光催化技术在电石渣浆废水处理中的实验研究
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摘要
本论文进行了光催化悬浮态催化剂TiO_2降解电石渣浆废水中污染物的实验研究。光催化反应以COD_(Cr)和氨氮为水质指标。考察了光催化反应的各个影响因素,并确定了其最佳值。实验结果表明:经过预处理的原水,光催化反应结束后,水中COD_(Cr)和氨氮的去除率高于未经预处理的原水;光催化反应光源为紫外灯,随着光强的增大,水中COD_(Cr)和氨氮的去除率持续增大;催化剂的最佳投加量为1g/L;在碱性条件下,光催化反应对COD_(Cr)和氨氮的去除率较高;通入空气既可以使催化剂与水充分混合均匀,又可以提供光催化反应所需要的氧气,但过多的空气会造成能量的浪费,实验中,最佳空气通入量为0.14 m~3/(h·L);加入双氧水和臭氧等物质,可以协同光催化反应对水中污染物质进行降解,实验表明双氧水的最佳投加量为0.4mL/L;在各影响因素的最佳条件下,光催化反应前90min,COD_(Cr)和氨氮降解速率很快,反应3h,COD_(Cr)和氨氮的去除率不再明显增加,此时COD_(Cr)的去除率为84%,氨氮的去除率为74%。
在悬浮态光催化体系研究的基础上,对光催化去除水中无机氮的机理进行了简单的探讨。研究表明:在碱性条件下,氨氮的去除主要有两种途径:空气的吹脱作用和光催化反应的氧化作用;电石渣浆废水中含有乙炔、硫根等空穴消除剂,从而光催化还原硝酸氮反应可以顺利地进行,并且反应生成物为氮气,氮气生成率比较高。在各影响因素最佳值条件下进行实验,反应3h,硝酸氮的去除率为60%左右,氮气的生成率为90%以上。反应过程中,氨氮的吹脱去除会消耗很多的OH~-,从而导致反应液的pH值随着时间的增加而逐渐降低。
另外,实验中对固着态纳米光催化剂制作及其催化活性进行了研究。采用溶胶-凝胶法,分别以耐高温高硅氧玻璃纤维布和普通玻璃纤维布为载体,制备固着态光催化剂,实验结果表明:以耐高温高硅氧玻璃纤维布为载体的催化剂,反应3h,对水中COD_(Cr)的去除率为41%,氨氮的去除率为39%,载体为普通玻璃纤维布的催化剂对水中COD_(Cr)的去除率为35%,氨氮的去除率为30%。
This paper is an experimental study about contamination degrading in calcium carbide wastewater through irradiating the catalyzer TiO_2 by UV.COD_(Cr) and the concentration of ammonia nitrogen is the criterion of water in the photocatalytic reaction.This paper reviews the main factors which affect the photocatalytic reaction,and also confirms the corresponding best values.The results of the experiment indicate that:after the photocatalytic reaction,the removal efficiency of COD_(Cr) and the ammonia nitrogen of the pretreated raw water is higher than the raw water which is not pretreated(Ultra-violet lamp is the lamp-house in this case);with increasing light strength,the removal efficiency of COD_(Cr) and the ammonia nitrogen in the water continues to grow;the optimum dose of the catalyzer is 1g/L;in alkali condition,the removel efficiency of COD_(Cr) and the ammonia nitrogen is higher in the photocatalytic reaction than in the acidic condition;the infusion of air can mix catalyzer and water sufficiently,further more,it can provide the oxygen needed in photocatalytic reaction,however,the over use of air will be a waste of energy.In the experiment,the optimum influx of air is 0.14 m~3/(h·L);H_2O_2 and O_3, together with photocatalytic reaction,can degrade the contamination in the water.The results of the experiment also indicate that the optimum dose of H_2O_2 is 0.4 mL/L;with all the factors at the optimum condition,in the first 90min,the removal rate of COD_(Cr) and the ammonia nitrogen is very high,but in 3 hours,the removel efficiency of COD_(Cr) and the ammonia nitrogen will grow much slower and until then,the removal efficiency of COD_(Cr) is 84%,and the removal efficiency of ammonia nitrogen is 74%.
On the basis of the study on degradation of COD_(Cr) and the ammonia nitrogen in aqueous suspension,this paper discusses the theory of inorganic nitrogen degradation by photocatalytic reaction.The study indicates that,in alkali condition,there are two ways to remove the ammonia nitrogen:blowing-off by the air and oxidation in the photocatalytic reaction.There are acetylene and sulfid to serve as the hole remover in calcium carbide wastewater,so the deoxidizing reaction of nitrate can go on smoothly,and the product is nitrogen,whose creating efficiency is very high.On the optimum condition of every factors,the removal efficiency of nitrate is about 60%in 3h,and the creating efficiency of nitrogen is up 90%.In the process of reaction,the blowing-off of ammonia nitrogen consumes a lot of OH~-,so the pH of the water decreases with the time goes by.
In addition,the experiment explores the preparation of photocatalytic oxidation of modified TiO_2 film coating on fiberglass cloth surface,and evaluates the activity of the TiO_2 film.The experiment prepares the modified TiO_2 film by using fiberglass cloth (which has strong resistance to high temperature) and the ordinary fiberglass cloth as the carrier through the way of sol-gel.The result of the experiment indicates that in the reaction of photo-catalytic,by using the catalyzer with carrier that has strong resistance to high temperature,the removal efficiency of COD_(Cr) is 41%,and the removal efficiency of ammonia nitrogen is 39%in 3h,higher than the reaction with cartier of ordinary fiberglass cloth,in which the removal efficiency of COD_(Cr) is 35%,and the removal efficiency of ammonia nitrogen is 30%.
在悬浮态光催化体系研究的基础上,对光催化去除水中无机氮的机理进行了简单的探讨。研究表明:在碱性条件下,氨氮的去除主要有两种途径:空气的吹脱作用和光催化反应的氧化作用;电石渣浆废水中含有乙炔、硫根等空穴消除剂,从而光催化还原硝酸氮反应可以顺利地进行,并且反应生成物为氮气,氮气生成率比较高。在各影响因素最佳值条件下进行实验,反应3h,硝酸氮的去除率为60%左右,氮气的生成率为90%以上。反应过程中,氨氮的吹脱去除会消耗很多的OH~-,从而导致反应液的pH值随着时间的增加而逐渐降低。
另外,实验中对固着态纳米光催化剂制作及其催化活性进行了研究。采用溶胶-凝胶法,分别以耐高温高硅氧玻璃纤维布和普通玻璃纤维布为载体,制备固着态光催化剂,实验结果表明:以耐高温高硅氧玻璃纤维布为载体的催化剂,反应3h,对水中COD_(Cr)的去除率为41%,氨氮的去除率为39%,载体为普通玻璃纤维布的催化剂对水中COD_(Cr)的去除率为35%,氨氮的去除率为30%。
This paper is an experimental study about contamination degrading in calcium carbide wastewater through irradiating the catalyzer TiO_2 by UV.COD_(Cr) and the concentration of ammonia nitrogen is the criterion of water in the photocatalytic reaction.This paper reviews the main factors which affect the photocatalytic reaction,and also confirms the corresponding best values.The results of the experiment indicate that:after the photocatalytic reaction,the removal efficiency of COD_(Cr) and the ammonia nitrogen of the pretreated raw water is higher than the raw water which is not pretreated(Ultra-violet lamp is the lamp-house in this case);with increasing light strength,the removal efficiency of COD_(Cr) and the ammonia nitrogen in the water continues to grow;the optimum dose of the catalyzer is 1g/L;in alkali condition,the removel efficiency of COD_(Cr) and the ammonia nitrogen is higher in the photocatalytic reaction than in the acidic condition;the infusion of air can mix catalyzer and water sufficiently,further more,it can provide the oxygen needed in photocatalytic reaction,however,the over use of air will be a waste of energy.In the experiment,the optimum influx of air is 0.14 m~3/(h·L);H_2O_2 and O_3, together with photocatalytic reaction,can degrade the contamination in the water.The results of the experiment also indicate that the optimum dose of H_2O_2 is 0.4 mL/L;with all the factors at the optimum condition,in the first 90min,the removal rate of COD_(Cr) and the ammonia nitrogen is very high,but in 3 hours,the removel efficiency of COD_(Cr) and the ammonia nitrogen will grow much slower and until then,the removal efficiency of COD_(Cr) is 84%,and the removal efficiency of ammonia nitrogen is 74%.
On the basis of the study on degradation of COD_(Cr) and the ammonia nitrogen in aqueous suspension,this paper discusses the theory of inorganic nitrogen degradation by photocatalytic reaction.The study indicates that,in alkali condition,there are two ways to remove the ammonia nitrogen:blowing-off by the air and oxidation in the photocatalytic reaction.There are acetylene and sulfid to serve as the hole remover in calcium carbide wastewater,so the deoxidizing reaction of nitrate can go on smoothly,and the product is nitrogen,whose creating efficiency is very high.On the optimum condition of every factors,the removal efficiency of nitrate is about 60%in 3h,and the creating efficiency of nitrogen is up 90%.In the process of reaction,the blowing-off of ammonia nitrogen consumes a lot of OH~-,so the pH of the water decreases with the time goes by.
In addition,the experiment explores the preparation of photocatalytic oxidation of modified TiO_2 film coating on fiberglass cloth surface,and evaluates the activity of the TiO_2 film.The experiment prepares the modified TiO_2 film by using fiberglass cloth (which has strong resistance to high temperature) and the ordinary fiberglass cloth as the carrier through the way of sol-gel.The result of the experiment indicates that in the reaction of photo-catalytic,by using the catalyzer with carrier that has strong resistance to high temperature,the removal efficiency of COD_(Cr) is 41%,and the removal efficiency of ammonia nitrogen is 39%in 3h,higher than the reaction with cartier of ordinary fiberglass cloth,in which the removal efficiency of COD_(Cr) is 35%,and the removal efficiency of ammonia nitrogen is 30%.
引文
[1]白剑臣.内蒙古PVC发展现状分析[J].内蒙古石油化工,2009,(1):70-72
[2]曹恩伟,张伟.电石渣废水的综合治理[J].江苏环境科技,2002,15(3):9-10
[3]蔡荣.电石法生产PVC需要注意的问题[J].中国氯碱,2004(11):10-12
[4]王晓毅,马家轩,杜玉杰等.空气催化氧化法处理电石渣上清液中硫化物的研究[J].河南化工,2001,(9):9-10
[5]郑卫国,王凯.PVC生产中的二次水回收工艺改造[J].聚氯乙烯,2006,(5):43-44
[6]桥本和仁,腾导昭.Titanium Dioxide:New Usea Through Nano-Technology.Nature,1997,88(8),431-432
[7]董晓艳.金属掺杂二氧化钛及其光催化脱除水中硝酸氮.大连理工大学硕士学位论文,2007:12
[8]雷乐成,汪大晕.水处理高级氧化技术[M].北京:化学工业出版社,2001
[9]Takeda K,Fujiwara K.Characteristics on the Determination of Dissolved Organic Nitrogen Compounds in Natural Waters Using Titanium Dioxide and Platinized Titanium Dioxide Mediated Photocatalytic Degradation[J].Water Research,1996,30(2):323-330
[10]Eva-Maria B,Stefan S,Herbert J,et al.Photocatalytic Degradation of Ammonia with TiO_2 as Photocatalyst in the Laboratory and under the Use of Solar Radiation [J].Chemosphere,1997,35(7):1431-1445
[11]Ranjit K T,Varadarajan T K,Viswanathan B.Photocatalytic Reduction of Nitrite and Nitrate Ions to Ammonia on M/TiO_2 Catalysts[J].Journal of Photochemical and Photobiolical A:Chemistry,1997,108(1):73-78
[12]Li Yue-xiang,Wasgestian F.Photocatalytic Reduction of Nitrate Ions on TiO_2 by Oxalic Acid[J].Journalof Photochemical and Photobiolieal A:Chemistry,1998,112(2-3):255-25
[13]常颖等.光催化氧化反应器的研究进展[J].中国给水排水,2004,20(4):34-37
[14]杨海明.沸石负载二氧化钛光催化脱氮研究.大连理工大学硕士学位论文,2006
[15]Kapoor A,Furushor A.Nitrate Removel from Drinking Water Review.The Journal of Environmental Engineering,1997,123(21):371-380
[16]Farm J C,Murakami S.The Chemical Reduction of Nitrate in Aqueous Solution.Coordination Chemistry Reviews,2000,199(3):159-179
[17]曹广秀,李贯良,陈淑敏.纳米TiO_2在水处理中的研究进展.工业水处理[J],2003,23(23):20-22
[18]李田.城市自来水光催化氧化深度净化效果[J].环境科学学报,1998,18(2):167-171
[19]魏宏斌,严煦世,徐迪民等.二氧化钛膜固定相光催化氧化法深度处理自来水[J].中国给水排水,1996,12(6):10-14
[20]徐悦华.纳米二氧化钛光催化降解有机磷农药的研究.华南理工大学学位论文,2000
[21]高濂,郑珊,张青红.纳米二氧化钛光催化材料及应用[M].北京,化学工业出版社,2002
[22]徐瑞芬,许秀艳,付国柱等.纳米TiO_2在抗菌塑料中的应用性能研究[J].塑料,2003,31(3):26-29
[23]徐瑞芬,余广为,许秀艳.复合涂料中纳米TiO_2降解污染物和抗菌性能研究[J].化工进展,2003,22(11):1193-1195
[24]雷阎盈,张秀成,余历军等.TiO_2纳米微晶膜杀菌玻璃的研究[J].建筑玻璃与工业玻璃,2003,4:21-23
[25]邓蕾.掺杂银离子的二氧化钛光催化剂的制备与活性评价.西安建筑科技大学硕士学位论文,2006
[26]国家环境保护总局,水和废水监测分析方法编委会编.水和废水监测分析方法[M].北京:中国环境科学出版社,2002
[27]L.C.Kinney et al.Taft.Research Center Report Numbe JWRC-13,Cincinnatiohio
[28]王燕石.纯碱废水中氨氮处理方法的研究[J].中氮肥,2008,(4):21-25
[29]刘春芳.臭氧高级氧化技术在废水处理中的研究进展[J].石油技术与应用,2002,20(4):278-280
[30]储金宇,吴春笃,陈万金等.臭氧技术及应用[M].北京:北京化学工业出版社,2002
[31]罗立贤,林雯雯,蒋轶锋等.紫外光降解气态氯苯的研究[J].浙江工业大学学报,2009,37(2):144-148
[32]Kormann C,Bahnemann D W,Hoffmann M R.Environ Sci Technol,1991,25(3):494
[33]Hoffmann M R,Martin S T,Choi W et al.Chen Rev,1995,95(1):69
[34]Li Y X,Wasgestian F J.Photochem Photobiol A,1998,112(2/3):225
[35]柳丽芬,董晓艳,杨凤林等.Ag/TiO_2光催化还原硝酸氮[J].无机化学学报,2008,24(2):211-217
[36]马慧,柳丽芬,杨凤林等.纳米TiO_2薄膜耦合光催化氧化还原反应脱除水中无机氮[J].感光科学与光化学,2006,24(1):18-27
[37]魏宏斌,徐迪民.固定相膜的制备及其光催化活性[J].中国给水排水,2002,18(7):57-59
[2]曹恩伟,张伟.电石渣废水的综合治理[J].江苏环境科技,2002,15(3):9-10
[3]蔡荣.电石法生产PVC需要注意的问题[J].中国氯碱,2004(11):10-12
[4]王晓毅,马家轩,杜玉杰等.空气催化氧化法处理电石渣上清液中硫化物的研究[J].河南化工,2001,(9):9-10
[5]郑卫国,王凯.PVC生产中的二次水回收工艺改造[J].聚氯乙烯,2006,(5):43-44
[6]桥本和仁,腾导昭.Titanium Dioxide:New Usea Through Nano-Technology.Nature,1997,88(8),431-432
[7]董晓艳.金属掺杂二氧化钛及其光催化脱除水中硝酸氮.大连理工大学硕士学位论文,2007:12
[8]雷乐成,汪大晕.水处理高级氧化技术[M].北京:化学工业出版社,2001
[9]Takeda K,Fujiwara K.Characteristics on the Determination of Dissolved Organic Nitrogen Compounds in Natural Waters Using Titanium Dioxide and Platinized Titanium Dioxide Mediated Photocatalytic Degradation[J].Water Research,1996,30(2):323-330
[10]Eva-Maria B,Stefan S,Herbert J,et al.Photocatalytic Degradation of Ammonia with TiO_2 as Photocatalyst in the Laboratory and under the Use of Solar Radiation [J].Chemosphere,1997,35(7):1431-1445
[11]Ranjit K T,Varadarajan T K,Viswanathan B.Photocatalytic Reduction of Nitrite and Nitrate Ions to Ammonia on M/TiO_2 Catalysts[J].Journal of Photochemical and Photobiolical A:Chemistry,1997,108(1):73-78
[12]Li Yue-xiang,Wasgestian F.Photocatalytic Reduction of Nitrate Ions on TiO_2 by Oxalic Acid[J].Journalof Photochemical and Photobiolieal A:Chemistry,1998,112(2-3):255-25
[13]常颖等.光催化氧化反应器的研究进展[J].中国给水排水,2004,20(4):34-37
[14]杨海明.沸石负载二氧化钛光催化脱氮研究.大连理工大学硕士学位论文,2006
[15]Kapoor A,Furushor A.Nitrate Removel from Drinking Water Review.The Journal of Environmental Engineering,1997,123(21):371-380
[16]Farm J C,Murakami S.The Chemical Reduction of Nitrate in Aqueous Solution.Coordination Chemistry Reviews,2000,199(3):159-179
[17]曹广秀,李贯良,陈淑敏.纳米TiO_2在水处理中的研究进展.工业水处理[J],2003,23(23):20-22
[18]李田.城市自来水光催化氧化深度净化效果[J].环境科学学报,1998,18(2):167-171
[19]魏宏斌,严煦世,徐迪民等.二氧化钛膜固定相光催化氧化法深度处理自来水[J].中国给水排水,1996,12(6):10-14
[20]徐悦华.纳米二氧化钛光催化降解有机磷农药的研究.华南理工大学学位论文,2000
[21]高濂,郑珊,张青红.纳米二氧化钛光催化材料及应用[M].北京,化学工业出版社,2002
[22]徐瑞芬,许秀艳,付国柱等.纳米TiO_2在抗菌塑料中的应用性能研究[J].塑料,2003,31(3):26-29
[23]徐瑞芬,余广为,许秀艳.复合涂料中纳米TiO_2降解污染物和抗菌性能研究[J].化工进展,2003,22(11):1193-1195
[24]雷阎盈,张秀成,余历军等.TiO_2纳米微晶膜杀菌玻璃的研究[J].建筑玻璃与工业玻璃,2003,4:21-23
[25]邓蕾.掺杂银离子的二氧化钛光催化剂的制备与活性评价.西安建筑科技大学硕士学位论文,2006
[26]国家环境保护总局,水和废水监测分析方法编委会编.水和废水监测分析方法[M].北京:中国环境科学出版社,2002
[27]L.C.Kinney et al.Taft.Research Center Report Numbe JWRC-13,Cincinnatiohio
[28]王燕石.纯碱废水中氨氮处理方法的研究[J].中氮肥,2008,(4):21-25
[29]刘春芳.臭氧高级氧化技术在废水处理中的研究进展[J].石油技术与应用,2002,20(4):278-280
[30]储金宇,吴春笃,陈万金等.臭氧技术及应用[M].北京:北京化学工业出版社,2002
[31]罗立贤,林雯雯,蒋轶锋等.紫外光降解气态氯苯的研究[J].浙江工业大学学报,2009,37(2):144-148
[32]Kormann C,Bahnemann D W,Hoffmann M R.Environ Sci Technol,1991,25(3):494
[33]Hoffmann M R,Martin S T,Choi W et al.Chen Rev,1995,95(1):69
[34]Li Y X,Wasgestian F J.Photochem Photobiol A,1998,112(2/3):225
[35]柳丽芬,董晓艳,杨凤林等.Ag/TiO_2光催化还原硝酸氮[J].无机化学学报,2008,24(2):211-217
[36]马慧,柳丽芬,杨凤林等.纳米TiO_2薄膜耦合光催化氧化还原反应脱除水中无机氮[J].感光科学与光化学,2006,24(1):18-27
[37]魏宏斌,徐迪民.固定相膜的制备及其光催化活性[J].中国给水排水,2002,18(7):57-59