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纳米TiO2光催化降解水中有机污染物的研究与发展 总被引:135,自引:4,他引:131
光催化降解水中有机污染物是一项新兴的颇有发展前任的废水处理技术,纳米Tio2因其活性高,稳定性好而在该领域广泛被用作光催化剂。本文系统介绍了纳米TiO2的制备,光催化降解水中有机污染物的机理,动力学规律及其研究现状和发展方向。 相似文献
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TiO2在微孔型活性炭纤维上的固载及其对苯酚的光催化降解 总被引:12,自引:4,他引:8
以环氧树脂作为TiO2与活性炭纤维(ACF)之间联结的前驱体,使TiO2粘附于纤维表面。后经氮气氛下400℃-580℃不同温度的煅烧处理,制得TiO2/ACF复合体。采用BET,SEM,XRD及UV—Vis光谱等手段对复合体的物理化学特性进行了表征。以水中苯酚为目标污染物考察了TiO2/ACF样品的光催化性能、结果表明,460℃煅烧品较其他样品对苯酚具有更好的去除能力。在其重复利用过程中,始终保持了高的光催化效率,直至第三次循环,其最终对苯酚的去除量仍与P25粉体相当。而且,牢固负载的TiO2更具实用性,易于从水中回收。 相似文献
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环境可降解塑料的研究开发 总被引:10,自引:0,他引:10
在介绍光降解塑料和生物破坏性塑料之后,着重综述了降解塑料尤其是全生物降解塑料的研究和开发现状,指出当前降解塑料发展所面临的问题和对策,并对生物降解塑料的发展前景和发展趋势进行了讨论。 相似文献
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聚硅烷的合成、表征及光敏性研究 总被引:6,自引:0,他引:6
研究了不同添加量的二甘醇二甲醚和15-冠醚-5两种助溶剂对聚(甲基乙基硅烷)简记为PM-PES)合成反应的影响,结果表明,反应体系中添加10%二甘醇(二甘醇二甲醚,甲苯的体积比),PMPES的产率明显提高,分子量趋于单分散分布,并向聚(甲基环乙基硅烷)(简主为PMCS)和甲基环乙基硅烷-甲基苯乙基硅烷共聚物(甲基环乙基二氯硅烷:甲基苯乙基二氯硅烷的单体摩尔比为2.0,1.0和0.5时,相应的共聚物分别简记为Copolymer1,Copolymer2和Copolymer3)的合成反应中添加10%二甘醇二甲醚助溶,春产率分别高达47%和52%以上,MW均达10^5 ,并且^1H-NMR,IR说烽UV吸收光谱对所合成的聚硅烷进行了表征,研究了PMCS膜在空气中经紫外光辐射前后的IR谱和高效凝胶渗透透色谱(GPC),表明,PMCS经紫外光辐照发生光降解的同时,还伴随着光氧化。 相似文献
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可光和生物降解淀粉聚乙烯膜的微生物降解研究 总被引:3,自引:0,他引:3
采用琼脂板培养试验法、菌体蛋白量的凯氏定量测定法、二氧化碳释放量和经微生物培养的失重测定等方法,对含淀粉和光敏促进剂的聚乙烯膜在不同的微生物环境下的可生物降解性进行了研究。随着膜中淀粉含量的提高,膜的生物降解性提高。经光降解的膜比未经光降解的膜有更好的生物降解性,并且光降解的时间越长,膜的生物降解效果越好。微生物种类不同,对膜的降解作用有一定的差异,霉菌比细菌对膜有更强的降解作用。 相似文献
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Kinetics and mechanism of para-chlorophenol photoconversion with the presence of nitrite in ice 总被引:3,自引:0,他引:3
Chun-Li Kang Hong-Jie Gao Ping Guo Ge-Shan Zhang Xiao-Jian Tang Fei Peng Xing-Juan Liu 《Journal of hazardous materials》2009,170(1):163-168
The photochemistry of para-chlorophenol (4-CP) under UV irradiation by using a 125-W high-pressure mercury lamp as light source with the presence of nitrite in a solid water ice matrix had been studied. The experiments were carried out in a photochemical cold chamber reactor at −14 to −12 °C. Each influence factor of the 4-CP photoconversion kinetics in the water ice was inspected. The results show that the 4-CP photoconversion obeys the first-order kinetics model and the initial concentration of 4-CP, the initial concentration of nitrite, pH value, light intensity, inorganic ions and the water quality all have significant influence on the photoconversion rate. In addition, nine intermediate products were characterized by GC–MS, HPLC–ESI-MS and HPLC techniques and the possible photoconversion mechanism was proposed accordingly. It is concluded that the mechanism and photoproducts of 4-CP photolysis in ice are changed due to the presence of NO2−. 相似文献
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Fe3+-doped TiO2 (Fe-TiO2) porous microspheres were prepared by controlled hydrolysis of Ti(OC4H9)4 with water generated "in situ" via an esterification reaction between acetic acid and ethanol, followed by hydrothermal treatment. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic absorption flame emission spectroscopy (AAS), electron paramagnetic resonance (EPR) spectrum, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and nitrogen adsorption-desorption methods. All of the undoped TiO2 and Fe-TiO2 samples exclusively consist of primary anatase crystallites, which further form porous microspheres with diameters ranging from 150 to 500 nm. The photocatalytic activity of Fe-TiO2 catalysts was evaluated from the photodegradation of methyl orange (MO) aqueous solution both under UV and visible light irradiation. Fe3+ doping effectively improves the photocatalytic activity under both UV light irradiation and visible light irradiation with an optimal doping concentration of 0.1 and 0.2%, respectively. The photocatalytic mechanisms of Fe-TiO2 catalysts were tentatively discussed. 相似文献
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Reactive dyes remotion by porous TiO2-chitosan materials 总被引:3,自引:0,他引:3
Zubieta CE Messina PV Luengo C Dennehy M Pieroni O Schulz PC 《Journal of hazardous materials》2008,152(2):765-777
In this work, the aim was to evaluate the remotion (adsorption plus degradation) of two reactive dyes, Methylene Blue (MB) and Benzopurpurin (BP), from aqueous solutions by the utilization of TiO2-chitosan microporous materials. Two different TiO2-chitosan hybrid materials were synthesized: TiO2-Chit A with 280 mg chitosan/gTiO2 and TiO2-Chit B with 46.76 mg chitosan/g TiO2. Adsorption data obtained at different solution temperatures (25, 35, and 45 degrees C) revealed an irreversible adsorption that decrease with the increment of T. Langmuir, Freundlich and Sips isotherm equation were applied to the experimental data. The obtained parameters and correlation coefficient showed that the adsorption of both dyes on TiO2-Chit A at the three work temperatures was best predicted by the Langmuir isotherm, while Sips equation adjusted better to adsorption data on TiO2-Chit B. The adsorption enthalpy was relatively high and varied with T, indicating that interaction between adsorbent and adsorbate molecules was not only physical but chemical. There is a change in the adsorption heat capacity, (Delta(ads)C(p)<0), related with intense hydrophobic interactions. The kinetic adsorption data were processed by the application of Lagergren and Avrami models. It was found that adsorption of both dyes on both adsorbents under the operating conditions was best predicted by Avrami model. The variation of kinetic order, n, and k(av) with T are related to a pore followed by intra particle diffusion control of the adsorption rate. MB photodegradation on both TiO2-chitosan hybrid materials was of 91 (in A) and 41% (in B) and augmented with the chitosan content. For BP can be seen that the process in darkness resulted in a high remotion capacity than in UV light presence. 相似文献