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Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 1
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 2
M U
Trong giai on hin nay, vic thc y pht trin kinh t cng vi qu trnh cng
nghip ha v hin i ha ngy cng gia tng, kinh t pht trin i sng con ngi
ngy mt c nng cao hn, hin i hn, nhng song song vi nhng mt tch cc
y th vic cng nghip ha hn i ha cng em li mt tri ca n l lm cho mi
trng b nhim, c bit l mi trng nc.
Nh chng ta bit, nc l ngun ti nguyn thin nhin qu gi, l yu t
khng th thiu c cho mi hot ng sng trn tri t, mi trng nc chim 2/3
din tch tri t, n ng vai tr rt quan trng. Tuy nhin qu trnh th ha, cng
nghip ha v thm canh trong nng nghip ngy cng pht trin nh hng xu n
ngun ti nguyn ny. Nhiu ni ngun nc b mt, thm ch c nc ngm b
nhim gy nguy him i vi sc khe con ngi. Vic mi trng nc b nhim l
iu v cng bt li, nh gi mc nhim ngun nc hin nay l mt vn ht
sc cp thit t c bin php x l kp thi, chng ta cn phi nghin cu gim
thiu s nhim mi trng nc, vi chnh mc ch chng ti nghin cu ti
Nghin cu xc nh tng hm lng st trong nc bng phng php trc
quang phn t UV-VIS vi thuc th o-phenantrolin. y l phng php c
nhy v chnh xc cao, ph hp vi iu kin th nghim ca nh trng.
Mc ch ca ti nhm:
Nghin cu iu kin ti u v xy dng quy trnh phn tch xc nh hm lng
st trong mi trng nc.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 3
CHNG 1: TNG QUAN TI LIU
1.1. St v d lng ca n trong mi trng
1.1.1. Gii thiu v st [3]
1.1.1.1. Tnh cht vt l
St l tn mt nguyn t ha hc trong bng h thng tun hon.
K hiu: Fe
S hiu nguyn t bng 26.
Nm phn nhm VIIIB chu k 4, c khi lng nguyn t 55,847
Cu hnh electron: 1s22s22p63s23p63d64s2
St l kim loi mu trng xm, d rn, d dt mng, v gia cng c hc.
Trong t nhin st c 4 ng v bn 54Fe, 56Fe (91,68%), 57Fe, 58Fe.
Nhit nng chy ca st l 15360C, nhit si 28800C, t khi 7,91 g/cm3.
St c tnh dn in, dn nhit tt (km ng v nhm). Di 8000C st c tnh
nhim t, b nam chm ht v tr thnh nam chm (tm thi).
St c 4 dng th hnh (l dng , , , ) mi dng bn nhng nhit nht
nh.
St l kim loi c tch ra t cc m qung st, v rt kh tm thy n dng t
do. thu c st t do, cc tp cht phi c loi b bng phng php kh ha
hc. St c s dng trong sn xut gang v thp, y l cc hp kim, l s ha tan
ca cc kim loi khc (v mt s kim hay phi kim, c bit l cacbon)
1.1.1.2. Tnh cht ha hc
St l cht c hot tnh ha hc trung bnh. iu kin bnh thng nu khng c
hi m, nhng nguyn t h st khng phn ng r rt vi kim in hnh nh O, S,
Cl, Br v n c mng bo v. Nhng khi un nng, phn ng xy ra mnh lit, nht l
khi kim loi trng thi chia nh, nguyn nhn l tng b mt tip xc rt ln gia cc
ht kim loi vi khng kh v s sai lch mng li tinh th ca ht so vi cu trc bn
ca kim loi.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 4
Khi un nng trong khng kh kh st to nn Fe2O3 v nhit cao hn to
nn Fe3O4.
3Fe + 2O2 = Fe3O4
Kh Cl2 phn ng rt d dng vi Fe to thnh FeCl3 l cht d bay hi to nn
khng to c mng bo v.
2Fe + 3Cl = 2FeCl3
Fe tc dng vi S khi un nng nh to nn hp cht khng hp thc FeS.
Fe tan d trong dung dch axit khng c tnh oxi ha gii phng kh H2. Axit
sulfuric c v axit nitric c khng tc dng khng tc dng vi Fe m cn th ng
ha khi ngui, v vy ngi ta vn chuyn nhng axit ny trong cc xitec bng thp.
St ha tan trong axit H2SO4 long.
Fe + H2SO4 = FeSO4
Trong dung dch H2SO4 c nng st b oxy ha n Fe (III).
2Fe + 6H2SO4 = Fe2(SO)3 + 3SO2 + H2O
Fe tinh khit bn i vi khng kh v nc, ngc li st c ln tp cht b n
mn di tc dng ng thi ca hi m, kh CO2 v kh O2 trong khng kh to nn
r st.
2Fe + 3/2O2 + nH2O = Fe2O3.nH2O
R st c to nn trn b mt l mt lp xp v gin khng bo v c st
khi tip tc tc dng v qu trnh n mn st tip tc xy ra.
Fe bn vi kim trng thi dung dch v nng chy v oxit ca n hu nh
khng th hin tnh lng tnh.
1.1.2. Ngun gc xut hin ca st trong nc
Ngun gc xut hin st trong nc c th do ngun gc t nhin hoc do nhn
to.
S xut hin st trong nc do t nhin nh nhng m khong vt ca st, st
c phn tn trong nc c th do ma, tuyt tan, nc ma ri xung mt t,
ng ph, khu cng nghip ko theo kim loi st xung h, sng
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 5
St c trong thin nhin di dng hp cht oxit, sunfua, cacbonat v silicat.
S xut hin st trong nc c th do nhn to do cc ngun nc thi, x nc
thi sinh hot, sn xut cng nghip thi ra nhiu loi bi kim loi, trong c st
khng nhng gy nhim mi trng khng kh, t m cn gy nhim mi trng
nc.
1.1.3. Vai tr ca st [6]
St l kim loi c s dng nhiu nht, chim khong 95% tng khi lng kim
loi sn xut trn ton th gii. S kt hp ca gi thnh thp v cc c tnh tt v
chu lc, do, cng lm cho n tr thnh mt trong nhng nguyn vt liu khng
th thay th c, c bit trong cc ng dng nh sn xut t, thn tu thy ln, cc
b khung cho cc cng trnh xy dng. Thp l hp kim ni ting nht ca st, ngoi ra
cn c mt s hnh thc tn ti khc ca st nh:
Oxit st (III) c s dng sn xut cc b lu t tnh trong my tnh. Chng
thng c trn ln vi cc hp cht khc, v bo tn thuc tnh t trong hn hp
ny.
St l cht xc tc hnh thnh nn dip lc v hot ng nh cht mang oxy.
St c vai tr rt cn thit i vi mi c th sng, ngoi tr mt s vi khun. N
ch yu lin kt n nh bn trong cc protein kim loi, v trong dng t do n sinh ra
cc gc t do ni chung l c vi cc t bo. Ni rng st t do khng c ngha l n
t do di chuyn trong cc cht lng trong c th. St lin kt cht ch vi mi phn t
sinh hc v th n s gn vi cc mng t bo, axit nucleic, protein
Trong c th ng vt st lin kt trong cc t hp heme (l thnh phn thit yu
ca cytochromes), l nhng protein tham gia vo cc phn ng oxi ha-kh (bao gm
nhng khng gii hn ch l qu trnh h hp) v ca cc protein chuyn ch xy
nh hemoglobin v myoglobin.
St v c tham gia trong cc phn ng oxi ha-kh cng c tm thy trong cc
cm st-lu hunh ca nhiu enzyme, chng hn nh cc enzyme nitrogenase (tham
gia qu trnh tng hp ammoniac t nitow v hydro) v hydrogenase. Tp hp cc
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 6
protein st phi-heme c trch nhim cho mt dy cc chc nng trong mt s loi hnh
c th sng, chng hn nh cc enzyme metan monoxygenase (oxi ha metan thnh
metalnol), ribonucleotidequ reductase (kh ribose thnh deoxyribose; tng hp sinh
hc DNA), hemerythrins (vn chuyn oxy v ngng kt trong c ng vt khng
xng sng bin) v axit phosphates ta (thy phn cc este photphat). Khi c th
chng li s nhim khun, n c ring st trong protein vn chuyn transferring v
th vi khun khng th s dng c st.
1.1.4. Tc hi ca st [1,6]
Vic hp th qu nhiu st gy ng c, v cc st (II) d tha s phn ng vi
cc peroxit trong c th sn xut ra cc gc t do. Khi st trong s lng bnh
thng th c th c mt c ch chng xi ha c th kim sot qu trnh ny. Khi
d tha st th nhng lng d tha khng th kim sot ca cc gc t do c sinh
ra.
Mt lng gy cht ngi ca st i vi tr 2 tui l ba gam st. Mt gam c th
sinh ra s ng c nguy him. Danh mc ca DRI v mc chp nhn cao nht v st
i vi ngi ln l 45 mg/ngy. i vi tr em di 14 tui mc cao nht l 40
mg/ngy.
Nu st qu nhiu trong c th (cha n mc gy cht ngi) th mt lot cc
hi chng ri lon qu ti st c th pht sinh, chng hn nh hemochromatosis.
Khi thiu st th hm lng hemoglobin b gim lm cho lng oxi ti cc t bo
cng gim theo, con ngi b mc chng bnh thiu mu do thiu ht st.
1.2. Cc phng php xc nh vi lng st
1.2.1. Phng php quang ph hp th nguyn t (AAS) [2]
Phng php phn tch da trn c s o ph hp th nguyn t ca mt nguyn
t c gi l php o ph hp th nguyn t (php o AAS)
Khi nguyn t tn ti t do th kh v trng thi nng lng c bn, th
nguyn t khng thu hay khng pht ra nng lng. Tc l nguyn t trng thi c
bn. Song nu nguyn t ang tn ti trng thi ny m chng ta kch thch n bng
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 7
mt chm tia sng n sc c nng lng ph hp, c di sng trng vi cc vch
ph pht x c trng ca nguyn t , th chng s hp th cc tia sng sinh ra
mt loi ph ca nguyn t. Ph ny c gi l ph hp th ca nguyn t.
Phng php ny c th phn tch c lng vt ca hu ht cc kim loi v c
nhng hp cht hu c hay anion khng c ph hp th nguyn t. Do n c s
dng rng ri trong cc nghnh: a cht, cng nghip ho hc, ho du, y hc, sinh
ho, cng nghip dc phm, nng nghip v thc phm
1.2.2. Phng php quang ph pht x nguyn t (AES) [2]
Khi iu kin thng, nguyn t khng thu hay pht ra nng lng nhng nu
b kch thch th cc in t ho tr s nhn nng lng chuyn ln trng thi c nng
lng cao hn (trng thi kch thch). Trng thi ny khng bn, chng c xu hng
gii phng nng lng tr v trng thi ban u bn vng di dng cc bc x.
Cc bc x ny c gi l ph pht x ca nguyn t.
Phng php AES da trn s xut hin ph pht x ca nguyn t t do ca
nguyn t phn tch trng thi kh khi c s tng tc vi ngun nng lng ph hp.
Hin nay, ngi ta dng mt s ngun nng lng kch thch ph AES nh ngn la
n kh, h quang in, tia la in, plasma cao tn cm ng (ICP)
Nhn chung, phng php AES t nhy rt cao (thng t n.10-3 n n.10-
4%), li tn t mu, c th phn tch ng thi nhiu nguyn t trong cng mt mu. V
vy, y l phng php dng kim tra nh gi ho cht, nguyn liu tinh khit,
phn tch lng vt ion kim loi c trong nc, lng thc, thc phm. Tuy nhin,
phng php ny li ch cho bit thnh phn nguyn t trong mu m khng ch ra
c trng thi lin kt ca n trong mu.
1.2.3. Phng php quang ph hp th phn t UV-VIS [2]
Phng php quang ph hp th phn t hay cn gi l phng php o quang,
phng php phn tch trc quang phn t l mt trong nhng phng php phn tch
cng c thng dng vi rt nhiu th h my khc nhau, t cc my n gin ca th
h trc cn gi l cc my so mu n cc my hin i c t ng ha hin nay,
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 8
gi l my quang ph hp th phn t UV-VIS. Cc my o quang lm vic trong vng
t ngoi (UV) v kh kin (VIS) t 190 nm n khong 900 nm.
iu kin thng, cc phn t, nhm phn t ca cht bn vng v ngho nng
lng. y l trng thi c bn. Nhng khi c mt chm sng vi nng lng thch
hp chiu vo th cc in t ho tr trong cc lin kt (, , n) s hp th nng lng
chm sng, chuyn ln trng thi kch thch vi nng lng cao hn. Hiu s gia hai
mc nng lng (c bn E0 v kch thch Em) chnh l nng lng m phn t hp th
t ngun sng to ra ph hp th phn t ca cht.
* Nguyn tc:
Phng php xc nh da trn vic o hp th nh sng ca mt dung dch
phc to thnh gia ion cn xc nh vi mt thuc th v c hay hu c trong mi
trng thch hp khi c chiu bi chm sng. Phng php nh lng php o:
A = K.C
Trong : A: hp th quang
K: hng s thc nghim
C: nng nguyn t phn tch
Phng php ny cho php xc nh nng cht khong 10-5 - 10-7M v l
mt trong cc phng php c s dng kh ph bin.
Phng php trc quang c nhy, n nh v chnh xc kh cao, c s
dng nhiu trong phn tch vi lng. Tuy nhin vi vic xc nh Cd, Pb th li gp rt
nhiu kh khn do nh hng ca mt s ion kim loi tng t. Khi phi thc hin
cc cng on che, tch phc tp.
1.3. Phng php quang ph hp th phn t UV-VIS
1.3.1. Gii thiu phng php quang ph hp th phn t UV-VIS [2]
L phng php phn tch da trn s so snh cng mu ca dung dch
nghin cu vi cng mu ca dung dch tiu chun c nng xc nh
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 9
1.3.1.1. S hp th nh sng ca dung dch mu
Dung dch c mu l do bn thn dung dch hp th mt phn quang ph (mt
vng quang ph) ca nh sng trng, phn cn li l ra cho ta mu ca dung dch,
chnh l mu ca phn nh sng trng b hp th.
Dung dch c mu xc nh th hp th bc sng n sc tng ng v th hin
qua:
Hnh 1.1. Dy mu ca nh sng trng
Bng 1.1. S hp th mu ca dung dch mu
TIA SNG N SC B HP TH MU CA DUNG DCH
400nm 450nm : vng tm Lc nh vng
450nm 480nm : vng chm Vng
480nm 490nm : vng chm lc Da cam
490nm 510nm : vng lc chm
510nm 560nm : vng lc ta
560nm 575nm :vng lc nh vng Tm
575nm 590nm : vng vng Chm
590nm 640nm : vng da cam Chm lc
640nm 720nm : vng Lc chm
720nm 800nm : vng ta Lc
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 10
S hp th bc x n sc cng mnh (mu cng m) khi dung dch c nng
cng ln.
S hp th ca dung dch theo mu v s ph thuc ca n vo nng ca cht
hp th chnh l c s ca phng php quang ph hp th phn t UV-VIS.
1.3.1.2. Cc nh lut c bn v s hp th nh sng
*nh lut Bug-Lamber (nh lut 1 ca hp th nh sng):
Lng tng i ca chm nh sng b hp th bi mi trng m n i qua
khng ph thuc vo nng ca tia ti. Mi mt lp b dy nh nhau hp th mt
phn dng sng n sc i qua dung dch nh nhau.
Biu thc:
I=I0.e-kl
Trong k: h s hp th
l: b dy ca lp vt cht
* nh lut Lamber-Beer:
Vi b dy ca lp dung dch, h s hp th K t l vi nng ca cht hp th
ca dung dch.
Biu thc:
I=I0.e-*cl
Vi C: Nng dung dch (mol/l)
l: B dy ca cuvet ng dung dch (cm)
: H s hp th phn t
1.3.1.3. Cc i lng hay s dng
truyn quang T(%): l t l gia cng chm sng n sc I sau khi i qua
dung dch vi cng chm sng n sc I0 chiu vo.
T=I/I0= 10-.l.c
* Mt quang D hay hp th A hay tt E
I
ITEAD 0lglg
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 11
Khi v l khng i: D = A = K.C
Nguyn tc chung ca phng php o quang xc nh mt cht X:
- Chuyn X thnh mt cht c kh nng hp th nh sng.
- o s hp th nh sng ca X.
- Suy ra hm lng cht cn xc nh.
1.3.1.4. Tnh cht ca mt quang v ng dng trong ha phn tch
-Mt quang c tnh cng tnh:
Trong dung dch c nhiu cht tan hp th bc x nh sng th mt quang o
c chnh l tng cc mt quang ca cc cht c trong dung dch.
-ng dng trong ha phn tch:
o c mt quang ca cht cn phn tch X
- D0: Mt quang ca dung dch trng (dung dch so snh)
Vi Dx = K.Cx
Dung dch trng (dung dch so snh) l dung dch cha tt c cc thnh
phn trong dung dch phn tch tr cht phn tch.
o mt quang ca 1 dy dung dch c nng khc nhau bng mt
cuvet ti mt bc sng nht nh.
(l, = const) th ng biu din D = f(C) s l mt ng thng.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 12
Hnh 1.2. th tuyn tnh gia D v C
1.3.2. Cc iu kin ti u ca php o quang [2]
1.3.3. Cc phng php phn tch nh lng s dng phn tch:
1.3.3.1. Phng php ng tiu chun
* Nguyn tc thc hin:
+ Xy dng ng chun: D = f(C) (y = ax)
- Chun b mt dy dung dch chun c nng tng dn: C1, C2, C3,
C4, C5, C6 ca cht chun phn tch.
- Thm lng thuc th, axit v cc iu kin khc nh nhau vo
dy dung dch chun a v dng dung dch mu.
- o mt quang D1, D2, D3, D4, D5, D6 ca dung dch chun ( xc
nh max, khong tuyn tnh).
- V th D = f(C).
+ Chun b dung dch phn tch ging ht vi dy chun.
+ o mt quang ca dung dch phn tch Dx ri da vo th ta
tnh c Cx.
nng
D3
D2
mt quang
C1 C2 C3 C4 C5 C6
D6
D5
D4
D1
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 13
Phng php ny c u im l xc nh c hng lot mu. iu kin p dng
ca phng php ny l cc dung dch mu hp ph nh sng tun theo nh lut
Lawmbe Bia.
1.3.3.2. Phng php thm chun
*Nguyn tc thc hin:
- Ly mt lng dung dch phn tch (Cx) vo 2 bnh nh mc 1 v 2.
- Thm vo bnh 2 mt lng dung dch chun ca cht phn tch (Ca).
- Thc hin phn ng hin mu c 2 bnh trong cc iu kin ti u
chn hon ton nh nhau.
- o mt quang ca 2 dung dch bc sng ti u max, khong tuyn
tnh v trong cng cuvet.
Theo nh lut Lm be Bia ta c:
Dx = .l.Cx (dung dch khng thm)
Da = .l. (Cx+Ca) (dung dch c thm)
Do ta tnh c: Cx = Ca
Dng phng php ny ta c th loi tr c nh hng ca cc ion l c trong
dung dch phn tch. Phng php ny cng c dng kim tra ng ca php
xc nh
1.3.3.3. u im ca phng php UV VIS
- C nhy cao, thng c th xc nh lng cc nng nh hn 10-7 M. u
im ny c ngha trong 2 lnh vc:
Trong lnh vc phn tch vt: cho php tin hnh php o nh lng cc vi cu
t ca mu c hm lng c 1 ppm v khi lng.
Trong lnh vc vi phn tch: c th xc nh lng cc cu t chnh trong mu
c kch thc rt nh.
- Thc hin c nhanh hn, thun li hn (so vi phng php chun v
trng lng truyn thng).
- C th tin hnh php phn tch t 5 n 10 mu trong 1 pht.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 14
- Cung cp cc s liu phn tch cho thng bo c bn v cu trc phn t v v
bn cht lin kt ha hc.
1.4. Cc phng php ly v x l mu
1.4.1. Phng php ly mu
Phng php ly mu th ng khng lin tc: mu c ly bng phng php
khuych tn t nhin ti cc b phn thu mu. Ly theo phng nm ngang, ly nc
b mt.
1.4.2. Cc phng php x l mu v bo qun mu
Ngay sau khi ly, axit ha n pH < 2 v bo qun mu trong chai nha, mu bn
trong 1 thng.
1.5. S lc vi nt v ni ly mu
1.5.1. H Thc Gin Vnh Trung
Thng tin c s: V tr a l
Bu Thc Gin-Vnh Trung nm gia hai phng Thc Gin v Vnh Trung,
qun Thanh Kh, Thnh ph Nng.
H Thc Gin:
- Pha ng: Gip vi ng Vn Cao
- Pha Ty: Gip vi ng Tn
- Pha Nam: Gip vi ng Hm Nghi
- Pha Bc: Gip vi ng Tn
H Vnh Trung:
- Pha ng: Gip vi ng Vn Cao
- Pha Ty: Gip vi ng T Ngc Vn
- Pha Nam: Gip vi ng Quang
- Pha Bc: Gip vi ng Hm Nghi
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 15
Hnh 1.3. Quang cnh h Thc Gin-Vnh Trung
Dn s v din tch khu vc xung quanh h
H Thc Gin -Vnh Trung nm gia hai phng Thc Gin v Vnh Trung thuc
qun Thanh Kh - TP Nng.
Qun Thanh Kh l qun c mt dn s ng nht thnh ph c:
* Din tch: 9,3km2, chim 0,74% din tch ton thnh ph.
* Dn s: 159.272 ngi, chim 21,17% dn s ton thnh ph.
* Mt dn s: 17.126ngi/km2.
Qun Thanh Kh bao gm 8 phng: Vnh Trung, Tn Chnh, Thc Gin, Chnh
Gin, Tam Thun, Xun H, Thanh Lc n, An Kh. Trong , 2 phng Thc Gin
v Vnh Trung nm v tr trung tm thnh ph l khu trung tm vn ha thng mi
ca qun v thnh ph.
Phng Vnh Trung c:
* Din tch: 0,52km2.
* S dn: 17539 ngi .
* Mt dn s: 33.729 ngi/km2.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 16
Phng Thc Gin c dn s l: 16.098 ngi.
Thng tin v bu Thc Gin Vnh Trung
Ngun gc:
Nguyn gc bu Thc Gin-Vnh Trung l mt ci m c din tch khong 11ha,
do qu trnh th ha nn din tch h b thu hp cn li khong 3ha.
Chc nng:
- iu tit v thot nc ma cho khu vc.
- iu ha vi kh hu.
- To cnh quan cho khu th.
Din tch
Gn 29.649m2.
Chiu di, chiu rng ln nht
H s 2:
Chiu di: gn 200m.
Chiu rng: khong 80m.
H s 1:
Chiu di: gn 158m.
Chiu rng: khong 125m.
su ln nht:
Bu Vnh Trung: 3.25m.
Bu Thc Gin: 4.03m.
Dung tch:
T 40.000 52.000m3, vo ma ma c th cha c hn 65000m3 nc.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 17
Hnh 1.4. Bn h Thc Gin Vnh trung
Hnh 1.5. Bn h Thc Gin Vnh trung
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 18
1.5.2. Sng Ph Lc
Sng Ph Lc bt ngun t thn Khnh Sn (Ha Khnh Nam, Lin Chiu,
Nng) chy qua cc phng Ha Minh, Thanh Lc n v ra vnh Nng thng
qua ca sng nm trn ng Nguyn Tt Thnh thuc P. Thanh Kh ng (Thanh
Kh).
1.5.3. Nh my thp [5]
Nh my thp Thi Bnh Dng, L C10-C19 Cm Cng Nghip Thanh Vinh m
rng, Huyn Ho Vang, Thnh ph Nng.
1.6. Chun b mu phn tch [4]
Ly lng nc cn phn tch cho vo bnh nh mc 50ml, thm vo 1ml dung
dch HCl long, c n th tch cn khong 40ml. Lm ngui, nu dung dch c th
phi lc.Thm 1ml dung dch hydroxylamine kh Fe3+ thnh Fe2+, ri thm 1ml
dung dch o-phenantrolin. Nh tng git dung dch ammoniac n khi PH khong bng
4(s dng my o pH). nh mc bng nc ct, lc u. o mt quang ca dung
dch so vi mu trng.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 19
CHNG 2: THC NGHIM V PHNG PHP NGHIN CU
2.1. Dng c, thit b, ha cht
2.1.1. Dng c
- My quang ph hp th phn t. .
- Cn phn tch, cn k thut.
- Bp in, t ht, t sy.
- Bnh nh mc cc loi.
- Pipet cc loi.
- Cc thy tinh, a thy tinh, ng ong
- L ng mu.
- Mt knh ng h.
2.1.2. Thit b
S khi tng qut ca 1 thit b o quang nh sau:
1. Ngun bc x lin tc
2. B phn to tia n sc
3. Cuvet ng dung dch
4. tect
5. Ch th kt qu
2
3
1
5
4
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 20
Hnh 2.1. My phn tch UV-VIS Hnh 2.2. Cuvet
-Ngun bc x: c hai loi ngun
+Vng kh kin: dng n Vonfram W-Lamp
+Vng t ngoi: dng n Hidro hoc n teri D-Lamp
- Cc ngun to bc x n sc: lm nhim v phn ly bc x thnh bc x n
sc c di sng khc nhau.
C 2 loi:
+My to bc x n sc bng lng knh
Hnh 2.3. Lng knh hp th quang ph
+My to bc x n sc bng cch t.
+Vng kh kin: dng cuvet thy tinh.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 21
+Vng t ngoi: dng cuvet thch anh.
- tect: l cc t bo quang in vi hiu ng quang in ngoi hoc cc nhn
quang in c nhim v bin i nng lng bc x thnh tn hiu in.
2.1.3. Ha cht
Ha cht tkpt gm :
- HCl, NH2OH.HCl.
- O-phenantrolin.
- Amoniac.
- Dung dch chun phn st amoni.
2.2. Pha cc loi dung dch
Pha ch dung dch chun Fe
Dung dch chun Fe3+ 100ppm c pha nh sau: Ha tan 0,8634g
NH4Fe(SO4)2.12H2O trong nc ct, thm 2ml HCl c, nh mc thnh 1 lt bng
nc ct.
Pha thuc th o-phenantrolin: ly 0,28 g o-phenantrolin trong nc ct thnh
100ml,(nh 1-2 git HCl, un cch thy) ng dung dch trong bnh nu v ch
mt.
Hydroxylamin 10%: Ha tan 10g hydroxylamine clohydric, nh mc bng nc
ct thnh 100ml.
Dung dch HCl 1:9: Pha 10ml HCl c vo 90 ml nc ct.
Pha ch cc dung dch nh hng
-Dung dch chun Cu2+ 100ppm: Ly 0,3906g CuSO4.5H2O ha tan vi mt t
nc ct c pha 1ml H2SO4 1:5 v nh mc thnh 1 lt bng nc ct.
- Dung dch chun Co2+ 1000ppm: Ly 3,1017g Co(NO3)2 ha tan bng nc ct
v nh mc thnh 1 lt.
- Dung dch chun Ni2+ 50ppm: Ly 4,9530g NiSO4.6H2O pha trong 200ml HNO3
35% ri nh mc ln 1 lt bng nc ct.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 22
- Dung dch chun Zn2+ 500ppm: Ly 1,1039g ZnSO4.7H2O ha tan bng nc
ct v nh mc ln 500ml.
- Dung dch chun Cr3+ 1000ppm: Ly 7,6923g Cr2(NO3)3.9H2O ho tan vo
nc ct v nh mc thnh 1 lt.
2.3. Nhng vn cn nghin cu
- Tm thuc th thch hp, nghin cu cc yu t nh hng n qu trnh xc
nh st trong nc v loi tr cc yu t nh hng.
- Kho st bn mu ca phc theo thi gian.
- Xc nh gii hn nng pht hin ca st trong nc thi bng php trc
quang phn t UV-VIS.
- Xc nh khong nng tuyn tnh ca st.
- Xc nh hiu sut thu hi ca phng php.
- nh gi sai s thng k ca phng php.
2.4. Thc hin nghin cu iu kin ti u phn tch hm lng st trong nc
bng phng php quang ph hp th phn t UV-VIS.
Da trn mt s qu trnh phn tch st trong nc tin hnh nghin cu mt s
iu kin ca qu trnh phn tch sao cho ph hp vi diu kin phng th nghim
nhm t c hiu qu cao nht. iu kin ti u c nghin cu theo phng php
n bin, thay i cc yu t cn kho st, bin i dn sao cho hiu sut t cao nht.
2.4.1. Chn thuc th thch hp
Thuc th thng dung trong vic phn tch hm lng st bng phng php
trc quang phn t gm c: thuc th tioxianat, axit sufuxalixilic v o-phenantrolin.
Trong iu kin cho php ca phng th nghim chng ti nghin cu s to phc mu
ca Fe2+ vi thuc th o-phenantrolin.
2.4.2. Kho st bn mu ca phc Fe2+ v thuc th theo thi gian
Chun b mu bit trc nng st (ly 50ml nc c nng st l
0,001mg/ml), thm vo 1ml dung dch HCl long, c n th tch cn khong 40ml.
Lm ngui, nu dung dch c th phi lc. Thm 1ml dung dch hydroxylamine
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 23
kh Fe3+ thnh Fe2+, ri thm 1ml dung dch o-phenantrolin. Nh tng git dung dch
ammoniac n khi pH khong bng 4 (s dng my o pH), sau nh mc bng
nc ct n 50ml, lc u. Tin hnh o mt quang ca mu trong nhng khong
thi gian khc nhau da vo ng chun xc nh hm lng st trong cc mu, t kt
qu o c ta rt ra c bn mu ca phc Fe2+ theo thi gian i vi php xc
nh st bng thuc th o-phenantrolin.
2.4.3. Kho st nh hng ca pH
Chun b 7 mu c cng nng st (ly 50ml nc c nng 0,001mg/ml),
thm vo cc mu 1ml dung dch HCl long, c n th tch cn khong 40ml. Lm
ngui, nu dung dch c th phi lc. Thm 1ml dung dch hydroxylamine kh Fe3+
thnh Fe2+, ri thm 1ml dung dch o-phenantrolin. Nh tng git dung dch ammoniac
sao cho cc mu c pH t 39 (s dng giy my o pH), sau nh mc bng nc
ct n 50ml, lc u, n nh 10 pht. Sau tin hnh o mt quang ca dy
da vo ng chun xc nh hm lng st trong cc mu. Rt ra kt lun v s nh
hng pH i vi php xc nh st bng thuc th o-phenantrolin
2.4.4. Kho st gii hn pht hin ca Fe2+
Tin hnh pha mu cha dung dch Fe2+ c nng gim dn, iu kin ch ha
tng t nhau. Cch tin hnh phn tch: Ly 50ml mu ,thm vo 1ml dung dch HCl
long, c n th tch cn khong 40ml. Lm ngui, nu dung dch c th phi lc.
Thm 1ml dung dch hydroxylamine kh Fe3+ thnh Fe2+, ri thm 1ml dung dch o-
phenantrolin. Nh tng git dung dch ammoniac n khi pH khong bng 4 (s dng
my o pH), sau nh mc bng nc ct n 50ml, lc u, n nh 10 pht.
Tin hnh o mt quang trn my UV-VIS tm nng ca Fe2+ m ti vn
cn pht hin c.
2.4.5. Kho st gii hn nng tuyn tnh
Trong phng php trc quang phn t UV-VIS th s ph thuc ca mt
quang D o c i vi nng ca cht phn tch ch tuyn tnh trong mt khong
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 24
nng nht nh. Do cn phi tin hnh kho st khong nng tuyn tnh ca
st m bo cho mc chnh xc ca php o.
Tin hnh pha dung dch chun Fe2+ 1000ppm. Chun b dy dung dch o vi
nng Fe2+ tng dn, ch ha cc mu dung dch ny nh sau:
Ly 50 ml mu, thm vo 1ml dung dch HCl long, c n th tch cn khong
40ml. Lm ngui, nu dung dch c th phi lc. Thm 1ml dung dch hydroxylamine
kh Fe3+ thnh Fe2+, ri thm 1ml dung dch o-phenantrolin. Nh tng git dung
dch ammoniac n khi pH khong bng 4 (s dng my o pH), sau nh mc bng
nc ct n 50ml, lc u, n nh 10 pht. Sau o mt m ti s ph
thuc ca mt quang D vo nng C l tuyn tnh nht.
2.4.6. Lp ng chun xc nh st
Tin hnh lp ng chun nh sau: chun b 6 bnh nh mc loi 50ml, ly ln
lt vo mi bnh 0; 0,5; 1,0; 2,0; 5,0; 10,0ml dung dch st chun c nng
0,005mg/ml. Thm vo mi bnh 1ml HCl long ri nh mc ln 50 ml bng nc ct,
chuyn sang 6 cc c nh th t, sau c n th tch cn khong 40ml, lm ngui,
nu dung dch c th phi lc. Thm 1ml dung dch hydroxyamin, thm 1ml dung dch
thuc th o-phenantrolin, nh tng git ammoniac c n khi pH khong bng 4 (s
dng my o pH), sau nh mc bng nc ct n 50ml, lc u, n nh 10
pht. Tin hnh o mt quang ca dung dch so vi mu trng.
2.4.7. Kho st cc yu t nh hng
2.4.7.1. Kho st nh hng ca Cu2+
i vi xc nh Fe2+
Chun b 6 mu c cng nng st bit trc trong iu kin ch ha tng
t nh khi lp ng ca chun, trong hm lng Cu2+ tng dn. Tin hnh o mt
quang ca dy da vo ng chun xc nh hm lng st trong cc mu. Rt ra
kt lun v s nh hng Cu2+ i vi php xc nh st bng thuc th o-
phenantrolin.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 25
2.4.7.2. Kho st nh hng ca Co2+ i vi xc nh Fe2+
Chun b 6 mu c cng nng st bit trc trong iu kin ch ha tng
t nh khi lp ng ca chun, trong hm lng Co2+ tng dn. Tin hnh o mt
quang ca dy da vo ng chun xc nh hm lng st trong cc mu. Rt ra
kt lun v s nh hng Co2+ i vi php xc nh st bng thuc th o-
phenantrolin.
2.4.7.3. Kho st nh hng ca Ni2+ i vi xc nh Fe2+
Chun b 6 mu c cng nng st bit trc trong iu kin ch ha tng
t nh khi lp ng ca chun, trong hm lng Ni2+ tng dn. Tin hnh o mt
quang ca dy da vo ng chun xc nh hm lng st trong cc mu. Rt ra
kt lun v s nh hng Ni2+ i vi php xc nh st bng thuc th o-phenantrolin.
2.4.7.4. Kho st nh hng ca Zn2+ i vi xc nh Fe2+
Chun b 6 mu c cng nng st bit trc trong iu kin ch ha tng
t nh khi lp ng ca chun, trong hm lng Zn2+ tng dn. Tin hnh o mt
quang ca dy da vo ng chun xc nh hm lng st trong cc mu. Rt ra
kt lun v s nh hng Zn2+ i vi php xc nh st bng thuc th o-phenantrolin
2.4.7.5. Kho st nh hng ca Cr3+ i vi xc nh Fe2+
Chun b 6 mu c cng nng st bit trc trong iu kin ch ha tng
t nh khi lp ng ca chun, trong hm lng Cr3+ tng dn. Tin hnh o mt
quang ca dy da vo ng chun xc nh hm lng st trong cc mu. Rt ra
kt lun v s nh hng Cr3+ i vi php xc nh st bng thuc th o-phenantrolin.
2.4.8. Phng php loi tr cc yu t nh hng
Cc cht oxi ha mnh: C th loi tr bng cch thm d cht kh hydroxyamin.
Xyanua, nitrit, photphat (polyphotphat nh hng nhiu hn octophotphat): loi
tr bng cch un si vi axit.
Cc ion kim loi crom, km (khi nng ca chng gp 10 ln nng st)
coban, ng (khi nng chng gp 5 ln st) niken (khi nng ca n gp 2 ln
nng st) bimut, cadimi, thy ngn molydat to kt ta vi o-phenatrolin. Loi tr
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 26
bng cch thm d o-phenantrolin, trong vn khng loi tr c nh hng ca
cc ion kim loi th phi s dng n phng php chit tch kim loi gy cn tr.
2.5. Chun b mu gi
Mu gi l mu bit trc c nng st, ly 50ml nc ct, thm vo
0,5ml dung dch Fe3+ tiu chun 0,1mg/ml. C nng 0,001mg/ml.
2.6. nh gi hiu sut thu hi
Da vo cc iu kin ti u kho st trn, chng ti tin hnh o mt
quang trn mu gi tnh s sai lch gia kt qu o c bng my vi kt qu thc t.
Lm 6 ln ly gi tr trung bnh.
2.7. nh gi sai s thng k ca phng php
Trong phn tch vic nh gi cc kt qu l mt trong cc bc khng th thiu
c ca cc qu trnh phn tch. Trong bc ny vic tnh ton sai s l quan trng
nht v n cho ta bit kt qu phn tch thu c ng v chnh xc ti mc no.
kim tra lp ca phng php ti phng th nghim ta lm nh sau: o
cng mt mu phn tch 6 ln, sau tm lch chun ca phng php. lch
chun ca phng php cng nh th lp ca phng php cng cao.
2.8. Quy trnh phn tch
Ly lng nc cn phn tch cho vo bnh nh mc 50ml, thm vo 1ml dung
dch HCl long, c n th tch cn khong 40ml. Lm ngui, nu dung dch c th
phi lc. Thm 1ml dung dch hydroxylamine kh Fe3+ thnh Fe2+, ri thm 1ml
dung dch o-phenantrolin. Nh tng git dung dch ammoniac n khi pH khong bng
4 (s dng my o pH), sau nh mc bng nc ct n 50ml, lc u, n nh
10 pht. Tin hnh o mt quang ca dung dich so vi mu trng.
2.9. Phn tch mu thc t
2.9.1. Ly v chun b mu
Mu c ly ti cc v tr khc nhau trong h, thi gian ly mu l 2 ln, sng v
chiu, mu c axit ha n pH
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 27
2.9.2. Phn tch mu [4]
Mu thc t sau khi c ly v a v phng th nghim bo qun.Ta tin hnh
phn tch nh sau:
Ly lng nc mu thc t cn phn tch cho vo bnh nh mc 50ml, thm
vo 1ml dung dch HCl long, c n th tch cn khong 40ml. Lm ngui, nu dung
dch c th phi lc. Thm 1ml dung dch hydroxylamine kh Fe3+ thnh Fe2+, ri
thm 1ml dung dch o-phenantrolin. Nh tng git dung dch ammoniac n khi pH
khong bng 4 (s dng my o pH), sau nh mc bng nc ct n 50ml, lc
u, n nh 10 pht. Tin hnh o mt quang ca dung dich so vi mu trng.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 28
CHNG 3: KT QU V BN LUN
3.1. Kt qu kho st xc nh st
3.1.1. Kt qu kho st bn mu ca phc Fe2+ v thuc th theo thi gian
Bng 3.1. S ph thuc ca mt quang D theo thi gian.(nng st
0,001mg/ml, pH=4)
Thi gian o(pht) 0 5 10 15 20 25 30
D 0,2179 0,2186 0,2326 0,2329 0,2356 0,2305 0,2335
Hnh3.1. S ph thuc ca mt quang D ca phc to bi st (II) v thuc th
o-phenantrolin theo thi gian.
Da vo s liu c th nhn thy rng dung dch c bn mu t 10 pht tr
ln. Do chng ta nn tin hnh o mt quang sau khi to phc mu khong 10
pht dung dch mu n nh.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 29
3.1.2. Kt qu kho st nh hng ca pH
Bng 3.2. Bng kt qu kho st nh hng ca pH.(nng st 0,001mg/ml,o
sau khi to phc 10 pht)
Hnh 3.2. th biu din s nh hng ca pH i vi vic xc nh st trong
nc.
Da vo kt qu kho st c c th thy rng trong khong pH 39 th mt
quang o c cao nht pH=4.
3.1.3. Kt qu kho st gii hn pht hin ca Fe2+
Kt qu kho st nhy i vi php xc nh st bng phng php trc quang
phn t dng thuc th o-phenantrolin:
Dung dch o trong mi bnh: Dung dch Fe2+ 5.10- 4 mg/ml (nng gim dn),
trong iu kin ch ha tng t nh khi lp ng ca chun, trong hm lng.
Tin hnh o mt quang.
Kt qu: Gii hn nng pht hin st l 3.10-6 (mg/ml).
pH 3 4 5 6 7 8 9
D 0,2031 0,2109 0,2045 0,1854 0,1886 0,1938 0,1976
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 30
3.1.4 Kt qu kho st khong nng tuyn tnh
Bng 3.3. Bng kt qu kho st khong nng tuyn tnh Fe2+
Nng Fe3+ (mg/ml) D
0 0,0003
1.10-5
0,0082
2.10-5
0,0098
5.10-5
0,0176
1.10-4
0,0218
2.10-4
0,0411
5.10-4
0,0983
1.10-3
0,2084
2.10-3
0,3583
4.10-3
0,6083
Hnh 3.3. th biu din nng tuyn tnh i vi xc nh Fe2+
Da vo kt qu kho st c ta rt ra nhn xt: Khong nng thch hp
tin hnh php o l t khong 1.10-5 n 4.10-3 (mg/ml).
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 31
3.2. Kt qu xy dng ng chun
Bng 3.4. Bng kt qu lp ng chun ca Fe2+(pH=4,o quang sau 10 pht)
Nng Fe3+ (mg/ml) 0 0,00005 0,0001 0,0002 0,005 0,001
D 0 0,0125 0,0219 0,051 0,1109 0,2076
Hnh 3.4. ng chun ca php xc nh st bng thuc th o-phenantrolin
3.3. Kt qu kho st cc yu t nh hng
3.3.1.Kt qu kho st nh hng ca Cu2+ i vi xc nh Fe2+
Bng 3.5. Bng kt qu kho st nh hng ca Cu2+ i vi xc nh Fe2+
STT Nng Fe3+
chun (mg/ml)
Nng Cu2+
(mg/ml)
D
Nng Fe3+ o
c (mg/ml)
Sai s
tuyt i
(%)
1 0,001
0 0,2096
1,0010.10-3
0,100
2 0,001
0,0002
0,2084
9,9500.10-4
0,400
3 0,001
0,0004
0,2116
1,0110.10-3
1,010
4 0,001
0,0010
0,2122
1,0130.10-3
1,300
5 0,001
0,0020
0,2093
9,9950.10-4
0,050
6 0,001
0,0040
0,2108
1,0067.10-3
0,670
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 32
Hnh 3.5. th biu din s nh hng ca Cu2+ i vi xc nh Fe2+.
Da vo kt qu kho st c ta thy rng Cu2+ nh hng khng ng k n
vic xc nh st trong nc bng phng php trc quang phn t UV-VIS bng thuc
th o-phenantrolin.
3.3.2. Kt qu kho st nh hng ca Co2+ i vi xc nh Fe2+
Bng 3.6. Bng kt qu kho st nh hng ca Co2+ i vi xc nh Fe2+
STT Nng Fe3+
chun (mg/ml)
Nng Co2+
(mg/ml) D
Nng Fe2+ o
c (mg/ml)
Sai s tuyt
i (%)
1 0,001
0 0,2156
1,0298.10-3
2,980
2 0,001
0,0002
0,2150
1,0269.10-3
2,690
3 0,001
0,0004
0,2075 9,9088.10
-4 0,912
4 0,001
0,0010
0,2104
1,0048.10-3
0,480
5 0,001
0,0020
0,2124 1,0144. 10-3
1,440
6 0,001
0,0040
0,2155 1,0293. 10-3
2,930
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 33
Hnh 3.6. th biu din s nh hng ca Co2+ i vi xc nh Fe2+
Da vo kt qu kho st c ta thy rng Co2+ nh hng khng ng k n
vic xc nh st trong nc bng phng php trc quang phn t UV-VIS bng thuc
th o-phenantrolin.
3.3.3. Kt qu kho st nh hng ca Ni2+ i vi xc nh Fe2+
Bng 3.7. Bng kt qu kho st nh hng ca Ni2+ i vi xc nh Fe2+
STT Nng Fe3+
chun (mg/ml)
Nng Ni2+
(mg/ml) D
Nng Fe2+
o c
(mg/ml)
Sai s tuyt
i (%)
1 0,001
0 0,2146 1,0250. 10-3
2,500
2 0,001
0,00025
0,2134 1,0192. 10-3
1,920
3 0,001
0,00050
0,2105 1,0053. 10-3
0,530
4 0,001
0,00100
0,2128 1,0163.10-3
1,630
5 0,001
0,00200
0,2057 9,8225.10-4
1,780
6 0,001
0,00400
0,2087 9,9664.10-4
0,336
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 34
Hnh 3.7. th biu din s nh hng ca Ni2+ i vi xc nh Fe2+
Da vo kt qu kho st c ta thy rng Ni2+ khng nh hng n vic xc
nh st trong nc bng phng php trc quang phn t UV-VIS bng thuc th o-
phenantrolin.
3.3.4. Kt qu kho st nh hng ca Zn2+ i vi xc nh Fe2+
Bng 3.8. Bng kt qu kho st nh hng ca Zn2+ i vi xc nh Fe2+
STT Nng Fe3+
chun (mg/ml)
Nng Zn2+
(mg/ml) D
Nng Fe2+
o c
(mg/ml)
Sai s tuyt
i (%)
1 0,001
0 0,2120 1,0125.10-3
1,250
2 0,001
0,00025
0,2150 1,0269.10-3
2,690
3 0,001
0,00050
0,2116 1,0106.10-3
1,060
4 0,001
0,00100
0,2077 9,9184.10-4
0,816
5 0,001
0,00200
0,2060 9,8369.10-4
1,631
6 0,001
0,00400
0,2057 9,8225.10-4
1,775
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 35
Hnh 3.8. th biu din s nh hng ca Zn2+ i vi xc nh Fe2+
Da vo kt qu kho st c ta thy rng Zn2+ nh hng khng ng k n
vic xc nh st trong nc bng phng php trc quang phn t UV-VIS bng thuc
th o-phenantrolin.
3.3.5. Kt qu kho st nh hng ca Cr3+ i vi xc nh Fe2+
Bng 3.9. Bng kt qu kho st nh hng ca Cr3+ i vi xc nh Fe2+
STT Nng Fe3+
chun (mg/ml)
Nng Cr3+
(mg/ml) D
Nng Fe2+
o c
(mg/ml)
Sai s tuyt
i (%)
1 0,001
0 0,2108 1,0067.10-3
0,670
2 0,001
0,0002
0,2016 9,6257.10-4
3,743
3 0,001
0,0004
0,2081 9,9376.10-4
0,624
4 0,001
0,0010
0,2099 1,0024.10-3
0,240
5 0,001
0,0020
0,1995 9,5250.10-4
4,750
6 0,001
0,0040
0,2027 9,6785.10-4
3,215
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 36
Hnh 3.9. th biu din s nh hng ca Cr3+ i vi xc nh Fe2+
Da vo kt qu kho st c ta thy rng Cr3+ nh hng khng ng k n
vic xc nh st trong nc bng phng php trc quang phn t UV-VIS bng thuc
th o-phenantrolin.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 37
3.4. Quy trnh phn tch xc nh hm lng st trong mu nc
Axit ha n pH
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 38
Bng 3.10. Hiu sut thu hi ca phng php i vi php xc nh st
Ln o Nng st
thc t (mg/ml) D
Nng st o
c (mg/ml) H(%)
1 0,001
0,1858 8,8676.10-4
88,676
2 0,001
0,1996 9,5298.10-4
95,298
3 0,001
0,1875 8,9491.10-4
89,491
4 0,001
0,2010 9,5969.10-4
95,969
5 0,001
0,1972 9,4146.10-4
94,146
6 0,001
0,1843 8,7956.10-4
87,956
Htrung bnh 91,923
Nh vy hiu sut thu hi trung bnh ca phng php l 91,923 %, p ng yu
cu ca phng php phn tch vt kim loi.
3.6. Kt qu nh gi sai s thng k ca phng php
Bng 3.11. Bng kt qu D nh gi sai s thng k ca phng php
Fe3+
nng 0.05 (mg/ml) Fe3+ nng 0.025 (mg/ml)
0,2076 0,0983
0,1996 0,0926
0,1875 0,0894
0,2010 0,0879
0,1972 0,0934
0,1843 0,1008
nh gi sai s thng k ca phng php cc s liu c ly bng 3.11.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 39
Bng 3.12. Bng kt qu nh gi sai s thng k ca phng php
Cc i lng c trng Fe3+ 0.05 (mg/ml) Fe3+ 0.025 (mg/ml)
Gi tr mt quang trung bnh 0,1962 0,0938
Phng sai S2 7,6572.10-5 2,5004.10-5
lch chun S 8,7505.10-3 5,0004.10-3
H s bin ng Cv 4,4600 5,3309
sai chun Sx 3,5724.10-3
2,0414.10-3
Sai s tin cy 9,1811.10-3 5,2464.10-3
3.7. Kt qu phn tch thc t
3.7.1. Kt qu phn tch mu thc t h Thc Gin Vnh Trung
M1: Mu ly h Thc Gin gip ng Hm Nghi.
M2: Mu ly h Thc Gin gip ng Tn .
M3: Mu ly h Thc Gin gip ng Vn Cao.
M4: Mu ly h Vnh Trung gip ng Hm Nghi
M5: Mu ly h Vnh Trung gip ng Vn Cao.
M6: Mu ly h Vnh Trung gip ng Quang Dng
M7: Mu ly h Vnh Trung gip ng T Ngc Vn.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 40
Bng 3.13. Kt qu phn tch mu thc t ti h Thc Gin-Vnh Trung(thng 3/2012).
Tn mu D Nng st trong mu
(mg/ml)
M1S 0,0146 6,5259.10-5
M2S 0,0147 6,5739.10-5
M3S 0,0260 1,1996.10-4
M4S 0,0128 5,6622.10-5
M5S 0,0144 6,4299.10-5
M6S 0,0153 6,8618.10-5
M7S 0,0170 7,6775.10-5
M1C 0,0150 6,7179.10-5
M2C 0,0145 6,4779.10-5
M3C 0,0240 1,1037.10-4
M4C 0,0137 6,0940.10-5
M5C 0,0169 7,6296.10-5
M6C 0,0143 6,3820.10-5
M7C 0.0192 8,7332.10-5
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 41
Bng 3.14. Kt qu phn tch mu thc t ti h Thc Gin - Vnh Trung (thng
4/2012).
Tn mu D Nng st trong mu
(mg/ml)
M1S 0,1159 5,5134.10-4
M2S 0,0931 4,4194.10-4
M3S 0,1092 5,1919.10-4
M4S 0,1140 5,4223.10-4
M5S 0,0870 4,1267.10-4
M6S 0,0818 3,8772.10-4
M7S 0,0917 4,3522.10-4
M1C 0,1025 4,8704.10-4
M2C 0,0935 4,4386.10-4
M3C 0,1042 4,9520.10-4
M4C 0,1140 5,4223.10-4
M5C 0,0893 4,2370.10-4
M6C 0,0834 3,9539.10-4
M7C 0,1007 4,7841.10-4
Mu S l mu ly vo lc 9h
Mu C l mu ly vo lc 16h
Da vo bng s liu ta thy rng tng hm lng st o c t cc mu ly
trong h khng c s chnh lch ln v khng c s thay i khc bit gia cc mu
bui sng v bui chiu.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 42
3.7.2. Kt qu phn tch mu thc t sng Ph Lc
Bng 3.15. Kt qu phn tch mu thc t sng Ph Lc
Tn mu D Nng st trong mu
(mg/ml)
Mth 0,1520 7,2457.10-4
Mtr 0,2845 1,3604.10-3
Mh 0,1437 6,8474.10-4
3.7.3. Kt qu phn tch mu thc t nh my thp
Mu c pha long 2 ln .
Bng 3.16. Kt qu phn tch mu thc t nh my thp
Tn mu D Nng st trong mu
(mg/ml)
Mnmt 0,2004 9,5681.10-4
Vy nng st thc t trong mu l: 1,91362.10-3
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 43
CHNG 4: KT LUN V KIN NGH
4.1. Kt lun
Qua mt thi gian nghin cu, trong ti ny chng ti t c mt s kt
qu nh sau:
- kho st c cc iu kin xc nh st (thuc th, mi trng, bn mu
ca phc, nh hng ca cc kim loi khc...).
-Xc nh c gii hn pht hin st bng phng php trc quang phn t,
nh gi c mc chnh xc ca phng php.
- kho st v tm ra iu kin ti u ca qu trnh phn tch tng hm lng st
trong nc bng phng php quang trc phn t UV-VIS vi thuc th o-
phenantrolin.
-Xy dng thnh cng quy trnh phn tch st trong nc s dng thuc th o-
phenantrolin bng phng php trc quang phn t UV-VIS.
-p dng phn tch mt s mu nc ti h Thc Gin Vnh Trung.
4.2. Kin ngh
Tip tc m rng phm vi nghin cu xc nh hm lng ca cc kim loi khc,
c bit l cc kim loi c hi.
Phn tch cc ch tiu khc ca nc, trn c s nh gi mc nhim ca
nc c bin php x l kp thi.
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 44
TI LIU THAM KHO
[1]. L Huy B L Th Nh Hoa Phan Kim Phng on Thi Yn-
Nguyn L, c hc mi trng, NXB ai hc Quc gia TP.H Ch Minh
[2].Phm Th H, Cc phng php phn tch quang hc, trng i hc s
phm-i hc Nng (3-2008)
[3]. Hong Nhm, Ha hc v c (tp 3), NXB Gio dc (2000).
[4].T Vng Nghi - Hunh Vn Trung - Trn T Hiu, Phn tch nc, Nh xut
bn khoa hc v k thut.
[5].http://pacificsteel.vn/index.php?option=com_content&view=article&id=1221
&Itemid=639&lang=vi
[6]. http://vi.wikipedia.org/wiki/S%E1%BA%AFt
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 45
MC LC
M U ........................................................................................................................ 1
CHNG 1: TNG QUAN TI LIU .......................................................................... 3
1.1. St v d lng ca n trong mi trng .................................................................. 3
1.1.1. Gii thiu v st .................................................................................................... 3
1.1.1.1. Tnh cht vt l .................................................................................................... 3
1.1.1.2. Tnh cht ha hc................................................................................................ 3
1.1.2. Ngun gc xut hin ca st trong nc ................................................................ 4
1.1.3. Vai tr ca st ....................................................................................................... 5
1.1.4. Tc hi ca st ...................................................................................................... 6
1.2. Cc phng php xc nh vi lng st .................................................................... 6
1.2.1. Phng php quang ph hp th nguyn t (AAS) ............................................... 6
1.2.2. Phng php quang ph pht x nguyn t (AES) ................................................ 7
1.2.3. Phng php quang ph hp th phn t UV-VIS ................................................ 7
1.3. Phng php quang ph hp th phn t UV-VIS .................................................... 8
1.3.1. Gii thiu phng php quang ph hp th phn t UV-VIS ................................ 8
1.3.1.1. S hp th nh sng ca dung dch mu .............................................................. 9
1.3.1.2. Cc nh lut c bn v s hp th nh sng ..................................................... 10
1.3.1.3. Cc i lng hay s dng ................................................................................ 10
1.3.1.4. Tnh cht ca mt quang v ng dng trong ha phn tch ........................... 11
1.3.2. Cc iu kin ti u ca php o quang .............................................................. 12
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 46
1.3.3. Cc phng php phn tch nh lng s dng phn tch: .............................. 12
1.3.3.1. Phng php ng tiu chun ......................................................................... 12
1.3.3.2. Phng php thm chun .................................................................................. 13
1.3.3.3. u im ca phng php UV VIS ............................................................... 13
1.4. Cc phng php ly v x l mu .......................................................................... 14
1.4.1. Phng php ly mu .......................................................................................... 14
1.4.2. Cc phng php x l mu v bo qun mu ...................................................... 14
1.5. S lc vi nt v ni ly mu ................................................................................ 14
1.5.1. H Thc Gin Vnh Trung ................................................................................. 14
1.5.2. Sng Ph Lc ...................................................................................................... 18
1.5.3. Nh my thp ...................................................................................................... 18
1.6. Chun b mu phn tch ......................................................................................... 18
CHNG 2: THC NGHIM V PHNG PHP NGHIN CU ......................... 19
2.1. Dng c, thit b, ha cht ...................................................................................... 19
2.1.1. Dng c ............................................................................................................... 19
2.1.2. Thit b ................................................................................................................ 19
2.1.3. Ha cht .............................................................................................................. 21
2.2. Pha cc loi dung dch ............................................................................................ 21
2.3. Nhng vn cn nghin cu ................................................................................. 22
2.4. Thc hin nghin cu iu kin ti u phn tch hm lng st trong nc bng
phng php quang ph hp th phn t UV-VIS. ........................................................ 22
2.4.1. Chn thuc th thch hp ..................................................................................... 22
2.4.2. Kho st bn mu ca phc Fe2+ v thuc th theo thi gian........................... 22
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 47
2.4.3. Kho st nh hng ca pH ................................................................................. 23
2.4.4. Kho st gii hn pht hin ca Fe2+ .................................................................... 23
2.4.5. Kho st gii hn nng tuyn tnh ................................................................... 23
2.4.6. Lp ng chun xc nh st .............................................................................. 24
2.4.7. Kho st cc yu t nh hng............................................................................. 24
2.4.7.1. Kho st nh hng ca Cu2+ i vi xc nh Fe2+ .......................................... 24
2.4.7.2. Kho st nh hng ca Co2+ i vi xc nh Fe2+ .......................................... 25
2.4.7.3. Kho st nh hng ca Ni2+ i vi xc nh Fe2+ ........................................... 25
2.4.7.4. Kho st nh hng ca Zn2+ i vi xc nh Fe2+ .......................................... 25
2.4.7.5. Kho st nh hng ca Cr3+ i vi xc nh Fe2+ ........................................... 25
2.4.8. Phng php loi tr cc yu t nh hng ......................................................... 25
2.5. Chun b mu gi .................................................................................................... 26
2.6. nh gi hiu sut thu hi ...................................................................................... 26
2.7. nh gi sai s thng k ca phng php ............................................................. 26
2.8. Quy trnh phn tch ................................................................................................. 26
2.9. Phn tch mu thc t.............................................................................................. 26
2.9.1. Ly v chun b mu ............................................................................................ 26
2.9.2. Phn tch mu ..................................................................................................... 27
CHNG 3: KT QU V BN LUN .................................................................... 28
3.1. Kt qu kho st xc nh st .................................................................................. 28
3.1.1. Kt qu kho st bn mu ca phc Fe2+ v thuc th theo thi gian .............. 28
3.1.2. Kt qu kho st nh hng ca pH ..................................................................... 29
3.1.3. Kt qu kho st gii hn pht hin ca Fe2+ ........................................................ 29
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 48
3.1.4 Kt qu kho st khong nng tuyn tnh ......................................................... 30
3.2. Kt qu xy dng ng chun............................................................................... 31
3.3. Kt qu kho st cc yu t nh hng ................................................................... 31
3.3.1.Kt qu kho st nh hng ca Cu2+ i vi xc nh Fe2+ ................................. 31
3.3.2. Kt qu kho st nh hng ca Co2+ i vi xc nh Fe2+................................. 32
3.3.3. Kt qu kho st nh hng ca Ni2+ i vi xc nh Fe2+ ................................. 33
3.3.4. Kt qu kho st nh hng ca Zn2+ i vi xc nh Fe2+ ................................. 34
3.3.5. Kt qu kho st nh hng ca Cr3+ i vi xc nh Fe2+ ................................. 35
3.4. Quy trnh phn tch xc nh hm lng st trong mu nc .................................. 37
3.5. Kt qu kho st hiu sut thu hi ca phng php ............................................... 37
3.6. Kt qu nh gi sai s thng k ca phng php ................................................. 38
3.7. Kt qu phn tch thc t ........................................................................................ 39
3.7.1. Kt qu phn tch mu thc t h Thc Gin Vnh Trung ............................... 39
3.7.2. Kt qu phn tch mu thc t sng Ph Lc .................................................... 42
3.7.3. Kt qu phn tch mu thc t nh my thp ..................................................... 42
CHNG 4: KT LUN V KIN NGH .................................................................. 43
4.1. Kt lun .................................................................................................................. 43
4.2. Kin ngh ................................................................................................................ 43
TI LIU THAM KHO ............................................................................................. 44
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 49
DANH MC CC BNG TRONG KHA LUN
STT NI DUNG Trang
1.1 S hp th mu ca dung dch mu 8
3.1 S ph thuc ca mt quang D theo thi gian.(nng st
0,001mg/ml, pH=4) 27
3.2 Bng kt qu kho st nh hng ca pH.(nng st
0,001mg/ml,o sau khi to phc 10 pht) 28
3.3 Bng kt qu kho st khong nng tuyn tnh Fe2+ 29
3.4 Bng kt qu lp ng chun ca Fe2+(pH=4,o quang sau 10
pht) 30
3.5 Bng kt qu kho st nh hng ca Cu2+ i vi xc nh Fe2+ 30
3.6 Bng kt qu kho st nh hng ca Co2+ i vi xc nh Fe2+ 31
3.7 Bng kt qu kho st nh hng ca Ni2+ i vi xc nh Fe2+ 32
3.8 Bng kt qu kho st nh hng ca Zn2+ i vi xc nh Fe2+ 33
3.9 Bng kt qu kho st nh hng ca Cr3+ i vi xc nh Fe2+ 34
3.10 Hiu sut thu hi ca phng php i vi php xc nh st 37
3.11 Bng kt qu D nh gi sai s thng k ca phng php 37
3.12 Bng kt qu nh gi sai s thng k ca phng php 38
3.13 Kt qu phn tch mu thc t thng 3 h Thc Gin-Vnh Trung. 39
3.14 Kt qu phn tch mu thc t thng 4 h Thc Gin - Vnh Trung 40
3.15 Kt qu phn tch mu thc t sng Ph Lc 41
3.16 Kt qu phn tch mu thc t nh my thp 41
Kha lun tt nghip GVHD: Ths Nguyn Th Hng
SVTH: Nguyn Th Hoa Lp 08CHP Trang 50
DANH MC CC HNH V, TH
STT NI DUNG Trang
1.1 Dy mu ca nh sng trng 8
1.2 th tuyn tnh gia D v C 11
1.3 Quang cnh h Thc Gin-Vnh Trung 14
1.4 Bn h Thc Gin Vnh trung 16
1.5 Bn h Thc Gin Vnh trung 16
2.1 My phn tch UV-VIS 19
2.2 Cuvet 19
2.3 Lng knh hp th quang ph 19
3.1 S ph thuc ca mt quang D ca phc to bi st (II) v thuc
th o-phenantrolin theo thi gian. 27
3.2 th biu din s nh hng ca pH i vi vic xc nh st trong
nc. 28
3.3 th biu din nng tuyn tnh i vi xc nh Fe2+ 29
3.4 ng chun ca php xc nh st bng thuc th o-phenantrolin 30
3.5 th biu din s nh hng ca Cu2+ i vi xc nh Fe2+. 31
3.6 th biu din s nh hng ca Co2+ i vi xc nh Fe2+ 32
3.7 th biu din s nh hng ca Ni2+ i vi xc nh Fe2+ 33
3.8 th biu din s nh hng ca Zn2+ i vi xc nh Fe2+ 34
3.9 th biu din s nh hng ca Cr3+ i vi xc nh Fe2+ 35