O3/H2O2催化氧化技术深度处理工业园区印染废水

为了获得一种高效低成本处理印染废水的工艺,采用O₃催化氧化、O₃/H₂O₂催化氧化两组氧化体系处理工业园区印染废水并对比处理效果和成本投入,考察反应时间、H₂O₂投加量、O₃气体流量和O₃气体浓度对工业园区印染废水处理效果的影响。结果表明：采用O₃/H₂O₂催化氧化处理工艺,在进水流量为1.2 m³/h、回流量为2.5 m³/h、O₃气体流量为1.0 m³/h、O₃进气浓度为16 g/m³、反应时间为60 min的运行条件下,COD由42.03 mg/L降至30.23 mg/L,去除率为28.08%;UV₂₅₄由0.497 cm^-1降至0.315 cm^-1     

TiO2作用下土霉素的可见光敏化降解

研究了二氧化钛(TiO₂)存在时土霉素(OTC)在可见光下的降解。结果表明：单独可见光照下,OTC的光解效率随着pH的升高而逐渐增大。可见光和TiO₂的联合能显著促进OTC的降解,这主要归因于OTC的自光敏化作用。淬灭实验表明,在可见光/TiO₂体系中,超氧阴离子自由基(O₂^·-)和羟基自由基(·OH)能够氧化降解OTC,且O₂^·-是主要的活性物种。OTC初始浓度会影响其在可见光/TiO₂体系中的降解,过高或过低的OTC浓度都不利于其自身的去除;但是TiO₂用量的增加却能逐渐提高OTC的降解效率。     

Ag3PO4光催化-臭氧催化氧化协同降解苯酚

以Ag₃PO₄为光催化剂并通入臭氧构建了光催化-催化臭氧氧化协同体系，大幅度提高了对苯酚的降解效率。协同处理6 min后可将30 mg/L的苯酚溶液完全降解，在达到相同降解效率时，与单一氧化技术相比时间缩短了3倍。协同体系降解性能的提升源于臭氧的亲电特性，不仅加速了光生电荷的迁移，提升了光催化降解活性；同时还有效提高了臭氧利用效率，催化分解臭氧能产生更多的羟基自由基(·OH)，协同促进了苯酚的降解矿化性能。进一步通过猝灭实验验证了·OH是协同降解体系的主要活性物种，考察了臭氧浓度、催化剂投加量、苯酚浓度和酸碱性对降解效率的影响，探讨了光催化-臭氧催化氧化协同降解苯酚的降解机理。     

MnFe2O4颗粒非均相电芬顿处理柠檬酸镍配合物废水

以 MnFe₂O₄ 颗粒为催化剂、石墨为阳极、泡沫镍为阴极,构建了非均相电芬顿氧化体系,并研究了其对柠檬酸镍(Ni-Cit)配合物废水的处理效果。在电流密度为 20 mA/cm²、pH 为 3、催化剂投加量为 0.6 g/L 的条件下反应 240 min,可去除废水中 98%的 Ni-Cit 和 92%的 Ni。自由基掩蔽和中间产物检测结果表明,羟基自由基(·OH)在 Ni-Cit 的氧化过程中起主导作用,主要降解路径为：Ni-Cit 首先被氧化为柠康酸并释放出 Ni²⁺,柠康酸被进一步氧化为乙二酸、甲酸,最终被氧化为 CO₂ 和 H₂O。     

KMnO4、UV/H2O2预氧化对微污染水中消毒副产物生成势影响研究

采用高锰酸钾（KMn O₄）、紫外/过氧化氢（UV/H₂O₂）两种预氧化方式,通过改变氧化剂的投加量对三卤甲烷（THMs）、卤乙腈（HANs）生成势去除效果进行研究。结果表明两种预氧化方式均能很好的削减生成势,其中 UV/H₂O₂预氧化效果较佳。在 KMn O₄预氧化过程中,KMn O₄投加量为 5 mg/L 时,THMs、HANs 生成势去除率分别为82.7%、80.2%;在 UV/H₂O₂预氧化过程中,紫外光强 12 W,H₂O₂投加量为 5 mg/L 时,THMs、HANs 生成势减少幅度较大,生成势去除率分别增长到 83.1%、83.7%。当两种预氧化方式的氧化剂投加量均大于 5 mg/L 时,两种物质生成势去除率增长缓慢并趋于平缓。     

商用TiO2催化臭氧降解活性黄3RE的研究

以活性黄3RE配置模拟实际印染废水,对商用TiO2催化臭氧(O₃)氧化降解活性黄3RE进行研究。考察了商用TiO₂晶相、pH值、O₃流量、初始浓度等参数对降解活性黄3RE的影响。研究结果表明,金红石相TiO₂表现出更高的催化活性,反应30 min活性黄3RE去除率达到96.5%。当活性黄3RE初始浓度为100 mg/L,pH值为4.4,臭氧流量200 mL/min,P25催化剂投加量为100 mg/L的条件下,30 min后活性黄3RE去除效率为95.6%,且降解动力学符合拟一级动力学。     

制药废水的响应面法优化O3/Fe-C微电解预处理工艺

研究将O₃与Fe-C微电解工艺相耦合，以浙江某大型制药企业产生的废水为研究对象，进行耦合工艺小试试验。分别探究了Fe-C球投加量、初始pH和O₃剂量3种主要因素，采用响应面法(RSM)对工艺参数进行了优化。得出了工艺最佳参数为：Fe-C球投加量为592 g/L,pH值为5.9,O₃剂量为285 mg/(L·h),处理后COD_Cr质量浓度为1 092 mg/L,去除率可达48.61%。3种因素对耦合工艺的影响程度为Fe-C球投加量>O₃剂量>初始pH,对应的F值分别为509.59、30.54、11.48。该工艺相较于传统的微电解工艺，具有更高的COD_Cr去除效果，可推广应用于工业中制药废水的预处理。     

Mn-Ti-Mg/Al2O3催化臭氧氧化处理煤化工废水

以浸渍法制备金属复合催化剂Mn-Ti-Mg/Al₂O₃，采用SEM-EDS、XPS、BET对复合催化剂的表观形貌、原子组成、金属元素的存在状态、比表面积和平均孔径进行表征，并测定了其pH_zpc。之后将其作为多相催化剂用于催化臭氧氧化处理煤化工废水，对其催化效果进行研究，考察了催化剂投加量、O₃流速、溶液初始pH对其催化效能的影响，并对其稳定性进行了研究。结果表明，Mn-Ti-Mg/Al₂O₃复合催化剂对于催化臭氧氧化处理煤化工废水效果较好，催化剂投加量和臭氧流速的增加有利于提高煤化工废水COD的去除率，废水在碱性条件下更易被处理。经过催化臭氧氧化处理之后，废水的pH显著降低，导致催化剂中金属活性成分溶出，催化剂活性降低。在温度22℃、溶液初始pH 7.8、催化剂投加质量浓度10 g/L、臭氧流速1.0 mg/min、反应时间40 min条件下，采用Mn-Ti-Mg/Al₂O₃催化臭氧氧化处理煤化工废水，处理后废水...     

内循环式铁碳微电解/H2O2耦合工艺处理多晶硅有机废水

针对铁碳微电解反应中填料易板结及处理效率低等问题,通过增加内循环装置改进反应器结构,同时将铁碳微电解与H₂O₂进行工艺耦合,用于处理多晶硅有机废水,考察了Fe-C投加量、初始pH值、H₂O₂投加量、反应时间等工艺条件对COD去除率的影响,并通过响应面法优化了工艺条件。结果表明,各工艺条件对多晶硅有机废水COD去除效果的影响大小为：铁碳投加量>反应时间>H₂O₂投加量>初始pH值,其最适宜工艺条件为：铁碳投加量250 g·L^-1,初始pH值2.8,H₂O₂投加量112 mL·L^-1,反应时间83 min,该反应条件下COD的去除率为71.26%。铁碳/H₂O₂降解多晶硅有机废水COD的动力学回归方程为Y=0.5273X-0.6347,降解COD的速率常数为0.527 3 min^-1。     

ZIF-67衍生Co3O4/g-C3N4复合材料光催化降解盐酸四环素废水的研究

将ZIF-67与g-C₃N₄按一定质量比复合制备Co₃O₄/g-C₃N₄复合光催化材料,并以此来提高Co₃O₄的光催化性能。利用XRD、SEM和FT-IR对复合材料结构、性能和元素分布进行表征。结果表明,当盐酸四环素(TC-HCl)质量浓度为3 mg/L、质量分数为3%的Co₃O₄/g-C₃N₄投加量为15 mg且pH为中性时,催化剂光催化性能最佳,90 min降解盐酸四环素效率达到了91.1%。3%Co₃O₄/g-C₃N₄复合光催化剂重复使用5次后,其降解率仍可达到88.5%,表明该材料具有一定的光催化稳定性和重复利用性。体系自由基捕获实验证明,产生了·O^-₂、h⁺、·OH...     

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.     

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.     

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%.     

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.     

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.     

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.