KHOA HOC CONG NGHE
TAIXI D U M G T H U H D I L O I PIIV S A U 5 U DUIVG LAIVI V A T U E U H A P P H U T H U d C [VHUOIVI D O 1 B O TROIXIG IMUOC
Nguyen Nhjt Huy\ Dang VSn Th^nh^ Phimg Thi Oanh^
Dang I l u H6ng Phucmg^, H^ XuSn linh*
T X D M T A T
0 nhiem moi tmong tir pin da qua sn dung la moi van de dau dau cho cac nha quan ly va ky thuat nioi Uirong. Cac d6 xual giai phap thu gom va tai che pin thai deu rat dugc khuyen khich va danh gia cao. BAi bao nay trinh bay mot each thirc don gian tai sir dung dien cue duong tir graphil cua pin khong chi da sir dung thanh vat lieu graphite oxide dang cau gai (CGO) duoc che- tao bang phuong phap dien ly plasma co sir ho trg cua sieu am. Klia nang hap phu pham do (RD120) ciia vat lieu CGO dupc nghien cuu sir dung phuong phap hap phu linh. Mot so yeu to anh huong den kha nang hap phu RD120 ciia CGO dugc khao sat bao gom anh huong ciia pH (2-11) va nong do ban 6ku ciia thu6c nhuom (20- 150 mg/L), Qua trinh hap phu cua pham do RD120 phu hop voi mo hinh hap phu Langmuir vol dung luong hap phu cue dai la 99,00 mg/g goi mo Uem nang ciia viec ung dung vat lieu nay trong xir ly nuoc tliai, dac biet la d ^ h cho cac hgp chat mau va cac chat hiru co kho phan hiiy sinh hoc.
Tir kh6a: Hap phu, graphite oxide. RD120. plasma, dien ly.
i.MaoJtu
Graphite oxide (GO) la san pham cua qua trinh trinh oxy hoa gi'aphite. Nghien ciiu dau tien ve graphite oxide dugc thuc hien each day hon 1.50 nam cho thay co the san xual vat lieu nay hen co sa graphite voi gia thanh tuong doi th^p. Vao nam 2(X)4, khi xu^l hien graphene thi vat heu GO bat dSu dugc nghien ciiu rong rai va dugc su dung nhu la tien ch&t ban dau de che tao gi-aphene thong qua qua trinh kbit GO [1]. Ngoai nhinig tinh chit coban giong nhu graphene, GO co them cac nhom chiic be mat thong qua lien ket ciia oxy nhu nhom hydroxyl, cacbonyl.
Cac nhom nay co ai luc manh voi cac chat o nhiem khac nhau hong nuac nen GO da dugc nhieu nhom nghien ciiu sii dung lam chat hap phu |2,3].
Ngay nay, GO duoc long hgp bang ba phuong phap chinh do la Brodie (1859) [4], Staudenmaier (1899) [5], Hummers va Offeman (1958) [6]. Tuy nhien nhiing phuong phap nay van con mot s6 han che nhat dinh. Vice tim ra mgt phuong phap co the che tao nhanh GO vol hieu su^t cao, sir dung cac trang thiet bi hr che tao va su dung cac vat heu nguon ban dau gia thanh thap, phu hgp voi dieu kien kinh te hong nuoc hien nay thuc su van con la thach thiic.
Tnrcmg Dai hpc Bach khoa. Dai hoc Quoc gia TP. HCM 'Tnrcmg Dai hoc Y-Dugc, Dai hoc Thai Nguyen 'Trung tam Nhici dai Viei - Nga
•"Khoa Quoc le. Dai hoc Thai N'guyen Email: ha\iianlinh@inu edu.\n
Pin thai, von la mot loai chat thai nguy hai, gay ra rat nhieu van de moi truong nhu gay o nhiem va lam nhiem doc nguon nuoc neu khong duoc thu gom va quan Iy dung each. Pin thai hien nay gan nhu khong CO bien phap xu ly ma chi dugc chon lap hong cac bai chon lap chal thai nguy hai, v6n doi hoi thiel ke nghiem ngai, ton kem, va trinh do quan Iy cao. Do do, viec tan dung lai pin thai hoSc mgt thanh phan ciia pin thai de ch^ lao thanh vat heu nano co gia tri hong viec xii Iy 6 nhi6m moi tmong la mgt hmmg nghien ciiu rat dang quan tam va dugc danh gia cao.
Trong nghien cim nay, sir dung cac thanh graphite tu pin da qua sir dung de lam tien chat ban dau cho viec che tao vat lieu graphite oxide cau tnic cau gai (CGO) su dung phuang phap dien ly plasma CO su ho trg cua song sieu am va ling dung hap phu pham do RD120 hong moi truong nude.
Z. PHUDNB PHAP NGHIBV CUU 2.LCh^taovatUeuCGO
So do mo hinh nghien cim duac the hien hong hinh 1. Trong nghien ciiu nay, sir dung the phan cue 60 V cho hai dien cue ciia mgt he dien phan, a do thanh graphite (tir loi pin thu h6i, ki hieu la RG) c6 duong kinh 6 mm va chieu dai 100 mm dugc vol nhgn b dau dong vai tro la catot. Mgt tam thep khong ri (dai 120 mm, rgng 60 mm) dugc sir dung lam anot cho qua trinh dien hoa plasma hoc lach graphite thanh graphite oxide. Dien tich anot lon hem dien tich catot (S3n,„/S^^,„| = 150). Dung dich dien Iy bao gom NaOH (200 mL, 15%) va (NH,)_50,, (40 mL, .5%)
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KHOA HOC CC.
CO pH khoang 14. Tai thoi diem ban dau d&u miu catot dugc dat each he mat cua dung dich dien ly khoang 1 mm, hong khi tam thep khong ri dong vai tro anot dugc dat ngap sau trong dung dich dien Iy.
Ca hai dien cue duac n6i voi nguon dien mgt chieu ben ngoai vbi dien ap phan cue 60 V.
Hinh 1, Sa do he (a) diSn Iy plasma sieu am ch^ tao CGO vi (b) anh chup phan ling dien ly plasma
De phan ling xay ra, dau mui catot dupc chuyen dpng cham dan tiep xuc voi be mat dien Iy thong qua mot mola buoc voi tdc do 1 mm/phut. Khi khoang each giCra dau mui catot va anot khoang 1 mm xay ra hien trrong phong dien (plasma) a khu vuc tiep giap voi dau mui nhgn ciia RG dong vai ho catot va dung dich dien Iy, Sau khi plasma xuat hien va 6n dinh, vi hi cua mui catot dugc ha xudng dan de duy tn mgt dong dien xung quanh khoang 1,7 - 2.0 A. Nhiet do ciia dung dich dien Iy hong cdc thiiy tinh duoc duy tri hong klioang 70 - SOT. De nang cao hieu suat cua viec hoc tach graphite thanh graphite oxide va tinh dong nhat cua phan ling, binh dien hoa phan mig duoc dat ti'ong mgt be mng sieu am cong suat Ion hoat dgng hen tuc trong qua trmh che lao. Do nhiet do phan ung cao, nen nuoc ti'ong dung dich chat dien Iy se bay hoi dan dan trong qua ti-inh phan ling, do do de qua trinh dien phan dugc dien ra on dmh va Hen tijc hong sudt qua trinh phong dien plasma, mgt binh chua lien tiJC bo sung them dung dich dien Iy voi t6c do 5 mL/phut. Sau thoi gian phan img (30 phiit), vat heu chiia hong hon hgp chat dien ly duac Igc qua he thong bom hut chan khong vai mang loc PVDF 0,2 pm (polyvinyhdene difluoride), riia sach bang nuoc cat 2 lan den tmng tmh, sau do dugc say chan khong d SOX hong vong 24 gid. Vat lieu thu dugc sau qua ti-inh nay dugc ki hieu la CGO.
2.2. Khao sat dac di^m b^ mat, tinh ch^t vat ly, Cciu tnic cua CGO
Dac diem hinh thai hgc ciia CGO duac khao sat sii dung kinh hien vi dien tii quel JEOL JSM-6500F
va kmh hien vi dien hr truyen qua (Tl-M) J 2100F. cau true ciia CGO dugc kiem tra boi may nhieu xa ke D2 sir dung biic xa Cu-Ko va phin loc Ni CO budc song X = 0.1542 nm. Cac phep do tren d ^ ^ tien hanh tai Khoa Khoa hoc va Ki thual vat lieu. D?i hoc Giao thdng Qudc gia Dai Loan, Dien uch be mat rieng ciia vat lieu duoc xac dinh theo phuong phap BET ti-en may ASAD 2010 tgi Klioa Hoa hoc, Tnidng Dai hgc Su pham Ha Xoi.
2.3. xac dinh di^m &kig di^n ciia CGO Chuan bi cac dung dich NaCl 0.1 M co pH ban dau (pH) da dugc dieu chinh tang dan tir 2,05 den 12,15. Lay 12 binh non cd dung tich 100 mL cho vao mdi binh mdi loai 10 mg vat lieu hap phu, Sau do cho lan lupt vao cac binh ndn 100 mL dung dich co pHi tang dan da chuan bi san b hen. De yen trong vong 48 gid, sau dd dem Igc lay dung dich va xac dinh lai pH (pHi) cua cac dung dich hen. Su chenh lech giua pH ban dau (pH,) va pH can bang (pH,) la ApH= pH^ - pH|, ve do thi bieu didn su phu thupc ciia ApH vao pH|. diem giao nhau ciia dudng cong voi loa dp ma tai dd gia tri ApH = 0 cho la di^ni dang dien can xac dinh.
2.4. Nghien cuu kha nang blip phu Thi nghiem hap phu {RD\20) dope bo hi hong dieu kien phdng Ihi nghiem va duoc Uen hanh hoan loan ngau nhien vdi 3 Ian lap lai d cac dieu laen thi nghiem gi6ng nhau lai nhiel do phong (25±2°C) sir dung cac binh tam giac (dung tich 100 ml) dirpc lac d tdc dp 200 vdng/phiit. Cac thi nghiem tien hanh de khao sat anh hudng cua pH dung dich va nong do RD120 ban ddu. Anh hudng cua pH ban dau duoc hen hanh bang each cho 0,05 g CGO vao binh tam giac CO chiia 50 mL dung dich RD120 co nong dp 20 mg/L vdi cac gia hi pH khac nhau tiiay doi tir 2 den 12 va lac hong 90 phut. pH cua dunj^ dich duoc dieu chinh bang cac dung dich HCI va NaOH 0,1 M. Anh hudng ciia ndng dp ban dau cua RD120 dupc khao sat bang each cho 0,05 g CCSO vao 50 mL dung dich RDi20 vdi nong do khac nhau (30-140 mg/L) Mc ti-ong 90 phut, dieu chinh pH = 3. Sau cac qua trinh tren, cac miu dugc ly tam d tdc do 4WX) rpm irons 20 phut va lay phan hen cua dung dich di do dp hdp thu quang tai budc sdng X = 510 nm de xac dinh nong dd tiieo phuang phap duong chuan sii dung may ^^^^' phd hap thu UV Hitachi UH5300 tai Tnrong Dai h Y-Dugc, Dai hgc Thai Nguyen-
Dung lugng hap phu va hieu sual hap phu tinh theocdngthiic [8]:
84 NONG NGHIEP VA PHAT -"''^*^ *^f^^^ THON - KY 1 + 2 - THANa i 72020
KHOA HOC CONG NGHE
'-xV H% = - X 1 0 0 %
(1)
(2)
Trong dd: V la the tich dung dich (L), m la khdi lugng ciia chat hap phu (g), C„ la nong do dung dich ban dau (mg/L), C^.^ Ia la ndng dp dung dich khi dat can bang hap phu (mg/L), q la dung lugng hap phu tai thdi diem can bang (mg/g), H% la hieu suat hap phu (%).
Md hinh hap phu dang nhiet Langmuir cung duoc ap dung de hnh toan va danh gia kha nang hap phu cua vat lieu CGO thdng qua phuang trinh [9]:
^ q p b C , , (3)
^'=^ 1+bCe
Trong dd: q^.,, (mg/g) la dung lugng hap phu d dieu kien can bang; C,,i, (mg/L) la ndng do can bang ciia RD120 hong dung dich khi d hang thai can bang; q„ (mg/g) kha nang hap phu don Idp va b hang sd Langmuir lien quan den nang lupng tu do hap phu.
3. KET QUA VA THAO LUAN
3.1. K^t qua khao sit dac di^m b^ m a t tinh ch^t v$t ly, c^u tnic cua CGO
Ket qua chup kinh hien vi dien tit quel (SEM) va hien vi dien tu tmyen qua CTEM) cua RG va CGO dupc ti"inh bay d hinh 2 va 3, Tir hinh 2 cho thay tmdc khi phan ung, RG cd cau hiic khdi gdm cac Idp day xep chdng len nhau. Sau khi phan img bdc tach bdi phan ling dien ly plasma, be mat ctia nd ddi ro ret, chuyen tu dang Idp khoi day sang hinh dang cac hat hinh cau vdi cac gai phia bdn ngoai, hinh dang gidng nhu qua cau gai vdi cac sgi kich thude nanomet nam xen ke nhau [10]. De quan sat ro hon hinh thai hoc cua CGO, phep do TEM dugc thuc hien, kdt qua dugc the hien dhinh 3 cho tiiay CGO la cac hinh cau, kha dong deu vdi cac sgi d bien cd kich Ihudc nano, tao ndn nhieu khoang trdng ti-en be mat gen md tiem nang ung dung him chat hap phu
Hinh 2. Hinh thai hgc b^ mat ciia vat heu CGO va RG (anh nhd)
Hinh 4. Gian dd nhi^u xa tia X cua RG (dudng miu do) va CGO (dudng m^u den) Hmh 4 la gian dd nhidu xa tia X cua RG va CGO tuong ling. Ket qua cho thay mau RG cd dinh nhieu xa vdi cudng do manh tai 20 = 26.4°, duoc gan cho cac dmh dac tiimg ciia mat phang mang (002) hong graphite, tuong ling vdi khoang each doo2 = 0,34 nm giua cac nguyen tii trong mang tinh the graphite [11]. Sau khi phan ling dien Iy plasma dinh dac trung lai 26 = 26,6° bien mat hoan toan va xual hien dinh nhilu xa mdi tai 20 = 9,76° luong ling vdi mat phang mang d,^„ - 0,90 nm cua dinh dac tnmg mat phSng mang (001) ciia GO [1], Hon nha, ban do rdng pho ciia CGO (1,47 nm) ldn hon so vdi RG (0,60 nm, su dich chuyen ciia dinh dac trung tii (26 = 26,6°, d,^,^ = 0,34 nm) tdi (26 = 9,76°, d,,,,, = 0,90 nm) va viec md rdng ban dp rdng cua CGO so vdi RG xac nhan viec da che tao thanh cdng graphite oxide lir graphite hong nghidn ciiu nay [12], [13]. Ngoai ra, theo phuong phap tieu chuan Brunauer-Emmett-Teller (BET), dien tich be mat neng cua CGO dugc xac dinh khoang 61,81 mVg, chimg minh rang vat heu CGO che tao cd dien tich be mat kha cao de cd the lam hap phu.
3.2. Xu ly pham dd RD120 hong mdi truimg nude
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H m h 5. (a) D 6 t h i b i ^ u d i e n d i ^ m d a n g di§n p H z ciia v a t h § u C G O v a (b) d 6 t h i b i ^ u d i e n s u p h u thuOc c u a
p H ddi vdi s u h a p p h u R D 1 2 0 C a c n g h i e n c u u h a p p h u va d d n g h o c ciia t h u d e n h u d m hiru c a n d i c h u n g , p h a m dd RD 120 ndi r i d n g s u d u n g vat Heu n d n e a c b o n c u n g d a d u g c tidn h a n h t r o n g n h i e u n g h i e n ciiu ti-udc [14-16]. T r o n g n g h i d n ciiu n a y b u d c d a u t h u n g h i e m k h a n a n g u n g d u n g C G O d e xir Ii n h u d m h u u c a RD120 h o n g m d i t r u d n g n u d e . Hieu s u a t h a p p h u va d u n g I u o n g h a p p h u ciia C G O doi vdi p h a m d o R D 1 2 0 d a d u o c h d n h a n h d t h e o p h u o n g p h a p h a p p h u tinh va k e t q u a d u g c t h e h i e n d h i n h 5 v a 6. Kdt q u a c h o t h a y C G O c d k h a n a n g x i i Iy p h a m d o R D 1 2 0 tai p H t h a p v a k h a n a n g xii ly g i a m d a n k h i t a n g p H . C o c h e h a p p h u g i u a t h u d e n h u d m h u n c a v a C G O cd t h e d u o c c h o la d u a t r e n s u tucmg t a c m a n h c u a luc v a n d e r W a a l s giiia t a m g r a p h e n e ( t h d n g q u a lidn k e t TI- n) va c a c v d n g t h o m c u a tiiudc n h u o m . N g o a i ra, q u a trinh h a p p h u c u a C G O c d n d o c a u t n i c b e m a t , dien tich b e m a t c a o , s u h e n h g p ciia h e t h d n g d i e n t u ;r- ;i vdi v d n g t h o m c u a h o p c h a t t h u o c n h u d m va s u tucmg t a c tinh
d i e n dien r a gitra c a c b e m a t m a n g dien tich duoi g c u a C G O ( p H , = 7.24) v a p h a n tii thuoc nhuom [ 1 4 1 . 6 h i n h 6a, vdi s u t a n g n d n g dd ban dau c u a p h a m dd RD120. h i e u s u a l h a p p h u giam nhmig d u n g l u g n g h a p p h u t a n g . O n d n g d p RDl-'i' thap, vi til h a p p h u h d n v a t h e u C G O k l i d n g bi chiem/Iap h o a n l o a n . S a u d d , sir t a n g n o n g d g RD 120 vcn Iuong c h a t h a p p h u k h d n g doi d a n d d n klidng du cac vi ti-i h o a t d d n g h d n b e m a t c h a t h a p p h u . dan ddn su giam h i e u suat h a p p h u . D u a Uieo d u d n g hap phu d a n g n h i e t L a n g m u i r va sir p h u Ihudc c u a C,i, va C^b/Q- t m h toan c h o thay d u n g I u o n g h a p phu cue dai c u a C G O ddi vdi p h a m dd RD120 la 99,00 m g / g , tuong t u vcri m d t sd c a c n g h i e n c u u k h a c [ 17], So sanh qn„L\ va didu kien t h i n g h i e m c u a c a c c h a t h a p phu khac nhau d u o c d u a ra h o n g b a n g 1.
i •: K X K a i
Hinh 6. (a) Anh huong ciia ndng dO Idn hi§u su^t hip phu va (b) su phu thude ciia C^t va C^i,/q
Bang 1. So s^nh vat lieu CGO vdi cic ch^t h^p phu k h i c Vat lieu hjip phu
Caebon hoat tinh tir phe tliai nong nghiep Vat heu nano alumina
Cetvlpvridijlium-benlonit Chisanto/bentonit CGO
pH 2 3 2 5 3.0
'Hioi gian (phiit)
90 120 75 180 90
(mg/g) 47,88 65,23 81,97 5,6 99.00
TLTK 1181 1171 [191 120]
Nghien cmi nay 4. KET LUAN
D a ch(^ t a o t h a n h c o n g v a t lieu h a p p h u C G O t u c a c t h a n h g r a p l i i t e c u a p m d a q u a sii d u n g t h o n g q u a p h u o n g p h a p d i e n ly p l a s m a sieu a m irng d u n g x u ly p h i i m d o R D 1 2 0 U'ong m o i t n r a i g n u o c . C a c k e t q u a S E M . T E M . XRD c h o Uiay C G O t h u dup-c CO c a u t n i c d a n g c^u gai. Q u a tinnh h a p p h u ctia p h a m d o R D 1 2 0 phii h g p voi m o h i n h h a p p h u L a n g m u i r voi d u n g
lirong h a p p h u c u e dai la 99,00 rag/g. Cic ket q u a n a y c h o t h a y C G O la m o t c h a t h a p phu hieu qua c h i phi t h a p d e loai b o p h a m d o R D 1 2 0 trong dung dich
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REUSE OF CARBON ROD IN USED BATTERY FOR ADSORPTION OF RED DYE 120 IN WATER
Nguyen Nhat Huy', Dang Van Thanh^, Phung Thi Oanh^
Dang Thi Hong Phuong*, Ha Xuan Unh^
'Ho CIn Minh city University of Technology, VNU-HCM -T\L'- University of Medicine and Pharmacy 'Vietnam-Russia Tropical Center
^ International School, Thai Nguyen University Summary
Environmental polluUon from used battel-)' is an unsolved issue for both environmenlal manaRers and engineers. New methods for collecUng and recycling used battery are all encouraged and appreciated. This paper presents a simple roule to recycle the carbon rod from used zinc-carbon battery as a precursor for synthesis of crumpled graphite oxide (CGO) viz ultrasonic assisted - calhodic plasma electrolysis. The application of the produced CGO was evaluated by batch adsorpUon of red dye 120 (Rr)120) dye in water.
The affecting factors such as pH (2 - 11) and intual concentration of RD120 (20 - 150 mg/L) were investigated. Tlie adsorpuon of RD120 by CGO matenal follows Langmuir adsorjJtion model with maximum adsorption capacity of 99.00 mg/g, suggesUng a potendal applicaUon of this CGO materia! for removal of dyes and persistent organic compounds m wastewater
Keywords: .Adsorption, graphene oxide. RD120, plasma, electrolysis.
Ngii6i phan bita: PGS.TS. U. Biic Ngay nhjn bai: 25/10/2019 Ngiy thang qua phan bita: 25/11/2019 Ngay duyet dang: 02/12/2019
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