二氧化锰纳米棒的制备和催化性能研究

采用水热法140 ℃下制备了二氧化锰的棒状结构.XRD和扫描电子显微镜研究了二氧化锰的晶相和形貌,对棒状二氧化锰降解品红催化性能进行了测试,实验表明,催化剂的加入量,双氧水的加入量和溶液的pH值对品红的脱色效果产生重要的影响,在催化剂的加入量为0.02 g时,双氧水的加入量为4 mL,溶液的pH值为6.2时有较佳的脱色...     

氧化银-二氧化钛／膨润土复合光催化剂的制备及性能研究

为了提高光催化剂的实用性,以工业偏钛酸为原料,采用液相掺杂制备了氧化银-二氧化钛/膨润土复合光催化剂.以酸性橙Ⅱ为目标污染物,采用降解率来表征复合光催化剂的光催化活性.结果表明:当氧化银掺杂量为1.72%(质量分数)时,氧化银-二氧化钛/膨润土复合光催化剂在紫外光照射下和在太阳光照射下都有良好的光催化活性,其对应的降解率分别为96.25%和100%.对双氧水加入量和溶液pH的研究表明:当双氧水加入量为3 mmol/L或溶液pH为9的弱碱性条件下,催化剂光催化活性都有明显的提高.XRD分析表明,成功合成了氧化银-二氧化钛/膨润土复合物.     

电动降解处理酸性品红染料废水的研究

研究了酸性品红在电动降解作用下的定向迁移及降解反应。在电场作用下,酸性品红定向迁移到阴极附近区域,聚集到一定浓度时被电动降解除去。考察了pH值、电压及电解质浓度对酸性品红电动降解的影响。实验表明,较好的酸性品红分子降解工艺条件为:pH=5,电压为18 V,电解质浓度为3 mg/L。     

超声波协同纳米锌催化降解染料废水

随着工业的发展,环境保护和可持续发展成为人们不得不考虑的问题,其中染料工业废水的降解是一个典型问题。文章主要介绍了利用自制纳米锌与超声波协调作用对活性黑染料进行降解,并考察了纳米锌加入量、双氧水加入量、超声波震荡时间等对活性黑染料降解率的影响。实验结果表明,纳米锌加入量为30 mg、双氧水加入量为0.6 m L、超声波震荡时间为30分钟时,活性黑染料降解效果较好,降解率可达95.3%。     

Cu掺杂TiO_2光催化剂降解有机染料的研究

采用溶胶-凝胶法制备Cu/TiO_2光催化剂,在汞灯下光催化降解酸性品红溶液。探讨了金属掺杂量,煅烧温度、煅烧时间、催化剂的用量以及溶液初始浓度对光催化降解效率的影响。结果表明,Cu掺杂量为1.5%(摩尔分数)、煅烧温度600℃,煅烧时间2h的制备条件下,催化剂的最佳用量为0.1%(g/mL)对酸性品红染料初始浓度为10mg/L的降解率较高,光照60min后品红降解率可达74.3%;掺杂1.5%(摩尔分数)的Cu/TiO_2催化剂的光催化活性高于TiO_2,其光催化降解率较TiO_2提高了21%。Cu的掺杂可以显著提高TiO_2的光催化效率。     

Cu掺杂TiO_2光催化剂降解有机染料的研究

采用溶胶-凝胶法制备Cu/TiO_2光催化剂,在汞灯下光催化降解酸性品红溶液。探讨了金属掺杂量,煅烧温度、煅烧时间、催化剂的用量以及溶液初始浓度对光催化降解效率的影响。结果表明,Cu掺杂量为1.5%(摩尔分数)、煅烧温度600℃,煅烧时间2h的制备条件下,催化剂的最佳用量为0.1%(g/mL)对酸性品红染料初始浓度为10mg/L的降解率较高,光照60min后品红降解率可达74.3%;掺杂1.5%(摩尔分数)的Cu/TiO_2催化剂的光催化活性高于TiO_2,其光催化降解率较TiO_2提高了21%。Cu的掺杂可以显著提高TiO_2的光催化效率。     

铜掺杂TiO_2改性光催化剂的制备及其应用

采用溶胶-凝胶法制备了铜掺杂改性的TiO_2光催化剂,以亚甲基蓝模拟水中有机污染物,在可见光下考察了不同pH值、催化剂和双氧水加入量对有机废水降解效果的影响,实验结果表明,硝酸铜和硫酸铜掺杂TiO_2光催化剂降解率达99.7%,铜尾矿掺杂在pH值=3,添加量为100 mg条件下降解率达99.8%。     

纳米Cu2O的特殊液相沉淀法制备及其光催化活性

采用高强度机械混合的特殊液相沉淀法制备了纳米Cu2O粉体,通过TEM和XRD对其进行表征。用它做催化剂在日光作用下对酸性品红溶液进行了光催化降解实验,研究了葡萄糖添加浓度、酸性品红溶液的初始浓度和催化剂的重复使用对光催化性能的影响。结果表明分散剂葡萄糖浓度为7g/L时制得的纳米Cu2O光催化活性最佳,当酸性品红溶液的初始浓度为6 mg/L时,2.5 h降解率高达99.1%,重复使用6次后其降解率仍可达到75%。     

纳米二氧化锰催化降解聚丙烯酰胺工艺条件研究

聚合物驱油技术在提高原油产量的同时,产生了大量含聚丙烯酰胺的废水,因此需要开发有效降解聚丙烯酰胺的工艺,降低污水中聚合物的浓度。通过水热法制备了纳米二氧化锰催化剂,并对该催化剂进行了评价,采用扫描电镜对其进行了表征。讨论了聚丙烯酰胺的相对黏度,对聚丙烯酰胺降解工艺条件进行了优化,考察了催化剂加入量、降解时间及降解温度对聚丙烯酰胺降解率的影响。结果表明:催化剂质量分数为1%、降解时间4 h及降解温度40℃时,聚丙烯酰胺降解率高达93.95%;自制纳米二氧化锰催化剂为均匀的棒状纳米晶,结晶度好,分散性好。     

树脂负载催化剂臭氧催化降解甲基红废水

该文进行了制备的载亚铁阳离子交换树脂对甲基红染料废水的降解效果的研究。通过对比试验验证催化剂活性,进而考察了pH、臭氧投加量及催化剂投加量对甲基红降解效果的影响。结果表明,对于100mg／L的甲基红溶液,加入一定量催化剂,臭氧投加量为O．5g／h,pH为9的条件下,甲基红的色度去除率可达99．1％,COD去除率为69．5％。通过试验证明,该催化剂能有效催化降解甲基红废水。     

CuCe氧化物催化剂的制备及CWPO降解双酚A废水研究

为解决Fenton法存在活性组分流失及通常在pH 2～3条件下运行的局限性，采用柠檬酸络合法制备了CuCe氧化物催化剂，建立了双酚A非均相催化湿式过氧化氢氧化（CWPO）反应体系。考察了焙烧温度、Cu/Ce摩尔比、H₂O₂用量、双酚A初始浓度和pH对催化剂物化结构和CWPO性能的影响。并分析了可能的降解路径。结果表明：催化剂具有良好的高温稳定性和pH适应性，在pH 1.6～7.9范围内对双酚A都具有较高的降解性能，不需要调节pH。在焙烧温度450℃、Cu/Ce摩尔比1.0、催化剂用量1 g·L^-1、H₂O₂用量196 mmol·L^-1、BPA浓度152 mg·L^-1、pH 6.6、反应温度75℃、反应95 min后，BPA和TOC去除率分别为91.8%和84.5%,Cu²⁺析出浓度为19.3 mg·L^-1。推测了双酚A可能的降解路径。     

银镍共掺催化剂光催化氧化硝基苯废水

在紫外光辐射下,以负载于γ-Al_2O_3上的银镍共掺TiO_2为催化剂、H_2O_2为氧化剂的催化氧化体系处理硝基苯废水。通过单因素实验法,研究了p H、H_2O_2用量、光照强度、温度、反应时间、催化剂用量等因素对该体系催化氧化硝基苯效果的影响。结果表明,对于100 m L 250 mg/L的硝基苯废水,当p H=3,30%H_2O_2投加体积为2.0 m L,反应温度为60℃,光照强度为70 W,催化剂投加量为0.5 g,反应时间为50 min时,该体系对废水中硝基苯的去除率可达到99.3%,COD去除率为69%。     

锰掺杂的二氧化钛光催化降解偶氮染料性能研究

采用超声分散法,以钛酸丁酯为前驱体,硫酸锰为掺杂剂,制备掺锰的纳米二氧化钛光催化剂。以甲基橙为目标降解物,对掺杂锰的二氧化钛粉体进行了光催化降解性能研究。结果表明：催化剂的最佳投加量为2 g/L,锰的掺杂量为10%[Mn占（Mn＋Ti）的摩尔分数]。焙烧温度为550℃,焙烧时间为2 h,锰掺杂的二氧化钛降解效果最佳。     

Preparation of high active nanometer TiO2 sonocatalyst by partial transition crystal in hydrogen peroxide solution under ultrasonic irradiation

The transition crystal nanometer TiO₂ sonocatalyst with high sonocatalytic activity was prepared utilizing the method of ultrasonic irradiation in hydrogen peroxide solution. The sonocatalytic activity of transition crystal nanometer TiO₂ powder was validated through the degradation of acid red B and azo fuchsin solutions by ultrasonic irradiation, respectively. The results show that the sonocatalytic activity of the transition crystal nanometer TiO₂ powder is obviously higher than ones of both original nanometer rutile and anatase TiO₂ powders. The degradation ratios of acid red B and azo fuchsin in the presence of the transition crystal nanometer TiO₂ catalyst surpass 96.5% and 85.3% within 40 min ultrasonic irradiation, respectively. At the same conditions, the degradation ratios are 62.5% and 45.0% in the presence of original nanometer anatase TiO₂ powders, 73.5% and 59.5% in the presence of original nanometer rutile TiO₂ powders, respectively, while the corresponding degradation ratios are only 29.8% and 14.2% in the absence of any TiO₂ catalyst, respectively. The degradation processes of both acid red B and azo fuchsin solutions are the pseudo-first-order reaction.     

Cu-SiO_2催化降解芳甲烷类染料的研究

采用溶胶—凝胶法（sol-gel）制备Cu-Si O2催化材料,以碱性品红为芳甲烷类染料的模拟污染物,进行微波催化降解实验,考察了H2O2用量、溶液PH值、催化剂用量、催化剂掺铜量、反应温度对降解效果的影响。实验结果表明,随着上述变量值的单项增加,微波催化降解效果增强,但达到一定的程度后,降解效果增强不明显。最佳实验条件为30%H2O2用量40μL/m L、p H值接近7、初始温度700C,降解效率大约在95%左右。     

漆酶预处理高浓度含酚废水的研究

采用漆酶对苯酚废水进行预处理,采用控制变量法对苯酚废水进行研究,考察了漆酶的反应pH值、漆酶用量,双氧水的用量以及反应时间等对苯酚降解速率的影响.实验结果表明,漆酶预处理的最佳条件为温度60℃,pH值为7,反应时间为35 min,漆酶用量控制在1.5 mL/100 mL,双氧水用量控制在1 mL/100mL,在此条件下,苯酚的去除率达到85％,废水COD去除率达到53％.     

Titanium dioxide mediated photocatalyzed degradation of a textile dye derivative, acid orange 8, in aqueous suspensions

Titanium dioxide mediated photocatalysed degradation of a textile dye derivative, acid orange 8(1), was investigated in aqueous suspensions of titanium dioxide by monitoring the depletion of total organic carbon (TOC) content as a function of irradiation time under a variety of conditions. The degradation kinetics were studied under different conditions such as pH, catalyst concentration, substrate concentration, different types of TiO₂ and in the presence of electron acceptors such as hydrogen peroxide (H₂O₂) and potassium bromate (KBrO₃) besides molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient compared with other photocatalysts. The dye was found to be adsorbed on the surface of the photocatalyst at acidic pH.     

Catalytic Olefin Epoxidation With H2O2 in Supercritical CO2. Synergic Effect by Hexafluoroacetone and Manganese‐Porphyrins

The heterogeneous oxidation of cyclooctene with hydrogen peroxide catalyzed by manganese 5,10,15,20‐tetrakis(2′,6′‐dichlorophenyl)porphyrinate, in the presence of hexafluoroacetone hydrate as co‐catalyst, has been studied in supercritical carbon dioxide, at 40 °C and 20 MPa. Under proper conditions, a complete olefin conversion may be obtained with the formation of cyclooctene oxide as the sole product. Fixation by hexafluoroacetone into its perhydrate derivatives provides a useful system to solubilize hydrogen peroxide in supercritical carbon dioxide, and to hamper catalyst bleaching and oxidant decomposition. Moreover, in the presence of both manganese‐porphyrin and hexafluoroacetone, the reaction rates are enhanced. Among the factors that may increase yields and rate of conversion, the use of a Teflon‐coated steel reactor rather than an uncoated one proved to be quite relevant, thus indicating the occurrence of a parasite radical decomposition of hydrogen peroxide promoted by steel reactor walls.     

Catalyst screening for oxidative desulfurization using hydrogen peroxide

Oxidation of a mixture of thiophene, benzothiophene and dibenzothiophene with hydrogen peroxide using supported Pd, Cr₂O₃, unsupported manganese oxides and a commercial Co-Mo/Al₂O₃ as catalysts has been studied in a mixture of hexadecane and acetonitrile. Based solely on the conversion of each organic sulfur compound, the ranking of catalyst efficiency found was: supported Pd > Cr₂O₃ ≈ manganese oxides ≈ Co-Mo/Al₂O₃. The influence of the calcination temperature on synthesized manganese oxides was also investigated. Mn₃O₄, amorphous manganese compounds, Mn₂O₃ and MnO₂ showed a similar catalytic activity independent of the hydrogen peroxide concentration. According to these preliminary results, it seemed that the catalyzed decomposition of the hydrogen peroxide competes with the oxidative desulfurization, however, at short reaction time (10 min) conversions at around 60–70% of thiophene were reached.