首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 718 毫秒
1.
微波在植物纤维漂白中的应用研究   总被引:4,自引:0,他引:4  
采用微波辐射技术,建立了次氯酸钠漂白麦草浆工艺。影响微波辐射漂白纸浆的因素有三项:微波辐射时间、辐射功率和次氯酸钠用量。当微波辐射功率为352w,辐射时间为2min,次氯酸钠用量为10mL时,2g绝干浆的白度达77%ISO以上。此外,通过与水浴的对比实验,发现微波加热2min纸浆达到的白度相当于水浴加热40min,这对于能源的节省是非常有意义的。  相似文献   

2.
微波辐射催化氧化处理含氯漂白废水的研究   总被引:2,自引:1,他引:1  
为降低漂白废水化学需氧量,采用微波辐射活性炭处理含氯漂白废水.实验可以得到:25mL废水在活性炭用量1.0g,微波辐射时间为8min,功率为800W时的处理效果最好,由初始CODcr1176mg/L化学需氧量(Chemical oxygen demand,COD)下降到50mg·I-1,CODcr去除率达95%以上.有效地降低了漂白废水COD.  相似文献   

3.
采用正交试验方法对纸浆多段漂白工艺中NaOH用量、辐射功率、碱处理时间及漂白工艺组合等因素进行了优化,并用红外光谱和纤维分析法对微波辐射纸浆漂白机理进行了研究。多段漂白的最佳工艺条件是:一段H2O2漂白,微波辐射功率240W,处理时间2.5min,H2O2用量5%,NaOH用量4%;二段NaOH碱处理,微波辐射功率200W,处理时间1min,NaOH用量3.5%;三段NaClO漂白,微波辐射功率240W,处理时间2.5min,NaClO用量4.2%,NaOH用量1%。在该工艺条件下,纸浆白度达78%ISO以上。红外光谱检测发现反应后木素的结构骨架大体上不起变化。纤维分析测定结果发现纸浆纤维形态基本上没有发生变化。  相似文献   

4.
进行了麦草浆的水浴加热漂白和微波辐射漂白对比实验,考察了微波辐射H2O2漂白过程中微波辐射功率、处理时间、H2O2及NaOH用量对漂白纸浆性能的影响,采用正交试验的方法对实验条件进行了优化,并用纤维分析法对纸浆纤维形态进行了研究。微波辐射H2O2漂白纸浆的最佳工艺条件是:微波辐射功率240 W、辐射时间2.5 min、H2O2用量5%、NaOH用量4.5%,在此条件下纸浆白度可达59%ISO左右。纤维分析测定结果发现微波辐射漂白前后纸浆纤维形态基本没有发生变化。结果表明,微波辐射替代水浴加热应用于H2O2纸浆漂白是一种切实可行的方法。  相似文献   

5.
微波辐射对NaClO漂白麦草浆白度与硬度影响的研究   总被引:1,自引:0,他引:1  
考察微波辐射对麦草浆漂白白度与硬度的影响。微波辐射影响微波辐射纸浆漂白白度与硬度的因素有3项:微波辐射时间、辐射功率、次氯酸钠用量。实验得到:随着微波辐射功率、时间、次氯酸钠用量增加自度升高硬度下降;与水浴的对比实验可见漂白纸浆达到相同白度时高锰酸钾值基本相同;漂白时间大大缩短至2mm。  相似文献   

6.
考察微波辐射对麦草浆漂白白度与硬度的影响.微波辐射影响微波辐射纸浆漂白白度与硬度的因素有3项:微波辐射时间、辐射功率、次氯酸钠用量.实验得到:随着微波辐射功率、时间、次氯酸钠用量增加白度升高硬度下降;与水浴的对比实验可见漂白纸浆达到相同白度时高锰酸钾值基本相同;漂白时间大大缩短至2min.  相似文献   

7.
采用2.5、5、10、15和20 mW/cm2强度微波辐射HeLa细胞20 min,观察了不同强度微波辐射对HeLa细胞增殖、细胞周期的影响。结果表明,受微波辐射的细胞生长受到抑制,数量明显减少,细胞皱缩变形,体积缩小。随着微波辐射强度的增加,细胞增殖受到明显抑制,呈现剂量依赖性。5、10和20 mW/cm2微波辐射的HeLa细胞培养24 h后,G2/M期的比例分别为11.6%、14.5%和18.2%,与对照组相比有显著性差异(p<0.05),由此可见微波辐射可将细胞阻滞于G2/M期。微波辐射后,细胞凋亡相关蛋白Bcl-2表达水平下降,Bax和Caspase-3表达水平逐渐升高,证明其作用机制可能与Bcl-2表达水平下调,Bax和Caspase-3表达水平升高相关。  相似文献   

8.
微波法检测造纸原料热水抽提物   总被引:1,自引:0,他引:1  
为了更快捷地对造纸原料热水抽提物进行检测,本研究用微波加热方法代替水浴加热。考察了功率和时间两个因素对造纸原料热水抽提率的影响。结果表明,对2g稻草粉末做热水抽提物检测时,采用微波辐射5min,辐射功率用400~600W,可获得与传统恒温水浴180min反应相同的检测效果。经重复实验,微波法大幅提高了检测效率,并且具有一定的可重复性。  相似文献   

9.
微波辐射对苜蓿种子发芽及种带固氮菌固氮酶活性的影响   总被引:1,自引:0,他引:1  
为探明微波辐射对苜蓿种子萌发和种子内生固氮菌固氮酶活性的影响,以不同微波功率对种子进行不同时长的辐射处理,并测定了各处理种子的发芽率、发芽速率和种带固氮菌纯培养物的固氮酶活性。结果表明:800W、20s和500W、40s的辐射处理下种子的首日发芽率最高,分别极显著高出对照122%和88.9%(P<0.01),且800W、20s和500W、40s处理的14d总发芽率最高,分别高出对照5.51%和3.35%。800W、24s和500W、40s处理下,发芽4d的种子胚根分别较对照伸长29.8%和41.9%;种带固氮菌的固氮酶活性对辐射时长较辐射功率更为敏感,两功率辐射下的短期处理能够明显提高种带固氮菌的固氮酶活性,超过32s的处理则会使固氮酶活性显著低于对照。800W、24s处理下种子内固氮菌的固氮酶活性高出对照104.9%。  相似文献   

10.
聚氧化乙烯水凝胶膜的辐射接枝研究   总被引:1,自引:0,他引:1  
为了得到一种理想的水胶伤口敷料,研究了应用电子束辐射接枝了不同比例聚乙烯醇(PVA)的聚氧化乙烯(PEO)水凝胶膜的制备和该膜的理化特性。实验结果显示。PEO接枝不凝摹凝胶分数主要依赖于辐射剂量和聚合物浓度。而其溶胀度与辐射剂量聚合物的浓度,混合比例和分子量密切相关。该膜的抗张强度和断裂工度则明显地领事于辐射剂量和聚合物的混合比例。实验发现,比例为7:3的20wt%PEOE-30接枝不凝胶膜与其它  相似文献   

11.
A catalytic approach using a synthesized iron and manganese oxide-supported granular activated carbon (Fe-Mn GAC) under a dielectric barrier discharge (DBD) plasma was investigated to enhance the degradation of oxytetracycline (OTC) in water. The prepared Fe-Mn GAC was characterized by x-ray diffraction and scanning electron microscopy, and the results showed that the bimetallic oxides had been successfully spread on the GAC surface. The experimental results showed that the DBD + Fe-Mn GAC exhibited better OTC removal efficiency than the sole DBD and DBD + virgin GAC systems. Increasing the fabricated catalyst and discharge voltage was favorable to the antibiotic elimination and energy yield in the hybrid process. The coupling process could be elucidated by the ozone decomposition after Fe-Mn GAC addition, and highly hydroxyl and superoxide radicals both play significant roles in the decontamination. The main intermediate products were identified by HPLC-MS to study the mechanism in the collaborative system.  相似文献   

12.
电子束辐照处理水溶液中的活性染料   总被引:4,自引:0,他引:4  
印染废水是我国工业废水的主要品种之一,如何有效处理印染废水是当今一个重要的研究课题。本文选择两种活性染料为处理对象,研究其在电子束辐照下的降解和脱色。通过染料水溶液受到辐照前后的紫外可见光谱的分析,以及化学需氧量、吸光度和溶液pH值的变化,研究其辐射降解脱色特性。同时研究了过氧化氢对染料辐射降解的协同作用。结果显示利用辐射技术处理印染废水具有相当好的应用前景。  相似文献   

13.
《等离子体科学和技术》2015,17(12):1053-1060
A discharge plasma reactor with a point-to-plane structure was widely studied experimentally in wastewater treatment.In order to improve the utilization efficiency of active species and the energy efficiency of this kind of discharge plasma reactor during wastewater treatment,the electrode configuration of the point-to-plane corona discharge reactor was studied by evaluating the effects of discharge spacing and adjacent point distance on discharge power and discharge energy density,and then dye-containing wastewater decoloration experiments were conducted on the basis of the optimum electrode configuration.The experimental results of the discharge characteristics showed that high discharge power and discharge energy density were achieved when the ratio of discharge spacing to adjacent point distance(d/s) was 0.5.Reactive Brilliant Blue(RBB) wastewater treatment experiments presented that the highest RBB decoloration efficiency was observed at d/s of 0.5,which was consistent with the result obtained in the discharge characteristics experiments.In addition,the biodegradability of RBB wastewater was enhanced greatly after discharge plasma treatment under the optimum electrode configuration.RBB degradation processes were analyzed by GC-MS and IC,and the possible mechanism for RBB decoloration was also discussed.  相似文献   

14.
疏水催化剂应用进展   总被引:1,自引:0,他引:1  
疏水催化剂主要用于反应物、产物或反应介质中有水的一些反应,包括氢-水液相催化交换、氢氧复合、有机物的低温氧化、NOx选择催化还原和含NH3废水的处理等。文章对疏水催化剂在各领域的应用进展进行综述,并对其催化特点及存在问题进行讨论。反应在室温或略高于室温的条件下进行,能耗低;对一些反应,疏水催化比亲水催化有更高选择性。针对具体的反应,研究疏水催化剂制备工艺,提高疏水催化剂对具体反应的催化性能有利于其工业上广泛应用。  相似文献   

15.
在间歇式超临界水氧化(SCWO)设备中,对粉碎处理后的阴离子交换树脂水悬浮液在超临界条件下进行了氧化降解处理。实验研究了反应温度、反应压力、反应时间、过氧系数对COD去除率的影响,同时考察了催化剂种类、反应压力和反应温度对氨氮去除率的影响。通过正交试验,得到主要因素对处理效果影响的显著程度排序为:反应温度>反应压力>反应时间>过氧系数。结果表明:在反应温度540 ℃、反应压力26 MPa、反应时间8 min、过氧系数3的条件下,COD去除率为99.65%。针对阴离子树脂中NH3-N含量高难以去除的问题,选用不同的催化剂CuSO4、MnO2、CeO2添加到反应体系中,结果表明对NH3-N的氧化效果顺序为CuSO4>CeO2>MnO2,对NH3-N的最高降解率达到96.53%。  相似文献   

16.
《等离子体科学和技术》2016,18(10):1020-1026
Thermal plasma was applied for the treatment of coke wastewater sludge derived from the steel industry in order to investigate the feasibility of the safe treatment and energy recovery of the sludge. A 30 k W plasma torch system was applied to study the vitrification and gas production of coke wastewater sludge. Toxicity leaching results indicated that the sludge treated via the thermal plasma process converted into a vitrified slag which resisted the leaching of heavy metals. CO2 was utilized as working gas to study the production and heat energy of the syngas. The heating value of the gas products by thermal plasma achieved 8.43 k J/L, indicating the further utilization of the gas products. Considering the utilization of the syngas and recovery heat from the gas products, the estimated treatment cost of coke wastewater sludge via plasma torch was about 0.98 CNY/kg sludge in the experiment. By preliminary economic analysis, the dehydration cost takes an important part of the total sludge treatment cost. The treatment cost of the coke wastewater sludge with 50 wt.% moisture was calculated to be about 1.45 CNY/kg sludge dry basis. The treatment cost of the coke wastewater sludge could be effectively controlled by decreasing the water content of the sludge. These findings suggest that an economic dewatering pretreatment method could be combined to cut the total treatment cost in an actual treatment process.  相似文献   

17.
A single-stage plasma-catalytic reactor in which catalytic materials were packed was used to remove nitrogen oxides. The packing material was scoria being made of various metal oxides including Al2O3, MgO, TiO2, etc. Scoria was able to act not only as dielectric pellets but also as a catalyst in the presence of reducing agent such as ethylene and ammonia. Without plasma discharge, scoria did not work well as a catalyst in the temperature range of 100℃ to 200℃, showing less than 10% of NOx removal efficiency. When plasma is produced inside the reactor, the NOx removal efficiency could be increased to 60% in this temperature range.  相似文献   

18.
In the paper, a hybrid gas–liquid dielectric barrier discharge (DBD) plasma system was set up to treat a methylene blue (MB) solution. The effects of the change of the carrier gas, the gas bubbling rate and different kinds of scavenger addition, including sodium carbonate (Na2CO3), para benzoquinone (p-BQ), triethylenediamine and sodium dihydrogen phosphate (NaH2PO4), on the MB decoloration were reviewed to clarify the critical active species for the dye decoloration in the DBD plasma system. The obtained results show that higher decoloration of the MB solution could be achieved when O2 was used as the carrier gas, which could be 100% after 20 min discharge treatment, and the result confirmed the crucial effect of O3 in the MB decoloration. Based on the experiments of the scavenger addition, it could be concluded that O2 and 1O2 were two other important reactive oxygen species (ROS) for the MB decoloration. The results of the higher chemical oxygen demand removal and faster disappearance of the characteristic peak of the MB from the UV–vis analysis under O2 bubbling conditions also proved the critical effect of the ROS formed by O2 on the MB decoloration.  相似文献   

19.
Two plasma reactors have been developed and used to degrade dye wastewater agents.The configuration of one plasma reactor is a comb-like extendable unit module consisting of 5 electrodes covered with a quartz tube and the other one is an array reactor which is extended from the unit module.The decomposition of wastewater by ns pulse dielectric barrier discharge(DBD) plasma have been carried out by atomizing the dyeing solutions into the reactors.During experiments,the indigo carmine has been treated as the waste agent.The measurements of UV-VIS absorption spectroscopy and the chemical oxygen demand(COD) are carried out to demonstrate the decomposition efect on the wastewater.It shows that the decoloration rate of 99% and the COD degradation rate of 65% are achieved with 15 min treatment in the unit reactor.The efect of electrical parameters on degradation has been studied in detail.Results from the array reactor indicate that it has a better degradation efect than the unit one.It can not only totally remove the chromogenic bond of the indigo carmine solution,but also efectively degrade unsaturated bonds.The decoloration rate reaches 99% after 10 min treatment,the decomposition rate of the unsaturated bond reaches 83% after 60 min treatment,and the COD degradation rate is nearly 74%.  相似文献   

20.
文炜  孙宇  邱永梅  但贵萍 《同位素》2012,25(2):78-81
在自制的氚污染不锈钢的高温热解析制样系统中对氚污染不锈钢样品进行解析分析,并对影响不锈钢样品中氚回收率的解析温度、解析时间、催化氧化效率、冷凝收集效率等条件进行了优化研究。结果表明,当载气(空气)流速为60~80 L/h,解析温度和催化氧化温度为700 ℃,冷凝温度为-20 ℃,解析时间为2 h时,氚污染不锈钢样品高温制样系统的冷凝收集效率为99%,催化氧化效率为98.6%,不锈钢样品中氚的解析率>95%。以上结果表明,该不锈钢高温热解析制样系统及其解析条件能够满足退役核设施不锈钢样品中氚的分析要求。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号