TAP CHi KHOA HOC - BAI HOC BONG NAI, SO 05 - 2017 ISSN 2354-1482 X A C DINH, DANH GIA H A M LlTOfNG SAT T R O N G N l T d C GIENG
SINH H O A T TAI M O T SO HQ DAN TREN DIA B A N XA PHUC T R ^ C H - B O T R A C H - Q U A N G BINH
Nguyin Mdu Thdnk TOM TAT
Xd hgi ngdy cdng phdt tiiin thi nhu cdu sir dung nu&c sack ngdy edng eao. Tuy nhien, su biing nd ddn so citng v&i tdc do do thi hda, cdng nghiip hda nhanh chdng dd tgo ra mot sue ep l&n t&i moi tru&ng sdng, dgc biet Id v&i nguon nu&c ngdm vd nu&c sinh hogt. Phucmg phdp quang phd hdp thu nguyen tu (AAS) duge dp dung de xdc dinh hdm lugng sdt tiong nu&c giing sinh hogt a khu virc xd Phuc Trgch. Bd Trgch - Qudng Binh. Phucmg phdp ndy eho do lap lgi eao v&i RSD < 4,38%, do thu hdi 94,25 -h 103,16 %, gi&i hgn phdt hiin thdp. Kit qud ndy cho thdy hdm lugng trung binh cita sdt Id 0,158 mg/L, tucmg ddi thdp. Hdm lugng sdt tiong nu&c dgt v&i cdc tieu ehudn cho phep cua VietNam.
Tu khda: Nu&e giing, phuangphdp AAS, sdt, tiiu chudn 1. Mo- diiu
Nudc Id tdi nguyen vd ciing quan frgng ddi vdi mgi su sdng tren frai dat, Id CO sd cho su sdng cua mgi sinh vdt.
Tuy nhien cung vdi su phdt tridn cua khoa hgc cdng nghd, qua frinh do thi hda dien ra manh me nhu cdu cua con ngudi ngdy cdng dugc ndng eao, cudc sdng ngdy cdng cai thidn. Keo theo do la cac van de d nhiera mdi trudng, d nhidm ngudn nudc ngdy cdng nghiem frgng do chdt thdi cfta cac nha may, xi nghidp, edng trinh dd thi thdi ra mdi trudng chua qua xft Iy, cdc ehdt thai rdn do con ngudi su dung trong sinh boat hang ngay khdng dugc thu gora de xu ly tridt de da lam d nhidm va dnh hudng den chat lugng cua cdc ngudn nudc ngam. Cho nen van de sue khde cita con ngudi dang bi de dga nghiem trgng neu
'Trucmg Dai hoc Quang Binh Email: [email protected]
nhu chat lugng nudc khdng dugc ddm bao [1,5].
Sat (Fe) Id mdt frong nhung tac nhdn, khi hdra lugng chung cao, nude se cd raui tanh va cd nhieu can bdn mdu vdng, mdu nau den. Neu thieu sdt ngudi se met radi, gidm khd nang tdp tnmg, rung tdc, dau ddu. Ngugc Iai, khi co the hdp thu qud nhieu sat se gdy hien tugng gidn dft, viera khdp, tao bdn [4-5].
Phuc Trach Id rapt xa raidn mii nam frong vftng ddra vudn Qude gia Phong Nha - Ke Bang, nam cdch trung tdra huyen khodng 36 km ve phia tay, gdm cd 12 thdn phdn bd thanh 4 khu vuc:
Khu vuc Phiic Ddng cd 4 thdn (tii thdn 1 den thdn 4); khu vuc Phiic Khd cd 3 tiidn (tiidn 1, 2 vd thdn 3); khu vuc Thanh Sen co 4 thdn (thdn I din tiidn 4). Khu vue Chay Lap co 1 thdn do la thdn Chay Lap. Theo thdng ke thuc t l
TAP CHI KHOA HOC - BAI HQC BONG NAI, SO 05 - 2017 ISSN 2354-1482 Clia xa thi tinh din nam 2016, fren toan
xa CO 100% hd dan diing nudc gieng dao hoae rat it gidng khoan cho sinh hoat. Dac biet, frdn dia bdn cua xa cd dia hinh khdng bang phang, bao gdra 3 dang chu ydu la: Dia hinh ddi niii dd vdi; dia hinh ddi nui nam xen ldn gifta vung ddng bang va dia hinh nfti da.
Phuong phdp phdn tich quang phd hdp thu nguydn tft Id rapt phuang phap phdn tich hidn dai da vd dang dugc ftng dung rdng rai dd xdc dinh ham lugng cac nguyen td vi lugng frong cac ddi tugng radu nhu: radu quang, raau nudc, thuc phdra, dugc phdra...[2]. Vi vay frong bdi bao nay chung tdi trinh bay kdt qud xdc dinh, ddnh gia ham lugng sat trong nudc gieng sinh boat cua mdt sd hd dan d xa Phtic Trach, huydn Bd Trach bang phuong phap AAS.
2. Noi dung
2.1. Thiit bi, dung cu, kda ckdt Cdc dug nghidm thuy tinh chiu nhiet 30 ml CO nap xoay; Cdc thuy tinh chiu nhiet, thi tich 100 rai, 250 rai, 1000 rai;
Binh dinh rauc thiiy tinh, thi tich 25 rai, 50 ml, 100 ml, 1000 ml. Thidt bi quang phd hdp thu nguydn tir AA 400 cua hang Perkin Elmer vdi ky thuat nggn Ifta; cac micropipette Eppendorf va ddu hiit.
Cdc hda chdt sft dung cd do tinh khidt PA cua Merck: Dung dieh chudn sdt (1000 ± 2 ppm) chuyen diing cho phep do AAS, axit HNO3 dac, H2O2 dac, nudc cat.
2.2. Nguyin lieu, thai diim vd thiit bi lay mdu
Mdu nudc sinh hoat dugc lay d 8 gieng dao eua 8 hd dan frong 4 khu vuc (Phuc Ddng, Phuc Khe, Thanh Sen va Chdy Lap) tai xd Phuc Trach huyen Bd Trach tinh Qudng Binh qua 2 dgt. Cac gidng duge lua chgn dk ldy mdu la nhiing gieng dang dugc diing thudng xuyen cho sinh hoat gia dinh.
Thdi diera ldy mdu: Dgt I ngay 19/06/2016 (frdi ndng bftc, nhidt do khdng khi 38°C); Dgt 2 ngay 07/08/2016 (frdi ndng nhe, nhidt do khdng khi 33''C, trudc thdi diem ldy mdu 1 ngay trdi cd mua gidng, thdi diem lay mau frdi khdng raua).
Thiet bi ldy mdu va bao qudn radu:
Thiet bi lay raau kieu ngang, loai chuyen diing cho ldy mau nudc mat.
Vide lay radu vd bao quan radu theo cac quy dmh trong Tieu chudn Viet Nam:
TCVN 5993:1995 - Chdt lugng nudc - Ldy mlu. Hudng dan bao quan va xft ly raau; TCVN 5996:1995 - Chdt lugng nudc - LSy mdu. Ky hidu radu nudc giing la Ni-j, frong dd: i = 1 -^ 2 (dgt lay mlu), j = I -^ 8 (vi tii giing lay mlu).
2.4. Pkuang pkdp pkdn tick Trong nghien cftu nay, dp dung ky thudt phdn tich quang phd hap thu nguyen tu vdi ky thuat pha mlu udt.
Thuc hien tai Tnmg tam Ky thuat Do ludng Thu nghiera - Chi cue Tidu ehuan Do lugng Chdt lugng Qudng Binh va
151
TAP c m KHOA HQC - BAI HOC BONG NAI, S6 05 - 2017 ISSN 2354-1482 chdp nhdn nhftng dieu kien hoat ddng neu dhdng I.
cua thiet bi da dugc cdng bd [2], nhu
Bang 1: Diiu kien do F-AASxdc dinh sdt trong nu&c Thdng sd
A.(nra) Khe do (ram) Hdn hgp khi ddt Kidu den Den bd chinh ndn
sat 248,33 2,7/1,8 KK-C2H2 Catot rdng sat
D2 3. Ket qua va thao luan
3.1. Xdy dung du&ng ehudn, khdo sdt gi&i kgn phdt kiin, gi&i hgn dfnh lugng
Dudng chuan xdc dmh hdra lugng sat frong nudc dugc the hien tren hinh 1 vd bdng 2, phuong trinh ed dang: Ape = 0,124 C - 0,001, trong dd C Id ndng do (ppra).
Hinh 1: Du&ng chudn xdc dinh De xdc dinh gidi ban phdt hien (LOD) va do nhay cua phuang phap, chftng tdi dp dung theo quy tac " 3 a "
[6]. Theo quy tac nay, gidi han phat hien dupe tinh nhu sau: y — yb + 3a hay y = yb "•" 3Sb . Trong dd, y Id gidi han phat hien hoac tin hieu ftng vdi gidi han phat hien. Biet tin hidu y se tinh dugc gidi ban phat hien tft phuong trinh dudng chuan y = a + bC, do dd LOD ^ (y - a)/b). Trong do, yt la ndng do hoac tin hieu mdu frang; ab (hoac Sb) Id do lech chudn cua ndng
do (ppm)
sdt tiong nu&c sinh hogt
do hoac tin hidu radu trang. Cd the xac dinh yb va Sb nhu sau: tien hanh thi nghiera de thidt lap phuong trinh dudng chudn y = a + bC. Tft dd xac dinh yb va Sb bang cdch chdp nhdn yb Id gia fri cua y khi C = 0 thi y = a vd Sb = Sy theo edng thftc sau [6]:
S . - S „
Uy-.-xf
Q ddy, y, la gia tn thuc nghiem eua y va Y, la cdc gid tri tinh tft phuang
TAP CHi KHOA HOC - DAI HQC DONG NAI, SO 05 - 2017 ISSN 2354-1482 trinh dirtrng chu^n Clia y. Tit phuoTlg
trinh duang chuan, bien ddi ta se tmh dugc LOD theo cong thijc sau: LOD = 3Sy/b. Vtji b la do doc ciia duong chuan hoi quy tuyen tinh va b cimg U do nhay ctia phuang phap: b = A A / A C .
Dg tinh duoc gioi han dinh lugng (LOQ) cua phep do, chiing toi sii dung cong thtic sau: LOQ = 10S,A is 3,3 LOD. Kk qua tinh toan LOD va LOQ cua phuong phap dugc trinh bay 6 bang 2.
Bang 2: Cdc gid tri a. b, S^ LOD, LOQ tinh tir phuang trinh dudng chudn A=bC+a Kim
loai Fe
a - 0,001
b 0,124
Oy/X
0,002 R 0,9997
LOD, ppm 0,054
LOQ, ppm
0,18 Tft bdng 2 ta thdy, gidi han phdt
hien (LOD), gidi han dinh lugng (LOQ) cua phep do F-AAS frong phep xac dinh sat da dugc xdc dinh. Cu the LOD xac dinh sat Id 0,054 ppm vd LOQ la 0,18 ppra.
3.2. Ddnk gid dp lap lgi vd do dung cua pkep do
Dd lap lai dugc xdc dinh qua do leeh chudn (S) hay do lech chudn tuong ddi (RSD). Chiing tdi tiln hdnh phdn tich tren mdu Ni.j. Do ba mdu Nj.j, mdi mdu do ba ldn. Theo Horwitz, khi phdn tich nhung ndng do cd ppb thi sai sd frong ndi bg phdng thi nghidm nhd hon Vz RSD tinh theo cdng tiiue: RSD(%)=
2(1 -o.5ieC) ^(. ^ j^x^g ^ g ^jjAj pf^g^ jj^,]^j thi diit yeu edu. Ldy raau Nj.j, rdi thera chudn vao mdu nay, lap lai ba ldn vdi ndng dd cfta sdt tang dan. Kdt qud cho thdy, phuong phdp F-AAS khi phdn tich sat frong raau nudc sinh boat dat do lap lai tuong ddi tdt vdi RSD < 4,38%.
Do diing cua phuong phap phdn tich sat bat ky dugc xdc dinh thdng qua do thu hdi (Recovery) theo cdng thftc [6]: Rev(%) = ^ - ^ x I 0 0 . Trongdo, Co la ndng do chat phdn tich dugc thdm vao frong mau that; C\ la ndng dp chdt phan tich trong radu that; C2 Id ndng dd chdt phdn tich frong mdu that da dugc them chudn. Ket qua phuang phdp xdc dinh ham lugng sdt sau ba Ian do khi them 0,5 ppm sdt vao ba mdu nudc ndi tren cho do thu hdi ldn lugt dat tu 94,25 ^ 103,16 %. Vay, phuang phap F-AAS dat dugc do dung tdt nen cd the dp dung dl phdn tich sdt trong nudc gidng sinh boat.
3.3. Xdc dink kdm lirffng sdt tiong nu&c giing sink kogt
Kdt qua phan tich hara lugng sat frong nudc gieng sinh hoat cua 8 hd dan thudc 4 thdn t^i xa Phiic Trach, sau 2
153
TAPCHI KHOA HQC - BAI HOC BONG NAI, SO 05 - 2017 ISSN 2354-1482 dgt vdi 16 mdu nudc dugc bieu dien frdn hinh 2.
O-IS —
li
• Dot!
• Oat 2 -QCVN (7]
Hinh 2: Kit qud xdc dinh hdm lugng sdt trong nu&e giing sinh hogt Tu ket qua tren hinh 2 eho thdy,
ham lugng sat frong gieng sinh hoat d vi tri 5 la cao nhat tuc la d khu vuc Thanh Sen. Ngugc lai thap nhat la vi tri 7 tftc Id thudc khu vue Phue Ddng.
Kdt qud cho thdy, hdra lugng sat trung -r. 0.35
binh frong cac nudc gidng sinh boat Id 0,158 mg/L.
3.4. Ddnk gid, so sank hdm luffng sdt trong nie&c gieng
3.4.1. Ddnh gid hdm lugng sdt tiong nu&c sinh hoat tai thai diim khdo sdt
Dir<ycsiah bo^t
Hmh 3 : Kit qud hdm lugng sdt trung binh tiong 16 mdu nu&c cua 8 giing Dd danh gid hdm lugng trung binh
sat theo vi tri vd thdi gian ldy mdu chiing tdi dp dung phuong phdp thdng kd vdo xft ly sd lieu. Tft ket qud thu dugc, chung tdi bieu dien qua hinh 3.
Diing Data Analysis trong Microsoft Excel 2010, dp dung phuong phdp Anova 1 chieu danh gia su khac nhau
vd hdm lugng sat qua hai dgt ldy mlu, thu dugc cac kdt qua d bang 3.
Bang 3: Cac gia tri so sdnh F tinh vd F bang Kim
loai Fe
Fliiih 0,038
P 0,848
P bang(fcrit) 4,600
TAP CHI KHOA HQC - DAI HQC DONG NAI, SO 05 - 2017 ISSN 2354-1482 Tft bang 3 ta tiidy, P > 0,05 va F,inh <
Fbang thi khdng cd sg sai khdc va khdng CO y nghia ve sai khae. Hay ndi each khdc ham lugng sat tdng frong cdc radu nudc gieng d hai dgt ldy mdu khdng khac nhau vl mat thdng kd.
Nguyen nhdn cfta su khdng khdc nhau cd the gidi thich do dia tdng nudc d ddy kha dn djnh, thdi gian lay raiu gdn nhau va chua co su bidn ddi rd ret ve lugng mua.
3.4.2. So sdnh kdm lugng sdt tiong nu&c giing v&i tiiu chudn nu&c udng cua VielNam
Ket qud so sdnh ham lugng sdt frong nude gidng vdi tidu chudn nudc udng, cu thd: Theo QCVN 01:2009/BYT (do Cue Y t l du phong va Mdi trudng bidn soan vd dugc Bg trudng Bd Y t l ban hdnh theo thdng tii sd 04/2009/TT-BYT ngay 17 thdng 6 nam 2009), (TCVN 6002-1995, ISO 6333-1986) [7] dugc thd hien d bang 4.
Bang 4: Kit qud so sdnh hdm lugng sdt v&i nu&c uong tiiu chudn
Kim loai
Fe Vitri
lay miu xa Phiic Trach
Ham lirorng TB (mgA.)
0,158 TCcho phipVN (mg/L)
171
<0,3 Phtrong
sai (S') 7,40.10"
3
D0 I§ch chuan
(S) 0,086
ttinh
6,585
liy Ihuyet
f=I5)
2,131 Qua bdng 4 cho thay, cdc gid tri tijnh
> ti^ thuyet (p ^ 0,05; f = 15). Dilu do cd nghia cho thay ham lugng sat frong nudc sinh hoat ciia mdt vdi hd dan d xa Phuc Trach, huydn Bd Trach khdng khac vdi tidu chudn cho phep vdi p <
0,05 ve mat thdng ke. Cu thi hdm lugng cho sat frong nudc giing sinh ho^t d ddy deu nam frong pham vi cho phep cua tidu chudn Viet Nam. Didu nay cho thdy chua cd su bdt an cho ngudi tidu dung vd sat trong nudc giing sinh hoat tai cdc dja didra khao sat.
4. K i t lu$n
Da dp dung phuang phdp AAS xdc dinh hdra lugng sat frong 16 mdu nude
gieng sinh boat d 8 hd ddn thudc xa Phiic Trach, huydn Bd Trach, tinh Qudng Binh. Kdt qud cd do lap lai, do chinh xac cao va gidi han phat hien thdp.
Kit qua phdn tich cdc mlu nudc d day cho thay ham lugng tiimg binh cua sdt la 0,158 mg/L, tuong ddi tiiap, ndm frong gidi h^n cho phep vdi tifiu chudn nudc udng. Cd till ndi rdng chua cd su bdt an vd sat frong nudc cho ngudi sinh boat d cdc dia diem khdo sdt.
Da tidn hanh danh gia su bien dgng ham lugng sdt tiieo thdi gian vd vi fri ldy mdu. Kit qua cho thdy ham lugng sdt trong mdu nudc gieng d hai dgt ldy mdu khdng khdc nhau vd mat thdng ke.
TAP CHI KHOA HOC - BM HOC BONG NAI, SO 05 - 2017 ISSN 23542Hg_
TAI LIEU THAM KHAO
1. Ld Huy Ba (2001), Ddc hgc mdi tiir&ng, Nha xudt bdn Dai hgc Quoc gia TP.
Hd Chi Minh
2. Pham Ludn (2006), Phuang phdp phdn tich phd nguyen tie. Nha xuat ban Dai hgc Qudc gia, Hd Ngi
3. Tft Vgng Nghi, Huynh Van Trang, Trdn Tft Hidu (1986), Phdn tich nu&c, Nha xudt ban Khoa hgc vd Ky thuat, Hd Ngi
4. Nguyen Thanh Son, Trdn Nggc Anh (2010), "Chdt Iugng nudc sinh hoat ndng thdn tinh Qudng Tri - kdt qud dilu fra nam 2008", Tgp chiKhoa hoc - Dai hgc Qudc gia Ha Ngi, Khoa hgc Tu nhien va Cdng nghe 26, sd 3S, fr. 443-448
5. Nguydn Mau Thanh, Tran Dftc Sy, Nguydn Thi Hoan (2015), "Phan tich vd ddnh gid hdra lugng sdt trong hdu d khu vuc sdng Nhat Le, thi frdn Qudn Hau - Qudng Bmh", Top cM.fir/ioa Ape vaG/aoi/Mc, Dai hgc Supham Hul, 1(33), fr. 111-117
6. Miller J. C , Miller J. N. (2010), Statistics and ChemomePies for Analytical Chemistry, Ed. 6*^, Pearson Education Limited, England
7. Bd Y T I (2009), "Quy chudn ky thudt qudc gia v l chdt lugng nudc an udng", Ban hdnh kem tiieo tiidng tir sd 04/2009/TT-BYT
DETERMINATION AND EVALUATION O F THE IRON CONTENT IN LIVING WELLS IN SOME HOUSEHOLDS AT PHUC TRACH COMMUNE,
BO TRACH DISTRICT, QUANG BINH PROVINCE ABSTRACT
The more developing the society is the higher need of using clear water is.
However, the overpopulation, the urbanization and the industiialization are so fast that it makes a high pressure to the environment especially to the groundwater resources and living water. The atomic absorption spectrophotometiic method is applied to deteinnine the iron content in living wells in some households at Phue Trach commune. Bo Trach distiict, Quang Binh province. This method has high repeatability with RSD < 4,38% and the recovery from 94,25% to 103,16% and low limit of detection. This result shows that the average iron content in water is relatively low 0,158 mg/L. The iron content in water meets the allowed standards of
Vietnam.
Keywords: Water wells; AAS method; iron; standard
(Received: 17/11/2016, Revised: 10/04/2017, Accepted for publication: 24/07/2017)
