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151.
一种新型电化学法处理硝态氮废水的初步研究 总被引:2,自引:0,他引:2
通过对Pd-Me双金属催化还原NO 3--N和折点氯化法处理NH 4+-N的相关理论分析,提出了一种基于电化学法的新型NO 3--N废水处理工艺.即利用具有电子空轨的常见金属元素修饰Ti基获得催化阴极,在电场的作用下,将NO 3--N催化还原;通过调整催化元素的配比和电解条件,控制NO 3--N还原产物主要为NH 4+-N;利用阳极氧化Cl-生成高氧化性物质HOCl,将NH 4+-N氧化为无害产物N2-N.结果表明,金属元素Co和Cu修饰Ti基制得阴极可以有效地催化还原模拟废水中的NO 3--N;按前驱物溶液金属元素摩尔比1∶1制得Ti基Co-Cu复合涂层催化阴极,可以将NO 3--N高效催化还原为NH 4+-N;电解体系中引入Cl-后,通过阳极作用可将NO 3--N还原生产的NH 4+-N有效地氧化为N2-N.在100 mg/L NO 3--N模拟废水中添加1 000 mg/L Cl-,设置极板间距6 mm、电流400 mA,电解2.5 h后出水NO 3--N、NO 2--N、NH 4+-N和TN分别为2.9、0.5、1.7和6.0 mg/L. 相似文献
152.
含硫油品储罐腐蚀产物自燃性的研究 总被引:1,自引:0,他引:1
通过模拟储油罐中硫铁化物的生成方式, 分析和研究了H2S气体在无氧条件下,与不同相对湿度的Fe2O3、Fe3O4和Fe(OH)3反应所生成的硫铁化物的自燃性.不同相对湿度的试样经6 h硫化后,其自燃性明显不同.以Fe2O3试样为例,相对湿度为0的硫化产物氧化升温最高为256 ℃,平均升温速率为10.8 ℃/min; 相对湿度为5%、10%和15%的硫化产物,氧化升温最高温度分别为474 ℃、408 ℃和388 ℃,平均升温速率分别为20.5 ℃/min、18.3 ℃/min和13.5 ℃/min.实验结果表明, 不同相对湿度、不同物质的硫化产物,其自燃性有显著差异,样品的相对湿度对硫化产物的自燃性有重要影响.对各种干燥样品的硫化产物进行电镜分析发现,由不同物质硫化所生成的硫化产物结构不同,致使其自燃性有较大差异.硫铁化物氧化反应放热是引发油罐着火的主要因素. 相似文献
153.
The catalyst of Fe-Mo/ZSM-5 has been found to be more active than Fe-ZSM-5 and Mo/ZSM-5 separately for selective catalytic reduction (SCR) of nitric oxide (NO) with NH3. The kinetics of the SCR reaction in the presence of O2 was studied in this work. The results show that the observed reaction orders were 0.74-0.99, 0.01-0.13, and 0 for NO, O2 and NH3, respectively, at 350-450℃. And the apparent activation energy of the SCR was 65 kJ/mol on the Fe-Mo/ZSM-5 catalyst. The SCR mechanism was also deduced. Adsorbed NO species can react directly with adsorbed ammonia species on the active sites to form N2 and H2O. Gaseous O2 might serve as a reoxidizing agent for the active sites that have undergone reduction in the SCR process. It is also important to note that a certain amount of NO was decomposed directly over the Fe-Mo/ZSM-5 catalyst in the absence of NH3. 相似文献
154.
155.
156.
María-Vicenta Galiana-AleixandreJosé-Antonio Mendoza-Roca Amparo Bes-Piá 《Journal of Cleaner Production》2011,19(1):91-98
The use of large quantities of sulfuric acid and other sulfur-containing chemicals causes high sulfate concentrations in the wastewater of a tannery. The aim of this work was reducing the sulfate concentration in the final wastewater from a tannery. For that, firstly a study about the main sulfate sources in a tannery was carried out and the total sulfates load in the tannery wastewater was evaluated. Two measures for sulfates reduction were studied: the recycling of unhairing wastewater to the soaking drums and the reuse of the chromium sulfate from the tanning washing wastewater after its separation by nanofiltration (NF). The first measure proposed was studied experimentally in laboratory drums of 5 L of volume. Two series of experiments with different volumes of unhairing wastewater in the soaking bath were carried out. The quality of the final leather was evaluated by means of mechanical tests. NF experiments were carried out in a laboratory pilot plant with a spiral wounded membrane element. Concerning the results, the combination of 50% unhairing wastewater and 50% of fresh water was appropriate in order to obtain leather with an acceptable quality. Besides, it drove to a diminution of approximately 10% in the addition of sulfide in the unhairing. Related to the NF experiments, 97% of the sulfates were rejected by the membrane. The separated ions could be recycled to the tanning drums. The application of the two measures (firstly the recycling of the unhairing wastewater and secondly the NF of the tanning washing wastewater) drove to a reduction of 14.82 kg SO4−2 t−1 of raw hide. 相似文献
157.
158.
探索了电渗析法再生CO2电还原电解液的可行性。以HCOOK溶液作为CO2电还原反应后的模拟液,采用单室电渗析装置对其进行再生,考察了电流、时间、温度等操作条件对电流效率和再生率的影响,研究结果表明:在常温条件下,操作电流低于极限电流时,采用电渗析法再生CO2电还原电解液具有高的电流效率和再生率。 相似文献
159.
The AgCl/Al2O3 catalyst has potential for use in the selective catalytic reduction (SCR) of NOx. A compound hydrocarbon, following
oxygenation is used as a type of reducing agent. In this experiment, the AgCl/Al2O3 catalyst was produced by four different methods,
and the differences among their reduction catalysis of NOx were compared. Ethanol was used as a type of reducing agent. X-ray
diffraction analysis was performed to study the crystalline structure and scanning electron microscope and transmission electron
microscope (TEM) were applied to determine the microindentation. The results indicated that, in the range of 350–400°C, there was
no significant difference on the NOx reduction rate; however, there was dispersion at high and low temperature ranges. The size of the
AgCl particles was about 20–100 nm. 相似文献
160.