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1.
超声波降解乐果的研究   总被引:10,自引:0,他引:10  
报道了用超声波降解摸拟废水中低浓度乐果的试验,探讨了超声波辐射时间、外加H2O2、溶液中乐果的初始浓度、溶液温度等因素对乐果降解效果的影响。试验表明,辐射时间延长,降解率增加;加入H2O2可明显提高乐果的降解率;在溶液初始浓度较低的范围内,降解速率随浓度增大而加快,浓度增大到一定值后,降解速率变化不明显;超声降解时溶液温度控制在15-16℃为宜。  相似文献   

2.
超声波降解废水中十二烷基苯磺酸钠的实验研究   总被引:1,自引:1,他引:1  
通过超声波作用于废水中的十二烷基苯磺酸钠(DBS)试验,讨论了辐照时间、溶液温度、溶液初始浓度、pH值、外加H2O2等因素对DBS降解效果的影响。结果表明:DBS的降解率随辐照时间的延长而增加;溶液温度在低于60℃时,DBS的降解率随温度的升高而增加,高于60℃降解率随温度的升高反而降低;溶液初始浓度增大降解率增加;溶液pH对降解率影响不大;外加H2O2可明显提高DBS降解率。  相似文献   

3.
研究了超声波降解苯酚废水的效果和超声波对降解效果的影响因素,实验结果说明溶液初始浓度,温度,pH等因素对苯酚降解效果有明显影响.结果表明:溶液的初始浓度为135.15mg/L,超声辐射时间为4小时,温度为30℃,pH=3.0时,超声波降解苯酚的效果较好,为5.64%.曝气可以促进苯酚的降解,加入H2O2可使降解率提高到61.60%.  相似文献   

4.
研究了超声波降解苯酚废水的效果和超声波对降解效果的影响因素,实验结果说明溶液初始浓度,温度,pH等因素对苯酚降解效果有明显影响.结果表明:溶液的初始浓度为135.15mg/L,超声辐射时间为4小时,温度为30°C,pH=3.0时,超声波降解苯酚的效果较好,为5.64%.曝气可以促进苯酚的降解,加入H2O2可使降解率提高到61.60%.  相似文献   

5.
采用小型光催化反应装置,以溶胶-凝胶法负载于玻璃纤维网上的固定膜TiO2为催化剂对布洛芬(IBP)进行光催化降解,分析了吸附、光解、IBP初始浓度、溶液初始pH和投加H2O2剂量对TiO2催化剂降解布洛芬的影响,并考察了IBP的矿化过程,对IBP降解中间产物进行定性分析.结果表明:吸附作用和在UV365下光解作用对降解布洛芬的影响不明显;IBP在较低浓度范围内,其降解呈伪一级反应,反应速率常数随初始浓度增大而减小;随着溶液初始pH的增大,IBP的光催化降解速率逐渐降低;H2O2投加剂量对IBP光催化降解影响显著,这是IBP在水中存在状态和TiO2界面电荷性质受到pH影响所致,为提高光催化降解布洛芬速率,较适宜的H2O2投加剂量为2.5 mg/L左右.光催化对IBP有较好的矿化作用.LC-MS分析表明,·OH攻击作用是IBP光催化降解的基本途径.  相似文献   

6.
研究了pH值,Fe2 浓度,H2O2浓度以及有无超声波条件的对胭脂红催化降解速率的影响.结果表明:随着模拟废液的pH值的增大,胭脂红的降解速率呈下降趋势.Fe2 的最佳浓度为5×10-3 mmol/L,而H2O2的最佳浓度为5×10-2 mmol/L;无论是大于或是小于最佳值浓度均会导致胭脂红降解速率的下降.在超声波存在的条件下可以明显的加快降解速率.  相似文献   

7.
超声波降解吲哚废水的实验研究   总被引:8,自引:0,他引:8  
研究了吲哚模拟废水在超声波作用下的降解, 并对超声波与电化学协同作用下吲哚的降解规律进行了初步探讨. 考察了废水初始浓度、pH值、处理时间、超声功率、外加催化剂以及声电协同作用下电流密度等因素对吲哚降解的影响. 结果表明, 超声处理吲哚的降解规律符合一级反应; 处理时间越长, 降解率越大; 吲哚初始浓度较低时, 降解率较大; 随着 pH值的增大, 降解率先增大后减小, 在 pH=8左右降解率最大; 降解率随超声功率的增大而增大, 在120 W时达最大值, 随后降低; 加入1 .5 mmol/L H2O2, 对吲哚的降解有较大的促进作用. 在超声波存在下, 电解电流在1 0~2. 2 A范围内, 降解率随电流先增大后减少, 电流为1. 9 A时, 降解率达最大值; 声电化协同作用能提高吲哚的降解率.  相似文献   

8.
以亚甲基蓝溶液为模型污染物,在超声波芬顿法协同作用下对亚甲基蓝染料废水的降解作用进行了研究,考察了反应时间、H2O2用量、溶液pH值、Fe2+的浓度等因素对亚甲基蓝溶液降解的影响。结果表明,超声波单独降解亚甲基蓝溶液脱色效果不明显,超声波协同H2O2降解亚甲基蓝,加入30%H2O26mL,脱色率约45.80%;溶液pH2.80,Fe2+浓度为30mmol/L时,超声波芬顿法协同降解甲基蓝180min,脱色率达92.70%。试验证明,超声波芬顿法是一种降解亚甲基蓝的有效方法。  相似文献   

9.
研究了有机溶剂中4,4'-二溴联苯(4,4'-DBB)的超声降解.考察了初始质量浓度、处理时间及添加氧化剂(H2O2)和盐(NaCl)后的联合作用对降解率的影响.采用超声频率20 kHz、固定声强0.16W/cm2的超声波作用一段时间,结果表明:初始质量浓度越大,降解率越低;超声时间越长,降解率越高.单独超声降解8 mg/L 4,4'-DBB溶液600 min,降解率可达16.0%.而加盐超声240 min,10 mg/L 4,4'-DBB溶液的降解率可提高到12.1%,符合一级反应规律,一级反应常数为-5.231 18×10-4 min-1.超声与过氧化氢(US/H2O2)联合作用180 min,2 mg/L 4,4'-DBB溶液的最终降解率可达到43.1%.  相似文献   

10.
研究了超声波降解水中二甲苯的降解效果,详细探讨了反应容器及沸石、声强、超声时间、H2O2投加量、温度、pH值等因素对降解二甲苯的影响.实验结果表明:二甲苯初始质量浓度为27.6 mg/L,H2O2的质量浓度为1.68 g/L,温度为24±1 ℃时,经141.32 W/cm2声强辐射1 h,其降解率可达99.2%.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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