TAP CHI HOA HOC HOI DONG BIEN TAP
jz ... . , Nguyln Vi?l B ^ A a Van Binh, Phan Dinh Chau, D^ng Kim Chi, . . Tran VTnh Divii, Urn Minh D^i, Trjnh Xuan Gian, Le Xuan Hi6ii, TRAN VAN SUNG y - pj^l^ j^^^^^g^ Nguyen Dure Hung, Phan Van Ki?m, Liru Cam Phd Tdiig bien lap: Lpe, D^ng Vu Minh, Nguyen Hiiu Nieu, Nguyln Kim Phi Phung, Tran VTnh Di^u. Chu Phgm Ngpc San. Phan Tong San, TrSn Van Sung, Dang Nhu-
Tai, Le Van Tan, Ngo Thj Thuan, Dao Van Tuang, Nguyen Van Tuyen, Qu^ch Dang Trieu, D^ng Ung Van.
Cdc ban giri bai dang chii y:
T^p chi Hoa hpc dang nhung cong trinh nghien ciru c6 gia In khoa hpc va thirc tien trong cac ITnh virc hoa hpc, cong ngh? hoa hpc, hoa sinh, cong ngh? vat li?u, cong nghe nano ... ciia cac nha khoa hoc trong va ngoai nuac. Tap chi dang bang tieng Viet hoac tieng Anh.
Do sir han che ciia khuon kho. Tap chi chi co the dang nhCrng bai khong dai qua 5 trang in, ke ca hinh
\c, bang so va tai lieu thain khao trir nhCrng truang hpp ngoai le do Hpi dong bien tap yeu cau. Trong moi bai c6 khong qud 5 hinh ve. Hpi dong bien tap khuydn khich viec cong b6 nhung cong trinh dual dang thong bao ngan; nhirng cong trinh do se dupe riit ngan thai gian cha dang.
Toa soan chi nhan nh&ng bai danh may ro rang, hinh ve d^t dimg ch6, ky hieu va cong thirc phai viet ro rang va chinh xac. Tai lieu tham khao, neu la tap chi can ghi theo thii tir: ten tac gia, ten tap chi, lap, so, trang. nam: neu la sach: ten tac gia, ten sach, trang, nha xuat ban, lan xuat ban, nam xuat ban; neu la bao cao hpi nghj: ten tac gia, ten bao cao, ten hoi nghi va tuyen t^p, trang, nam; nlu la dl tai (hoac luan van):
ten tac gia, ten de tai (luan van), nai bao ve, nam; trong moi truang hop nam de trong ngoac dan. Neu tai lieu tham khao thupc he chij Tupng hinh thi dich sang tieng Viet, thupc he Slave thi phien am ra chiJ la tinh. Bai giri dang phai c6 torn tat noi dung bang tieng Anh, de phia tren bai. Phan tom tat npi dung bang tieng Anh ciia bai viet bang tieng Viet phai neu dupe day dii npi dung ciia bai (tir 250 ti!r den 300 tir), CO the dai het trang thu nhat cua bai bao, Cac bai deu phai co dau de bang ca hai thir tieng Viet va tieng Anh (de lam muc luc cho so ciia Tap chi).
Ten tac gia Viet Nam can viet day dii hp, ten dem va ten (khong viet tat), tac gia nuac ngoai can viet tat ten, CO dau cham sau tir viet tat, hp can viet day dii.
De tien lien lac, nguai viet can ghi ro dja chi ca quan, dia chi email, so dien thoai ca quan va so dien thoai nha rieng (neu co) ciia tac gia lien he vao phia dual dau de bai giri dang.
Tap chi xuat ban moi nam (1 tap) 6 so.
Bai khong dang khong tra lai ban thao.
Bien tap ky thuat: Doan Thi Yen Oanh Thu tir, bai va xin gui theo dia chi:
Tda soan Tap chi Hoa hpc
Tang 3, nha A16, Vien Khoa hoc va Cong nghe Viet Nam 18 Hoang Quoc Viet, C5u Giay, Ha Noi
Dien thoai. 3 7917412
E-mail: [email protected]; [email protected].
TAP CHI HOA HOC T. 49(6) 661-665 THANG 12 NAM 2011
NGHIEN CUU K H A NANG H A P PHU NIKEN B A N G VAT LIEU MnzOa KiCH THU-aC NANOMET TREN SiOz
Liru Minh Dai*, Dao Ngoc Nhiem, Pham Dik Th5ng, Vu The Ninh, Pham Ngoc Chiic Vi?n Khoa hgc Vgl li^u, Vien Khoa hoc va Cong ngh^ Viet Nam
Den Toa soan 24-4-2009
Abstract
The Mn203/Si02 material containing nanosized Mn^Oj has been synthesized at low temperature (550°C) by the combustion method. MnjOj/SiO, characterization is examined by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and BET (Brunaure-Emmet-Teller) measurements. The Mn203/SiO: material is used for removing the nickel from wastewater. The nickel absorption capacities by the nanosized manganase oxide have calculated using Langmuir method.
L MO DAU
Su o nhilm moi truang do nganh cong nghiep phat trien, do s\r bung no dan so a cac nuac cham phat trien va dang phat trien,.... Da pha va nhCrng qui lu|t tu nhien ve su phat trien sinh thai, lam giam tuoi thp, tang b?nh tat ciia con nguai. Do vgy bao ve moi truang la muc tieu chung cua toan nhan loai [1,2].
Hien nay co nhilu phuang phap xu ly kim loai nang nhu: Phuong phap kit tua, phuang phap trao doi ion, phuang phap tham thau nguac, phuang phap hap phu,.... Dac biet phuang phap hap phu vai vat lieu hap phu dugc che tao tii cac nguon san co nhu: Than bim, miin cua, tro bay, dat set, cat... dang rat dugc quan tam cua cac nha nghien ciru va xu ly moi truang [ 3 ^ 8 ] .
Trong bai bao nay su dung vat lieu chira oxit mangan kich thuac nanomet ih hip phu Ni^* va tir do djnh huong ihig dung loai vat lieu nay de xir ly niken trong mdi truang nuac thai.
2. THl/C NGHIEM 2.1. Hoa chat, thiet bi
Mu6i Mn(N03)2 tinh khilt, Ni(N03)2.6H20 (^9%), polivinyl ancol (PVA), cat thach anh dugc ray cd hat 0,75-1 micromet va mot so hoa chat khac CO dp sach phan tich. May khu§y tir gia nhiet (Y), tii say (Due), 16 nung (Anh).
May so mau quang hpc (Anh) xac djnh mangan tai bude song 525 nm, len mau bang phuang phap persunphat.
May quang pho hip thu nguyen tir (AAS) hang Shimadzu (Nhat Ban) de xac djnh ham lugng niken.
Gian do nhieu Ronghen dugc thyc hien tren may D-5000 (CHLB Dire) vdi buc xa CuK„ bude song d
= 1,5406 A.
Anh vi cau triic va hinh thai hpc ciia mau duac chup bang may hien vi dien tur quet (SEM) JEOL- 5300 (Nhat Ban).
Dien tich be m^t dugc do bang phuong phap BET (Brunaure-Emmet-Teller) tren may SA ciia hang COULTER (My).
Danh gia kha nang hSp phu cua vat lieu chira Mn203 kich thudc nanomet theo mo hinh dang nhiet Langmuir.
May do pH (Y), may khuay tir gia nhiet (Bi) va mot so dung cu thi nghiem khac.
2.2. Tong hffp vat lieu
Mau dugc tong hgp bang each hoa tan mpt lugng PVA vao nudc d nhiet dp thich hgp den khi tan hit tao thanh he trong suot, d pH = 4, giu nhiet d 80°C trong 4 gid. Cho mpt lugng dung dich Mn(N03)2 vao he tren de tao he gel ddng nh4t Mn- PVA (vdi ty le moi Mn/PVA = 1/3). Sau do cho Si02 kich thudc 0,1 din 1 micromet vao khuSy trpn diu trong 15 phut. Xu: ly mlu d nhiet dp 550°C trong 1,5 gid va rira mau nhilu I5n de thu nh^n san phSm la vat lieu Mn203 co kich thudc nanomet tren chSt mang Si02.
2.3. Thi nghiem hap phu
Qua trinh h4p phy tTnh: Dugc tiln hanh d ap suSt va nhiet dp phong; 1 g Mn203 dugc khuay trpn vdi 100 ml dung djch Ni^^ ndng dp diu thay doi tir 1 - 60 mg/l trong thdi gian 2,5 gid (thdi gian dat can bang) d pH = 5,5. Tach dung djch khdi v^t lieu bing
mx
TCHH,T. 49(6), 2011
qua trinh lpe, ndng dp Ni^* con l^i dugc xac dinh bang may hip thy nguyen tu (AAS).
Qua trinh hap phu dpng: 200 g vat li?u Mn203/
SiOi dugc nhoi vao mpt cpt thiiy tinh (dudng kinh 3 cm) ndi vdi binh cau thanh mpt hp kin.
Dung dich chira Ni^^ (nong dp dau 1^ 15,5 mg/l d pH = 5,5) dugc ch^y qua cpt, vdi toe dp ddng 30 ml/phiit. Dung djch dau ra dugc phan lich sau moi lan lay mau la 500 ml, dung djch cdn l9i dugc thu gom l^i, phan tich nong dp tong khi qu^ trinh ch^y cpt ket thiic.
3. KET QUA VA Tl lAO LUAN
3.1. Khao sat kha nang phu MniOi kich thu-dc nanomet tren mau iVln203/SiOi
Mau dugc long hgp nhu phan tren vdi khoi lupng Mn^Oj ngam tam dua vao thay doi tir 1,00 den 20,00 % MSu dugc xir ly nhi?t d 550"C trong 1.5 gid de thu dugc san phim la vgt li?u Mn203 co
Lmi Minh Bgi va cong sir kich thudc nanomet tren chat mang Si02. Ham lirpng mangan trudc va sau khi ngam tim dugc xac djnh bing phuang phip persunphat [10]. Ket qua dugc chi radbiing 1.
Qua cic so lipu thay ring khi tSng lugng oxit mangan vko v§t li?u thi hi?u suit ngam tam giam va qud trinh ngSm tam gan nhu d^t bao hda khi khdi lugng oxit mangan dgt 8,06% vdi khoi lugng dua v^o li 10% (hipu suit ngam tam kha cao 80,6%). Do dd, khoi lirgng oxit mangan dua vao 10% da dugc chpn cho cic nghien ciru tiep theo.
3.2. Xic djnh thinh phan pha v^ hinh thai h9c cua vat lif u che tao dvcffc
Miu vgt lipu trudc va sau khi tong hgp dugc tra xat, nghien mjn roi dugc xac djnh cau true bing phuong phip nhieu X9 Ronghen, hinh thai hpc dugc chyp inh hien vi dipn tur quet. Ket qua dugc chi ra d tren hinh (la, lb, 2a, 2b).
Bdng 1: Ket qua khao sat hipu suit ngam tam Mn203 kich thudc nanomet tren nen Si02 Mn203 dua vao (% khoi lup'ng)
MnjOs thirc te (% kh6i lugng) Hi?u suit ngam tam (%)
1,00 0,95 95,00
2,50 2,30 92,00
5,00 4,42 88,40
10,00 8,06 80,60
20,00 10,79 53,95
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Hinh la: Gian do tia X ciia mau SiO; Hinh lb: Giin do tia X cua mau Si02 ngam tam Mn203
Ket qua tren gian do tia X (hinh la vi lb) chi ra hai loai pic dac trung pha tinh the ciia Si02 va Mn203, gian dd cung chi ra cac h&t Si02 khi chua dugc ngam tim Mn203 cd kich thudc vai micromet, khi dugc ngam tim Mn203 miu Mn203/Si02 dugc bao phu rat diu bdi cac hat MnjOs < 30 nm (hinh 2a
3.3. Danh gia kha nang hap phy Ni^^ cua \%X liSu MniOj/SiO:
De dinh gia kha ning hip phy cQa mgt lo^i v^t li^u nao do cd nhieu cac yeu to can khao sat nhir thdi gian dat can bing hip phy, dung lugng hip phy, anh
TCHH, T. 49(6), 2011
trudng,.... Trong bai bao niy khao sit thdi gian d^t can bang hip phy va dung lugng hip phu. Kit qua dugc dua ra d phin sau.
3.3 1. Xdc dinh thai gian dat cdn bang hap phu niken cua vdt lieu Mn203/Si02
Nghien ciru khd ndng hap phu niken. . Thi nghiem dugc tien hanh vdi 100 ml dung djch Ni^"^ cd ndng dp 10 mg/l, 1 g vat lieu dugc khuay trpn trong cic khoang thdi gian khac nhau 10, 3D, 60, 90, 120, 150 va 180 phut tren miy khuiy tir. Ket qui phan tich ham lugng niken duoc bieu dien d hinh 3.
Hinh 2a. Anli SEM cua mau S1O2 Hinh 2b: Anh SEM ciia S1O2 ngam tam Mn203
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Thdi gian, phut Hinh 3: Anh hudng thai gian dat can bing hip phy niken cua vat lieu Mn203/Si02 Qua trinh hap phu chii yeu xay ra trong 120 phut
diu sau dd giam dan va gin nhu dat cin bang trong thdi gian 150 phut va dugc chpn cho cac thi nghipm tiep theo.
3.3.2. Hap phu Ni^* cda vgt lieu chira Mn20s/Si02 theo mo hinh Langmuir
Trong cac thi nghiem hap phu dugc tien hanh nhu phin tren. Khi qua trinh hap phy dat can bang, miu dugc lpe vi xac dinh him lugng Ni^* tren miy hip thu nguyen tu AAS (Shimadzu-Nhat Ban).
Cac hang so dang nhiet cua qua trinh hip phy Ni^"^ tren vat lipu chiia Mn203 kich thudc nanomet
dugc xac dinh tir ket qua hdi qui cac so lieu thuc nghiem tren phan mem tinh toin Table Curve.
Su hip phu Ni^^ tren vat lipu chua Mn203 kich thudc nanomet dugc md ta kha tdt bang md hinh dang nhiet hip phu Langmuir vdi he sd hdi qui cho mo hinh niy ddi vdi Ni^'' la 97,63%. Kit qua ciing chi ra dung lugng hip phu cue dai tinh theo mo hinh Langmuir la 3,575 mg/g.
3.4. Dinh gia kha nang hap phu Ni^^ cua vat lieu Mn203/Si02 tren cot hap phu
Mau nudc thai sau khi liy tir be thu gom cua xudng dien phan dugc tien xir li bang dung dich 663
TCHH, T. 49(6), 2011
Ca0(H)2. Ket qua phan tich thinh phin dugc dua ra trong bing 3.
Liru Minh Bgi va cqng sv
Dudng ddng nhiCI h.1'p phu Langmuir t l = Q i n u x . b . C r / ( H - b . C O
r«2=0.97630874 DF Adj 1^2=0 96683224 FiiSi<ll:rr=0,24037104 Fsiai=247.25798
E
Ndng dp cdn lai, mg/l
Hnih 4: Dudng dang nhiet hap phy Ni^* ciia v^t lipu Mn203/Si02 Bang 3: Ket qua phan tich mau nudc thii dipn phan Chi tieu
Niken (Ni'*) Crom Dong sit pH
Ham luiTng niken triroc XLT ly, mg/l
112 0,14
0,34 8,64
Ham lirgng niken sau xu ly bang Ca(0H)2, mg/l
15,5 0,01
-
9,7
TCVN 7209-2002, mg/l
2 0,05
1 1-5 6,5 - 8,5 Nhu vay qua bang 3 thay rang nudc thai ciia
xudng dien phan sau khi da xir ly bang Ca(0H)2 cd mpt sd chi tieu ham lugng vugt chi tieu cho phep vai lan, dac biet la Ni^"" cd ham lugng vupt nhieu lan so vdi tieu chuin cho phep ddi vdi nudc thai, ndng do sau khi xu li bang sira voi thi nong dp niken van cdn cao can phai tiep tyc xu ly, do do chung tdi tien hinh hap phu ddng tren cpt bang vat lipu chua Mn203 kich thudc nanomet
Dpi lien tuc ddng dung djch cd nhieu kim loai nang qua cpt vdi tdc dp 30 ml/phut, tiln hinh phan tich ham lugng Ni^^ d diu ra dugc xic djnh ham lugng mpt sd kim loai khac trong mau thu hdi. Ket qua phan tich dugc dua ra trong bang 4.
Nhu vay cd the thiy rang v§t lieu che tao chira Mn203 kich thudc nanomet co kha nang hap phu rit tot Ni^* tir dung djch, sau 4 dan vi the tich dau, cic
dd ndng dp niken tang din va sau 8 don vj the tich van dat TCVN 7209 - 2002, ( N\-*< 2 mg/l).
Tii trpng hap phy Ni'* dgng an toin tren cpt ciia vat lipu che t^o chua Mn203 kich thudc nanomet d?t qan loan " 0,29 mg/g (vdi q;„ ,^„ = {A ^ \ 5,5 - 3,84 « 0,96): 200 = 0,29 mg/g). Ngoii ra, tiir kit qua phan tich mau thu hdi thiy ring vat lieu chiia Mn203 kich thudc nanomet cdn xir h' dugc cic kim loai nang khic nhu Cr, Fe, diy la nhung kim loai thudng xuat hipn trong ngudn nudc thai dien phan hay ma dien.
4. KET LUAN
Da dinh gia kha nang ngam tam Mn203 kich thudc nanomet tren Si02 v i gii tri cue d^i la 8,06%.
Ket qui xic dinh cau true, hinh thai hpc cua mau trudc va sau khi ngiin tam Mn203 kich thudc nanomet cho thiy tren b l mat vat lieu sau khi ngam
