共查询到19条相似文献,搜索用时 171 毫秒
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《给水排水》2017,(11)
研究考察水中存在的阴离子(Cl~-、HCO_3~-/CO_3~(2-)、NO_3~-)对紫外/过硫酸氢钠(UV/PS)光解2,4-DCP的降解率、反应速率常数、反应动力学级数等的影响,同时选用3种实际水源水体和自来水做为水质背景来验证UV/PS光解2,4-DCP的降解效果。还考察UV/PS氧化2,4-DCP溶液在氯和氯胺消毒工艺过程中消毒副产物生成的种类和产量。结果表明溶液中分别存在Cl-、HCO_3~-/CO_3~(2-)、NO_3~-等常规离子时,低浓度的Cl~-抑制反应进行,高浓度的Cl-促进反应进行,HCO_3~-/CO_3~(2-)对反应有明显的抑制作用,NO_3~-对反应有促进作用。推测出了UV/PS光氧化工艺光解2,4-DCP的五种中间产物及可能的降解反应路径。溶液在氯和氯胺消毒过程中生成的含碳消毒副产物是三氯甲烷、二氯乙酸和三氯乙酸;生成的含氮消毒副产物主要是二氯乙腈和三氯硝基甲烷。UV/PS工艺降低了溶液中2,4-DCP做为前体物生成消毒副产物的量。 相似文献
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负载型纳米TiO2光催化降解罗丹明B动力学与机理研究 总被引:6,自引:0,他引:6
采用负载型纳米TiO2/AC在流化床反应器中降解罗丹明B染料废水。研究了罗丹明B的光催化降解反应动力学与降解机理。结果表明,负载型纳米TiO2光催化降解罗丹明B过程符合一级动力学方程,降解机理首先是罗丹明B分子发色基团苯氨基、羰基键被破坏,然后是无色中间产物的逐渐降解。 相似文献
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Fenton反应催化降解苯胺及影响因素研究 总被引:4,自引:0,他引:4
对Fenton反应催化降解水中苯胺和影响催化氧化效果的几种因素进行研究和探讨。试验表明,除废水pH,Fenton试剂用量是影响苯胺降解的主要因素外,水中Cl-也对催化性能产生明显的抑制作用。虽单纯的Fenton反应对苯胺的催化降解率可达98%以上,但CODCr去除率却相对较低,表明Fenton反应对苯胺降解后的某些中间产物难于再进一步矿化,而紫外线辐照可提高Fenton反应的催化降解性能和CODCr去除率,实现对某些中间产物的持续矿化作用。 相似文献
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为研究在催化臭氧化过程中,载锰污泥活性炭对草酸废水降解的催化效果,以及为污泥的资源化探索一条新途径,本实验采用连续流臭氧氧化实验,通过单因素实验方法考察了载锰污泥活性炭催化臭氧化反应的主要影响因素及最佳反应条件,同时对催化臭氧化反应机理进行了探讨。结果表明:在臭氧浓度为5.0 mg/L,载锰污泥活性炭投加量为100 mg/L,pH值为3.5的最佳反应条件下,60 min内草酸的去除率最高达91.2%。叔丁醇对草酸降解具有抑制作用,催化臭氧化反应符合羟基自由基的反应机制。该方法的处理效果较为明显,对评价催化臭氧法的效果具有较明显的参考价值。 相似文献
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OH氧化性能力极强,可以氧化各种有机物和无机物,特别适用难降解污染物的处理,具有氧化效率高、反应速度快、无选择性、无二次污染等优点。但作为化学反应的中间体,羟基自由基寿命极短,定量检测非常困难。 利用电化学分析法和氧化还原分析法的原理,建立了一种直接检测·OH浓度的新方法。以过量Fe2+与羟基自由基反应,然后用高锰酸钾返滴剩余的 Fe2+,根据高锰酸钾的滴定量计算羟基自由基的浓度。该方法再现性好(s= 3.28×10-3),灵敏度高,检出限为1.50×10-7mol/L。 相似文献
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细菌对黄河水和底质中2-氯酚的降解作用 总被引:1,自引:0,他引:1
为考察黄河水中和黄河底质中的细菌对氯基酚的降解过程及其差异,以黄河花园口段的黄河水和黄河底质为试验样品,分别将其接种进以2-氯酚为唯一碳源的液体培养基进行了试验.结果表明:①黄河水和黄河底质中的细菌对2-氯酚的降解过程符合二项式方程;②接种黄河底质的试验瓶,经过204 h培养,对2-氯酚的降解率达到91.14%;接种黄河水的试验瓶,经过300 h培养,对2-氯酚的降解率达到94.20%;黄河底质中的细菌对2-氯酚的降解速率是水中的1.32倍. 相似文献
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采用纳米自组装法制备了具有吸附性和光催化性的Ti/MCM-22/MCM-41微介孔复合材料,利用X射线衍射、N2吸附、扫描电镜等方法对其进行表征。将复合材料用于光催化降解酸性红B的实验,考察了催化剂用量、光照时间、pH值和染料初始浓度对光催化降解率的影响,并对光降解产物进行了紫外光谱分析。结果表明:当染料的初始浓度为50 mg/L,废水pH在6左右,催化剂投加量为0.1 g/L,光照时间120 min,酸性红B的去除率可达98%以上,光催化降解反应遵循一级反应动力学方程。降解产物的紫外光谱图表明,降解后酸性红B的两个特征吸收带消失,结构的共轭系被打破,颜色消失,说明该复合材料去除水中的酸性红B主要是通过光催化作用。 相似文献
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《水科学与水工程》2015,8(3):233-238
The degradation of acephate in aqueous solutions was investigated with the ultrasonic and ozonation methods, as well as a combination of both. An experimental facility was designed and operation parameters such as the ultrasonic power, temperature, and gas flow rate were strictly controlled at constant levels. The frequency of the ultrasonic wave was 160 k Hz. The ultraviolet-visible(UV-Vis) spectroscopic and Raman spectroscopic techniques were used in the experiment. The UV-Vis spectroscopic results show that ultrasonication and ozonation have a synergistic effect in the combined system. The degradation efficiency of acephate increases from 60.6% to 87.6% after the solution is irradiated by a160 k Hz ultrasonic wave for 60 min in the ozonation process, and it is higher with the combined method than the sum of the separated ultrasonic and ozonation methods. Raman spectra studies show that degradation via the combined ultrasonic/ozonation method is more thorough than photocatalysis. The oxidability of nitrogen atoms is promoted under ultrasonic waves. Changes of the inorganic ions and degradation pathway during the degradation process were investigated in this study. Most final products are innocuous to the environment. 相似文献
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A. M. Filonidov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1988,22(5):276-280
Conclusion The investigations permit recommending the ultrasonic method for inspection and flaw detection of joints of precast-monolithic penstocks of PSS. This nondestructive inspection method has a sufficient reliability for field conditions. Ultrasonic flaw detection of the joints of precast-monolithic penstocks was adopted as the main and most large-scale type of field inspection at the construction site of the Zagorsk PSS.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 5, pp. 24–27, May, 1988. 相似文献
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超声强化臭氧降解高浓度苯酚废水研究 总被引:4,自引:0,他引:4
石新军 《水科学与工程技术》2006,(4):33-36
超声及其组合技术对有机物废水降解是一种新兴的污水处理技术,有着广阔的发展前景和应用市场.对超声强声动力强化臭氧降解高浓度苯酚废水过程中的臭氧通气量、溶液的pH值、反应时间及溶液的初始浓度进行了实验研究,并对单一臭氧和超声强化臭氧降解效果进行了比较.结果表明:由于超声独特的物理、化学效应为臭氧降解提供了极端的物理、化学环境,二者协同作用使得反应进行彻底,COD去除率可达100%. 相似文献
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Chang-ping ZHU Bo HUANG Qing-bang HAN Cai-hua NI Guang-jun ZHU Ming-hua LIU Ming-lei SHAN 《水科学与水工程》2011,4(1):74-82
The process of decomposing p-nitrophenol (PNP) with power ultrasound requires strict control of acoustic and electric conditions. In this study, the conditions, including acoustic power and acoustic intensity, but not ultrasonic frequency, were controlled strictly at constant levels. The absorbency and the COD concentrations of the samples were measured in order to show the variation of the sample concentration. The results show significant differences in the trend of the solution degradation rate as acoustic power increases after the PNP solution (with a concentration of 114 mg/L and a pH value of 5.4) is irradiated for 60 min with ultrasonic frequencies of 530.8 kHz, 610.6 kHz, 855.0 kHz, and 1130.0 kHz. The degradation rate of the solution increases with time and acoustic power (acoustic intensity). On the other hand, the degradation rate of the solution is distinctly dependent on frequency when the acoustic power and intensity are strictly controlled and maintained at constant levels. The degradation rate of the PNP solution declines with ultrasonic frequencies of 530.8 kHz, 610.6 kHz, 855.0 kHz, and 1130.0 kHz;the COD concentration, on the contrary, increase. 相似文献
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机组PSS参数整定及其抑制系统低频振荡的效果 总被引:1,自引:0,他引:1
在对云南大朝山水电厂机组的ABB公司UNITROL 5000数字式励磁调节器的电力系统稳定器(PSS)、漫湾电厂机组的南瑞集团SJ-800型励磁调节器的电力系统稳定器(PSS)进行初步理论计算研究的基础上,通过对其励磁系统进行在线无补偿频率特性的测量,分别提出了一组PSS参数,并详细进行了PSS电压阶跃响应试验、原动机功率突然改变时的反调试验、系统扰动试验,结果表明,这两组参数可以有效地阻尼系统低频振荡,具有良好的鲁棒性。大朝山电厂、漫湾电厂发电机组PSS投入运行后,对保证云南电网乃至南方电网安全稳定运行起到了重要作用。 相似文献
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为提高膜蒸馏在处理垃圾渗滤液膜浓缩液时渗透通量的稳定性,设计了一种新型的超声强化直接接触膜蒸馏(US-DCMD)装置,试验研究了超声对膜渗透通量的影响,并采用电子显微镜、X射线能量色散光谱等手段分析超声对膜面污染层的影响。试验结果表明:在60W的超声辐照条件下,渗透通量最高提升19.4%,并在膜溶液浓缩系数达到4时,相对渗透通量最高维持在77.1%,而未施加超声的相对渗透通量在膜溶液浓缩系数为2时降至20.7%;膜面的主要污染物为CaCO_(3)及腐殖酸,其中CaCO_(3)是限制膜渗透通量的主要因素;超声使污染层钙的质量分数从25.6%降至15.0%,并且不会引起有机物的降解或改性;超声辐照使膜面污染层不均匀且存在裂隙,减少了污染层厚度,维持了渗透通量的稳定。 相似文献
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F. F. Gubin M. F. Gubin 《Power Technology and Engineering (formerly Hydrotechnical Construction)》1973,7(2):139-145
Conclusions An essential virtue of a PSS with an underground downstram basin consists in the possibility of constructing it in practically
any region, since its location is not related with topographic conditions. The deep founding of the basins and power house
of the PSS permit locating it under favorable geologic conditions in the greater part of the territory of our country. The
construction of such PSS can be based on a standard design if the same capacities, heads, and daily energy production of a
series of PSS of the given type are used. The combined construction of SPS, APS, and PSS permits creating a power system with
an optimal structure of the generating capacities with a substantial decrease of expenditures for industrial facilities, housing,
etc.
It is possible to locate PSS near maximum load centers which increases the stability of the power system and reliability of
the electrical supply and quality of electric energy delivered to consumers with a decrease in expenditures for the construction
of transmission lines. The location of PSS on seacoasts and near lakes opens prospects for the effective use of these bodies
of water as the upstream basins of PSS.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 29–33, February, 1973. 相似文献