Khảo sát phương pháp xử lí tăng khả năng hấp thu các ion kim loại nặng trong nước của khoáng bentonite việt nam

DAI HOC QUOC GIA HA NOI TRUING DAI HOC KHOA HOC Tl/NHIEN ^ : ) : ;J: ^ ^; ^ Jj: ^' -.'^ -N ^ ^ ^ -1^ ^ ^ ^ :i^ ^ ^ BAO CAO DE TAI KHAO SAT PHUONG PHAP XlTLI L A M N A N G HAP T H U CAC TANG KHA ION KIM LOAI NANG TRONG NUdc CUA K H O A N G BENTONITE VIET NAM Ma sd: Chii tri de tai: PGS TS Ng6 Sy Luang Can bg phdi hgp: TS Than Van Lien ThS Ha Van Van ThS Pham Van Tien CN Nguyen Thuy Mai DAI HOC Q U O C GlA HA NOi TPUNG TAt^ THOr.'G TIN THO VlFN DT J4 t Ha Noi 2005 PHAN L BAO CAO TOM TAT DE TAI BANG TIENG VIET Ten detai: Khdo sdt phuang phdp xir ly ldm tdng khd ndng hdp thu cdc ion kim logi ndng nUdc ciui khodng bentonite Viet Nam Ten tieng Anh: Research of treatment method to improve the ability of absorption for heavy metal ions on Vietnamese bentonite Chu tri de tai: PGS TS A^^^ Sy Luang Hgc ham, hgc vi: PGS TS Dan vi cong tac: Khoa Hod hgc Tel: 8241169 Cac can bg tham gia de tai: TS Than Van Lien Thac sy Ha Van Van Thac sy Pham van Tien CN Nguyen Thuy Mai Muc tieu va ngi dung nghien cuu: Bentonite la loai khoang set tu nhien, cd cau true Idp, cd dicn tfch be mat Idn nen cd khci nang hap thu tu m6i trudng nudc nhieu chat v6 ca va huu co Vl vay bentonite dugc ung dung nhieu ITnh vuc cd lien quan den kha nang hap thu cua no: xu li moi trudng, lam sach cac chat Idng khoi cac tap chat, che dung dich khoan, lam chat don Nudc ta cd triT lugng bentonite tuong ddi Idn, gdm mot sd mo nhu: Di linh - Lam Ddng, Thuan hai - Binh thuan, v.v Theo danh gia sa bg ham lugng montmonllonite khoang bentonite cua nudc ta kha thap Vi vay viec nghien cuu cac phuong phap lam tang ham lugng montmorillonite, ddng thdi hoat hoa de lam tang kha nang hap thu cua loai vat lieu nluTm muc dich tang kha lulng su dung ngudn tai nguyen phuc vu cho cac nganh kinh te qudc dan la mot van de rat dang dugc quan tam Mot nhung ung dung quan trgng cua khoang bentonite la sir dung nd lam vat lieu hap thu ion kim loai nang ITnh vuc xu If n^oi trudng nude Do vay, viec nghien cuu cac phuong phap hoat hoa lam tang kha nang hap thu eua bentonite ddi vdi cac ion kim loai nang la mdi quan tam cua nhieu nha khoa hgc va ngoai nude Bentonite cd mat dat, cd kha nang hap thu nen nd hoat dons nhu cac ludi loc tu nhien Khi nudc tham qua cac Idp dat thi bentonite giiTr lai cac ion kim loai \'a cac chat huu CO Vi vay, bentonite tu nhien bao gid cung da chi'ra sfin (du ft hoac nhieu) mot lugne nhat dinh cac chat da bi hap thu va vice loai bd cac chat de lam tang kha naiio hap thu cua bentonite trudc kin sudung la nhiem vu quan trgng De lam tang ham lugng ciia montmorillonite khoang bentonite, ngirdi ta thudni sir dung cac phuang phap tuyen khoang va phuang phap thudng dugc sir dung la tuyen trgn^ luc Hien cd mot sd phuang phap mdi dugc ap dung, vf du nhu tuye'n bang xyclon De hoat hoa lam tang kha nang hap thu cua bentonite, ngudi ta thudng su dung mot sc phuong phap sau: - Phuang hoat hoa bang nhiet: Dicing nhiet cao de loai nudc hap phu, loai cac cha huu ca khoi khoang bentonite - Phuang phap hoat hoa bang dung dich kiem: Dung dung dich kiem cd ndng thfcF hgp de xu If khoang bentonite - Plurang phap hoat hoa bang dung dich axit vo ca: Dung dung dich axit v6 co (thudng la axit sunfuric, axit clohydric) cd nong thfch hgp di xu If khoang bentonite Ccic phuang phap hoat hoa ndi tren dugc su dung mot each thfch hgp theo phfin, ham lugng montmorillonite bentonite va dac biet la thugc vao muc dfch sii dung Trong dd phuang phap hoat hoa bang cac dung dich axit sunfuric la dugc su dung nhieu nhai va cd hieu qua nhat 4.L Muc tieu nghien cuu - Ddi tugng nghien cuu la bentonite vung Di Linh - Lam D6ng va vising Tuy Phong Binh thuan Day la nhung vising co khoang bentonite co tru lugng thugc loai Idn nhat nude ta hicn - Tim phuoug phap thfch hgp nang ham lugng montmorillonite bentonite - Tim dieu kien tdi iru cho qua trinh hoat hoa bang axit nham lam tang kha nang hap thu ciia bentonite ddi vdi cac ion kim loai nang mdi trudng nirdc Nhu vay san pham bentonite sau hoat hoa nham muc dfch xu If moi trudng: tach loai cac ion kim loai nans tu moi truoug nuac, - Khao sat kha nang hap thu cac ion kim loai nang ciia bentonite dung dich nudc 4.2, Ndi dung nghien cuu - Phan tfch phfin khoang va phan hoa hgc cua man bentonite nghien ci'ru - Kluio sat phuang phap lam sach va hoat hoa bentonite bang axil H^SOj cd ndng va dieu kien thfch hgp de lam tang kha nang hap thu cac ion kim loai nang tromz nude - Khao sat kha nang hap thu ciia bentonite sau xu ly va so sanh vdi kha nang hap thu ciia bentonite nguyen khai chua xu ly Ciic kel qua da dat dugc g Anh hudng cua cdc chdt dien li moi trudng nudc Chuang II Phuang phap nghien cu*u 2.1 Phuang phap hoat hoa quang 2.2 Phuang phap phan tfch phan hoa hgc ciia bentonite a Xdc dinh hdm SiO^ b Xdc dinh hdm FeiO:^ c Xdc dinh hdm luang AFOj d^Xdc djnh MgO vd CaO 2.3 Phuo'ngphdp xdc dinh sdt, mangan dung dich a Phuo'ng phdp trdc r/uang xdc dinh ndng ion sdt dung dich vdi thudc thir thioxianat b Xdc dinh mangan bdng phuo'ng phdp trdc c/uang 2.4 Phuang phap xac dinh hap dung cua cac ion kim loai tren bentonite Chuang III - Ket qua va thao luan 3.1 Khao sat cac yeu td anh hirdng den kha nang hap phu cac ion kim loai nang moi Irudng nirdc cua bentonite 34.FF Anh hudng cua pH dung dich dcdi khd ndng hdp phu Fc'^ vd Mm^ tren bentonite 3.1.2 Anh hudng cua thdi gian khuay tdi sUhdp phu Mm^vd Fc'^ tren bentonite 3.1.3 Anh hudng ciia ndng chdt bi hdp phu 3.F3 Anh hudng ciia ty le the tich ciui dung dich hdp phu vd khdi lugng be/itonite 3.2 Mau khoang bentonite sir dung de nghien cuu 3.3 Khao sat qua trinh hoat hoa bentonite 3.3.1 Logi axit 3.3.2 Ndng axit 3.3.3 TvleRIL 3.3.4 Nhiet hogt hod 3.3.5 Tdc khuay tron 3.3.6 Thai gicm hogt hod Ke't luan Tai lieu tham khiio MOiDAU Bentonite la loai khocing set tu nhien, cd ca'u tnic Idp, co dien tfch be mat Idn nen cd kha nang ha'p phu nhieu chat vo ca va hxiu ca [1,51 Vi vay bentonite la loai vat lieu dugc ii'ng dung nhieu ITnh vuc khac Nudc ta cd tru lugng bentonite tuang ddi Idn, d mot sd mo nhu: Di linh - Lam Dong, Thuan hai - Binh thuan, v.v Quang bentonite Viet Nam cd ham lugng montmorillonite kha thap, chat lugng kem, do viec nghien cuu lam tang chat lugng de cd the sir dung tdt han ngudn lai nguyen de phuc vu cho cac nganh kinh le qudc dan la mdt va'n de ra't dang quan tam De tang cudng cha't lugng cua khoang bentonite, cd hai van de can dugc tien hanh: - Lam tang ham lugng montmorillonite khoang bentonite Giai doan thudng ditgc tien hanh bang cac phuang phap tuyen khoang th6ng thudng, chu yeu la phuang phap tuyen trgng luc - Hoat hoa khoang bentonite sau lam giau de tang kha nang hap phu cua no De hoat hoa bentonite, ngirdi ta thudng sir dung cac phuang phap hoat hoa nhict, hoat hoa bang dung dich kiem, hoat hoa bang dung dich axil, dd phirong phap hoat hoa bang dung dich axit vo ca, nlur H2SO4, HCl dirge sir dung ph6 bie'n nhat De danh gia chat lugng bentonite sau lam giau va hoat hoa, phuang phap phd bie'n la danh gia qua kha nang hap phu cua bentonite ddi vdi cac ion kim loai nang dung dich nirdc Dong tlidi muc dfch sir dung bentonite lam vat lieu hap phu tach loai cac ion dd khdi m6i tnrdng nudc gdp phfin chdng nhiem m6i trudng cung la mdi quan tam hang dau ddi vdi cac nha nghien cuu nirdc va tren the gidi ITnh vuc [5-8] Xuat phat tu y tudng do, chung t6i dat van de khao sat kha nang lam giau va hoat hoa bentonite bang phuong phap axit, cu the la H2SO4 Muc tieu nghien cuu dirac dat de tai nghien cuu la tim dugc phuong phap xu If lam tang kha nang hap phu cua bentonite ddi vdi cac ion kim loai nang in6i tnrdng nudc Cac ngi dung nghien ci'ru dugc dat de tai nghien cuu la: - Phan tfch phan khoang va phan hoii hgc ciia mau bentonite nghien cuu - Khao sat phuong phap lam giau dc tang ham lugng montmorillonite khoan" bentonite - Khao sat phuang phap xu ly axit H.SO^ cd nong va d dieu kien thfch hop de lam tang kha nang hap phu cac ion kim loai nang nudc - Khao sat kha nang hap phii cua bentonite sau xu ly va so sanh vdi kha nang hap phu cua bentonite nguyen khai chua xu ly Cac thf nghiem nghien cu*u ciia de tai dugc tien hanh d phong thf nghiem Vat lieu mdi thugc bg mon Hoa Vo ca - Khoa Hoa hgc - Tnrdng DHKHTN - DHQG HN va phdng thf nghiem thugc Trung tam Xu If quang - Vien C6ng nghe Xa - Hiem thugc Vien Nang lugng nguyen tir Viet Nam Kinh phf cua de tai dagc DHQG HN cap qua de tai cap DHQG mang ma sd Chung t6i xin chan cam an DHQG HN da cap kinh phf de chung toi hoan cac ngi dung nghien cuu cua de tai CHUONG I GICJI THIEU VE BENTONITE I.GI6I THIEU VE BENTONITE LI Thanh phan hoa hgc cua bentonite Bentonite la loai khoang set tu nhien, co phan chfnh la montmorillonite Vi vay cd the ggi bentonite theo phfin chinh la montmorilonite Cong thuc dan gian CLia montmorillonite ALOv4Si02.nH20 I'mg vdi nua te bao don vi cau tnic Cong thuc ly tudng cua montmorillonite la SiyAl402o(OH)4 cho mot dan vi ca'u tnic Tuy nhien phfin cLia montmorillonite luon khac vdi phan bieu dien ly thuyet cd sir thay the ddng hinh cua cac ion kim locai nhu Fe"*"", Fe^"^, Mn""" vao vi trf cua Si"*"" tu dien Si04 va ciia Al"^^ bat dien AlO^ Nhu vay phfin hoa hgc montmorillonite, ngoai sir co mat cua Si va AI, ta cdn iha'yeo sir xua't hien ciia cac nguyen td khac nhu: Fe, Zn, Mg, Na, K, v.v , ty le ALQvSiO.tu 1:2 den 1:4 Ngoai phfin chfnh la montmorillonite, bentonite chua mot sd khoang set khac nhu liectorit, saponit va mgl sd khoang phi set: canxit, pirit, manhetit, cac mudi kicm va mot sd cha't huu ca khac 1.2 Cau tnic cua montmorillonite Trong c6ng thi'rc ly lirdng cua montmorilonite, cac nguyen tu Si nfim d mang tu dien, cac nguyen tu Al nam d tam mang bat dien (trong tnrdng hgp mang nhom silicat la trung hoa dien) va cong thi'rc khai trien cua nhu sau hinh O o ^ ^o o : Si1ic o o O : O xI Hinh! Cong thirc khai trien khong gian ciia montmonllonite li tirdng Do montmorillonite cd cau tnic 2:1 dang diocta nen cau tnic lap montmorillonite da dugc hinh tir hai mang tir dien lien ket vdi mot mang bat dien d giua, tao nen mgl Idp nhdm silicat vdi cac khe trdng d giua Cac cation co kha nang trao d6i bi hydrat hoa va nudc bi ha'p thu cd the chie'm cho d cac khe trdng giua cac lap nhom sislicat Chieu rdng CLia khe trdng giiJa cac Idp cau tnic ca ban ciia montmorillonite la 9,6 A, chidu rong dd cd th^ bi thay ddi ft hay nhieu thugc vao sd lugng, ban chfi't cation trao doi va lugng nude hap thu, thudng c6 the den 15 A So d6 ca'u tnic khong gian mang lircri ciia montmorillonite, dugc trinh bay tren hinh 2, la mgl cau tnic trung hoa dicn Neu Si"^^ ti'r dien hay AL"^ bat dicn bi thay the dong hinh bdi cac cation duong thap hon thi cac phan mang dd tfch dien am Dien am cao hay thap thugc vao sd lugng va ban chat cua cac cation thay the Dien tfch am cua mang se dugc bi^i tri^r bang cac cation mang dicn tfch duang Na"^, K"*^, Ca^"^, Fe""^, Mn""^ d khoang kh6ng gian giua cac Idp Nhu vay kha nang trao ddi cation cua montmorillonite la tuang dirang vdi dien tfch ciia cac Idp Ci* i i o o O.Va « SLLLc J h o j c trs.c ^ i -f nW^c nhom Hinh Sa dd cdu true khong gian nigng ludi cua montmorillonite 1.3 Cac kha nang bien tinh Bentonite 7.3.7 Bien tinh giir nguyen cdu true cda lop aluniinosilicat Dac trung ca ban cua bentonite la tfnh chat trao ddi Tfnh chat dd cd dugc la sir thay the ddng hinh Si'*'' bang Ah^"*" mang ti'r dien va Ah^^ bang Mg""" mang ludi bat dien lam xua't hien dien tich am mang ludi cau true Kha nang thay doi manh hay yeu phii thugc vao lugng dien tfch am be mat va sd lugng ion trao ddi Neu sd lugng dien tfch am be mat cang Idn, sd lugng cation trao ddi cang Idn thi dung lugng trao d6i cLia bentonite cang Idn Kha nang trao ddi ion ciia nhdm silicat phu thugc vao dien ti'ch va ban kfnh cation trao doi Dien tfch cation cang thap thi cang de trao ddi hon cation dien tfch cao Me^>Me2-^>Me^L Ddi vdi Ccic cation ciuig dien tfch, ban kfnh cang nho thi kha nang trao d6i cang Idn cd the xap xe'p theo trat tu sau Li > Na > K > Cu > Fe > Al Tuy nhien kha nang trao d6i cua nhom silicat chii yeu van phu thugc vao dien tfch am be mat va luanc dien tfch am iron" manti ludi Bentonite ^6m be mat Irons va be mat ngoai Kha nang trao doi ion be mat ngoai phan anh kfch thudc tinh the, phu thugc vao kfch thudc tinh the, phu lhuoc vao su di'rt gay lien ke't va khuyet tat be mat Kfch thudc hat cang nhd thi kha nang trao doi cang Idn Kha nang tiao d6i be mat phan anh lugng dien tfch am mang ludi va khii nang hfip phu cua bentonite No phu thugc vao lugng cation bu tri^r mang ludi Sd lugng cation cang Idn ihl kha nang trao dcii cang Idn Dung lugng cation dao dong lir 80 -^ 150 mgdl/lOOg Dung lugng trao ddi anion dao dong tu 15H-40mgdI/100g Ngoai ra, sir trao doi ion ciia bentonite lien quan den sir thay the cac nguyen lir hydro cac nhdm hydroxyl ciia montmorilonite Theo mot sd nghien ci'ru, dinh ciia cac tir dien Si04 hirdng phfa ngoai ciia Idp cfi'u true O dinh cac nguyen tir ciia oxy bi thay the bdi cae nhom hydroxyl va cac nhom dam nhiem viec tri lien ket yeu giua Ciic Idp va gop phfin vao su can bang dien ti'ch Trong montmorilonite co cac nhdm hydroxyl nfim d dinh ciia cac bat dien AlO^ Trong sau dinh ciia bat dien co hai dinh la nhom OH cdn bdn dinh la oxy( hinh3) OH OH / 0 I I I I Al \ 0 I' II H d 1 6^-A/ in / \ ? f Hinh Vi ni ciiu ciic nlioni OH c6 rroiii; maii;.^ luai can Hue ciia l)eiiionlfe Trong dd nhdm hydroxyl ciia lien ket Si-OH (1) kh6ng co kha nang trao doi hydro, nhdm hydroxyl lien ket Al - 0H(11) cd tfnh axit yeu nen kha nang trao doi yeu Nhdm hydroxyl lien le't Si-0-Al(l 11) cd tfnh trao ddi manh nen cd tfnh quyet dinh den dung tfch trao doi cation H"' 1.3.2 Bien tinh ldm bien ddi cdu triic Idp aluniinosilicat Khoang bentonite tu nhien chi'ra nhieu tap chat nhu cac mudi can xii (CaCOO, dolomit (MgC03), mot sd oxyt: FcjO^ , FeO, Ti02, v.v va cac tap chat khac Qua trinh hoat hoa bentonite dugc thuc hien bang each dimg kiem hoac axit hoa tan mot sd oxyt luang tfnh nhu AI2O3, Fe203, de tao tren be mat set nhung 16 xdp va trung tam hoat dong, Viec sir dung nong kiem hoac axft cao cd kha nang hoa tan nh6m oxyt lam thay doi cau true bentonite 1.4 Dac tinh cau true bentonite va kha nang hap phu Chfnh V] bentonite co ca'u tnic Idp va phan tan cao nen no cd cfiu true xdp phuc tap va be mat rieng Idn Ca'u tnic xdp anh hudng rat Idn de'n tfnh cha't hap phu ciia cac cha't, dac iiung ciia nd la tfnh chat chon loc chat bi hfip phu Chl co phan tir nao cd dudng kfnh dii nhd so vdi 16 xdp thi mdi chui vao dugc de tham gia va qua trinh ha'p phu Dua vao dieu ngudi ta cd the tien hanh hoat hoa cho co the diing bentonite lam vat lieu tach chat Day cung la diem khac giua bentonite va cac chat ha'ji phu khac Nhd du dicn tfch tren cac nguyen tir ciia cac nut mang tinh the eho nen bentonite la mot chat hfi'p phu phan cue va vl vay no se uu tien hfip phu cac chat phan cue Tuy nhien, bentonite van cd the hap phu cac chat khong phan cue lire van der Walls va tuang tac hfip phu chii ye'u la tuang tac cam ung Be mat bentonite eo dien tfch tuong ddi Idn bao gdm be mat ngoai va be mat Be mat bao g6in be mat ciia cac lap nhom silicat chdng len va dugc ngan each bang cac cation kim loai den bu dien tfch tren be mat Idp bentonite Be mat ngoai dugc xac dinh bdi be mat ciia cac mao quan chuyen tiep Cac mao quan dugc lao nen su tiep xiic ciia cac hat bentonite va cd kfch thudc khoang 40 A -^ 90 A Dien tfch ciia be mat ngoai phu thugc vao kfch thudc cac hat bentonite, hat cang nhd thi dien tfch be mat ngoai cang Idn Kha nang trao ddi ion Idn cung vdi kha nang hfip phu tdt ma ta cd mgl loai vat lieu xir ly kim loai nang ra't hieu qua tir bentonite II NHUNG UNG DUNG CHU YEU CUA BENTONITE Do cd kha lulng hfip phu lot nhieu cha't v6 co va hiru co, nen bentonite cd nhieu Uim dung kha da dang va phong phii sir phat trien ciia xa hgi 2.1 Sudung bentonite lam chfit hap phu a Phuong phdp trdc quang xdc dinh ndng ion sdt dung dich voi thudc thu thioxianat Do ion Fe"^" de tiio vdi ion SCN theo phiin ung Fe-'" + SCN' - Fe(SCN) , Phirc tao cd mi\u dd mau cd cue diii hfip thu d budc song X = 500 nm, hfip thu quang ty le vdi ndng ion Fe "; Cd mfit amoni tioxianat 20%, b Xdc dinh mangan bdng phuong phdp triic quang Dua viio phiin irng oxy hoit Mir" thimh Mn04" iheo phim irng sau: Mn-" + 5/2 S2O,- + H.O = Mn04 + 5S04 -H 16 H" Phim irng xiiy m6i trudng axit H2SO4, HNO3 vdi sU xiic tac ciui Ag" Ion Mn04' dugc Uio dung dich co mau dam, co the ABS de xiic dinh ndng cua nd duii viio dudng chufin d budc sdng X - 523nm 2.4 Phuong phiip xac dinh hfip dung ciia cac ion kim lo;ii tren bentonite Dung dich ciui ciic ion kim loai co n6ng khiic dugc chufin bi bi'mg each hoii tan mudi d diing linh the viio uirdc cfit r6i axit hoii bang axit sunfuric de'n pH = Bentonile dugc can vdi khoimg 2g cho vao ciic binh non chi'ra 50 ml dung dich Sau can nuUi cfin xac dinh fim ciui mfui de tinh chfnh Xiic lugng benlonite cho viio Ciic binh dugc day kfn cho \ao nuiy klc vdi tdc 140 \ong/phut thc^i gian 3h Siiu lfiy lgc tren pheu thuy tinh \'di giiiy loc bfmg Xiinh Ciic dung ciich dfiu \'ii ciic dich loc tuong irng dugc deni plu'm u'ch trac c|Uiing theo phuong phiip neu lien Thf nghiem ticn himh d nhiet phdng Lugng ion kim loiii dugc hfip phu bdi bentonite, dugc xiic dinh tir sir chenh lech nong trudc va sau hfip plui Dung lugng hfip phu dirge tinh theo cong thirc siiii a=||Co-CLV|/m Trong dd: a lii dung lugng hfip phu ciia bentonite; CQ la n6ng ciia ion kim loai dung dich dfiu; C la n6ng ciia ion kim loiii can bfmg dugc thiet lap; m la khdi iirgim benlonite dimg de hfip phu; V Iii the tfch dung dich kim loiii IS PHAN III - KET QUA VA THAO LUAN Phfin thuc nghiem nghien ciiu bao gom ngi dung sau: - Khao sat xac dinh dieu kien hfip phu tdi uu ciia bentonite moi tnrdng nudc ddi vdi mot sd ion kim loai nang Nghien eu'u niiy nham muc dfch xac ding dugc dieu kien tdi uu cho qua trinh danh gia chfit lugng bentonite sau hoiit hoa va diinh gia khii nang sir dung betonite lam cha't hfip phu xiia If m6i tnrdng - Khiio Siit qua tiinh lam giau vii hoiit hoa bentonite nham xac dinh dugc dieu kien tdi uu cho qua trinh ddi vdi khoiing bentonite Dilinh Lam Dong Sau day chung toi xin Ifin lugt trinh biiy cac ngi dung nay; 4.1 Khiio sat ciic yeu td anh hudng den kha nang hap phu cae ion kim loai nilng moi trudng nudc ciia bentonite Chiing loi da sir dung bentonite Iii loiii khoiing bentonile Dilinh Lam Ddng da dugc chfit hoii nhu sau: bentonite sau dugc liim giau bang thiet bi xyclon, dugc hoiit hoa bang H2SO4 15% (d nong benlonite dugc hoiit hoa tdt nhfii, cho dung lugng hfip phu tdt nhii't) vdi thdi gian hoiit hoii lii 2h, ty lc R/L = :3, nhiet hoat hoii la 85-95*^0 Hiim lugng montmorillonite khoang bentonite niiy Iii > 70% Dc khao sat khii nang hfip phu, chiing toi sir dung hai ion kim lo.ai nilng lii Mn~" va 4.1 F Anh hudng cua pH dung dich den khd ndng hdp phu Fe~^ vd Mn~^ tren bentonite Pha Ciic dung dich Mir" va Fe"" nong Iii 3g/l vii 0,9 g/1 co cac gia tri pH xac dinh la 2,0; 2,5; 3,0; 3,5; 4,0; 4,5 va Lfiy biiy binh non dung tfch 250inl, theo viio mdi binh 2g bentonite, 50 ml ciia mot ciic dung dich co pH khiic tren Day kfn mieng binh va lien hanh hic vdi tdc 140 vong/phiit, ddieu kien nhiet phdng, thdi gian h Sau hlc, Igc dung dich bang gifiy Igc bang xanh va tien hanh xac dinh n6ng ciui ciic ion Mir" vii Fe'" dich lgc, hiip dung eiia bentonite dugc xac dinh theo cong thirc: a = ( CQ - C).V/m Ket quil thuc nghien dugc dua nen bang Bdng /• Sir phu thugc hdp dung bentonite ddi vdi Fc^ vd Mn~^ vdo pH cua dung dich pH 2,0 2,5 3,0 3,5 4,0 4,5 5,0 Hfipdung ddi vdi 8,7 10.5 12,6 13,8 14,3 14,2 13,7 Fe'^ mg/g Hfipdung ddi vdi 10.2 15,4 19,7 23,5 26,7 23,1 19,4 Mir"*", nm/ii 19 TiJ* ke't quii da trinh bay tren bang co the thfiy rang, pH dung dich thay d6i tir 2,0 den 5,0 hap dung ciia bentinit ddi vdi Fe"^ va Mn"" deu cd dang bien ddi nhu Hap dung ciia bentinit ddi vdi Fe^"^ va Mn^"^ tang len pH tang tir 2,0 den 4,0, diit cue dai tai pH nay, sau dd giam xudng tang pH tiep Ket qua niiy cung phii hgp vdi ke't qua cira cac tac gia cong trinh [6] Nhu vay pH tdi uu cho qua trinh hfip phu hai ion Fe"^" va Mn^''"tren bentonite tir moi tnrdng nudc lii 4,0 4.7.2 Anh hudng cua thdi gian khuay tdi sir hdp phu Mtr^vd Fc'^ tren bentonite Tien hanh thf nghiem nhu sau: pha ndng ciia Mir" va Fe'^" vdi nong la 3g/l va 0,9 g/1, tien hanh thf nghiem: ddi vdi mdi thf nghiem lay binh non, can vao m6i binh 2g bentonite da hoiU hoii, dd viio mdi binh 50ml dung dich Mn'" hoac Fe'" vdi n6ng nen, chinh ve pH = 4, day kfn cho vao nuiy Ific vdi tdc 140 vdng/ phiit thdi gian khuay khac nhau: 0,5 ; ; 1,5; 2; 2,5; 3; 3,5; h sau nhQ-ng khoimg thdi gian iren, lay dung dich lgc vdi gifiy lgc bang xanh va lien hanh Xiic dinh nong ciui dich lgc, hfip dung ciia bentonite dirge xiic dinh theo cong thiic: a = (CQ - C).V/m Trong dd, a la hfip dung (mg/g); CQ - nong ciia dung dich ban dfiu trirdc lac; C - ndng ciui dung dich sau lac; in- khdi lugng ciia bentonite Ket quii khiio siit sir phu thugc giua hfip dung ciui Mn'^ vii Fe"" vdi thdi gian Lie khiic dugc dua bang va ciic hinh va Bdng 2: Sd lieu hdp dung cua Mn''' vd Fe''' vdi thdi gian lac khdc nhcui Tlidi gi an khiiay(h) 0,5 1.5 2,5 3,5 Mn-^ 2.53 2,31 2.1395 2.046 1.98 1.925 1.914 1.92 15.98 18.53 21.5 23.85 25.85 26.87 26.9 26.91 0.58 0.492 0.417 0.3628 0.324 0.3244 0.324 7.99 10,2 12.07 13.43 14.4 14,39 14.4 nong can bring (g/1) hap 1 1 Fe^^ dung (mg/g) nong can 0.696 bring (g/1) hap dung 5.1 (mg/g) 20 • lico [(t:i(J7~l "5 E 22 -J 00 05 10 15 20 25 30 35 ':0 45 T h o i j;i.in h Hinh 4: Dd thi hieu dien sir phu thugc hdp dung ciia Mm^ tren bentonite vdo then gian lac 0 S 20 i 30 3S 40 i b T h o i g 1,1II h Hinh 5: Sir phu thugc cua hdp dung Fe~^ tren bentonite vdo thai gian lac Nhan xet: Tir d6 thi hinh vii hinh co the thfiy rang: Khi thdi gian thay d6i tir -=3h, lugng Mn^"; Fe'" bi hfip phu tang theo thdi gian Sau 3h, dung lugng hap phu khong ddi, dill gia tri cue diii Qua trinh hfip phu niiy la phan i'mg can bang trao ddi ion: H^(bentonite) + Mu"" (Fc'"),^, o H".,, + Mn-"(Fe-")(bentonite) (I) Su chenh lech hoii the ciia Ciic ion ngoai dung dich va cac khe xdp tron" bentonite la dong luc thiic dfiy quii trinh trao doi ion xiiy Liic dfiu, n6ng ion kim loai trone dung dich cao, can bfing chuyen dich sang phiii Den mot thdi gian nao dd (3h), 21 hoa the'cua cac ion (H", Mn^", Fe"^) vii ngoiii bentonite bang nhau, phim I'rng diit den giii tri can bfmg, dd lugng ion kim loiii bi hfip phu lii cue dai d nhiet va ndng khao sat Ngoai ra, cac ion kim loai cdn bi hap phu vat ly nhung khe xdp trung hoa dien tren be mat bentonite Qua trinh dan gian la su khuech tiin ion lir dung dich vao 16 xdp chu'a nudc, lugng ion kim loiii eo the khuech tan viio nhung 16 xdp la mot hang sd d dieu kien ndng do, nhiet khiio siit Vay thdi gian 3h !a thdi gian ldi uu cho sir ha'p phu ciui Mn va Fe tren bentonite J Anh hudng cua ndng chdt bi hdp phu Pha dung dich M i r " va Fe^" cd n6ng khiic nhau, tien hanh hfip phu tren bentonite khoiing thdi gian 3h sau Xiic dinh dung lugng hfip phu, Ket quii khao Siit sir phu thugc giua hfip dung ciia Mn (11) dung dich tren bentonite viio nong Mn^" dugc dua biing vii hinh Ket quii khao siil su phu thugc giua hfip dung ciia Fe (11) dung dich tren bentonite vao n6ng Fc"" dugc dua rii biing va hinh Bdng 3: Sir phu thuoc cua hdp dung A vdo ndng Mif^ Mir" Q, g/1 0.5 0.25 Q,, g/1 A 3,86 2.88 1.94 1.03 0.29 0.04 O.OI 28.56 28.04 26.61 24.32 17.74 11.4 ihco 11611" M i i d l 0 • 15 N,)iii: ; d .111:, J ^l\ Hinh 6: Sir phu thugc ciia dung lugng hdp phu vdo ndng cdn bdng dung dich ddi vdi Mm^ 22 Bdng 4: Sifphu thugc cua hdp dung A vdo ndng Fc + U Co (g/1) 0.54 0.63 0.72 0.9 1.56 3.31 3.68 4.73 5.1 Q„ (g/1) A 0.13 0.17 0.23 0.33 0,65 1.64 2.78 3.58 4.2 10.85 11,45 12.25 19.62 20.05 25.64 26.04 26,64 26.8 I • A I h e o F e a 11 — 20 < 15 N(MIL; clo T L - d h c m b l i i - ( g / L i Hinh 7: Sir phu thugc cua hdp dung vdo ndng cdn bdng trudng hgp Fe''' Nhan xel: Tir ciic biing 9,10 vii ciic hinh 9, 10 co the' thity rfmg, dudng dfmg nhict trao doi hfip phu co diing dirdng Langnuiir: ii.b.C A n +b.C Trong dd: A lii hfip dung; a: lugng chfit bi phu cue diii hiiy hap dung cue dai phu thugc vao bim chfit chfit hfip phu, chfit bi hfip phu vii nhiet do; b: hiuig sd; C: ndng can bang Tir can bang iiuo ddi ion: H"(bentonite)+Mn-"(Fe""),^j H",^+Mn-" (Fe*^^)(bentonite) Sir triio d6i ion niiy plui thugc viio bim chfit bentonite, nhiet do, sir khuech tiin ion kim loiii, vii kfch thudc lo xdp tren be mat vat lieu, d nhung dieu kien khiio siit chi co nong ion kim loiii tluiy doi, tiro"ng ling vdi nong cfin bang hfip phu thay ddi Do dd: + Vdi nhung nong ion kim loiii nho (C nho) bC « , hfip dung lang tuyen ti'nh theo C theo mot thi dui^ng thfmg, bdi sir khuech Uin ciia ion kim loiii hfiu nhu khong bi bien doi 23 4- Khi bC dang ke vdi 1, nong imh hudng Idn den sir khuech tan ion kim loi;ii A tang theo C dang dudng cong + C Idn, ion Idp sonviit hoa kim loiii Idn, su* khuech Uin ion kim loiii viio 16 xdp bi hiin che Han nu'ii tdng lugng ion cd the trao ddi khdng vugi qiui tdng lugng ion bii trir cfiu triic mang bentonite Nhu vay C tang den mgl giii tri niio A se dat den mot gia tri cue dai, dd thi nfim ngang Tir d6 thi ta co hfip dung cue diii cua Mu""^ (5g/l) la 28,56mg/g, va 26.8mg/g ddi vdi Fe"" 4.F3 Anh huong cua ty le the tich cua dung dich hdp phu vd khdi lugng bentonite Tien hanh thf nghiem hfip phu tuong tu nhu tren, vdi ndng ciui Mir" l(g/l)va Fe~" la 0,443(g/l), cac budc lien himh tuong tu nhung vdi the tfch ciia dung dich hap phu thay ddi liim cho ty le V|/ni, ihiiy ddi, ket quii thuc nhiem dugc duii tren bimg va hinh 8,9 Bdng 5: Sir thay dot hdp dung A ddi vdi Mm^ vd Fe~^ vdi cdc ty le V,/m, khdc + 30 50 40 60 70 V, (ml) 10 20 80 Q„ (g/L) 0.44 0.442 0.417 0.442 0.442 0.442 0.442 0,442 0.443 A (ing/g) 6.19 9.98 12.9 15.5 17.9 19.9 20.9 21.8 21,8 V, (ml) 10 18 30 35 40 50 80 120 150 170 Q„ (g/L) 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0,99 0.99 A (mg/g) 4.37 7.24 11.8 13,2 14.5 17.2 22.8 26.1 27.2 27.2 + C A t Iheo V/m C u a M n < 100 V /„i Hinh 8: Sifphu thugc cua dung luo'ng hdp phu mg/g tren bentonite vdo ty lc V/m^ doi vdi Mm 24 —" - A 2* Iheo v / m cuaFe -, 22 20 18 16 § < 12 10 •iO 60 V /m Hinh 9: Su phu thugc cua hd'p dung mg/g tren bentonite vd ty le Vl/mr ddi vdi Fc'' Nhan xet: Tir hinh vii cd the thfiy rang, su hfi'p phu tang theo su tang the tich dung dich hfip phu, sau timg cham vii khong thay ddi d6 lii hap phu diit can bang Bdi vl, the ti'ch dung dich nho lugng ion dung dich ft, su hfip phu co xu hudng tang ciing vdi sir tang ciui the tfch dung dich, nhung den mot the ti'ch nao lugng ion dung dich cao hon nhieu so vdi lugng ion bi hfip phu Khi neu tang the tfch ciui dung dich thi dung lugng ciing kh6ng lluiy doi iiCra, dung lugng hfip phu diil gia tri cue dai Tir thi cd the thfiy luiig, vdi khdi luo'ng ciui bentonite Iii 2g, vii ndng ciui Mn^" va Fe-" la l(g/I) ; 0,443(g/l) ihi ty le V|/m, lot nhfit cho su hfip phu Ifin lugt la 75 vii 40 Tdm liii: dieu kien tdi iru cho qiui trinh hfip phu ciic ion Mir" \'a Fe"" tir dung dich nudc la: - pH dung dich tdi uu la 4,0 - Thdi gian lac: 3h - Ty le the tfch dung dich (ml)/ khdi lugng benlonite (g) (V|/m,,) de hfip dung dat cue diii (vdi khdi lugng ciia bentonite Iii 2g, ndng ciui Mn"" vii Fc"" la Ig/I ; 0,443g/l) hui lugl la 75 vii 40 4.2 Mau khoang bentonite sii dimg de nghien ciiu Cac miUi quang bentonite nghien ciiu dugc lfiy tir mo bentonite kiem thd Dilinh Lam ddng vii md bentonile kiem Tuy Phong - Binh Thuan Thimh pluin khoiing vat ciia cac mi'ui bentonile dd dugc Xiic dinh bi'mg phirong pluip nhieu xa XRD vii dirge chi d biing 25 Bdng Thdnh phdn khodng vdt cua cdc mdu bentonite Dilinh - Ldm Ddng (DL) vd Tuy Phong - Binh Thugn (TP) dung de nghien cuu Ham lugng cac khoang, % khdi lugng Kl hieu Caolinite Hydromica Clorit montmorillonite Thach anh Fenspat Gatit Canxit TP 5-7 8-10 5-7 10-20 30-35 15-19 ft 19-21 DL ft 10-12 5-7 40-50 10-12 10-12 8-10 ft Tir biing co the thfiy, md bentonite cua ta co chfit lugng thfip, ham lugng montmorillonite bentonite Tuy Phong - Binh Thuan chi nam khoimg 10-20% va bentonite Dilinh - Lam ddng viio khoiing 40- 50% Do khuon khd ciui dc liii nen cluiim t6i dat vfin de chi khiio sat bentonite Dilinh Lam ddng, la loiii bentonite kiem thd, co hiim lugng montmorillonite giau han 40-50%, khoiing bentonite kiem Tuy Phong - Binh Thuan cd hiim lugng montmorillonite ngheo han 10-20% chua dfii vfin de nghien ciru d dfiy Thimh phfin thimh phfin hoii hgc ciui quang bentonite kiem tho Dilinh - Lam ddng dirge diui rii d bimg Bdng Hdm hrgng cdc cdu tU chinh mdu bentonite Dilinh - Lcim ddng dung de nghien ciru Ham krgng cac can lu' chi'nh Lioiig man bentonile nghien cuu, % kho'i luong SiO, AUO, Fe,0, CaO 50,2 16J 7,5 3,50 • MgO Na.O + K , 1,2 2,30 4.3 Khiio sat qua trinh hoat hoa bentonite Qiui trinh hoiit hoii dugc thirc W\en nlur da neu d muc 2.1 Qua Irlnh hoiil hoa bentonite dugc lien himh bang phuong phiip sir dung axit vo co d Ciic ndng khac Khoang bentonite dugc iron vdi ciic dung dich axil cd ndng thay ddi vdi ty le riin/ldng (R/L) thfch hgp, dnn ndng den nhiet Xiic dinh dieu kien khufiy trgn manh thdi gian xiic dinh Sir tiich pha ran khoi pha long dugc thuc hien bang phuong phiip litng giin Bentonile siiu ho.it hoa dugc rira siich axit, dem phan cap hiit de lay huyen phil co ci'i'p hat < 40 micromcl (ty le thu hoi khoang 55-60'^.i) Phfin huyen phu 26 dugc Igc bang may lgc chan khong Sim pham dugc sfiy d nhiet lOO'^C, danh toi, nghien De xiic dinh dfic trung ciui sim pham, cac niiUi san pham sau hoiit hoa da dugc phan tfch phfin khoang bi\ng nhieu xa XRD va tien hiuih cac thf nghiem hii'p phu cac ion kim loi.ii nang dung dich nudc O day chiing toi tie'n himh kluio sal mot sd ye'u td cd kha nang anh hudng nhieu de'n chfit hrgng ciia bentonite: - Loiii axit dung de hoiit hoii - Ndng axit - Ty le R/L - Nhict hoiit hoii - Tdc khufiy Iron - Thdi gian hoiit hoa Sau day Ifin lugt trinh biiy cfic ket quii thu dugc Lord axit Trong de tai niiy cluing toi chi khiio sal qua stiinh hoiit hoii bang dung dich axit, khong kluio siit hoiit hoii bfmg dung dich kiem Theo cac tiii lieu tluim kluio, thfiy rang co the sir dung hai loai iixit: HCl, HNO3 va H2SO4 l\ty vay khuon khd de tai chiing toi chi khiio siit vdi tile nhan hoiit hoa la dung dich H2SO4 Theo mot sd liii lieu thu thap dugc thi sir dung dung dich kinh te han, hiui che dirge an mdn thiei bi vii ft doc hiii hon vl vdi loiii axit HCl co ndng > 20% thi tdc biiy hoi da 16 ret Ndng axit Ndng axil H2SO4 d dfiy dugc thay ddi khoiing tir 10-20% Ciic dieu kien khac ciui thf nghiem dugc giu cd dinh: nhiet hoat hoa: 90*^C, thdi gian hoat hoa: 6h, ty le R/L lii 1:3, dieu kien cd khufiy iron numh Qua trinh thi nghiem dugc tien hanh nhu da m6 tii d muc 2.1 De diinh giii hieu quii ciui quii tiinh hoiit hoa bentonite, chiing toi da khao sat su phu thugc ciui hitp dung ciui bentonite ddi vdi mot sd ion kim loiii nang: Mir", Fe"", Cu"", Pb"", Cd-\ Zn"", Cr^", L'Oj"^ (ciic ion kim loiii niiy co dgc tfnh cao ddi vdi ngirdi va thudng dugc quan tam nhieu ciic quii trinh xir li moi trudng nudc) vao dieu kien hoat hoii (thdi giiin, ndng axit dimg de hoat hoa) Sir phu thugc ciui hap dung cac ion kim loai Viio thd"i gian, ndng iixit diing dc hoiit hoii bang axit sunfuric da dugc dira tren biiniz 27 Bdng Hdp dung cdc ion kim logi ndng tren bentonite (mg/g bentonite) vdi nhung dieu kien hoat hod bentonite khdc H2S04 (%) 10 15 20 HiYp dl.mg ciia benlonite do'i voi cac ion kim loai nang, mg/g Thdi gian hoiit hoa (h) Mn-" Fe^* UO,-" Cu^-" 18,76 18,03 19,43 17,00 15,77 15,20 Pb-" Cd-" Zn-" Cr-'" 16,41 15,87 16,22 17,81 19.20 17,22 15,01 14,65 15,17 15,94 17,10 14,42 14,70 14,12 13,94 14,25 14,32 16,40 13,81 11,88 12,95 13,70 12,00 13,41 12,41 13,21 13,01 10,63 12,70 11,52 9,37 10,59 11,30 12,43 11,75 10,62 9,78 9,53 8,35 9,34 10,48 11,54 21,78 18,60 23,02 14,22 13,41 13,87 15,46 22,42 24,32 20,31 25,30 16,54 15,33 15,89 17,45 25,14 19,21 15,92 18.34 16,45 15,02 15,64 17,02 23,15 17,55 14,75 17,46 16,01 14,75 14,85 16,44 20,83 14,63 13,37 13,57 12,35 14,42 13,24 14,32 14,14 13,09 12,27 13,09 12,40 13,04 12,80 13,41 13,15 16,44 15,35 17,83 11,04 9,12 10,61 11,15 15,21 16,65 15,59 18,00 11,25 9,41 10,82 11,47 15,34 ^ 17,05 15,79 17,81 12,03 10,45 11,51 12,03 15,79 16,96 16,90 18,23 12,14 10,58 11,95 11,89 15,84 17,09 16,67 18,10 11,84 10,62 12,04 11,45 16,01 17,00 15,56 17,95 11,91 10,89 12,13 12,20 16,35 i 14,20 13,81 15,89 10,78- 9,41 10,22 11,32 15,11 1 Tir Ciic ket qua thuc nghiem tren biing co the thfiy rfmg, d vimg ndng axit hoat hoii 209c, thdi gian hoiit hoii Uuig elfin thi hfip dung ciui bentonile ddi vdi Citc ion kim loiii deu giiim vimg nong axit hoiit hoii 15%, thdi giiin hoiit hoii tang dfin thi hap dung ciui bentonite ddi vdi cac ion kim loiii tang dfin lir Ih den 2h sau d6 giiim dfin thdi gian hoiit hoii tang len, hfip dung diit gia tri cue dai tiii thdi gian hoiit hoa 2h viing ndng axit hoiil hoii 109(, hfip dung ciui bentonite ddi vdi ciic ion kini loai nang thap han kha nhieu so vdi viing nong iixit cao hon TyleR/L: 28 Trong Ciic thf nghiem niiy, ly lc R/L dugc thay ddi tir 1:2 den 1:5 theo khdi lugng Qua khao siit thfiy rfmg: Vdi ly le lii 1:2 ve khdi lugng thi viec khufiy hdn hgp de dat sir ddng deu kha khd khan Khi ly le R/L thay ddi tir 1:3 den 1:5 ket quii khiio sat khong sai khiic nhieu VI vfiy theo chiing tdi ty le R/L = 1/3 la thfch hgp vii cac thi nghiem sau chiing t6i ddu sir dung ty le R/L la 1/3 Nhiet hogt hod: Chiing toi da tien himh khiio siil bi'iiig thuc nghiem khii nang hoa tan Ciic ion kim loiii biing dung dich axit H2SO4 10% lir bentonite Ket quii cho thfiy rang, tang nhiet dung dich thi khii lu'mg hoa tan lang len Nhiet thfch hgp cho qua trinh hoiit hoii lii tLr85-90*^C Tdc khiuiy tron: Ke't quil khiio siit so bo cho thfiy rang, idc khufiy trgn cung co anh hudng nhieu de'n hieu qiui hoiit hoii bentonite Tdc khufiy Iron co iinh hudng de'n hieu quil hoiit hoa bentonile tren hai mat: - Liim cho bentonite khdng bi von cue, tiep xiic tdt hon vdi pha Idng - Liim cho tdc khuech tiin pha long tdl hon KluuYy trgn numh de tiiinh sir von cue vii diim biio sir tiep xiic ran - Idng thudng xuyen Thdi gian hoat hod O biing chl sir bien ddi thimh phfin cfiu tir ciiii quang bentonite theo thdi gian hoiit hoii ndng axit dimg de hoiit hoii lii 15% Ket qua eho thay khoiing thdi gian hoiit hoa Ih, ciinxi oxit luui nlur bi hoii tiin hoim toiin, ddng thdi lugng oxit kidm ciing giiim xudng diing ke Trong sir hoii um ciic thiinh phfin chinh ciui benionitela Si02 va ALO^, kli ehi xfiy numh \bng 6h dau ciia quii Crmh hoat hoa Ty le giua Si02 / AI2O3 bie'n ddi tir 1:3,1 den 1:31,3 sim phfim hoat hoii Tren ca sd co the dua ke't Iui)ii dudi tiic dung ciui axil, khoiing bentonite da bien ddi phfin cau tir ciia no biing cho thfiy sir bien ddi dicn ti'ch be mfit rieng ciia bentonile viio thdi gian hoiit hoii ndng axit dimg dc hoiit luxi lii 15% Trong 6h hoiil hoii dfiu tien, dien tfch be mat rieng tang ien nhieu, vii siiu 6h hoiil hoa thi dien tfch be mat rieng ciia bentonite tang tdi 6,3 Ifin Neu tiep tuc hoiil hoa eho tdi thai gian la 18h thi dien ti'ch be miit rieng cd xu hudng giiim di Dieu niiy cd the dugc giiii thfch bang sir bien ddi cfiu tnic tinh the ciia khoang bentonite dirdi tac dung cuii iixit Trong khoiing thdi gian 6I1 dfiu ciia qua trinh hoat hoii Ciic cfiu tir thimh phfm ciui bentonite tan dfin vii uich khdi mang luoi tinh the the, thdi gian niiy khung ciui nvdng tinh the bentonite vim dugc giu nguyen cac "16 29 hdng'' miing ludi tang len VI vay dien tfch be mat rieng ciui khoang bentonite tang len nhieu Tuy nhien neu keo dai thai gian hoiit hoii thi khung tinh the se bi pha vd diln, vl vay dien tich be mat rieng se bi giam theo Nhu vay, vdi ket qua ho.at hoii da lam eho bentonite trd nen "xdp" ho'n, tir dfin den viec la tang khii nfing trao ddi ion ciia bentonite so vdi bentonite chua dugc hoiit hoii (bentonite tir nhien) eung nhu liim cho dung dich chay qua Idp bentonite dugc de dang han Bdng Sir hien diii thdnh phdn cdu td cua bentonite theo thai gian hogt hod Ham luong ci'ic ihanh phan chi'nh bentonite, % Thai gian hoat hoii, h SiO, AUO_, Fe,0, CaO MgO Na^O + KjO 50,2 16,1 7,5 3,50 1,2 2,30 52,1 15,8 6,0 0,77 0,8 0,65 53,3 14,6 4,9 0,30 0,73 0,60 56,4 11,9 3,2 0,28 0,72 0,59 76,1 6,1 1,6 0,25 0,64 0,58 10 79,2 4,5 0,72 0,21 0,31 0,57 12 81,5 2,6 0,31 0,20 0,25 0,55 Being 107 Anh hudng cua then gian hogt hod ddn dien tich he mat rieng cua bentonite Thoi gian hoat hoa, h Dien ti'ch hi mat rieng, 30 \^y 114 170 10 12 14 16 18 190 158 126 102 90 86 84 nr/g Tir Ciic ket quii da thu dugc, chiing t6i thfiy rang, sir dung dung dich H2SO4 liim tiic nhfm hoiit hoa khoiing bentonite Dilinh - Lam Ddng, ndng iixii thfch hgp cho qua trinh Iii 15%, thdi gian hoiil hoa Iii 2h Tdm bi, qua kluio siit quii trinh hoiil hoa khoiing bentonite Dilinh - Lam Ddng bang dung dich axit sunfuric, chiing loi da xac dinh dugc dieu kien thfch hgp cho quii lii: ndng axit H2SO, 15%, nhiet hoat hoii: 90'^C, thi^i gian hoiit hoii: 6h, ty le R/L lii 1:3, dieu kien cd khufiy trgn numh Sau dugc hoiit hoii didu kien da neu d tren, ty le giua Si02 / AUO^ diit 3,65, hiim lugng Ciic oxit kim loiii kicm tho hii thfip (himi lugng canxi giiim -12 Ifin, 30 hiim lugng magic giiim luii Ifin), dicn tfch be nu'it rieng diU kha Idn (114 nr/g), hfip dung ddi vdi Ciic ion kim loiii nfmg tang kha ciio: hfip dung ddi vdi Mir" tang 1,71 Ifin, hap dung ddi vdi Fe^"^ tang 1,47 Ifin 31 KET LUAN Nudc ta CO ngudn tiii nguyen bentonile tuang ddi ddi diio, luy nhien ham luang montrmorillonite khdng cao Cae ket qua phan tfch XRD, be mi'it rieng vii ciic dirdnf^ dang nhiet hap phii dugc khiio siit khuon khd de tiii deu cho thity rang, bentonite Di Linh va bentonite Binh Thuan cd hiim lugng montrmorillonite thfip hon nhieu so vdi cac tai lieu thong boa dia chfil vii rfit thfip so vdi benlonite thuong mai nen the gidi VI vay mudn sir dung chiing cd hieu qua hon thi phiii liim giau vii hoiit hoii Da Xiic dinh dugc dieu kien tdi iru cho qua trinh hfip phu mgl sd ion kim loai nang (Mn^"" va Fe^"") moi tnrdng nudc ciui bentonite kiem thd Dilinh - Lam Ddng: pH = 4,0; thdi gian tiep khufiy iron: 3h Da khiio sat quii trinh hoiil hoii bentonite sau da liim giiiu ddi vdi bentonite Dilinh Lam Ddng vii xiic dinh dugc dieu kien thfch hgp cho qua trinh hoat hoa lii: ndng dd axit H2SO4 15%, nhiet hoiit hoii: 90*^C, thai gian hoiil hoii: 6h, ty lc khdi lugng R/L la 1:3, dieu kien co khufiy trgn numh Sau dugc hoiit hoii dieu kien da neu d tren, ty lc giUii SiO^ / ALO^ diit 3,65, ham lugng Ciic oxit kim loiii kiem thd liii thfip (hiim lugng canxi giiim -12 Ifin, ham lugng nuigie giiim luii Ifin), dicn tfch be mat rieng diit khii Idn (1 14 mVg), hfip dung ddi vdi Ciic ion kim loiii niing tang klui ciio: hfip dung ddi vdi Mu""*^ tang 1,71 kin, hfip dung ddi vdi Fc""*^ tang 1,47 Ifin Bentonile sau dugc liim giiiu vii hoiit hoii diip ung dugc yeu cfiu cita nhieu ITnh vuc irng dung co huh virc xir If moi trudng TAI LIEU THAM KHAO N^^uyen Van Binh - Hoiit tinh xiic liic ciia bentonite Thufm Hiii da dugc bien tfnh tron^T pluin ii'ng chuyen hoa mot sd hop chitt huu co - Luan an tien s) 1998 N^uiyen Diic Chfui Sir dung set niontmorinolit liim chat xiic tiic cho tdng hgp hiru CO Hgi thao cong nghe tdng hgp lulu co ung dung n6ng nghiep, cong nghiep va ddi sdng Tap chf Vien Hoii cong nghiep, 10-1995, 33-36 Dd Quy So'u Nghien ciru Llimg bentonite Di Linh loai di oxit khoi nudc Tap chfHoiihgc,3, 1990,4-7 O Abollino cl iil Adsorption o[ heavy metals on Na - montmorillonite Effect of pH and organoic substances Water Research 37 (2003) 1619 - 1627 R Niisscm iind S S ^riihir Removal of Pb(ll) from aqueous/acidic solutions by usins bentonite iis an a.Noibcni; Wai Res Vol 35, No 16, pp 3982-3986,2001 32 ... ndng hdp thu cdc ion kim logi ndng nUdc ciui khodng bentonite Viet Nam Ten tieng Anh: Research of treatment method to improve the ability of absorption for heavy metal ions on Vietnamese bentonite. .. iiuo ddi ion: H" (bentonite) +Mn-"(Fe""),^j H",^+Mn-" (Fe*^^) (bentonite) Sir triio d6i ion niiy plui thugc viio bim chfit bentonite, nhiet do, sir khuech tiin ion kim loiii, vii kfch thudc lo... vii lugng cation bii trir miing ludi Bentonite cd the hap phu tdt cac ion kim loiii nang, khii nang hfip phu ddi vdi Ciic ion la khac No phu thuoc vao dicn tfch va biin kfnh ion Ion cd hoii tri