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81.
CATAZONE is a new process of heterogeneous catalytic ozonation in which water is ozonated in the presence of a solid catalyst composed of titanium dioxide. The efficiency of this O3/TiO2 system has been compared to the two well-known oxidant systems: ozone alone and ozone combined with hydrogen peroxide.
This comparison was undertaken on three models of natural organic compounds : an aquatic fulvic acid, a protein and a disaccharide. The first results showed the following order of relative efficiency: O3/TiO2 > O3/H2O2 > O3 as far as Total Organic Carbon (TOC) removal was concerned. 相似文献
82.
83.
黄俊涛 《自动化与仪器仪表》2012,(3):6-8
针对以三沟式氧化沟为核心的污水处理工艺的特点,采用由工控机(IPC)与可编程控制器(PLC)组成的自动控制系统,实现了对污水处理全过程的自动控制。本文首先讨论了文章中所采用的进化工艺,接着就自动控制系统的控制系统和软件设计进行了探讨。 相似文献
84.
HE Zhiyong PENG Xiaoyan LIU Kaiqi LI Lin 《中国耐火材料》2007,16(4):21-23
B4C was added into the low-carbon MgO-C materials in order to improve the oxidation resistance. The results show adding 0. 3wt% B4C can get the best oxidation resistance and adding 0. 2 wt% B4C can get the highest hot modulus of rupture. Altogether, adding 0. 2wt% B,C into the low-carbon MgO-C materials can get better oxidation resistance and hot strength. 相似文献
85.
SiO2 surface film is insufficient to protect SiC from the oxidation at widely varying partial pressures of oxygen, in particular in the presence of water vapor (e.g. in gas turbines) and also in other environments, e.g. during brazing for hard “tipping” of turbine blades. This work demonstrates that sol–gel alumina, coated on 0.5 mm coarse SiC grit, may form an acceptable, up to 10 μm thick “environmental barrier coating” EBC for some of these applications. The sol–gel has advantages over other methods (such as CVD) is the simplicity and low cost. We have used NH4OH pre-treatment to hydroxylate surface of SiC prior to applying alumina coating. Such modified SiC/SiO2 surface helped to deposit the positively charged alumina sol, and thus allowed to build thick coatings on the SiC grit. There is some indication that these coatings partially convert to mullite through reaction at the interface with the native silica on SiC. Oxidation resistance tests at 1200 °C were performed to show effectiveness of such coated SiC grit. 相似文献
86.
Chul-Ho Park Mi-Sook Won Chul-Su Lee Won-Hyo Cha Young-Gook Son 《Journal of Electroceramics》2006,17(2-4):619-623
PZT thin films and interlayers were fabricated by the radio frequency (r.f.) Magnetron-sputtering from the Pb1.1Zr0.53Ti0.47O3, PbO and TiO2 target. As a result of the XPS depth profile analysis, we can confirm that the substrate temperature affects the oxidation
condition of each element of interlayers and the PZT film. Compared to the PZT/Pt structure, the dielectric and pyroelectric
properties of PZT thin films inserted by interlayers were measured to a relatively high value. In particular, the PZT/PbO
structure had the highest pyroelectric properties (P = 189.4 μC/cm2K; F
D = 12.7×10−6 Pa−1/2; F
V = 0.018 m2/C). 相似文献
87.
Methyl tert-butyl ether (MTBE) is a gasoline oxygenate that has become a significant threat to groundwater supplies across the United States. Due to its physiochemical properties it has proven difficult and costly to remove from contaminated sites. This study was conducted to determine whether the alternative oxygenates (AO)—diisopropyl ether (DIPE), ethyltert-butyl ether (ETBE), tert-amyl methyl ether (TAME), tert-butyl alcohol (TBA), and ethanol (EtOH)—present a more efficient and less costly option from a remediation standpoint. Air stripping, carbon adsorption, and ultraviolet/H2O2 and O3/H2O2 advanced oxidation processes were examined at pilot scale to develop design parameters from which technical and economic comparisons were made for each alternative oxygenate versus MTBE. The experimental results showed that the ether AOs—DIPE, TAME, and ETBE—were each more efficiently and more economically treated than MTBE. The alternative alcohol oxygenates—TBA and EtOH—were less efficiently and less economically treated by the processes studied. The paper details the effects of primary process parameters and properties of individual oxygenates on process efficiency. 相似文献
88.
In this paper we present the results of XPS study of the surface chemistry of L-CVD SnO2 thin films onto Si(100) before and after subsequent additional oxidation. Moreover, the ageing effect was also studied in order to check the influence of ambient oxidation. As-deposited L-CVD SnO2 thin films exhibit evident nonstoichiometry with the relative concentration [O]/[Sn] equal to 1.29 ± 0.1. After in situ oxidation at high temperature (800 K) the relative concentration [O]/[Sn] increases to 1.95 ± 0.05 which corresponds to the almost stoichiometric SnO2. Almost the same relative concentration [O]/[Sn] of L-CVD SnO2 thin films has been obtained after long term exposure to air. The oxidation states of L-CVD SnO2 thin films in both cases were confirmed by the shape analysis of corresponding XPS O1s and Sn3d5/2 peaks using the decomposition procedure. For the as-deposited L-CVD SnO2 thin films a mixture of SnO and SnO2 was observed, while for the oxidized L-CVD SnO2 thin films the domination of SnO2 was determined. 相似文献
89.
陈建初 《武汉化工学院学报》1997,19(2):34-37
本文用交联、氧化二种化学方法加工玉米淀粉,制取了复合变性淀粉,并重点研究、筛选了反应体系中催化剂、淀粉浓度、交联剂、氧化剂、反应温度及碱量等工艺条件. 相似文献
90.
The purpose of this work was to determine the influence of ion implantation on the oxidation resistance of ZrN coatings. Samples were prepared on AISI 304 stainless steel by cathodic arc deposition. They were submitted to Y implantation at 150 °C with various fluences using a metal vacuum vapour arc ion implanter. The oxidation behaviour of as-deposited and Y-implanted ZrN coatings was characterized by weight gain measurement. The oxidation resistance of the ZrN coating was reduced after it was implanted with yttrium at a low fluence but improved at higher fluence. X-ray photoemission spectroscopy and glancing angle X-ray diffraction were employed to analyze the valence states of the oxide scale and the phase composition of the oxidation layers. Yttrium implantation can greatly improve the oxidation resistance of the ZrN coating. 相似文献