共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
研究了TiO2/H2O2/超声波协同作用对二甲酚橙溶液降解率的影响以及影响降解率的主要因素.结果表明:当二甲酚橙初始质量浓度为20 mg/L,pH值为1,TiO2用量为0.4 g/L,H2O2:用量为0.4 mL/L时,经TiO2/H2O2/超声波协同作用后,二甲酚橙的降解速率大大加快,降解效果也比较好,降解率可达92%. 相似文献
4.
比较不同制备方法制得的复合催化剂,由超临界干燥法制备的光催化剂具有粒径小,分散性好,光催化活性高等特点.以TiCl4为原料,采用溶胶凝胶法结合超临界流体干燥法(SCFD)制备了纳米级SnO2TiO2/MMT(蒙脱土)复合光催化剂.采用XRD和TEM对样品进行了表征.结果表明:TiO2以锐钛矿型形式存在,催化剂粒径在13~20 nm.以活性红X-3B溶液、活性橙K-NG和活性紫X-2R为反应模型,对所得催化剂的催化活性进行了评价,降解率分别达到99.9%、99.6%和99.5%,化剂循环利用时仍具有较高的催化活性. 相似文献
5.
6.
以钛酸丁酯、正硅酸乙酯、无水乙醇等为原料,采用Sol-Gel法制备TiO2-SiO2光催化剂,通过单因素实验得到最佳制备工艺条件为:n(钛酸丁酯)∶n(正硅酸乙酯)为2.33∶1,煅烧温度为600℃,煅烧时间为3 h,反应溶液pH值为3。当进水CODCr为379.5 mg/L,TiO2-SiO2光催化剂的投加量为0.5 g/L,紫外光照时间为3 h时,出水CODCr为67.8 mg/L。TiO2-SiO2光催化剂颗粒大小为100~500 nm,具有较高的催化活性和稳定性,可以多次重复使用。对比实验表明,TiO2-SiO2处理制浆中段废水的效率比TiO2高。 相似文献
7.
8.
采用溶胶—凝胶—浸渍法制备RuO2/La2O3/TiO2纳米粉体.以汞灯为光源,直接红棕M溶液的光催化降解为模型反应.结果表明:掺杂质量百分比为1.39%的La2O3,0.12%的RuO2,煅烧温度500℃时,RuO2/La2O3/TiO2的催化活性最高;当通气量为100mL/min,催化剂投加量为3.00g/L,初始pH值为8.98时,该催化剂对直接红棕M的降解率可达100%. 相似文献
9.
TiO2纳米颗粒光催化降解甲醛的影响因素 总被引:3,自引:0,他引:3
采用溶胶-凝胶法合成TiO2纳米颗粒,TEM结果表明,颗粒的平均粒径为20nm,电子衍射环图结果表明,TiO2颗粒晶体结构为锐钛矿型;在光催化反应系统中对TiO2颗粒制备的薄膜进行了甲醛的光催化降解实验,考察了TiO2颗粒制备的薄膜的层数、溶胶体系pH值、活化温度及活化时间等条件对TiO2薄膜光催化降解甲醛性能的影响.实验结果表明,溶胶-凝胶法的制备工艺条件对TiO2薄膜的光催化活性有较大影响,活化的温度和活化的时间影响最大,其次是溶胶体系的pH值,当pH=2,活化温度为500℃,活化时间5h,制成的TiO2薄膜光催化降解甲醛的降解率可达60%以上. 相似文献
10.
以钛酸四丁酯为前驱体,采用溶胶-凝胶法制备了I掺杂改性纳米TiO2光催化剂(I-TiO2).在模拟太阳光照射下,研究了该催化剂的制备条件、溶液pH值以及添加H2O2浓度等对酸性红B光催化降解性能的影响.结果表明:以TiO2为母体掺杂I[χ(I)=10%],在500℃下煅烧2 h得到的I-TiO2光催化剂对太阳光有良好的响应性;当催化剂用量为1.5 g/L,pH=8时,对10 mg/L酸性红B的降解率可达95%.此外,加入H2O2可提高催化剂活性,选择c(H2O2)=O.18 mol/L. 相似文献
11.
12.
分光光度-低压离子色谱法测定Cu2+、Ni2+、Zn2+、Pb2+、Fe2+和Mn2+ 总被引:1,自引:1,他引:0
建立了分光光度-低压离子色谱法测定Cu2+、Ni2+、Zn2+、Pb2+、Fe2+和Mn2+6种重金属离子的分析方法.选用柠檬酸-草酸混合液作为洗脱体系进行梯度洗脱,将6种金属离子完全分离,柱后采用1-(2-吡啶偶氮)-2-萘酚(PAN)进行衍生反应,于波长560 nm处进行检测.6种离子的检出限分别为0.006、0.012、0.005、0.125、0.070、0.020 mg/L.该方法用于环境水样测定,结果与原子吸收法所测值基本吻合,分析结果令人满意. 相似文献
13.
14.
添加助剂的过氧化氢漂白 总被引:2,自引:0,他引:2
麦草NaOHO2/NaOH两段蒸煮纸浆具有良好的可漂性,采用简单的酸处理H2O2漂白(AP)程序,仅用15%的H2O2可使漂白浆的白度达到74%~753%(ISO)。为了进一步提高麦草NaOHO2/NaOH两段蒸煮纸浆无氯漂白的效果,又进行了添加助剂的H2O2漂白试验。1试验部分漂白用浆为麦草NaOH预处理O2/NaOH蒸煮的氧碱浆,其白度为594%(ISO),卡伯值109,粘度827ml/g。漂白采用酸处理H2O2漂白(AP)程序,浆样先用H2SO4进行预处理,再进行H2O2漂白。酸处理在烧杯中进行,H2… 相似文献
15.
16.
17.
Cerrato JM Barrows CJ Blue LY Lezama-Pacheco JS Bargar JR Giammar DE 《Environmental science & technology》2012,46(5):2731-2737
The dissolution of UO(2) in a continuously stirred tank reactor (CSTR) in the presence of Ca(2+) and Zn(2+) was investigated under experimental conditions relevant to contaminated groundwater systems. Complementary experiments were performed to investigate the effect of adsorption and precipitation reactions on UO(2) dissolution. The experiments were performed under anoxic and oxic conditions. Zn(2+) had a much greater inhibitory effect on UO(2) dissolution than did Ca(2+). This inhibition was most substantial under oxic conditions, where the experimental rate of UO(2) dissolution was 7 times lower in the presence of Ca(2+) and 1450 times lower in the presence of Zn(2+) than in water free of divalent cations. EXAFS and solution chemistry analyses of UO(2) solids recovered from a Ca experiment suggest that a Ca-U(VI) phase precipitated. The Zn carbonate hydrozincite [Zn(5)(CO(3))(2)(OH)(6)] or a structurally similar phase precipitated on the UO(2) solids recovered from experiments performed in the presence of Zn. These precipitated Ca and Zn phases can coat the UO(2) surface, inhibiting the oxidative dissolution of UO(2). Interactions with divalent groundwater cations have implications for the longevity of UO(2) and the mobilization of U(VI) from these solids in remediated subsurface environments, waste disposal sites, and natural uranium ores. 相似文献
18.
氯化钙用于高得率浆H2O2漂前预处理 总被引:2,自引:1,他引:2
研究了CaCl2用于高得率桦木浆H2O2漂前预处理的效果,并与DTPA、EDTA、H2SO4等预处理剂的预处理效果进行了比较。结果表明,CaCl,是一种优良的预处理剂。CaCl2预处理的适宜条件为:用量0.5%,pH值7,温度40℃,时间25min。 相似文献
19.
Yu-Jing Zhu Han-Tao Zhou Yong-Hua Hu Jian-Yang Tang Ming-Xing Su Yun-Ji Guo Qing-Xi Chen Bo Liu 《Food chemistry》2011
The inhibition kinetics of 2-phenylethanol, 2-phenylacetaldehyde and 2-phenylacetic acid on the enzyme activity of mushroom tyrosinase have been investigated. The results showed that these aromatic compounds can lead to reversible inhibition of the enzyme; furthermore, 2-phenylacetaldehyde and 2-phenylacetic acid are uncompetitive inhibitors and 2-phenylethanol is a mixed-type inhibitor. The inhibition constants have been determined and the inhibiting ability was: 2-phenylacetaldehyde > 2-phenylacetic acid > 2-phenylethanol, indicating that the functional group on the benzene ring group played an important role in the inhibition of the enzyme. In addition, 2-phenylacetic acid and 2-phenylethanol were found to have effective antibacterial activities, and 2-phenylacetic acid was more effective against Escherichia coli and Ralstonia solanacearum than 2-phenylethanol, but 2-phenylacetaldehyde lacked of antibacterial activity. 相似文献
20.
蔗渣化机浆过氧化物漂白及返黄的研究 总被引:1,自引:1,他引:1
本文的研究表明,白度为31.1%的蔗渣CMP原浆在H_2O_2消耗约4%时经单段或两段H_2O_2漂白后,白度分别达54.8%和75%;瀑白前后分别用EDTA、草酸等处理能有效地提高白度;H_2O_2总量不变时,提高第二段H_2O_2用量有利于浆料白度的提高。增加漂白段数能有效地减少漂浆返黄。与未漂浆相比,漂白浆的打浆度、成纸紧度、撕裂度和裂断长均有提高,不透明度下降。FI-IR显示用H_2O_2漂白蔗渣CMP浆有一定脱木素作用。 相似文献