Khảo sát khả năng phân hủy paraquat trong thuốc trừ cỏ dưới nguồn ánh sáng nhìn thấy trên bột nano y tio2 được điều chế bằng phương pháp thủy nhiệt

TAP CHi HOA HQC

T. 50(6)704-710

THANG12NAM20I2

KHAO SAT KHA NANG PHAN HUY PARAQUAT TRONG T H U 6 C TRLf c6

DU'QI NGUdN ANH SANG NHJN THAY TREN BOT NANO Y-TiOj BUOC
OI^U CH^ BANG PHU'ONG PHAP THUY NHIET
Nguyen Van Hung'", Ngo Sy Luong^, Nguyen Hiru Hieu^
'Khoa Hda hgc, Tnrdng Dgi hgc Dong Thdp
^Khoa Hoa hgc. Tnrdng Dgi hgc Khoa hgc Tu nhien Hd Ngi. DHQG Hd NQi
Den Tda sogn 22-4-2012
Abstract
The effecl of experimental conditions on the degradation of paraquat in herbicide over Y-Ti02 powder prepared by
hydrothermal method (particle size about 6-7 nm, specific surface area - 223.6 mVg) have been investigated.
Experimental results showed that suitable conditions arc' time for adsorption equilibrium about 60 minutes, amount of
Y-TiOi per 200 ml herbicide solution with concentration of paraquat 19 mg/1 about 0.3g, the pH of solution about 7-8
and the degradation limes about 4 hours. In the conditions, the concentrations of paraquat in herbicide after
decomposing were lower than threshold (0.9 mg/1) It showed that ihe promise applications of Y-Ti02 powder in
degradation of paraquat as well as other organic pollutants can obtain.
Keywords: Titanium dioxide, Photocatalysl, paraquat, herbicide, Y-Ti02, doping, Y(III).
1. GIOI THIEU
Paraquat la mpt logi thudc diet cd khdng chpn
Ipc, thudng dugc sir dyng d cac nudc ndng nghiep
cho sy kiem soat cd dgi va cd la rdng tai khu vyc dat
trdng cay va cac khu vyc thiiy san. Paraquat dugc
biet den nhu la chat gay d nhiem mdi trudng dat va
nudc mat, dpc hai ddi vdi con ngudi va dpng vat [I].
Lieu lugng gay hgi ciia nd tuang ddi thap. Vi du,

lieu lugng gay hgi tuong lirng la 35 mg/kg doi vdi
ngudi va 36-54 mg/kg ddi vdi gia siic [1]. C) Vipt
Nam, paraquat dugc sir dyng nhieu d cac tinh phia
Nam vdi ten thuong pham nhu Tungmaxone,
Nimajion 20SL nham dipt cd dgi d cac rupng liia va
hoa mau. Gan day, d nudc ta sd ca ngp dpc paraquat
ngay cang tang va ngp dpc cap paraquat bat ke lieu
lugng nao deu cd the tu vong va hipn chua cd bipn
phap dieu trj hiru hipu nao. Do paraquat cd dpc tinh
cao va ben vimg trong mdi trudng ddt va nude nen
viec nghien ciru tim ra phuang phap thich hgp d6
logi bd du lugng ciia chung la rat cdn thiet.
Trong nhieu chat ban dan cd kha nang quang
xuc tac (QXT) nhu: TiOi, WO3, SrTiO,, FejOj,
ZnO, ZnS, CdS... TiOj dugc chirng minh la phii hgp
nhat cho cac ung dyng rpng rai trong xir li mdi
trudng do Ti02 cd hogt tinh QXT cao nhdt, tro ve
hda hpc va sinh hgc, ben virng, khdng bj an mdn
dudi tac dung cua anh sang va hda hgc, gia thanh

thap [2]. Tuy nhien, nang lugng vimg cam ciia TiO;
tinh kliiet klia ldn (3,25 eV ddi vdi anata va 3,05 eV
ddi vdi rutin) nen chi hoat dpng QXT trong viing tii
ngoai gdn, va do dd chi cd the tan dung dugc mdt phan
nhd (< 4%) ngudn nang lugng ddi dao tir mat trdi, lam
gidi hgn kiia nang img dung thyc tien cua nd. Do do, kl
thuat bien tinh da dugc sir dung nham thay ddi cau tnic
dipn tir va nang cao hoat tinh QXT ciia TiO: trang
vimg anh sang nhin thay. Cac ion ddt hiem dugc biet
den vdi kha nang tgo phirc ciia chung vdi cac bazo

Lewis (nhu amin, andehit, thiol,...) thdng qua tuong tac
giira cac nhdm chirc ciia nhung baza vdi cac obitan f
ciia ion dat hiem. Do dd, ket hgp cac ion ddt hiem
trong mgng ludi Ti02 cd the tgp trung cac chat 6 nhiem
len be mgt chdt ban din, md rgng phan dng quang hoa
den viing anh sang nhin thay va nang cao hipu qua tach
giiJa cac c$p electron-Id trong cam quang ciia TiOi [3].
Da cd mpt so cdng trinh nghien ciru phan hiiy cac hpp
chat huu ca (d dgng tinh khiet) h^n bpt TiOj bien tinh
bdi ion Y^* va danh gia hogt tinh QXT cua chiing trong
viing anh sang tu ngogi gdn [4, 5]. Tuy nhien, den thdi
diem hien tgi, chua cd cdng trinh nao cdng bo ve vi?c
phan hiiy paraquat cd trong thudc trir cd (mau that) bdi
bpt nano Y-Ti02 dudi sy chieu xg anh sang nhin thay.
Trong cdng trinh nay, chung tdi thdng bao mOt
sd ket qua khao sat kha nang ung dyng bpt Y-TiOj
kich thudc nano dugc dieu che bdng phuang phip


TCHH,T. 50(6), 2012
thiiy nhipt dung djch TiOS04 cd m^t ure thdng qua
kha nang phan huy hogt chdt paraquat cd trong thuoc
trir cd dudi buc xg cua dhn compact.
2. PHUONG PHAP NGHIEN CUV

Nguyen Vdn Hung vd cgng su
40 den 100 kV. Dipn tich be mat BET dugc xac dinh
til dudng ddng nhipt hdp phy-giai hdp nito tai 77 K
tren thiet bj Micromeritics (My).
cac gia trj dp hap thy quang cua dung djch

paraquat dugc xac djnh bdng each ghi phd hdp thy
UV-VIS tren may UV245D-Shimadzu (Nhgt Ban).

2.L Thyc nghifm
3. KET QUA VA T H A O LUAN

Cac hda chdt duprc su dung trong thyc nghipm
deu d dgng tinh khiet ma khdng can ch£ hda bo
sung.
Chi t\k quy trinh dieu ch6 va cac y6u to anh
hudng da dugc cdng bo d cdng trinh [6]. Ket qua
cho thdy, bpt Y-TiO; d ty Ip moi Y/TiO; 0,168% cd
hogt tinh quang xuc tac cao nhat nen mau nay va
mau Ti02 khdng bien tinh dugc tien hanh dieu che
theo nhCrng dieu kipn da dugc khao sat, cy the nhu
sau: Hda tan 4 gam TiOSOj vao 50 ml dung dich
H2SO4 0,18 M. Cho tiep 10 gam ure va lugng muoi
Y(N03)3 xac djnh vao dung djch TiOSOj thu dugc
va khuay deu trong khoang 15 phiit, Ihu dugc dung
djch hon hgp. Dung djch nay dugc cho vao
autoclave dung tich 100 ml va lien hanh thiiy nhipt
trong 18 gid d nhipt dp thich hgp. Huyen phii thu
dugc sau khi thiiy nhipt dugc rua vai lan bdng nudc
cat va sau dd la etanol cho den khi khdng cdn phat
hien ion S04^" trong nudc riia (thir vdi dung djch
BaCb 0,2M). Bpt Y-TiO; thu dugc bdng each sdy
kho huyen phii sau khi rua d IIO^C trong 24 gid.
Mau Ti02 khdng bien tinh dugc dieu che tuong ty
nhung khdng cd sy bd sung lugng mudi Y(N03)3.
Hogt tinh QXT cua cac mau san pham dugc

danh gia bang each trpn lugng xac dinh bpt Y-Ti02
vao 200 ml dung dich thudc trir cd cd ndng dp
paraquat thich hgp, khuay deu hdn hgp trong bdng
toi den khi dat can bang hap phu-giai hap. Sau do,
huyen phii dugc chieu xa trong khoang thdi gian
thich hgp bdi den compact Golstar 40 W vdi 3 vung
budc song dgc trung la 435 nm, 545 nm va 610 nm.
Hieu suat phan irng QXT dugc xac djnh bang each
so sanh dp hap thy quang ciia dich trudc va sau phan
ung d eye dgi hdp thu X = 557 nm.

3.1. Mpt so dac tinh chii yeu cua san pham bpt
TiO: dieu che dugc
Mau Ti02 khdng bicn tinh va mlu Y-Ti02 d ty
Ip moi Y/Ti02 0,168% sau khi dieu che dugc tien
hanh ghi nhieu xg tia X. Gian do XRD cua chimg
dugc dua ra d hinh 1. Ket qua tinh loan kich thudc
hat trung binh cho thdy, mau Ti02 khdng bign tinh
cd kich thudc hgt trung binh (~ 7,3 nm) Idn hem so
vdi mau Y-Ti02 (6,1 nm).

Hinh J: Gian dd XRD ciia mau Y-Ti02 va mau Ti02
khdng bien tfnh
Ket qua nay cung phu hgp khi chung tdi tien
hanh ghi dang nhiet hap phu-giai hap phy N; (BET).
Ket qua BET cho thay, mau Ti02 khdng bien tinh cd
dien tich be mat rieng (218,9 m'/g) be han so vdi
mau Y-Ti02 (223,6 m^/g). Anh TEM cua mau YTi02 d ty le moi Y/Ti02 0,168% dugc dua ra d hinh
2. Hinh 2 cho thay, mau Y-Ti02 cd kich thudc hat be
(- 6-7 nm) va phan bd kha ddng deu.

k^^j

2,2. Cac phu-Qng phap xac dinh
Gian dd XRD ciia bpt Ti02 dugc ghi tren nhi6u
xg ke tia X D8 Advance Brucker (Due) vdi tia CuK^
wX = 0,154056 nm, nhipt dg ghi 25°C, gdc 29: 10
^70°, toe dp quet 0,037s. Kich thudc hgt trung binh
dupc xac djnh dya vao pic dac trimg tren gian dd
XRD theo cdng thuc Scherrer.
Cac anh TEM cua san pham bpt TiO: dugc chyp
tren kinh hi^n vi dipn tir truyln qua JEMIOIO
(JEOL-Nhat Ban) cd hp sd phdng dgi M = x50 den
X600.000, dp phan giai 5 = 3 A, dien ap gia tdc U =

Uii4&,i»-

Hinh 2: Anh TEM ciia mau Y-Ti02 d
tylp moi YATiOj 0,168%


Khao sal kha nang phan huy...

TCHH.T. 50(6),2012
3.2. Khao sat mgt so yeu to anh hirong den qua trinh
phan huy paraquat (PD) tren bgt Y-Ti02
3.2.1. Xac dinh thai gian can bSng hip plw - giai hdp
Thuoc trir co Niainaxon 20SL mua tren thj
trudng CO nong dp PD ghi Ihco nhan lii?u 14 200 g/l.
Chung toi sir dung phuang phap s5c ki long lii?u
nang cao (HPLC) tiii Vi?n Kicm nghipm an loan v?

sinh thirc phjm quoc gia de xac djnh l?i nong dp PD.
Phuong phap xac dinh PD dirpc dira tren TCVN
(2010) do Vien Kicm nghifm An toan V? sinh thirc
pham Quoc gia bicn soan, bp Y tc dc nghj, Tong cgc
Tieu chuSn Do luong Chat luong tham djnh. Bo
Khoa hpc va Cong nghp cong bo. Ket qua Ihu dupc
n6ng dp thirc eiia PD la 259 g/l. Nong dp nay, dupc
chung toi pha loang thanh cae nong dp can thiet cho
nhiing nghien ciru tiep theo.
De xac djnh thcri gian dgt can bang hap phu giai hdp PD tren bgt Y/TiO; chimg toi thay doi thcri
gian hap phu tir 0 d£n 90 phiit va giir co dinh cac
lupng: Y/TiO, 0,3 g, nong dp PD 19 mg/1 (pH - 7).
Dung lugng hap phu PD tren bpt Y/TiOi duge xac
djnh thong qua bieu thire:
Q, = V(Co-C,)/m

la nong dp t?i thai di^m t ciia chat bj hap phy (mg/1)
va m la lirpug chat hap phy (g). Nong dp PD con Iji
sau khi bi hap phy dypc xac djnh bang each do dj
hap thy quang (Abs).
Cac thong so hap phy ciia v^t li?u Y/Ti02 dugt
trinh bay cr bang 1. Do thj bieu dien sy phy thu^c
giita dung lugng va thdi gian hap phy dugc dua rao
hinh 3. Ket qua eho thay, khi tSng din thtri gian hap
phy dung lugng hap phy tang. Qua trinh hap phy xay
ra nhanh eh6ng trong khoang 30 phiit dau tien, sau
do toe dp hap phy cham l^i va gan nhu can bang tai
thcri diem 30 phiit. Tuy nhien, de dam bao can bang
dugc thiet lgp hoan tpan eac thi nghi?m ti6p theo
duge chimg toi giii eo djnh thai gian hap phy 60

phut.

(1)

Trong do, Qi la dung lugng hap phu tgi thdi diem t
(nig/g); V la th^ tich dung dich chat bi hap phu (I);
Co la nong dp ban dau ciia chat bi hap phu (mg/1); Ci

Thdi Kill ^P Phu> P'lut

Hinh 3: Dd thj bieu dien sir phu thupc
giira dung lugng va thdi gian hap phu

Bdng !: Cac thdng sd hap phu PD tren bpt Y-Ti02
N6ng dp
C, cua PD,
mg/1

Dung lupng
hap phu Qi,
mg/g

The tich
dung dieh, 1

Nong dp Co
cua PD, mg/1

0,2

19

19

0

15

0,3
0,3

0,2

19

13,40

3,733

PD30

30

0,3

0,2

19

11,46

5,026

PD45

45

0,3

0,2

19

11,38

5,080

PD60

60

0,3

0,2

19

11,36

5,093

PD90

90

0,3

0,2

19

11,35

5,100

Ki hieu
mau

Thcri gian
hap phu,
phiit

Lugng
TiO,,

PDO

0

PD15

g

3 2-2. Anh hirdng ciia lugng bgt Y-TiO}
Bpt Y-Ti02 dugc cho vao 200 ml dung djch thuoc
trir cd cd ndng dp PD 19 mg/1 vdi cac lugng thay ddi tir
0,10 den 0,35 g. Dung djch huyen phu sau khi khuay
60 phut trong bdng tdi dugc tien hanh chieu sang trong
3 gid. Phd UV-VIS ciia dung djch PD sau khi phan
huy d cac lugng bpt Y-Ti02 khac nhau dugc thS hi$n d
hinh 4. Tir hinh 4 cho thay, khi tang dan lugng bpt Y-

TiOj tu 0,1-0,15 g thi dp hap thy anh sang cua dung
dich PD sau khi phan hiiy giam manh. Dp hap thy nay
ti^p tyc giam nh? khi lugng Y-Ti02 trong khoang 0,150,3 g. Neu ti^p tyc tang lugng bpt Y-TiOa > 0,3 g thi
dp hap thy anh sang ciia dung dich PD cd xu hucmg
tang.
cac gia trj nong dg dung djch PD trudc (Co) va
sau (C) khi phan huy va hi?u suat phan huy quang
(HSPHQ) dugc trinh bay trong bang 2. Tir bang 2


TCHH, T. 50(6), 2012

Nguyen Vdn Hung vd cgng stf

eho thSy, khi tang dan lugng Y/TiOj tit 0,1-0,15 g
HSPHQ tang m?nh. HSPHQ tiSp tyc tang nh? khi
tang dan lupng hot Y-Ti02 va dgt gia tri eye dai irng
voi mlu CO lut^g Y-Ti02 la 0,3 g. Neu tiep tyc tang

lugng Y/TiO; > 0,3 g thi HSPHQ co xu huong giam
(do hi$u irng ehan sang).
Bang 2: Anh hucmg eiia lugng bpt Y-Ti02 den
HSPHQ dung tijch PD
Ki hieu mau

Co, mg/1
19
19
19
19
19
19

C,mg/I
2,38
1,45
1,42
1,34
1,29
1,30

H,%
87,47
92,37
92,53
92,95
93,21
93,16

1 A

m

P01D

INI

PDTiOAlO
PDTiO20,15
PDTiO20,20
PDTiO20,25
PDTiO20,30
PDTiO20,35

Theo Carp O. [7], toe dp phan hiiy cac chat hiru co
thudng the hi?n dgc diem bao hda. Hang so tdc dp
thu dugc giam lien tuc ciing vdi su gia tang ndng dp
chat d nhiem hiiu co ban dau. Carp O, cho rang, cac
budc chinh trong qua trinh QXT xay ra tren be mat
cua chat ran QXT. Do lai ndng dp ban dau cao tat ca
cac vj tri xuc tac da bao hda nen sir gia tang hon nira
nong dp chat huu co ciing khdng anh hudng den
ndng dp be mgt chat xiic tac va do do, cd the dan den
lam giam hang so tdc dp phan hiiy. Tuy nhien, trong
khoang nong dg PD tir 19-29 mg/1 thi HSPHQ van cao
(dao dpng khoang 90-93%). Vi vay, de thuan lgi cho
nhirng nghien cim tiep theo chiing tdi chpn ndng dp PD
la 19 mg/1.

::

_

.

.

„

Hmh 5: Phd UV-VIS ciia dung djch PD sau khi bi
phan hiiy d cac ndng dp PD ban dau khac nhau
Bdng 3. Anh hudng ctia ndng dp PD ban dau den
HSPHQ dung djch PD
Hinh 4. Phd UV-VIS ciia dung dich PD sau khi bi
phan huy d cac lugng bpt Y-TiOj khac nhau
3.2.3. Anh hudng ciia nong do PD
Nham xac dinh ndng dg PD thich hgp cho qua
trinh phan hiiy, thudc trir cd Nimaxon dugc hda tan
vao dung mdi nudc sao cho dung dich thudc trir cd
dgt dugc d cac nong dp PD khac nhau: 9, 14, 19, 24
va 29 mg/1. Cac d\h\x kien cd djnh khac bao gdm: 0,3
g bdt Y-Ti02, hap phu trong toi 60 phut va chieu
sang dung dich huy^n phii trong 3 gid. Ndng dp
dung dich PD sau khi phan huy dugc xac dinh bang
each ghi phd hip thu UV-VIS. Pho hap thy UV-VIS
cua dung djch PD sau khi phan hiiy irng vdi cac
ndng do PD ban dau khac nhau dugc dua ra d hinh
5. Tir hinh 5 cho thay, khi tang dan ndng dp PD dp
hap thu anh sang cua cac mau tang. Di6u nay chirng

td rang ndng do ban dau ciia PD cang ldn thi
HSPHQ cang giam.
cac gia tri nong dp PD trudc va sau khi phan
hiiy va HSPHQ dugc trinh bay trong bang 3. Bang 3
cho thay, khi tang dan ndng dg PD thi HSPHQ giam.

Ki hieu mau

Co, mg/1

C,mg/I

H,%

PDIO

9

0,46

97,58

PD15

14

0,95

95,00

PD20

19

1,43

92,47

PD25

24

1,47

92,26

PD30

29

1,90

90,00

3 2.4. Anh hudng mdi irudng pH ciia dung dich PD
De khao sat anh hudng ciia pH dung djch PD
den qua trinh phan hiiy QXT, 0,3 g bdt Y-T1O2 dugc
cho vao 200 ml dung djch thudc trir cd cd ndng dp
PD 19 mg/1. Dung djch PD dugc dieu chinh pH
(bang HCl va NaOH) d cac gia tri khac nhau: 4, 6, 7,

8 va 10. Huy6n phii PD va TiOi dugc chieu sang
trong 3 gid. Pho UV-VIS ciia dung djch PD sau khi
phan hiiy cua cac mau d cac gia trj pH khac nhau
dugc dua ra d hinh 6. Tti hinh 6. cho thay, khi tang
dan gia trj pH thi dp hap thu cua dung dich PD sau
khi phan huy giam. Dilu nay chirng td, HSPHQ tang
ciing vdi vi?c tang cac gia trj pH.


Khdo sdt khd nang phdn huy...

T C H H , T. 50(6), 2012

3.2.5. Anh hudng cua thdi gian phdn

LTinh 6: Phd UV-VIS ciia d u n g djch PD sau khi phan
hiiy d cac gia trj PH d u n g djch PD khac nhau
HSPHQ ciia cac m l u d cac gia Irj pH thay doi
d u g c trinh bay trong bang 4. T u bang 4 cho Ihay, khi
tang dan gia tri pH thi H S P H Q lang. T h e o Hoffmann
[2], cac nhdm hydroxyl tren b6 mat T i 0 2 ton tgi can
bane axil - bazo nhu sau:
>TiOHj<-

> > T i O H + H"

(1)

>TiOH<-^

• > T i O ' + H*

(2)

Tir cac p h u a n g trinh (1) va (2) nhan thay, khi
tang dan gia trj pH can bang se chuyen djch theo
chieu tang tich dien am tren be mat T i O j (>TiO').
K^t qua nay tao digu kien thuan Igi cho viec hap phu
PD* va do dd lam tang kha nang phan hiiy PD"" tren
be mat Ti02.

inx]

\

^~^-.^>

Bdng 4. Anh h u d n g mdi t r u d n g pH cua dung djch
Ki hieu mau

Co, mg/1

C,mg/1

H,%

PDH4

19

2,41

87,31

PDH6

19

1,63

91,42

PDH7

19

1,46

92,31

PDH8

19

0,90

95,26

PDHIO

19

0,60

96,84

hiiy

D e khao sat anh h u d n g c u a thdi gian phan hiiy,
0,3 g c h o mdi logi bgt; T i 0 2 k h d n g bien tinh va YT i 0 2 d u g c c h o v a o 2 0 0 ml d u n g djch thudc trir co co
nong dp PD 19 mg/1 ( p H ~ 7). D u n g djch huyen phu
d u g c khuay 60 phiit trong b d n g toi de dat can bang
hap phy - giai h a p va sau dd d u g c chieu sang vdi cac
thdi gian thay doi tir 1 den 4,5 gid. Cac thdng s6 cho
qua trinh phan hiiy d u n g dich PD tren cac mau bot:
T i 0 2 khdng bien tinh va Y - T i 0 2 d cac khoang thai
gian phan hiiy khac nhau d u g c trinh bay trong bang
5. D o thj bicu di£n s\r phy thupc giiia HSPHQ va
thdi gian phan phan hiiy ciia mau T i 0 2 khdng bl^»
tinh va mau Y - T i 0 2 d u g c d u a ra d hinh 7. Tir bang 5
va hinh 7 c h o thay, khi t a n g thdi gian phan huy thi
H S P H Q cua cac mau tang. Mlu Y - T i O i cd HSPHQ
cao h a n so vdi m l u T i 0 2 k h d n g bien tinh d cac
khoang thdi gian phan hiiy t u a n g irng. Pho UV-VIS
ciia d u n g djch PD sau khi bj phan hiiy d cac khoang
thdi gian tir 2,5-4,5 gid tren mau bpt Y-Ti02 iu(}c
dua ra d hinh 8. Tir hinh 8 c h o thay, khi cang keo dai
thai gian phan hiiy thi d g h a p thy quang cang giam.
PD trong d u n g djch thudc tru cd gan nhu bj phan
hiiy hoan loan sau 4,5 gid chieu sang.

X
1

1.0

1.1

2.0

^^—*N^_(2|
1.1 ID 11 (.0 1.1 l

Hmh 7: D o thj bieu dien s g phy thupc gi&a HSPHQ
va thdi gian phan hiiy ciia cac m l u : TiO^ khong biSn
tinh v a Y-T1O2

Bang 5: Cac thong so cho qua trinh phan hiiy PD tren bpt T i O ; va Y-TiO; cr cac thoi gian pi an huy khae nhau

Mau T i O ; d u p c bien tinh Y(Ill)
Ki hieu
mau
PDl,Oh
PDI,5h
PD2,0h
PD2,5h
PD3,0h
PD3,5h
PD4,0h
PD4,5h

Tph,

h

1,0
1,5
2,0
2,5
3,0
3,5
4,0
4,5

Co, mg/1 C, mg/1

19
19
19
19
19
19
19
19

lnC/C„

M l u T i 0 2 k h o n g d u g e bien tinh
H,

%

Ki hipu
mau

5,72

-1,200

69,89

0Til,0h

4,24

-1,500

77,68

0Til,5h

3,14

-1,800

83,47

0Ti2,0h

1,90

-2,300

90,00

0Ti2,5h

1,50

-2,538

92,11

0Ti3,0h

1,22

-2,744

92,31

OTi3,5h

0,61

-3,440

96,79

0Ti4,0h

0,48

-3,687

97,47

0Ti4,5h

708

TpK,

h

1,0
1,5
2,0
2,5
3,0
3,5
4.0
4,5

Co,
mg/1

19
19
19

19
19
19
19
19

InC/Co

H,%

12,20

-0,443

35,79_

10,35

-0,607

45,52

9,50

-0,693

50,00_

8,94

-0,754

52,9i_

8,37

-0,820

55,95.

7,06

-0,990

6,44

-1,082

66,10_

6,00

-1,152

68^

C,mg/I


TCHH, T. 50(6), 2012

Nguyen Vdn Hung vd cgng su
Theo quy chuAn ky thuat qudc gia \'i chat lugng
nudc mgt (QCVN 08; 2008/BTNMT) thi ham lugng
PD cd mat trong nudc khdng dugc phep vugt qua
0,9 mg/1. Nhu vgy, vdi lugng chat QXT la 0,3 g,
ndng dg PD 19 mg/1 (Idn hon quy chuan cho phep
khoang 21 lan) va sau 4 gid chi6u sang thi ham
lugng PD trong thuoc trir cd sau khi phan hiiy da
thap han ngudng cho phep.
4. KET LUAN

Hinh 8: Phd UV-VIS ciia dung djch PD sau khoang
thdi gian phan huy tir 2,5-4,5 gid
Theo cdng trinh nghien cuu [8], qua trinh phan
buy QXT cac hgp chat huu co cd the dugc dac
trimg bang phuang trinh dpng hgc LangmuirHinshelwood nhu sau:

- ^ = k.e = k J i ^
dt

(2)

1 + KC

Trong dd, k la hang so toe dp thyc, K la hang sd hap
phu, t la thdi gian va C la ndng do chat d nhiem hiiu
CO. Vdi ndng dp ban dau thap ciia nhung chai d
nhiem hiJu ca, nhdm KC trong mau sd phuong trinh
(6.3) cd the bd qua va tdc dp oxi hda QXT dugc dac

trung bang phuong trinh dpng hpc bac mpt:
In-

-k-t

(3)

Trong dd, k' la hang sd tdc dp bieu kien, cung dugc
biet nhu la hang so tdc dp gia bac mpt va Co la ndng
dp chat hiru ca ban dau.
Dd thi bieu dien sy phu thudc giua InC/Co va
thdi gian phan hiiy dung djch PD ciia mau Ti02
khong bien tinh va mau Y-Ti02 dugc dua trong
hinh 9. Tir hinh 9 thu dugc cac gia tri hang sd tdc dp
phan ung ciia cac mau Ti02 khdng bien tinh va YTiOj lan lugc la 0,197 va 0,718 h"'. Nhu vgy, cac
mlu Ti02 dugc bien tinh bdi Y(III) cho thay hogt
tinh QXT cao hon nhilu so vdi mau Ti02 khdng
bi6n tinh.

, r^^^-^-^E;—--iL_(i
'
• ^•.x"-°""
1.Ti02
2. Y-TIO2

'^S!'

Hinh 9: Do thi bi^u diln sy phy thupc giira InC/Co
va thai gian phan hiiy cua cac mau Ti02 va Y-Ti02

Da xac djnh dugc cac dieu ki?n thich hgp cho
qua trinh phan hiiy hogt chat PD cd trong thudc trued tren bpt nano Y-Ti02 dugc dieu che bang
phucmg phap thiiy nhi|t. Di^u kien thich hgp cho
qua trinh phan hiiy nay bao gdm: thdi gian dat can
bang hap phy-giai hap 60 phiit; lugng bpt Y-TiOi la
0,3 g/ 200 ml dung djch thudc trir co cd ndng dp PD
19 mg/1; pH dung djch PD ~ 7-8 va thdi gian phan
hiiy khoang 4 gid. Vdi cac dieu kien nay, thi ham
lupng PD cdn Igi trong dung djch sau khi phan buy
dat thap hon ngudng cho phep (0,9 mg/1). Dieu nay
cho thay kha nang dng dung tdt ciia bpt Y-Ti02
trong xir li paraquat va cac chat d nhiem hiru ca
khac. Ngoai ra, nghien cuu cdn cho thay bpt Ti02
dugc bien tinh bdi Y(lll) cd boat tinh quang xuc tac
cao hon so vdi mau Ti02 khdng dugc bien tinh.
Ldi cam ffn: Cong trinh ndy duac su ho trg kinh
phi tir di tdi md so B20IJ-20-01 cua Bg Gido Due
vd Ddo Tgo.
TAI LIEU THAM KHAO
1

K. Ekkachai, G. Nurak, T. Raumpom, N. Arthit.
Degradation of paraquat under visible light over
fullerene modified V-T1O2, Reac. Kinel. Mech. Cat,
103,227-237(2011),

2. Michael R. Hoffmann, Scot T. Martin, Wonyong
Choi, and Detlef W. Bahnemann. Environmental
Applications of Semiconductor Photocatalysis,
Chem. Rev., 95, 69-96(1995).

3. T. L R. Hewer, E. C, C Souza, T. S, Martins, E. N.
S. Muccillo, R. S. Freire. Influence of neodymium
ions on pholocalalylic activity of TiO; synthesized by
sol-gel and precipitation methods, Journal of
Molecular Catalysis A: Chemical, 336, 58-63
(2011).

4. X. Yan, J. He, D. G. Evans, yv. Duan, Y. Zhu.
Preparation, characterization and pholocalalylic
actrvity of Si-doped and rare earth-doped T1O2 fro
mesoporous precursors. Applied Catalysis B:
Environmental, 55,243-252 (2005).

5. D. Xu, L. Feng, A. Lei. Preparation of r/Oj
nanopowders doped with Y^* by plasma spray and


TCHH, T. 50(6). 2012

Khdo sdt khd ndng phdn huy...

characterizations, Materials Letters, 62, 3297-3300
(2008).

reactivity of titanium dioxide. Progress in Solid Stale
Chemistry, 32, 33-177 (2004).

6. Ng6 Sy Luong, Nguyen VSn Hung. Anh hudng cua
Y den cdu triic linh the va linh chdt quang xiic Idc

cua bpt Y-Ti02 kich thudc nano dieu che bdng
phuong phdp thuy nhi^t, Tgp chi H6a hpc, 49(3A),
337-342(2011).

Liu WenXiu, Liu Qing, Li XiuFang, Song YunTing
& Cao WenBin. Photocatalytic degradation of
coking wastewater by nanocrystalline (Fe. N) codoped TiO} powders, Sci. China Tech. Sci., 53,
1477-1482(2010).

7. O. Carp, C. L. Huisman, A. Rcllcr. Photoinduced
Lien h(': Nguyen VSn Hung
Khoa Hda hgc, Trudng Dgi hgc Dong Thap
Trudng Dgi hpc Ddng Thap, 783 - Phgm 1 liru Lau, P6, TP. Cao Lanh, Dong Thap
Email:

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