JOURNAL OF SCIENCE OF HNUE Natural Sci., 2014, Vol. 59, No. 4, pp. 9-18 This paper is available online at http://stdb.hnue.edu.vn
TONG HOP VA NGHIEN CUU SU DUNG HAT NANG CHITOSAN - OXIT SAT TU DE XtJ LI ASEN TRONG N U 6 C S I N H HOAT
T r i n T h i H o n g V a n , T r i n h Q u y l t T h a n g , T r S n M i n h D t i c , D a o V a n B a y v a N g u y e n Q u a n g T u y e n Khoa Hod hoc, Trudng Dai hpc Su Pham Hd Noi Tom tat. Hat nano chitosan-oxit sat ttjf dUdc long hdp theo phUdng phap khU mot phan Fe^+ vdi su co mat chitosan de dUdc chitosan:oxit sat liJt theo cac ti le khac nhau (1:1, 2:1, 3:1 va4:l). Cac san pham dadUdc nghien ciiu cau triic, kich thudc va be mat vat lieu qua pho XRD va anh SEM. San pham long hdp dUdc sii dung de nghiSn cUu xu" li asen trong moi trUdng nudc. Hat nano chitosan-oxit sat tU vdi ti le chitosanioxit sat tic la 3:1 cd kha nang hap phu asen tot nhat.
TUkhoa: Nano oxit sat tU, chitosan, asen.
1. Md
dau
Asen va cac hdp chat cua chiing rit doc, neu di vao cd the cdn ngudi se gay tac hai cho siJc khde. NgUdi u6ng nUdc bi nhilm asen lau ngay se mhc mot s6 benh nhU: benh Bowen, benh siing boa da, benh "ban chan den",.,. Ngoai ra, nhifim doc asen lau ngay con cd the gay ung thu hoac viem rang, khdp, gay benh tim mach, cao huyet ap [4].
Cd nhi€u phUdng phap dUdc dung de xOf li asen trong moi trudng nude nhU: phUdng phap ddng k^t tua [31, phUdng phap Ipc va ipc mang [3], phUdng phap s5c ki trao doi ion, phUdng phap hSp phii [ I ], . . . Trong do phUdng phap hap phu dUdc sif dung kha pho bi^n vdi cac vat lieu h i p phu asen khac nhau [1, 7].
Oxit s5t tit la hdp chat tUdng d6i dl dieu chS vdi chi phi thap nen hien nay dUdc sijf dung pho bi^n de xtf li nude 19]. Tuy nhien phUdng phap nay cd mot sd han ch6 anh hudng den kha nang h§p phu ciia oxit sat tU. De giai quyet nhiing han che do, mot hudng mdi dUdc de xuat: nlu cho hat nano oxit sat tif ket hdp vdi mot chat hUu cd, trong dd chat hiJu cd ddng vai tro tao ra mang hoc oxit s5t tif, lam cho oxit sat tit sc ben vUng hdn va cd Ngay nhan bai: 10/3/2014 Ngay nhan dang: 15/5/2014.
Tac gia lien lac: Tran Thi Hong Van. dia chi e-mail: [email protected]
Trjn Thi Hang Van, Trinh Quylt Thang, Tran Minh Dilc, Dao \ ^ Bay va Nguyen Quang Tuyen Idia nang hdp phii ciic chat 6 nhilm t6t hdn, khi do chac chan Icha nang xii li nildc se hieu qua hdn [2].
Chitin ton tai trong v6 torn, cua, con trung, la cay,... la nguyen lieu rat pho bien trong tiX nhien, gia thanh re. Chitosan la dan xult de axyl hoa chitin, la chit co kha nang tao mang t6t. Mang chitosan la vat lieu kha dai, kho xe rach, co dp ben tifdng diTdng cac chat deo [8]. Til cau tao va tinh chat ciia chitosan cho thSy mang chitosan (khi dupe hoa tan trong axit d pH = 5 - 6) co dang ket tua keo nen co tac dijng t6t trong viec xii: h' nUdc nhilm biin [2. 5].
Trong bai bao nay chiing toi trinh bay phlldng phap tdng hdp-bat nano chitosan-oxit sat tii va nghien ciiu kha nang hSp phu asen bang san pham da tong hdp, tii do danh gia kha nang xii li asen trong nUdc bang nano chitosan-oxit sat tuf.
2. Noi dung nghien cufu 2.1. Thiic nghiem
* Uoa chdt
- Dung dich chitosan: Hoa tan 1,1765 gam chitosan (ham liidng 85%) trong 100 mL dung dich CH.,COOH 2% de co nong do 1 g chitosan/100 mL dung dich (1%).
- Dung dich g6c As(III)' Hoa tan 0,1320 gam As20,i (loai PA ciia hang Merck - Difc) trong 50 mL dung dich NaOH 1%, dinh miJc bang ml6c cat ve 100 mL thu dUdc dung dich As(IIl) goc ! ,0 g/L. Tii dung dich %t]C co the pha thanh cac dung dich As(III) l,0mg/I„0,4mg/I., ...
- Dung dich goc As(V): Hoa tan 0,3790 gam As20.r,.3H20 (loai PA ciia hang Merck - Diic) bang nitdc cat, dinh miic bang nUdc cat ve 100 mL thu dUdc dung dich g6c As(V) 100 mg/L. Lay dung dich g6c pha thanh cac dung dich As(V) co n6ng dp 10,0 mg/L; 1,0 mg/L; 0,4 mg/L,...
- Cac hoa chat khac: FeClj.bHjO, NajSO,,, NHj dac, HCl, CH3COOH, NaCl, CaCl,, MnSOj.
Tit ca cac hoa chat sir dung trong nghien ctiu d6u dat do tinh khilt phan tich.
* Thiit bi
- Can phan tich Startorius co dp chi'nh xac ± 0,1 mg ciia DiJc.
- May quang pho hSp thu nguyen tii Shimadzu AA-6300 ciia Nhat Ban.
- May do pH TOA pH METER HM - 16S cua Nhat Ban.
- Pho nhieu xa tia X dupe gili do tren may SIEMENS D5005 Brucker - CHLB DiJc.
- Anh SEM cua mSu vat lieu dupe chup b5ng kinh hien vi dicn tii quel SEM-JMS54I0 ciia hang JOE Nhat Ban (Vien Han lam KH va CN Viet Nam).
- Cac thicl bi khac: may khuay, tii say, may cat nUdc hai lan,...
Tong hdp vd nghien cihi sif dung hat nano chitosan - oxit sdt tii de'xix it asen trong m(dc sinh Iwal
* Phuangplidp tong hOp hat nano chitosan-oxit sat tii
Sd do tong hdp hat nano chitosan-oxit sat tir dUdc md ta d Hinh 1. Theo li thuyet, nSu trpn Fe^+ va SO3" vdi ti le 6:1 (theo s6 moi), ddn khi phan Ung hoan toan se thu dUdc tileFe-^'^:Fe^+ =2:1 [9], NhUng trong thuc t^de dam bao thu dUdc tl leFe^+: Fe^+ - 2 : 1 chiing toi trpn Fe'*"*" va SO3" vdi gia tri R < 6 (gpi R la ti le so moi Fe^"^: 803"^ khi trpn).
Hat nano chitosan-oxit sat tiif dUdc tong hdp dua thed phUdng phap khil mot phan [5]. Hon hdp (Fe*'^: Fe^"*" = 2:1 ve so moi) dupe trdn vdi chitosan theo cac ti le khac nhau se thu dUdc san pham co ti le chitosan:oxit sat tU khac nhau (1:1, 2:1, 3:1 va 4:1). Viec tong hdp dUdc thUc hien d nhiet dp 30 °C (nhiet dp phdng); thdi gian khuay khac nhau: 6h, 12h, 24h, 48h; toe dp khuSy khoang 600 vdng/phiit. Chi tiet qua trinh tdng hdp xem trong tai lieu [6].
Khuay, 30 C, 30ph
Dung dich do nau chuyen mau vang Khuay, 30''C, 6^24h + chitosan + dd NH3 dac
Sdy a 45 "C, 2 ngay I Lpc, nVa bang nude c^t San pham dupe nghien nho
(mau den)
Hinh L Sd do tong hop hat nano chitosan-oxit sat tii
* Nghien ctJtti phUdng phap xic li asen bang hat nano chitosan-oxit sat tii
• Phuang phap xu If mau nuc'fc tu tao chiki as en
Dung mau hat nano chitosan oxit sat tiT cd ti Ic chitosan: I'"e;j0^ khac nhau da tdng hdp de nghien ciJu xif li As(V) va As(lII) trong mau tu tao.
+ Mdi mSu xu: If nude nhiem As d trong cac dieu kien khac nhau:
- Cac thi nghiem dUdc thUc hien d nhiet dp phong (25 - 35 "C).
- Khao sat xijf If (khong dung may khuay) vdi cac thdi gian khac nhau: 6h. 12h, 24h, 48h, 3 ngay, 4 ngay, 5 ngay, 6 ngay, 7 ngay.
- Khao sat xii li cd diJng may khuay d cac toe dp khoang 240 vdng/phiil va vdi thdi gian khuay khac nhau: Ih, 3h, 6h. 12h, 24h.
II
Trin Thi H6ng Van, Trinh Quyet Thang, Tran Minh DUc, Dao Van Bay va Nguyen Quang Tuyen - Khao sat x^ li cd them cac chat khac cd trong mau nUdc (ngoai asen) cd kha nang anh hudng den kha nang hap phu asen nhU: Fe^+, Mn^"*", Na"*", Ca^"*", Cl~, S04~,- • •
+ PhUdng phap tien hanh:
Diing 0,1 gam mdi mau nano chitosan-oxit sat tif de xif li 100 mL va 200 mL mau nude tu tao chiia As(V) va As(in) cd ciing ndng dp 400 /ig/L. Sau khi x ^ li, kiem tra nong dp asen cdn lai bang phUdng phap quang pho h i p thu nguyen tif khong ngpn Wa (GF-AAS).
Tit cac ket qua thu dUdc qua cac mau xii" li d tren chiing toi chpn ra mau vat lieu cd kha nang XLf If toi uu nhat dUa vao ling dung xu" li nUdc sinh hoat nhiem asen.
• Phuang phap xii' li mau nUdc sinh hoat nhiem asen (mau nUdc thUc te) M l u nUdc dUdc lay trUc tiep tiJf nUdc giSng khoan cua cac ho gia dinh d Thon Thdng Nhat - Xa Ddng Lo - Huyen Ong Hoa, Ha Noi, la dia phUdng cd ngudn nUdc ng§m bi nhilm asen kha cao. Sau khi phan tich ndng dp asen trong cac mau nUdc dUdc lay trUc tiep tCt cac dia diem cd ngudn nUdc nhiem asen, chiing toi dung 0,1 gam mau nano chitosan-oxit sat tii cd kha nang xuf li tfii Uu nhSt de xif If 100 mL mau nUdc thUc te theo cac dieu kien tdi Uu da khao sat xii If m^u nude tU tao chiJa asen d tren.
2 . 2 . K e t q u a v a t h a o l u a n
2.2.L Ket q u a nghien ci^u xac dinh cau true h a t n a n o chitosan-oxit sat tuf
* Ket qua phan tich bang nhieu xa tia X
Cac mSu chitosan-oxit sat tit cd cac ti le chitosan:Fe,i04 khac nhau (1:1, 2:1, 3:1 va 4:1) dUdc tdng hdp trong thdi gian 6h, 12h, 24h theo sd dd d Hinh 1. Cac mSu tdng hdp dupe de ngoai khong khi 1 tuln, sau dd dUdc do pho nhilu xa tia X (phd XRD) de xac dinh c&u triic.
8 ' ^ ' ' • ' • - — • ' - • - • 1
Hinh 2. Pho XRD mau co ti le chitosan:Fe:,Oi = 3:1, tong hop 24h, H=S
Tonfi hdp vd nghien cvtu sU dung hat nano chitosan - oxii sat tU dexvt li asen trang nUdc sinh hoat Dua vao pho XRD cua cac mau dupe tdng hdp theo ti le chitosan:Fe.)04 khac nhau va d cac dieu kien khac nhau chiing toi thay mau cd ti le chitosan:Fe304 = 3:1 va 4:1, dupe tdng hdp trong 24 gid vdi R = 5 (ti le sd moi Fe'+: SO3" khi trpn ban diu) cho ham lUdng Fe304 tot nhat (Hinh 2, 3). Vdi thdi gian tong hdp trong 24 h kha nang "tao mang"
bao ve ctia chitosan ddi vdi Fe304 tdt hdn nhifiu so vdi thdi gian tdng hdp ngSn hdn.
5
1 , 1 , , 1,
Hinh 3. Pho XRD mau co ti le chitosan.Fe^Oi = 4:1, tong hop 24 h,R = 5 0 mSu tdng hdp theo ti le 3:1 va 4:1 san pham hSu nhU chi co FeijOi, the hien viec chi xuSt hien vach phd cua Fe304 va vach phd nay gSn nhu d chinh giiia ciia cac pic trong dd d pic cUc dai la rd net nhat. So sanh phd XRD ciia mau tdng hdp theo li le 3.1 va 4:1 vdi phd XRD ciia Fe,j04 (Hinh 4) cho thiy chiing cd pic cUc dai giong nhau. Nhu vay vdi thdi gian tdng hdp lau hdn, gia tri R cao hdn, san pham Fe;iOi dUdc tdng hdp ra tUdng tU nhau. Tren cd sd dd chiing toi chpn hai m5u vat lieu iren dc nghien ciiu tiep kha nang bSp phu asen.
Hinh 4. Pho XRD cua mdu Fe.^O 1 diiOc tong hdp 6h, R = 3 (6]
Tran Thi Hong Van. Trinh Quyet Thing, Tran Minh Diic, Dao Van Bay va Nguyin Quang Tuyen
* Ket qua nghien ciiu kick thuSc vd be mat vat lieu
De nghien ciiu hinh dang va kich thudc cua vat lieu, cac mau tdng hpp theo ti le 3:1 va 4:1 d tren dUdc dem chup bang kinh hien vi dien tiJ quet (anh SEM). So sanh anh SEM ciia cac mau tong hdp theo ti le 3:1 va 4:1 (Hinh 5, 6) vdi anh SEM ctia Fe304 [9] (Hinh 7) cho thSy: mlu tdng hpp Fe304 theo [9] thu dUdc cac hat cd kich thUdc tUdng doi nho (khoang 15 - 30 nm) nam tach rdi nhau, trong khi dd cac mau tdng hdp theo phUdng phap ciia chung toi thu dUdc cac phan tu: lien Vki vdi nhau tao ra cac polime cd kich thudc Idn (khoang 100 - 200 nm) (Hinh 5, 6). dd cd the la dang poUme cua chitosan.
Hinh 5. Anh SEM ciia mau tring bo-p ti le.?.- / (24lt, R = 5)
Hinh 6. Anh SEM ciia man tdng hop ti le 4:1 (24h, R = 5)
Hinh 7. Anh SEM ciia man FeiO^ fSng hop (6lt, R = 3) Trong cac mau tdng htip tren khong thay xuat hien cac hat Fe304 rieng re nhu trong anh SEM cua Fe,j04 (Hinh 7) chiing to cac phan tif FcjO.i da dupe chitosan "bao bpc"
phia ngoai, giiip cho Fc:,Oj khong bi anh hudng bdi cac tac nhan ben ngoai. Dilu nay giai thfch VI .sao cac mSu tdng hpp ciing de ngoai mdi trildng khong khi nhU nhau (khoang 1 tuan) nhUng 2 mau tdng hdp nay (ti le 3:1 va 4:1 vdi R = 5) van giiJ nguyen mau den va ttf tinh nhu ban dau trong khi cac mlu tdng hdp khac cung nhu mau tdng hdp Fe;j04 chuyen dan sang mau nau dd va cd tit tinh kem. So sanh anh SEM ctia ti le 3:1 va 4:1 cho thSy ti le 4:1 cd lupng chitosan "bao bpc" nhilu hdn.
2.2.2. Ket qua nghien ciJu u n g dung hat n a n o chitosan - oxit sat tuf trong xii \\ asen Chung toi siV dung hat nano chitosan-oxit sat tCf tdng hdp theo li le 3:1 v a 4 : l d tren de nghien cUu xif li asen trong nUdc hh\g phUdng phap hap phu f i].
* Nghien cihi xti liasen trong mau tu tao
Cac mSu nude tu tao chiJa As(V), As(in) dUdc lay tif cac dung dich tU pha cd ndng dp chinh xac biet trudc, dieu chinh pH = 6,5 -;- 8,5. Trong qua trinh xii If chiing toi dung 0,1 gam hat nano chitosan-oxit sat tif de xii If 100 mL mau nUdc chtia asen da dUdc pha san d nhiet dp phdng (25 - 35 °C) trong cac didu kien khac nhau dc tim ra phUdng phap toi Uu nhat.
SLV dung hat nano chitosan-oxit sdt tif tdng hdp theo ti le 3:1 va 4:1 dc xiif li asen deu Ihu dUdc ket qua tot (Bang 1,2). Vdi thdi gian xif li ngan, ham lUdng asen ban dau (C„) r^t cao (gap 40 lan miic cho phep) deu giam xudng dudi miic cho phep ciia asen tron* nude udng. Trong dd ti le 3:1 cho ket qua xii If tot hdn. Vi vay chiing toi tilp tuc nghien cUu ifng dung san pham nay de xu: If asen trong nUdc sinh boat.
14
Tong hdp vd nghien ciin sit dung hat nano chitosan - oxit sal tit dexH li asen trong nUdc sinh hoai Bang 1. Nong do As(V) theo thdi gian x& li cua mau
CO ti le chitosaniFe^OX = 3:1 (R = 5)d trang thdi dgng (khuay trgn) Co (//g/L)
371,5 371,5 371,5 371,5 371,5
C(Mgfl.) 15,29 9,58 7,61 5,56 2,70
Thai gian xii li (h) 1 2 3 6 12
% As(V) bi xut li 95,88%
97,42%
97,95%
98,50%
99,27%
Bang 2. Nong do As(V) theo thdi gian xu^ li cua mau CO ti le chitosan:Fe^Oi = 4:1 (R = 5) d trang thdi dgng (khuay trpn) Co (/i/L)
371,5 371,5 371,5 371,.5 '
C (/i/L) 16,06 10,87 6,01 5,24 4,09
Thtii gian xiir li (h) 1 2 3 6 12
% As(V) b | XUT li 95,68%
97,07%
98,38%
98;59%
98,90%
Cac thi nghiem cho thay san pham long hdp ciia chiing idi d tren cd tac dung xii;
ii As(V) rat tot, cdn doi vdi As(III) cung cd kha nang xU li tot nhUng khong bang As(V) (Bang 3). Qua dd cho thay san pham cd kha nang hap phu asen ton tai dUdi dang ion mang dicn tich tot hdn asen tdn tai dudi dang khong mang dien tich. Trong thUc te doi vdi nUdc sinh hoat neu asen tdn tai dudi dang H2ASO4 va HAsO.^~ (ion mang dicn tich am) thi kh;i nang xii If chac chan se rat tdl, nhUng n6u asen tdn tai d dang As(UI) hoac asen trong chat hUu cP (thudng la trung hoa ve dien) thi kha nang xiif li se gap khd khan. Trong trUdng hpp nay phai diing chat oxi hoa manh (KMnOi/H^SOj) de oxi hda As(III) len As(V), ddng thdi chuyen asen trong chat hUu cd sang As(V) vd cd dc ihuan Idi cho qua trinh xif If.
Bang 3. Nong do As(Ill) theo thdi gian xit li cua mau cd ti le chitosan:Fe.iO, = 3:1 (R = 5) d trang thdi dpng (khuay trgn) C„ ((/gA.)
391,0 391,0 391,0
C (/ig/L) 1 14,23 56,20 24.25
Thai gian xis li'(h) 3 6 12
% AsdII) bj xu If 70,79%
85,63%
93,80%
* Nghien ciiu xi'i liasen trong niidc gieng khoan diing cho sinh hoat Mau nUdc sinh boat ciia chung tdi dUdc lay trUc tiep tU ngudn nUdc ngam tai Thdn Thdng Nhat, Xa Ddng Ld. Huyen L/ng Hda, Ha Noi. Mau nUdc dUcJc lay lU cac ho gia dinh khac nhau trong thdn, bao gdm: mau nUdc trUc tiep tif nUdc gicng khoan trUdc khi 15
Tran Thi Hong Van, Trinh Quya Thang, Tran Minh Dtfc, Dao \ ^ n Bay va Nguyin Quang Tuyen x^ li va nUdc da dupe qua xuf If bang be loc cat.
Ham lugng asen trong mau nude chua xv( li
Trong qua trinh lay va bao quan m l u niJdc, chiing toi cho vao 0,5 lit nUdc khoang 2 mL HNO3 dac. Sau khoang 2 ngay de trong moi trUdng lanh (0 - 5 °C), lUdng axit dU trong mau nUdc dupc trung hda bang NaOH loang den pH = 6,5 - 8,5. Sau dd cac mau dUdc dem xac dinh ham lUdng asen bang phUdng phap do phd hSp thii nguyen tuf khong ngpn Ilia diing Id graphit (GF-AAS), ket qua dUdc trinh bay d Bang 4.
Bang 4. Nong do As trong man nUdc ngdm tai thdn Thong Nhat stt
1 2 3 4 5 6
Nong do As (/(g/L) trirdc khi loc cat
26,90 (Ml) 36,26 (Ml) 11,38 (M3) 64,34 (M4) 92,14 (M5) 89,10 (M7)
Nong do As (//g/L) sau khi loc cat
38,28 (M6) 33,90 (M8)
Ten chii ho Ngo Tien Manh Nguyen Van Binh
Bill Van Xuyen Nguyen Van Dai Nguyen Thi Huyen Nguyin Xuan Loat (Ml, M2,... MS la h' hieu cac mdu nude sinh hoat dem xac dinh ham lucfng'asen)
Ket qua phan tich cho thSy tai thdi diem lay m l u (13-9-2010), nong dp asen trong mau nude ngam d cac gia dinh diu co nong do asen cao hdn cho phep ( < 10 //g/L). Nong do asen con lai trong nude da qua loc cat con kha cao til 92,14 /ig/L (M5) xudng con 38,28 (ig/L (M6). Chiing toi lay m l u nUdc M5 va M6 ciia mot ho gia dinh chUa qua va da qua loc cat de tiSn hanh khao sat kha nang x i li bang hat nano chitosan-oxit sat til duoc tong hdp theo ti le 3:1.
2.2.3. Ket qua xiir li nude gicng khoan nhilm asen
De xii li mau nUdc, chiing toi diing 0,1 gam hat nano (ti le 3:1) xii li 100 mL nUdc nhilm asen theo philong phap khuly, kit qua thu dUdc d Bang 5.
Co (iigIL) 92,14 92,14 92,14
" 9 2 7 1 4 " " "
38,28
Bang 5. Nong do As trong mau ntfdc theo thdi gian xic li C(//g/L)
45,96 27,43 25,20 15,91 17,41
Thoii gian xur Ii(h) Ih 2h 3h 6h Ih
% As bi xur li 50,12%
70,23%
72,65%
82,73%
54,52%
Kit qua thu ditdc cho thay vdi ham lUdng asen trong thuc t l chi bang 1/4 so vdi asen trong mau tu tao nhung kha nang xii li ciia hat nano da tong hap kem hon nhieu. Sau 3h
Tong hdp vd nghien ctiu sit dung hat nano chitosan - oxit sat tif dexU li asen trong nude smh iioat xtf li, ham ItJdng asen chi giam 72,65% (so vdi 97,95% ctia As(V) - Bang 1) va tupng tu nhu As(in) la 70,79% (Bang 3), sau 6h xut It ham lupng asen giam 82,73% (so vdi 98,50%
cua As(V) - Bang 1) va ciing tUdng ttX As(IH) la 85.53% (Bang 3).
Dieu do chiing to trong mau nude thUc te 6 tren khong chi cd As(V) ma cdn cd As(IlI) va asen d dang hiiu cP. Chung tdi cho vao cac mau nUdc tren dung dich KMnOj trong moi trUdng axit H2SO4 de pha buy chat hiiu cd chUa asen va oxi hda As(III) len As(V), sau do trung hda bang NaOH va loc bd k6t tua mau den. Nudc loc dupe xii li lai bang hat nano da tdng hdp va thu dUdc kSt qua d Bang 6.
Bang 6. Nong do As (cua mau nUdc sau khi hi oxi hoa) theo thdi gian xA li C„(/ig/L)
92,14 37,54 37,54 37,54
C(/i,g/L) 37,54
3,14 1,87 1,45
Th((i gian xur li(h) Sau khi xiir li biing hdn hdp
KMnOi/HjSOi Ih 2h 3h
% As bi xiir li 59,26%
91,64%
95,02%
96,14%
Nhu vay ngay sau khi cho them chSt oxi hda KMn04/H2S04 va trung hda bang kiem lUdng asen trong nUdc da giam dang ke (giam 59,26%). Sau 3h khuay lUdng asen con lai thay doi khong dang ke so vdi thdi gian khuiy 2h.
3. Ket luan
1-Chiing tdi da tong hpp hat nano chitosan-oxit s3t tif theo phUdng phap khii mot phan vdi ti le tot nhat theo khdi lUdng chitdsan:Fen04 = 3:1. San pham di6u che ben virng trong khdng khf do dUdc chitosan bao bpc nen it bj anh hudng bdi tac nhan ben ngoai.
2-Suf dung san pham da tdng hpp de xil li asen trong nUdc sinh boat cho k6t qua rat tdt. Sau khi dUdc xii If ndng dp asen ban dau da giam manh xudng dudi mUc tieu chuan cho phep cua asen trong nude uong (< 10 /ig/L).
3-Ket qua nghien ciiu budc dau cho thiy, vdi ngudn nguyen lieu re (chitin va chitosan lay tif vd tom. cua... va hpp chat ctia Fe), phUdng phap tdng hpp ddn gian, san pham thu dUdc cd hieu qua xii If asen tot. Hat nano chitosan-oxit sat tU dupe tdng hpp mang y nghia thUc tien Idn, cd the sii dirng lam vat lieu hap phu asen trong mdi trUdng nudc noi chung.
Tby nhien kit qua nghien ciiu ciia bai bao mdi chi d pham vi phong thf nghiem, budc dau nghien ciiu tdng hdp mot vat lieu mdi la hat nano chitosan-oxit sat tCf de ling dung hap phu xiJ li asen. Mudn sii dung vat lieu de xii li asen trong thuc tl can phai cd nhiing nghien cUu tiep theo.
Tran Thi Hong Van, Trinh Quyjt Thing, Tran Minh Diic, Dao Van Bay va NguySn Quang Tuyen TAI LIEU THAM KHAO
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Nxb Thong ke.
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http://www.elsevier.com.
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Trudng Dai hpc su pham Ha Noi.
[7] Pham Hung Viet, Tran Hong Con, Cao The Ha, Hoang Van Ha, M.berg, W.Giger, R.Schertenleib, 2003. Investgitation of asenic removal technologies for drinking water in Vietnam, in "Arsenic Exposure and Health Effects V", Published by Elsevier Science, Chapter 35, pp. 459-469.
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ABSTRACT
Synthesis and study of application of magnetic iron oxide nanoparticles coated with chitosan to remove arsenic from water
Magnetic iron oxide nanoparticles coated with chitosan were synthesised using the method of partial reduction of Fe^+ in the presence of chitosan. The structure of the synthesised" product as well as morphology of the product were examined referring to XRD spectrum and SEM photos. The obtained magnetic iron oxide nanoparticles coated with chitosan were used to remove arsenic from water. The study results showed that the synthesised product can be used to efficiently eliminate arsenic from ground water.
