Chitosan va cac che' phii'm tu n6 dil dli<;1C nghi,m cuu M bilt kim lo",i trong nliOc qua vi~c t",o phuc. Trang lu~n van dil dung chitosan nhli mi)t tac nhan hilp phy cho vi~c tach lam giau cac ion kim lo",i nang-di)c: d6ng, kern, cadimi ~a thUy ngan trong nliOc va bliOC d:l.u nghien cuu kha nang bilt kim lo",i cua chitosan dung ky thu~t phiin tich kich ho", t notron.
T6c di) hilp phy cua chitosan d",t gia trj can bilng sau khi khuily 90 phUt. Chitosan hilp phy thUy ngan cao nhilt, thilp d:l.n Mn cadimi, d6ng va kern, cac ion kim lo",i ad",ng mu6i sulphat hilp phy tren chitosan cao nhilt, thilp d:l.n de'n nitrat va clorua.
pH cua moi trlii1ng c6 anh hliang dang kEl Mn qua trinh hilp phy ion kim lo",i cua chitosan. pH t6i l1u cho qua trinh hilp phy cua chitosan la tu 4-6. H~ so' phan b6 cua cac ion kim lo",i tren chitosan theo pH moi trlii1ng cung dli<;1C khiio sat va tinh toano Dil khiio sat dung amonisulphat nhli mi)t tac nhiin di~u ki~n h6a M tang kha nang hilp phy cua chitosan.
Chitosan di~u che' theo phlietng phap dj thEl (heterogeneous hydrolysis) voi cac muc d~axetyl h6a khac nhau (70-99%) khOng anh hliang nhi~uMn qua trinh hilp phy.
Qua trinh hilp phu cua chitosan trong dung djch chilt di~n Iy la nliOc, la mi)t qua trinh tach giua 2 pha long va dn. Cac khiio sat cho thily qua trinh hilp phy cua chitosan tuan thea dlii1ng hilp phy dilng nhi~t Langmuir, dil tinh toan dli<;1C Mng so' can bling hilp phy cac ion kim lo",i thuy ngan, cadimi, d6ng va kern cua chitosan tli<1ng ung la: 6,72: 12,58; 16,33 va 20,95.
Dil khiio sat va tinh toan lli<;1ng chitosan c:l.n thie't dEl hilp phy he't cac ion thUy ngan, d6ng, kern va cadimi trong 50ml dung djch c6 n6ng di) 2glL.
Nhung khao sat trong lu~n van nay da lam r6 them rilng khii nang hilp phy cua chitosan voi tung ion kim lo",i la khac nhau. Qua trinh hilp phy c6 chQn IQc cua chitosan cho thily mi)t khii nang sli dyng chung nhli mi)t tac nhan tach va lam giau, phyc vy cho nhu c:l.u phan tich cac kim lo",i nang-di)c trong moi trlii1ng nliOc. Trong phan tich kich ho", t natron vi~c tach va lam giau trlioc khi chie'u x'" c6 y
Dai HocEd Lat· 2002
nghla quan tn;.H1g vi h~n che qua trlnh tiep xuc va lam vj~c vai
phOng X(I. Hi~u suat hap ph~ eua ehitosan doi voi d6ng, Hm, eadimi va thuy ngiln d(lt tren 98%.
Cae ko't qua philn tieh nh;j.n duqe eho thay doi voi cae mau nuoe b~ m~t eua cae h6 tren dja ban Da L(lt co ham luqng d6ng, kem, eadimi va thuy ngiln thap so voi nguang eho phap. Nuoe thai eua cae nha may va nuoe fio'ng khu vye khu eong nghi~pciing co ham luqng duoi nguang eho phep.
Chitosan la mi)t polyme tu nhien ma lqi feh eua no co nhi~u m~t phai ehu '1. No khong nhung giup eho vi~e philn tieh thii'm dinh moi truong ma con trye tio'p tham gia vao qua trinh xu 1'1 va bao v~ moi
tntang. Do do, myc dich va I1Qi dung cua lu4n van nay la khao sat
cae dae trung hap ph~ eua ehitosan ung d~ngky thu;j.t philn tieh h(lt nhiln eho cae doi tuqng moi truong, dong gop vao vi~e danh gia va lam giam nguy ea ti~m iln eua cae kim 10(li n~ng-di)e anh huang do'n
moi tntang sinh thai, moi truang song cua cQng d6ng. II. Kie'n nghj:
Ciln tio'p t~e cae nghien euu M khao sat cae dae trung hap ph~
ch9n 19C cac ion kim lOf;li trong nUdc cua chitosan. Nghien cuu cae
hqp chat duqe bio'n tinh tU ehitosan co cae nhom ehue d~e thu chi hap ph~ mi)t hOae mi)t vai ion kim 10(li, ung d~ngeho ky thu;j.t tach va lam giau trong philn tieh kfeh hO(lt natron.
Nghien euu eho' t(lO ehitosan d(lng h(lt eilu co kich thuoe thich hqp dung eho ky thu;j.t hap ph~ va giai hap ph~tren ei)t.
Tio'p t~e cae khao sat M dua ra qui trinh ehuii'n eho philn tieh kieh hO(lt natron xu 1'1 hoa truoe khi ehio'uX(I.
Tio'n hanh cae thi nghi~m tren di~n rling dung ehitosan xu 1'1 kim 10(li nang-dQe trong cae ngu6n nuoe thai.
Doi Hoc Dtl Lat 2002 2.0 1.0 1.6 AI 28 1.4 1.2 AJ·4\ 1.0 1 600 Mn·5lj 600 511 t-eV 1 ens ~l<l24 OJ, 400 Mg27 1 1 t l'b-24 200 Ji-_I t .~ -t·+ --- ----oj 0.0 0.B605 "V 4092
Ph5 Chitosan chi€u x~ 4 phUt, M nguQi 3 phUt, do 100 giii.y
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Ph5 Chitosan chi€u xa 20 giG, M nguQi 3 ngay, do 30 phUt
Lilli" udu TlwcsfJ-Jim hoc 5X
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