Al_2(SO_4)_3-CPAM复合絮凝剂在造纸脱墨废水中的应用

实验制备了无机/有机高分子复合型絮凝剂,考察了这类絮凝剂的组成、用量以及造纸脱墨废水pH值对其絮凝效果的影响。发现复合絮凝剂比单一的无机或有机高分子絮凝剂具有更佳的絮凝效果,并对复合絮凝剂的絮凝机理进行了初步研究。在最佳的复合絮凝剂的组成和废水的pH值的条件下,处理后的脱墨废水的悬浮物含量、COD和浊度可分别降低80%、75%和95%以上。     

新型复合絮凝剂γ-PGACa的性能研究

对新型有机-无机复合絮凝剂γ—PGACa处理废水进行了实验研究，考查了pH、总投药鞋、投配比和浊度四个影响因素，确定了最佳使用条件；然后将复合絮凝剂γ-PGACa与常见絮凝剂絮凝处理废水的效果和成本进行比较。结果表明γ-PGACa与常见无机絮凝剂结合使用，能大大查提多絮凝效果，性价比比常见的高分子絮凝剂如PAM高，且对环境污染较小，无毒、高效、可降解且不存在二次污染。     

腈纶工艺废水复合絮凝剂的开发及其处理研究

通过选取几种有机、元机絮凝药剂进行单一、复配絮凝实验,研究丁不同絮凝剂处理腈纶工艺废水的絮凝效果,找出一种能够提高腈纶工艺废水预处理效果的复合絮凝剂。实验表明：对腈纶工艺废水来说,无机高分子絮凝剂处理效果较有机高分子絮凝剂要好,其中PFS絮凝效果最好;无机、有机絮凝剂进行复配的絮凝效果明显比使用单一无机、有机絮凝剂要好,最佳组合为PFS与阳离子聚丙烯酰胺（PAM）;若该复合絮凝剂加入一定量的MgSO4后。对CODcr去除效率有较大提高,并且MgSO4用量越多,效果越好;改性聚丙烯酰胺与MgSO4、PFS复配,可使CODCr去除率达到32．5％。     

聚合铝基复合絮凝剂脱色性能的初步研究

在众多印染废水脱色处理方法中，絮凝-沉淀法以其投资费用低、设备占地少、处理容量大、脱色率高而普遍采用。无机高分子絮凝剂与有机高分子絮凝剂相比，在聚合度及相应絮凝效果方面要差：有机高分子絮凝剂具有用量少、絮凝速度快、受pH值及温度影响小的优点，但价格昂贵，难以推广使用。     

明矾-壳聚糖复合絮凝处理含油废水的研究

利用无机絮凝剂明矾和有机絮凝剂壳聚糖复合作用对含油废水进行絮凝处理。对影响絮凝过程的主要因素,如温度、溶液pH值、絮凝剂用量及复合絮凝剂配比进行了实验研究,结果表明:最佳絮凝条件为温度40℃和pH值6~7,复合絮凝剂明矾:壳聚糖配比为3∶1,絮凝剂用量为0.5 g/L时,絮凝效果最好。处理后的含油污水澄清度高,除油率可达到97%。     

高浓度含油乳化废水的复合絮凝气浮处理

针对冷轧高浓度含油乳化液废水,使用有机和无机复合絮凝剂处理进行了系统的研究。考察了絮凝剂种类、pH值、絮凝剂投加量以及有机-无机联合使用对絮凝效果的影响。加压溶气气浮动态试验表明处理效果是令人满意的。     

微波法复合絮凝剂的制备及其絮凝性能研究

以聚合氯化铝铁(PAFC)和阳离子聚丙烯酰胺((CPAM)为原料,采用微波法制备了新型复合絮凝剂,并将其用于处理高岭土模拟废水.当CPMA与PAFC的质量比为1:4时,絮凝效果最优.红外光谱分析表明,通过微波作用,无机高分子絮凝剂已接枝到有机高分子絮凝剂上,形成了新型复合絮凝剂.该复合絮凝剂pH适应性宽,投加量少,成本低.当模拟废水pH值为6～9、投加量为1.8mg/L时,去浊率可达到98.5%以上.     

絮凝剂在水处理中的应用与展望

主要探讨了无机絮凝剂中铝盐、铁盐的絮凝机理与应用效果,天然有机高分子絮凝剂中的改性淀粉、改性纤维素、改性木质素及壳聚糖和人造有机高分子絮凝剂在水处理中的应用机理与效果,无机与有机复合絮凝剂的种类、絮凝机理、应用效果。并对无机、有机、无机与有机复合三种类型絮凝剂在水处理中的优缺点与应用现状进行比较,指出复合絮凝剂与天然有机絮凝剂在饮用水处理方面具有良好应用前景。     

聚硅酸铝铁Q6a及有机絮凝剂F2处理印染废水

以硅酸钠，硫酸和硫酸铝为原料制备了无机高分子复合聚硅酸铝铁絮凝剂Q6a及Q6b。对染整工业排放的靛蓝废水的絮凝性能优于聚合氧化铝，更优于聚硅酸铁，加入10分钟左右，絮凝物即可沉降，废水经絮凝处理后透光率达到99%，又以原料淀粉，丙烯酰胺，ETA开发成功了有机高分子阳离子絮凝剂F2，Q6a与F2配合絮凝时效果更好。     

复合型絮凝剂PAC-PAM处理含乳化油废水的试验研究

研究了不同条件下的聚合氯化铝和聚丙烯酰胺复合絮凝剂(PAC-PAM)对含乳化油废水的絮凝效果,并与使用单一絮凝剂的效果进行了对比。通过单因素条件试验研究pH值、PAC:PAM配比、溶液温度和沉降时间等操作条件对PAC-PAM复合絮凝剂处理含油废水效果的影响,从而得到PAC-PAM复合絮凝剂处理含油废水的最优条件及絮凝机理。结果表明:PAC-PAM复合絮凝剂处理含乳化油废水的最佳操作条件为:PAC为30mg/L、PAM为6mg/L、溶液温度40℃、溶液pH值为7和沉降时间30min。以COD去除率代表絮凝效果的好坏,最优条件下的COD去除率达到84.57%。复合絮凝剂处理含乳化油废水的絮凝机理主要是:电中和破乳及高分子链的架桥综合作用。与使用单一絮凝剂PAC或PAM相比,PAC-PAM复合絮凝剂对含乳化油废水的絮凝效果更好。     

Photocatalytic activity of Cu2O/TiO2, Bi2O3/TiO2 and ZnMn2O4/TiO2 heterojunctions

Cu₂O/TiO₂, Bi₂O₃/TiO₂ and ZnMn₂O₄/TiO₂ heterojunctions were studied for potential applications in water decontamination technology and their capacity to induce an oxidation process under VIS light. UV–vis spectroscopy analysis showed that the junctions-based Cu₂O, Bi₂O₃ and ZnMn₂O₄ are able to absorb a large part of visible light (respectively, up to 650, 460 and 1000 nm). This fact was confirmed in the case of Cu₂O/TiO₂ and Bi₂O₃/TiO₂ by photocatalytic experiments performed under visible light. A part of the charge recombination that can take place when both semiconductors are excited was observed when a photocatalytic experiment was performed under UV–vis illumination. Orange II, 4-hydroxybenzoic and benzamide were used as pollutants in the experiment. Photoactivity of the junctions was found to be strongly dependent on the substrate. The different phenomena that were observed in each case are discussed.     

Al_2(SO_4)_3/FeCl_3催化合成乙酸异戊酯

以冰乙酸和异戊醇为原料,Al_2(SO_4)_3/FeCl_3为催化剂,对催化合成乙酸异戊酯的条件进行研究。考察催化剂用量、乙酸与异戊醇物质的量比以及反应时间对乙酸酯化率的影响。结果表明,Al_2(SO_4)_3/FeCl_3具有良好的催化活性,在乙酸物质的量为0.1 mol、乙酸与异戊醇物质的量比为1∶4、催化剂用量1.0 g、反应时间2.0 h和带水剂环己烷用量10 m L反应条件下,重复实验3次,平均乙酸酯化率为93.50%。     

稀土固体超强酸SO2-4/TiO2/La3+催化合成醋酸丁酯

研究了以固体超强酸SO24-/TiO2/La3+催化剂,醋酸和正丁醇为原料合成醋酸丁酯,并考察了影响反应的因素.结果表明醇酸物质的摩尔比为1.61、催化剂用量0.6 g、带水剂甲苯7 mL、反应时间2.5 h是最适宜的反应条件,其酯化率可达96.2%.     

ZrO2/SiO2- and La2O3/Al2O3-supported platinum catalysts for CH4/CO2 reforming

Surface-phase ZrO₂ on SiO₂ (SZrOs) and surface-phase La₂O₃ on Al₂O₃ (SLaOs) were prepared with various loadings of ZrO₂ and La₂O₃, characterized and used as supports for preparing Pt/SZrOs and Pt/SLaOs catalysts. CH₄/CO₂ reforming over the Pt/SZrOs and Pt/SLaOs catalysts was examined and compared with Pt/Al₂O₃ and Pt/SiO₂ catalysts. CO₂ or CH₄ pulse reaction/adsorption analysis was employed to elucidate the effects of these surface-phase oxides.

The zirconia can be homogeneously dispersed on SiO₂ to form a stable surface-phase oxide. The lanthana cannot be spread well on Al₂O₃, but it forms a stable amorphous oxide with Al₂O₃. The Pt/SZrOs and Pt/SLaOs catalysts showed higher steady activity than did Pt/SiO₂ and Pt/Al₂O₃ by a factor of three to four. The Pt/SZrOs and Pt/SLaOs catalysts were also much more stable than the Pt/SiO₂ and Pt/Al₂O₃ catalysts for long stream time and for reforming temperatures above 700 °C. These findings were attributed to the activation of CO₂ adsorbed on the basic sites of SZrOs and SLaOs.     

K_2SO_4对V_2O_5/TiO_2脱硝催化剂表面形态的影响

采用XRD和XPS对新鲜的和K2SO4掺杂的V2O5/TiO2脱硝催化剂的表面形态进行了分析。结果表明,K2SO4的掺杂未对V与Ti之间的相互作用造成显著的影响,但是引起催化剂表面V和Ti的浓度降低,V5+在催化剂表面消失。K与钒氧物种上的晶格氧发生了强烈的相互作用。     

Solid state metathesis synthesis of BaTiO3, PbTiO3, K0.5Bi0.5TiO3 and Na0.5Bi0.5TiO3

A solid state metathesis approach has been applied to synthesize perovskite oxides such as BaTiO₃, PbTiO₃, K_0.5Bi_0.5TiO₃ and Na_0.5Bi_0.5TiO₃, these were characterized by powder XRD, IR and energy dispersive spectra (EDS). Potassium titanium oxalate and metal chlorides are used as the starting materials. X-ray analysis shows the formation of a single phase with tetragonal structure for BaTiO₃, PbTiO₃, K_0.5Bi_0.5TiO₃ and a monoclinic structure for Na_0.5Bi_0.5TiO₃. The Infrared spectra of these compounds show the characteristic band due to Ti–O octahedron for all the compounds. The EDS spectra show the relative ratio of the metal ions. The morphology of synthesized compounds was obtained from SEM measurements.     

New acrylic monolithic carbon molecular sieves for O2/N2 and CO2/CH4 separations

The modification of activated carbon fibres prepared from a commercial textile acrylic fibre into materials with monolithic shape using phenolic resin as binder was studied. The molecular sieving properties for the gas separations CO₂/CH₄ and O₂/N₂ were evaluated from the gas uptake volume and selectivity at 100 s contact time taken from the kinetic adsorption curves of the individual gases. The pseudo-first order rate constant was also determined by the application of the LDF model. The samples produced show high CO₂ and O₂ rates of adsorption, in the range 3-35 × 10⁻³ s⁻¹, and in most cases null or very low adsorption of CH₄ and N₂ which make them very promising samples to use in PSA systems, or similar. Although the selectivity was very high, the adsorption capacity was low in certain cases. However, the gas uptake in two samples reached 23 cm³ g⁻¹ for CO₂ and 5 cm³ g⁻¹ for O₂, which can be considered very good. The materials were heat-treated using a microwave furnace, which is a novel and more economic method, when compared with conventional furnaces, to improve the molecular sieves properties.     

Electrocatalyst materials for fuel cells based on the polyoxometalates—K7 or H7[(P2W17O61)Fe(H2O)] and Na12 or H12[(P2W15O56)2Fe4(H2O)2]

Free acids of the iron substituted heteropoly acids (HPA), H₇[(P₂W₁₇O₆₁)Fe^III(H₂O)] (HFe1) and H₁₈[(P₂W₁₅O₅₆)₂Fe^III₂(H₂O)₂] (HFe2) were prepared from the salts K₇[(P₂W₁₇O₆₁)Fe^III(H₂O)] (KFe1) and Na₁₂[(P₂W₁₅O₅₆)₂Fe^III₄(H₂O)₂] (NaFe4), respectively. The iron-substituted HPA were adsorbed on to XC-72 carbon based GDLs to form HPA doped GDEs after water washing with HPA loadings of ca. 1 μmol. The HPA was detected throughout the GDL by EDX. Solution electrochemistry of the free acids are reported for the first time in sulfate buffer, pH 1-3. The hydrogen oxidation reaction was catalyzed by KFe1 at 0.33 V, with an exchange current density of 38 mA/cm². Moderate activity for the oxygen reduction reaction was observed for the iron substituted HPA, which was dramatically improved by selectively removing oxygen atoms from the HPA by cycling the fuel cell cathode under N₂ followed by reoxidation to give a restructured oxide catalyst. The nanostructured oxide achieved an OCV of 0.7 V with a Tafel slope of 115 mV/decade. Cycling the same catalysts in oxygen resulted in an improved catalyst/ionomer/carbon configuration with a slightly higher Tafel slope, 128 mV/decade but a respectable current density of 100 mA/cm² at 0.2 V.     

Properties of char particles obtained under O2/N2 and O2/CO2 combustion environments

Pulverized coal combustion in O₂/N₂ and O₂/CO₂ environments was investigated with a drop tube furnace. Results present that the reaction rate and burn-out degree of O₂/CO₂ chars (obtained in O₂/CO₂ environments) are lower than that of O₂/N₂ chars (obtained in O₂/N₂ environments) under the same experimental condition. It indicates that a higher O₂ concentration in O₂/CO₂ environment is needed to achieve the similar combustion characteristic to that in O₂/N₂ environment. The main differences between O₂/N₂ and O₂/CO₂ chars rely on the pore structure determined by N₂ adsorption and chemical structure measured by FT-IR. For O₂/CO₂ char, the surface is thick and the pores are compact which contribute to the fragmentation reduction of particles burning in O₂/CO₂ environment. The organic functional group elimination rate from the surface of O₂/CO₂ chars is slower or delayed. The present research results might have important implications for further understanding the intrinsic kinetics of pulverized coal combustion in O₂/CO₂ environment.