一体式光催化—膜分离反应器的研究
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摘要
本文通过对有机膜分离技术与光催化技术的耦合,设计了一体式光催化氧化一膜分离三相流化床反应器;并采用u型PVDF中空纤维膜,通过对以工业级TiO_2光催化氧化降解低浓度Acid Red B模拟废水的实验,对一体式反应器的性能进行了研究。
实验结果表明:本实验系统中适宜的运行条件为:TiO_2浓度2g/L,Acid RedB浓度为10 mg/L,pH值控制在2.5,膜通量为15 L/h,膜丝底部曝气量0.6 m~3/h,反应区曝气量为3.6 m~3/h。当采用光源为350 W紫外高压汞灯时,反应器预反应时间为2 h时;一体式反应器连续运行120 h膜出水脱色率稳定在90%以上。
膜丝底部曝气可有效地提高膜丝表面的错流率,对减缓膜污染有明显效果,反应区适宜的曝气量不仅可保证反应器内催化剂呈良好的悬浮状态,同时还可使膜分离区的紊流程度加强,有利于减缓膜污染。在酸性及碱性条件下有利于减缓膜污染,膜污染的主要影响因素是催化剂,且随TiO_2浓度增加膜污染变的严重。采用在线反冲的清洗方式可以保证反应器长期、稳定地运行,且采用“表面冲洗+碱洗+碱液反冲”相结合的清洗方式可以使污染后的膜通量恢复到99%以上。
An new kind of integrative reactor, coupling with the technologies of organic membrane separation and photocatalytic oxidation, was designed. The fundamental performance of the reactor are investigated by photocatalytic degrading Acid red B wastewater with TiO_2 which the average granularity diameter is 0.258μm, the membrane module is U-shape PVDF hollow fiber membrane.
The results show that the best operating conditions are as follows: the concentration of TiO_2 and Acid Red B is 2 g/L, 10 mg/L respectively, the pH value is 2.5, aeration rate is 3.6 m~3/h, membrane fluxation is 15 L/h, aeration flux bellowing the hollow fiber membrane is 0.6 m~3/h. When the light source is uvtraviolot light that is 350 W, the pre-reactor time is 2 h. The decolourization efficiency of the waste water can reach as higher as 90% during the integrative reactor runing in 120 h.
Membrane fouling rate can be controlled greatly with bubbling under membrane module and bellow reactor, because of cross-flow rate on face of the membrane and turbulence is enhanced. Membrane fouling rate can be decreased in the conditions of acidic and alkaline.The main factor which cause membrane fouling is TiO_2, and membrane fouling become serious with TiO_2 concentration increasing. guarantee The reactor can run in a long and stable way in the condition of backwash online. Alkaline-backwash after face-wash followed by alkaline rising can make the membrane flux recover to 99%.
实验结果表明:本实验系统中适宜的运行条件为:TiO_2浓度2g/L,Acid RedB浓度为10 mg/L,pH值控制在2.5,膜通量为15 L/h,膜丝底部曝气量0.6 m~3/h,反应区曝气量为3.6 m~3/h。当采用光源为350 W紫外高压汞灯时,反应器预反应时间为2 h时;一体式反应器连续运行120 h膜出水脱色率稳定在90%以上。
膜丝底部曝气可有效地提高膜丝表面的错流率,对减缓膜污染有明显效果,反应区适宜的曝气量不仅可保证反应器内催化剂呈良好的悬浮状态,同时还可使膜分离区的紊流程度加强,有利于减缓膜污染。在酸性及碱性条件下有利于减缓膜污染,膜污染的主要影响因素是催化剂,且随TiO_2浓度增加膜污染变的严重。采用在线反冲的清洗方式可以保证反应器长期、稳定地运行,且采用“表面冲洗+碱洗+碱液反冲”相结合的清洗方式可以使污染后的膜通量恢复到99%以上。
An new kind of integrative reactor, coupling with the technologies of organic membrane separation and photocatalytic oxidation, was designed. The fundamental performance of the reactor are investigated by photocatalytic degrading Acid red B wastewater with TiO_2 which the average granularity diameter is 0.258μm, the membrane module is U-shape PVDF hollow fiber membrane.
The results show that the best operating conditions are as follows: the concentration of TiO_2 and Acid Red B is 2 g/L, 10 mg/L respectively, the pH value is 2.5, aeration rate is 3.6 m~3/h, membrane fluxation is 15 L/h, aeration flux bellowing the hollow fiber membrane is 0.6 m~3/h. When the light source is uvtraviolot light that is 350 W, the pre-reactor time is 2 h. The decolourization efficiency of the waste water can reach as higher as 90% during the integrative reactor runing in 120 h.
Membrane fouling rate can be controlled greatly with bubbling under membrane module and bellow reactor, because of cross-flow rate on face of the membrane and turbulence is enhanced. Membrane fouling rate can be decreased in the conditions of acidic and alkaline.The main factor which cause membrane fouling is TiO_2, and membrane fouling become serious with TiO_2 concentration increasing. guarantee The reactor can run in a long and stable way in the condition of backwash online. Alkaline-backwash after face-wash followed by alkaline rising can make the membrane flux recover to 99%.
引文
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[17]彭峰,任艳群.TiO_2-SnO_2复合纳米膜的制备及其光催化降解甲苯的活性[J].催化学报,2003,24(4):243-247.
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[19]Shoji N.Yuu H.Ishihara S I.etal.Preparation of carbon/TiO_2 microsphere compaosites from cellulose TiO_2 microphere compaosite and their evalution [J].J Mol Catal A:Chem,2002,177(12):253-263.
[20]江立文,李耀中,周岳溪,等.负载型TiO_2固定相光催化氧化剂固定化技术研究[J].工业水处理,2000,20(9):8-11.
[21]Chatterjee D,Mahata A.Photoassisted detoxification of Organic pollutants on the surface modified TiO_2 semiconductor particulate system[J].Catal Commun,2001,2(1):1-5.
[22]苏文悦,傅贤智,魏可镁.溴代甲烷在TiO_2上的光催化降解研究[J].高等学校化学学报,2001,22(2):272.
[23]刘守新,王岩,李海潮,等.载银光催化剂Ag-TiO_2合成及光催化性能[J].东北林业大学学报,2001,29(6):56-59.
[24]Uchihara T,Matsumura M,etal.Effect of EDTA on the photacatalytic activties and flatbandpotentials of cadmium and cadmium selenide[J].J Phys Chem,1990,94(1):415-418.
[25]刘冬妮,陈健波,郑鸣.半导体光催化氧化技术的研究进展[J].江苏大学学报(自然科学版),2003,24(3):40-44.
[26]Yao W F,Wang H,Xu X H.Photocatalytic property of bismuth titanate Bi_2Ti_2O_7[J].J Applied Catalysis A:General,2004,259:29-33.
[27]Yao W F,Wang H,Xu X H.Photocatalytic property of bismuth titanate Bi_(12)TiO_(20)crystals[J].JApplied Catalysis A:General,2003,243(22):185-190
[28]任树林.超声TiO_2光催化协同降解对氨基偶氮苯废水[J].西北大学学报(自然科学版),2004,34(4):425-428.
[29]符小荣,张校刚,宋世庚,等.TiO_2/Pt/glass纳米薄膜的制备及对可溶性染料的光电催化降解[J].应用化学,1997,4:80-82.
[30]赵玉光,王宝贞.生物-催化反应器系统处理印染废水的研究[J].环境科学学报,1998,18(4):373-379.
[31]Fu S,Jerome O N,et al.Treatability kraft pulp bleaching wastewaterby b iochemical and photoatalytic oxidation[J].Journal Photochemistry and Phot obiology A:Chemistry,2004,167(23):223-228.
[32]薛向东.废水光催化处理特性及高效光催化反应器研究[D].西安:西安建筑科技大学,2002,11.
[33]Zouiti R,Benjelloun.Depollution photocatalutique enpresencede TiO_2 fixe sursupport finementdivise,in Proceedings of the 3rd international sympaosium on environment catalysis and process engineering,Book of Abstracts.2000,11(17):13-14.
[34]Pozhiak G,Pryjak M,Trochimczuk W.Sulfonated polysulfone membranes with antifouling activity.Die Angewandte Makromolekulare Chemie,1995,233(15):23-35
[35]超滤技术与应用[M].华耀祖,化学工业出版社,2003.12.
[36]膜分离技术及其应用[M].任建新,化学工业出版社,北京2002.12.
[37]Tsuru T,Toyosada T,Yoshioka T,etal.Photocatalytic reactions in filtrateion system through porous titanium dioxide membranes[J].J Chem Eng Jpn,2001,34(4):844-847.
[38]Molinari R,Borgese M,Drioli E,etal.Hybrid processes coupling photocatalysis and membranes for degradation of organic pollutants in water[J].Catal Today,2002,75(1):77-85.
[39]Wenmin,Xi.Separation of titanium didoxide from photocatalytically treated water by crossflow microfiltration[J].Water and Research.2001,359(21):1256-1262.
[40]Enrico Drioli,Leonardo Palmisano.Photocatalytic membrane reactors for degradation of organic pollutants in water[J].Water and Research.2001,67(12):273-279.
[41]Xi W,Geissen S U.Separation of titanium dioxide from photocatalytically treated water by crossflow microfiltration[J]Water Res,2001,35(5):1256-1262.
[42]杨群豪,孟耀斌,黄霞,等.悬浮床光催化-膜分离反应器中膜污染的控制[J],净水技术,2002,21(2):28-30.
[43]Song W,Ravindran V,Koel B,etal.Nanofiltration of natural organicmatter with H_2O_2/UV pretreatment:Fouling mitigation and membrane surface characterization[J].Journal of Membrane Science,2004,241(1):143-160.
[44]柳闽生,杨边之,余赤贞,等.半导体纳米粒子的基本性质及光电化学特性[J],化学通报,1997,1(1):20-24.
[45]孙奉玉,吴鸣,李文钊,等.二氧化钛表面化学特性与光催化活性的关系[J],催化学报,1998,19(2):229-233.
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[2]Zhao J C,Octa H,Hidaka H.Photodegradation of surfactants X comparison of the photo-oxidation of thearomatic moieties in sodium Do-Decylbenz-ene sulphonate and in sodium phenyldodecyl sulphonate at TiO_2-H_2O interfaces [J].JP-PAC,1992,69(12):251-256.
[3]Jgeorge P,Fotou,Sotirise,etal.Photocatalytic destruction of phenol and salicylie acid with aerosol made and commercial titania powders[J].Chem Eng Comm,1996,151(16):251-255.
[4]孟楠,张爱茜.TiO_2和Cu_2O光催化降解硝基苯酚的对比研究[J].环境化学2005,24(6):660-662.
[5]Zhang R B,Gao L,Zhang Q H.Photodegradation of surfactants on the nanosized TiO_2 prepared by hydrolysis of the alkoxide titanium[J].Chemosphere,2004,54(3):405-411.
[6]Hidaka H,Zhao J C.etal.Photodegradation of surfactants & Comparison of photocatalytic processes between anionic DBS and cationic BDAC on the titania surface[J].Phys Chem,1992,96(41):2226-2230.
[7]张天永,李祥忠,赵进才,等.国产二氧化钛在光催化降解染料废水中的应用[J].催化学报,1999,20(3):356-358.
[8]Abdullah M,Low G K C,Mattews R W.effect of common inorganic anions on rates of photocatalytic oxidation of organic carbon over illuminated titaniumdioxide[J].J Phys Chem,1990,94(17):6820-6825.
[9]蒋伟川,王琪全,余传明.半导体光催化降解分散染料溶液的研究[J].上海环境科学,1995,14(5):8-10.
[10]孙尚梅,康振君,魏志仿.TiO_2膜太阳光催化氧化法处理毛纺染整废水[J].化工环保,2000,20(1):11-14.
[11]罗洁,陈建山.TiO_2光催化氧化降解印染废水的研究[J].工业催化,2004,12(6):36-38.
[12]魏凤玉,彭书传,等.非均相光催化氧化法处理含酚废水.合肥大学学报(自然科学版),2002,25(4):565-568.
[13]胡将军,周荣迁,等.光催化氧化处理有机废水[J].环境污染与防治,2000,22(1):31-32.
[14]席北斗,刘纯新,孔欣,等.负载型催化剂光催化氧化五氯苯酚钠效果[J].环境科学,2001,22(1):41-44.
[15]Anpo M,Kawamura T,Kodama S,etal.Photocatalysis on titanium-aluminum binary metaloxides:enhancement of the photocatalytic activity of titania species[J].J Phys Chem,1988,92(2):438-440.
[16]Choi W K,Hoffmann M R.The role of metal ion dopants in quantumsized TiO_2:correlation between photoreactivity and charge carrier recombination dynamics[J].J Phys Chem,1994,98(51):13669-13679.
[17]彭峰,任艳群.TiO_2-SnO_2复合纳米膜的制备及其光催化降解甲苯的活性[J].催化学报,2003,24(4):243-247.
[18]Durgakumari V,subrahmanyan M.etal.An easy and efficient use of TiO_2supported HZSH-5 and TiO_2+HZSM zeolite combine in the photodegradation of aqueous phenol and pchlorophenol[J].Appl Catal A:General,2002,234(14):155-165.
[19]Shoji N.Yuu H.Ishihara S I.etal.Preparation of carbon/TiO_2 microsphere compaosites from cellulose TiO_2 microphere compaosite and their evalution [J].J Mol Catal A:Chem,2002,177(12):253-263.
[20]江立文,李耀中,周岳溪,等.负载型TiO_2固定相光催化氧化剂固定化技术研究[J].工业水处理,2000,20(9):8-11.
[21]Chatterjee D,Mahata A.Photoassisted detoxification of Organic pollutants on the surface modified TiO_2 semiconductor particulate system[J].Catal Commun,2001,2(1):1-5.
[22]苏文悦,傅贤智,魏可镁.溴代甲烷在TiO_2上的光催化降解研究[J].高等学校化学学报,2001,22(2):272.
[23]刘守新,王岩,李海潮,等.载银光催化剂Ag-TiO_2合成及光催化性能[J].东北林业大学学报,2001,29(6):56-59.
[24]Uchihara T,Matsumura M,etal.Effect of EDTA on the photacatalytic activties and flatbandpotentials of cadmium and cadmium selenide[J].J Phys Chem,1990,94(1):415-418.
[25]刘冬妮,陈健波,郑鸣.半导体光催化氧化技术的研究进展[J].江苏大学学报(自然科学版),2003,24(3):40-44.
[26]Yao W F,Wang H,Xu X H.Photocatalytic property of bismuth titanate Bi_2Ti_2O_7[J].J Applied Catalysis A:General,2004,259:29-33.
[27]Yao W F,Wang H,Xu X H.Photocatalytic property of bismuth titanate Bi_(12)TiO_(20)crystals[J].JApplied Catalysis A:General,2003,243(22):185-190
[28]任树林.超声TiO_2光催化协同降解对氨基偶氮苯废水[J].西北大学学报(自然科学版),2004,34(4):425-428.
[29]符小荣,张校刚,宋世庚,等.TiO_2/Pt/glass纳米薄膜的制备及对可溶性染料的光电催化降解[J].应用化学,1997,4:80-82.
[30]赵玉光,王宝贞.生物-催化反应器系统处理印染废水的研究[J].环境科学学报,1998,18(4):373-379.
[31]Fu S,Jerome O N,et al.Treatability kraft pulp bleaching wastewaterby b iochemical and photoatalytic oxidation[J].Journal Photochemistry and Phot obiology A:Chemistry,2004,167(23):223-228.
[32]薛向东.废水光催化处理特性及高效光催化反应器研究[D].西安:西安建筑科技大学,2002,11.
[33]Zouiti R,Benjelloun.Depollution photocatalutique enpresencede TiO_2 fixe sursupport finementdivise,in Proceedings of the 3rd international sympaosium on environment catalysis and process engineering,Book of Abstracts.2000,11(17):13-14.
[34]Pozhiak G,Pryjak M,Trochimczuk W.Sulfonated polysulfone membranes with antifouling activity.Die Angewandte Makromolekulare Chemie,1995,233(15):23-35
[35]超滤技术与应用[M].华耀祖,化学工业出版社,2003.12.
[36]膜分离技术及其应用[M].任建新,化学工业出版社,北京2002.12.
[37]Tsuru T,Toyosada T,Yoshioka T,etal.Photocatalytic reactions in filtrateion system through porous titanium dioxide membranes[J].J Chem Eng Jpn,2001,34(4):844-847.
[38]Molinari R,Borgese M,Drioli E,etal.Hybrid processes coupling photocatalysis and membranes for degradation of organic pollutants in water[J].Catal Today,2002,75(1):77-85.
[39]Wenmin,Xi.Separation of titanium didoxide from photocatalytically treated water by crossflow microfiltration[J].Water and Research.2001,359(21):1256-1262.
[40]Enrico Drioli,Leonardo Palmisano.Photocatalytic membrane reactors for degradation of organic pollutants in water[J].Water and Research.2001,67(12):273-279.
[41]Xi W,Geissen S U.Separation of titanium dioxide from photocatalytically treated water by crossflow microfiltration[J]Water Res,2001,35(5):1256-1262.
[42]杨群豪,孟耀斌,黄霞,等.悬浮床光催化-膜分离反应器中膜污染的控制[J],净水技术,2002,21(2):28-30.
[43]Song W,Ravindran V,Koel B,etal.Nanofiltration of natural organicmatter with H_2O_2/UV pretreatment:Fouling mitigation and membrane surface characterization[J].Journal of Membrane Science,2004,241(1):143-160.
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