, aqueous solutions of the metal salts are mixed with a flow of supercritical water (450?°C and 24.1?MPa) in a confined jet mixer for continuous synthesis of metal ions-mixed nano-titania. Characterization of the particles was made using Brunauer–Emmett–Teller technique for specific surface area, powder X-ray diffraction analysis and transmission electron microscopy for identification and crystallite size, X-ray photoelectron spectroscopy for surface analysis and infrared spectroscopy for distinct group identification. Following the already existing procedures and using the titanates synthesized, dye-sensitized cells of 1?cm² area were assembled and their photovoltaic parameters were evaluated under standard test conditions. The power conversion efficiencies (η %) for 40?mol % Zn²⁺, 5?mol % Zr⁴⁺ and 10?mol % Zn⁴⁺ titania were obtained to be 4.8, 4.95 and 4.9, respectively. The promising efficiency results from a greener and large-scale production of nano-titania is a step forward towards commercializing DSC technology.     

Promotional effect of ion-exchanged K on the low-temperature hydrothermal stability of Cu/SAPO-34 and its synergic application with Fe/Beta catalysts

• K⁺ hinder the structural degradation of Cu/SAPO-34 under humid condition<100°C. • K⁺ on Cu/SAPO-34 brings lower acidity and inferior SCR activity at high temperature. • Fe/Beta was used to compensate the low activity of Cu/SAPO-34 at high temperature. • The hybrid catalysts with KCu/SAPO-34 and Fe/Beta show a great potential for using. K ions were introduced onto Cu/SAPO-34 catalysts via the ion-exchange process in order to improve their stability under low-temperature hydrothermal aging. The changes in structure and copper-species contents of these catalysts upon hydrothermal aging were probed in order to investigate their effects on selective catalytic reduction (SCR) activity. For the fresh Cu/SAPO-34 catalysts, K ions had little influence on the chabazite framework but effected their acidities by exchanging with acid sites. After hydrothermal aging, the structural integrity and amount of active sites decreased on pure Cu/SAPO-34. While the K-loaded catalysts showed improved chabazite structure, acidity, and active site conservation with increasing K loading. However, although the 0.7 wt% K catalyst maintained the same crystallinity, active site abundance, and low-temperature SCR activity as the fresh catalyst upon aging, an apparent decrease in SCR activity at high temperature was observed because of the inevitable decrease in the number of Brönsted acid sites. To compensate for the activity disadvantage of K-loaded Cu/SAPO-34 at high temperature, Fe/Beta catalysts were co-employed with K-loaded Cu/SAPO-34, and a wide active temperature window of SCR activity was obtained. Thus, our study reveals that a combined system comprising Fe/Beta and K-loaded Cu/SAPO-34 catalysts shows promise for the elimination of NO_x in real-world applications.     

褐煤脱水及水质净化研究

为实现褐煤提质并缓解褐煤产区缺水现状,采用微波及水热脱水方法对褐煤进行脱水改性并回收褐煤所脱水分.通过检测水分化学需氧量、氨氮、总磷、硬度、离子、有机化合物等各项指标,对褐煤中水分进行深入分析,并比较两种脱水方法的脱水、净化效果.结果表明微波方式脱水率可达70%~80%,除化学需氧量外,其它水质指标均符合工业用水标准,且杂质含量随微波功率增加而降低,利于净化回收.水热方式可有效改善褐煤煤质,脱水率最高可达87.44%,但各项水质指标均大大超出标准范围,且杂质含量在250℃工况下达到最大.两种冷凝水均检测到微量有毒金属元素、有毒致癌的多环芳烃及酚类化合物,将成为后续净化的主要脱除对象.     

溴掺杂TiO2光催化剂的制备与性能研究

以KBr和Ti（SO4）2为原料,通过水热法制备了高催化活性的溴掺杂纳米TiO2（Br-TiO2）光催化剂,利用XRD、XPS、TEM、BET和UV-Vis DRS等测试手段对其进行了表征。通过苯酚降解实验评价了Br-TiO2的光催化活性。结果表明,700℃焙烧、溴与钛的摩尔比为0.35∶1时,Br-TiO2具有最佳光催化活性。该催化剂为晶体发育完整的锐钛矿相TiO2,粒径平均大小为50 nm,比表面积为16.81 m2/g,在紫外区的吸收得到加强,光催化能力优于Degussa P-25。确定了降解苯酚的最佳条件：催化剂投加量为0.5 g/L,苯酚初始浓度为10 mg/L,pH值为6.0。