MCM-41分子筛去除水中邻苯二甲酸二丁酯的研究

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氮掺杂Ti/13X/ MCM-41分子筛去除水
中邻苯二甲酸二丁酯的研究
摘 要
邻苯二甲酸二丁酯(DBP)是邻苯二甲酸脂类物质,属于环境内分泌干扰物。它
普遍存在于大气、废水、河流、土壤中,对环境和人体具有较大的危害。近年来,
针对邻苯二甲酸二丁酯去除技术的研究越来越多,其中光催化降解技术因其高效彻
底的优点受到了普遍的关注和推广。本文以13X分子筛、正硅酸四乙酯为原料,十
六烷基三甲基溴化铵为模板,加入钛酸四丁酯和尿素,采用水热合成法制备了新型
氮掺杂Ti/13X/MCM-41复合材料。通过降解DBP实验,考察了复合材料合成过程中
诸多影响因素,确定了最佳合成工艺参数,主要包括硅铝比、溶液pH值、晶化时
间、煅烧温度以及氮钛比。将制备的复合材料通过XRDTEMFT-IRN2吸附-
脱附等手段进行了结构分析。在可见光条件下,研究了影响DBP光催化降解效率的
各项因素,如催化剂用量、光照时间、溶液初始pH 以及DBP初始浓度,利用气质
联用(GC-MS)分析了DBP光催化降解的中间产物,初步分析了DBP的可能的降
解过程。
本文的主要结论:
1、通过测定复合材料的光催化效率,确定新型氮掺杂Ti/13X/MCM-41复合材
料合成的最佳工艺参数为:硅铝比为15(摩尔比)、合成体系pH9、晶化时间为
48h、煅烧温度为350ºC以及氮钛比为4(摩尔比)
2XRD分析表明复合材料中微孔和介孔结构均存在;从 TEM图中可以看到有
序的六方晶体结构和分布均匀的孔道;N2吸附脱附实验得出比表面积以及孔径分
别为664m2/g2.79nm,复合材料具有较大的孔径和比表面积,有利于大分子有机
物在孔道中的扩散,提高了材料对有机物质的吸附和降解效率。FT-IR证明13X
孔和MCM-41介孔结构单元成功的在材料中合成,波数960cm-1900 cm-1处的吸收
峰则分别证明了钛源和氮源的成功引入。
3、通过测定复合材料对DBP的吸附和可见光下光催化降解效率,证明了复合
材料具有良好的吸附性能和光催化降解性能。氮元素的成功引入引起了光催化剂的
激发,吸收光谱明显红移并具较好的可见光响应性。将使用后的复合材料回收处理
后,再进行光催化实验,发现回收的材料仍保有一定的光催化性能。
4、将复合材料用于DBP的光催化降解实验,结果表明,在催化剂用量为
0.15g/L、初始浓度为10mg/L、初始pH6、可见光光照时间为180min条件下,
DBP的光催化降解效率可达90%左右随着DBP初始浓度的大,光催化降解
变小半衰期增大,合一级动力学方程。
5、通过GC-MS测分析,光照激发自由首先作用于DBP
,光催化降解过程由侧链断裂开始。DBP的中间产物主要为苯甲酸、苯甲酸甲
酯和邻苯二甲酸单丁酯。降解中间产物推DBP的主要降解过程可能是光照邻
苯二甲酸二丁酯分解成短链的邻苯二甲酯类,再进一步分解成苯甲酸,最
CO2H2O
键词:邻苯二甲酸二丁酯 微孔-介孔复合材料 光催化降解
氮掺杂Ti/13X/MCM-41
ABSTRACT
D i-n-b u t y l p h t h a l a t e ( D B P) i s a k i n d o f p h t h a l a t e e s t e r s , w h i c h i s c l a s s i f i e d a s
environmental endocrine disruptors. As a kind of pollutants having serious harm on the
environm e n t a nd the huma n , i t i s found w i d e l y i n a ir, w a s t e w ate r, r i v e r an d soi l . I n
recent yearsthe study on the removal of DBP is more and moreand Photocatalytic
d e g r a d a t i o n i s c o n c e r n e d a n d e x t e n d b e c a u s e o f i t s e f f i c i e n t a n d t h o r o u g h
ad v a n t a g e s. T h e c o m p o s i t e m a t e r i a l o f ni t r o g e n - d o p e d T i/ 1 3 X / M C M - 4 1 w a s
s y n t h e s i z e d b y u s i n g 1 3 X a n d t e t r a e t h y l o r t h o s i l i c a t e a s r a w m a t e r i a l, C T A B a s
s t r u c t u r a l t e m p l a t e, t e t r a b u t y l t i t a n a t e a n d u r e a u n d e r t h e h y d r o t h e r m a l
c o n d i t i o n. T h e o p t i m i z ed e x p e r i m e n t a l c o n d i t i o n s, s u c h a s , S i / A l ( m o l a r r a t i o ) , p H
value, crystal dur a t i o n, c a l c i n ation t e m p eratu r e and N /Ti ( molar r a t i o), w a s tested b y
the p h o tode g ra d a t ion e x p e riment s of D B P. The s amples w e re chara c t e r i zed b y X RD,
TE M , F T - I R , N
2 adsorption-desorption. The study on influencing factors of the
DBP photodegradation was tested under visible light, such as, catalyst dosage, reaction
t i m e, i n i t i a l p H a n d i n i t i a l c o n c e n t r a t i o n. In a d d i t i o n , b y u s i n g G C - M S, t h e
intermediates of the DBP photodegradation were identified, and according to the
intermediates, the degradation pathway of DBP was primarily analyzed.
The main conclusions of this thesis are summarized as follows:
1 . B y t e s t i n g t h e c a t a l y t i c a c t i v i t y o f t h e c o m p o s i t e m a t e r i a l, th e p r e p a r a t i o n
o p t i m u m c o n d i t i o n s o f t h e ni t r o g e n - d o p e d T i/ 1 3 X / M C M - 4 1 w a s c o n f i r me d a s
Si/Al=15, crystal duration=48h, pH=9, calcination temperature=300 ºC and N/Ti=4.
2. Th e an aly sis of X RD shows that the c o mpo s ite material had meso poro us and
microporous bimodal pore systems; Transmission electron micrographs of the sample
s h o ws a r e g u l a r h e x a g o n a l a r r a y o f u n i f o r m c h a n n e l s; T h e s p e c i f i c s u r f a c e a r e a
is 664m2/g and the pore diameter is 2.79nm, which improve the adsorption and
degradation efficiency of the material for organics.The units of 13X and MCM-41 were
synthesized in the composite material, and the absorption peaks at 960cm-1 and 900cm-
1 prove that Ti and N was introduced into the framework successfully.
3. The experimental results of the DBP photodegradation prove that the composite
material has high adsorption capacity and catalytic capacity. The N-doping could make
t h e l i g h t a b s o r p t i o n o f t h e p h o t o c a t a l y s t o b v i o u s l y e x t e n d e d i n t o
v i s i b l e-l i g h t r e g i o n, a n d i n c r e a s e t h e v i s i b l e-l i g h t r e s p o n s i v e p h o t o c a t a l y t i c
a c t i vi t y. Af t e r r e g e n er a t i o n p r o c e s s, t h e u s e d c o m p o s i t e m a t er i a l s ti l l k e e p s a c e r ta i n
degree of catalytic capacity.
4 . Th e o p t i m u m c o n d i t i o n s o f t h e D B P ph o t o c a t a l y t i c d e g r a d a t i o n w a s c a t a l y s t
d o s a g e 0 . 15g / L , i n i t i a l p H 6 , r e a c t i o n t i m e 1 8 0 m i n a n d i n i t i a l c o n c e n t r a t i o n
1 0m g / L. T h e ph o t o c a t a l y t i c d e g r a d a t i o n e f f i c i e n c y o f D B P c a n r e a c h 90%
approximately. The DBP photodegradation process obeys first-order reaction.
5. With the analysis of GC-MS, the main intermediates of DBP are mainly benzoic
acid, methyl benzoate and Mono-n-butyl phthalate during the photodegradation
process. Under visible light, ·OH firstly act on side chain of DBP, generating a series
different short-chain phthalate esters, then which were oxidized to benzoic acid. Finally,
the benzoic acid is mineralized to CO2 and H2O.
K e y W o r dD i - n - b u t y l p h t h a l a t e, M i c r o - m e s o p o r o u s c o m p o s i t e
material, Photocatalytic degradation, Nitrogen-doped Ti/13X/MCM-41
目录
中文
ABSTRACT
.....................................................................................................................1
1.1环境内分泌干扰物..............................................................................................1
1.2 邻苯二甲酸二丁酯.............................................................................................1
1.2.1 DBP的物化性质.......................................................................................1
1.2.2 DBP的应用...............................................................................................2
1.3 DBP在环境中的分布.........................................................................................2
1.3.1 大气环境中DBP的分布...........................................................................3
1.3.2 水环境中DBP的分布...............................................................................3
1.3.3 土壤中DBP的分布...................................................................................5
1.4 DBP的危害.........................................................................................................6
1.4.1致畸(生殖毒).........................................................................................6
1.4.2致突变....................................................................................................6
1.4.3 致癌.......................................................................................................7
1.4.4危害....................................................................................................7
1.5 DBP测方法.................................................................................................7
1.5.1DBP的收集与前处理................................................................................7
1.5.2 DBP的分析测定.......................................................................................8
1.6 DBP的去除.........................................................................................................9
1.6.1 物法.......................................................................................................9
1.6.2 吸附.........................................................................................................10
1.6.3 级氧化技术.........................................................................................11
1.7论文课题来源及选题意义、研究内............................................12
1.7.1论文课题来源及选题意义..................................................................12
1.7.2论文研究的内......................................................................................13
1.7.3论文研究的技术路线..............................................................................13
1.7.4新点......................................................................................................14
/介孔复合分子筛光催化剂的研究进.....................................................15
2.1 13X分子筛........................................................................................................15
2.1.1 13X分子筛的..................................................................................15
2.1.2 13X分子筛的合成..................................................................................16
2.1.3 13X分子筛的应用..................................................................................16
2.2 介孔MCM-41分子筛.......................................................................................17
2.2.1 MCM-41的合成机理.............................................................................17
2.2.2 MCM-41性及应用.........................................................................18
2.3 TiO2光催化的研究...........................................................................................19
2.3.1 TiO2光催化应机理.............................................................................19
2.3.2 TiO2光催化剂的合成.............................................................................20
2.3.3 TiO2光催化剂的.............................................................................20
2.4/介孔复合材料的研究背景..........................................................................21
2.4.1 /介孔复合材料的合成.......................................................................21
2.4.2 /介孔复合材料的表.......................................................................22
2.4.3 /介孔复合材料的应用.......................................................................22
氮掺杂Ti/13X/MCM-41分子筛的制备..........................................................24
3.1 实验...........................................................................................................24
3.1.1 实验药品.................................................................................................24
3.1.2 实验仪器.................................................................................................24
3.1.3复合材料的制备......................................................................................25
3.1.4复合材料的性能测定..............................................................................26
3.2复合材料的合成主要影响因素........................................................................28
3.2.1 Si/Al比对复合材料的影响....................................................................28
3.2.2合成体系的pH值对复合材料的影响.....................................................29
3.2.3晶化时间对复合材料的影响..................................................................30
3.2.4煅烧温度对复合材料的影响..................................................................31
3.2.5 N/Ti摩尔比对复合材料的影响.............................................................32
3.2.6复合材料吸附及光催化性能的比较......................................................33
3.2.7复合材料复利用..................................................................................35
3.2.8可见光下掺NN复合材料的对比................................................35
3.3样品测定及表................................................................................................37
3.3.1 X射线衍射分析(XRD.....................................................................37
3.3.2 N2吸附-脱附分析...................................................................................38
3.3.3透射电子显微......................................................................................39
3.3.4傅里叶变换光谱测FT-IR)分析............................................40
3.4....................................................................................................................41
复合材料对水中DBP的光催化降解...............................................................42
4.1实验............................................................................................................42
4.1.1 实验药品.................................................................................................42
4.1.2 实验仪器.................................................................................................42
4.1.3 实验操作过程.........................................................................................42
4.2结果与讨........................................................................................................43
4.2.1 复合材料的吸附性能.............................................................................43
4.2.2 复合材料用量对降解效率的影响.........................................................44
4.2.3 光照时间对降解效率的影响.................................................................45
4.2.4 pH对降解效率的影响............................................................................46
4.2.5 DBP溶液初始浓度对其降解效率的影响.............................................47
4.2.6 DBP降解过程分析.................................................................................49
4.3....................................................................................................................51
第五章 结论与建议.......................................................................................................53
5.1 结论...................................................................................................................53
5.1.1 氮掺杂Ti/13X/MCM-41复合材料的制备.............................................53
5.1.2 氮掺杂Ti/13X/MCM-41复合材料对DBP的光催化降解.....................53
5.2 建议...................................................................................................................53
参考文........................................................................................................................54
摘要:

氮掺杂Ti/13X/MCM-41分子筛去除水中邻苯二甲酸二丁酯的研究摘要邻苯二甲酸二丁酯(DBP)是邻苯二甲酸脂类物质,属于环境内分泌干扰物。它普遍存在于大气、废水、河流、土壤中,对环境和人体具有较大的危害。近年来,针对邻苯二甲酸二丁酯去除技术的研究越来越多,其中光催化降解技术因其高效彻底的优点受到了普遍的关注和推广。本文以13X分子筛、正硅酸四乙酯为原料,十六烷基三甲基溴化铵为模板,加入钛酸四丁酯和尿素,采用水热合成法制备了新型氮掺杂Ti/13X/MCM-41复合材料。通过降解DBP实验,考察了复合材类成过程中诸多影响因素,确定了最佳合成工艺参数,主要包括硅铝比、溶液pH值、晶化时间、煅烧温...

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作者:牛悦 分类:高等教育资料 价格:15积分 属性:59 页 大小:17.74MB 格式:DOC 时间:2024-11-11

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