Nghiên cứu ảnh hưởng của axit humic đến sự di chuyển của một số kim loại nặng trong các đối tượng môi trường : Đề tài NCKH. Qt-03-27

DAI HOC QU6C GIA HA N O I TRUCJNG DAI HOC KHOA HOC TLf N H I £ N D^TAI NGHIEN CUfU ANH HUONG CUA AXIT HUMIC DEN SU Dl CHUYEN CUA MOT SO KIM LOAI NANG TRONG CAC DOI TUONG MOI TRUONG MA SO : QT - 03 - 27 CHU TRI Dfi TAI: PGS.TS Bui Du v Cam CAC CAN Bp THAM GIA: -TS Pham Van Tinh -ThS Nguyen Bao Cham DAI HOC Q U O C GIA HA NO* TRUNG TAM THONG TIN THU VIL' N or/ HA NOI 2005 ^36 MUC LUC Trang Bao cao torn tat Mddau Chuong Axit humic va vai tro ciia no moi trudng 1.1 Su ton tai ciia axit humic lir nhien 1.2 Thanh phan va cau tao ciia axit humic 1.3 Tfnh chat ciia axit humic 1.4 Vai trd cua axit humic xii ly moi trudng Thuc nghiem Chuong 2.1 Dung cu, thiet hi 2.2 Vat lieu 2.3 Hoa chat va thudc thu 2.4 Phuong phap nghien cuu 2.4.1 Piui'tm^ phdp ns^lucn cihi tinli 2.4.2 PhU(/ni^ phdp nghien cUu dong 2.5 Phuang phap phan tich kim loai 2.5.1 Phiurng plidp xdc dinh Ph (H) 2.5.2 Phif(/nsi phdp xdc dinli Cd (H) 2.5.3 PliU(/Hi^ pluip xdc diidi Cu (//) 2.5.4 PhU(my, phdp xdc dinh Zn (H) 2.5.5 PhU(my, phdp phdn tich As Ket qua va thao luan Chuong 3.1 Nghien cuu kha nang hap giu cua axil humic ddi \'di Ph ' 3.1.1 Ni^hicn cuu anh hUony, cua pH den kha ndnsj, hdp •^iil Ph ' 1.2 Nghien cihi dnh hudng cua thdi i^ian den kha ndn_'^ hap i,'//?' 3.2 Nghien ciiu kha nang hap giu cua axil humic \'di Cu^* 2.1 Nghien ciiu anh hudng cua pH den kha ndn chia thdi gian den kha ndng hdp gill 3.3 Kel qua nghien cuu kha nang hap giu' cua axit huinic vdi Zn'' 3.1 Nghien ( uu anh hii'chig cua pH den kha ndng hap gift 3.2 Nghien cUu anh huong cua thdi gian den kha nd/i'^ hap ;^iu 3.4 Nghien cuu kha nang hap giu cua axil humic \ di Cch' 4.1 Nghien cuu anh hiuhig c ua pH den kha ndng hdp giil' 4.2 Nghien eu'u anh hiuhig cua thdi gian den kha ndng hap giil' ^.5 Ket qua nghien cuu kha nang hap giucua axil huinic \'di Asen 5.1 Kel qua nghien cuu kha ndng hdp giU As (11/) cua axil humic 5.2 Ket qua nghien cii'ii kha ndng hap gitl' As (\'} hoi axil hiiinu 5.^ Kel qua nghien cuu kha ndng hap ^^iu As M / hoi a\ii huniu CO nidi cua Fe'' 5.4 Nghien eu'u kha ndng hdp giil' A.\ cua sal liunial 3.6 Nghien cuu anh hudng cua mot so dien 1\ den qua trinii hap giu" Cch* 3.7 Tiich cac ion kim loai tren cot chua axil hunuc Ket luan Tai lieu tham khao 7 11 14 14 14 15 15 15 16 17 17 17 18 18 20 2f) 20 23 25 25 28 30 30 33 36 36 3X 41 41 42 42 43 45 46 49 50 BAO CAO • l.Ten de t a i ; TOM T A T Bt T A I Nghien cAu dnh huang cua axit humic den su di chuyen ctia mot so kim loa nang cdc doi tuang moi tru&ng 2.Maso; QT-03.27 3.Chu tri de tai: Biii Duy Cam 4.Cac can bo tham gia: -TS Pham Vdn Tinh -ThS Nguyen Bdo Cham Muc tieu va noi dung nghien cihi : - Nghien cihi kha nang phan ling cua axit humic vdi cac kim loai nang moi truang nu6c - Nghien ciJu cac yeu to anh hudng den kha nang hap phii cac ion kim loai nang ciia axit humic - Nghien cihi kha nang sir dung axit humic lam chat hap phii tach cac ion kim loai nang khoi dung dich nudc Cac ket qua dat duac 6.1 Ket qua khoa hoc - Ve khd ndng phdn dng cua axit humic vai cdc kim loai nang moi trudng nuac: La mot axit hiJu ca chua phan tir nhi^u nhom chiic hoat dong nhu cacboxyl, phenolic hydroxyl, nito di vong, amino tham nen axit humic la mot hgp chat rat hoat dong ve mat hoa hoc No co kha nang tham gia phan ling trao doi cation, tao ket tiia, tao phiic vdi nhieu hap chat vo ca va hiJu ca Axit humic cd the tao phiic tan hoac khdng tan vdi nhi6u ion kim loai nang va phdng xa.Vi vay, cac nguon nudc axit humic dugc xem la tac nhan ldi keo va phan tan cac kim loai nang d cac nguon nudc Kha nang phan ling cua axit humic vdi cac ion kim loai nang Pb^"", Cu""^, Zn^"", Cd^"", As^"", As^^ da dugc nghien ciiu Ket qua cho thay axit humic r^n cd the hap phu kha manh cac ion kim loai - Ve cdc yeu to dnh huang den khd ndng hdp phu cua axit humic Mot so yeu to' da dugc nghien ctiu la pH dung dich, thdi gian phan ling, sir cd mat ciia chat dien ly Trong viing pH tii den 6, neu pH cang tang thi hieu suat hap phu cang tang.Tuy nhien viing pH thfch hgp nhat la 4,5 den 5,5 va khoang 70% den 98% lugng kim loai dung dich cd the dugc hap phu viing pH cao hon dt xuat hien sir thuy phan ciia cac ion kim loai Thdi gian phan ling dugc nghien ciiu tir 20 den 360 phiit Sau 20 phiit hieu suat hap phu da dat tii 50% den 70% doi vdi ca hai loai axit Cac chat dien ly hau nhu khdng anh hudng den phan ling cua axit - Ve khd ndng su diojg axit humic de tdch kim loai nang khoi dung dich nUdc Kha nang sir dung cot trao doi chiia humic dang r^n da dugc nghien ciiu Ket qua cho thay cd the sii dung cot chiia axit humic dang rdn dugc tach tii than biin ciia Viet Nam de tach cac ion Pb^"^, Cu^"^, Zn^"", Cd^'^khdi nudc thai cd mdi trudng axit Hieu suat tach d pH = 4,6 - 4,8 dat 98% B^ng phuang phap cd the lam giam ndng cua cac ion tii 20mg/l xudng cdn 0,004mgA- Ve cong trinh dd cong bd: Da cong bd 01 bai bao tap chf Phan tfch Ly Hoa sinh 6.2 Ket qua dao tao - 01 Thgc sT Moi truang - 01 Cunhdn Hod hpc Tinh hinh su dung kinh phi cua de tai: - Kinh phi dugc cap : 20.000.000 d Kinh phi da sir dung Van phdng pham 1.000.000 d Thue khoan chuyen mdn 7.000.000 d Vat tu hoa chat 10.000.000 d Quan ly hanh chinh 800.000 d Hdi nghi, hgi thao, cdng tac phi XAC NHAN CUA BAN CHU NHlfiM 2.200.000 d CHU TRI D £ TAI KHOA HOA HOC P / H T^ ~IM^^%' jM^u.' PUf PGS.TS Bui Duy Cam XAC NHAN CUA TRUCTNG DAI HOC KHOA HOC TU NHIEN KT.HIEU TRUONG PHO HIEU TRUONG GS.TS Trdn Nghi BRIEF OF PROJECT Title of project: The effect of humic acid on mobilization of heavy metals in the invironment, Code number : QT- 03 27 Coordinator : Assoc.Prof Dr Bui Duy Cam Participants : Dr Pham van Tinh MS Nguyen Bao Cham Purpose and contents of project: - To research the reaction of humic acid with some heavy metals in solution - To determine the factors influenced on adsorption capacity of heavy metal ions by humic acid - To use solid humic acid for decontaminating polluted water by heavy metals Activities and main results : - Humic acid - the fraction of humic substances that is not soluble in water under acidic condition (pH < ) but is soluble at higher pH value - Humic acids are used most effectively in particular in the stage subsequent to chemical treatment of water Due to their outstanding properties of adsorption of liphophlic substances, their high cation exchange capacity, their ability to form hardly soluble complexes with polyvalence cations and heavy metals and their high electron exchange capacity, hmic acids are ideal as sorption medium for a number of water impurities and especially for heavy metals and liphophlic substances In our works, we prepaired two kindes of humic acid One is from peat of Vietnam, one is comercial product of Wako company in Japan and compared their adsorption properties , The complexation of humic acid with cations Pb^"^, Cu^"^, Zn^"^, Cd^"^, As^"", As^ was studied.The adsorption capacity of humic acid depends on pH value of solution and increases with increase of pH (range from to ) After 20 minutes, about 70% to 98% these ions absorbed on solid humic acid at pH = 4.5 - 5.0 We have shown that humic acid packed column 9(0.15 - 0.45 mm particle diameter) can remove 98% these ions at pH = 4.6- 4.8 The extraction effiences were highest for Pb^"^, Cu^"^and lower for Zn^"^, Cd^"^ Arsenic was not absorbed by humic acid MO DAU Cung vdi su gia tang dan sd va phat trien khoa hgc cdng nghe ma nhu cau nudc sinh hoat cua cac qudc gia cang tang manh Song, hien tai van de d nhilm cac ngudn nudc (nudc ng^m, nudc be mat, nudc sinh hoat, nudc thai) cang cd xu hudng gia lang d nhi6u nudc, dd cd Viet Nam Tha'y dugc tam quan trgng cua viec khai thac, bao ve va sii dung hgp ly ngudn nudc ma nha nudc ta da dua nhieu chinh sach vt van dt nhi6u hgi thao qudc gia va qudc te to chiic tai Viet Nam da de cap den viec phan tfch danh gia chat lugng cac ngudn nudc, dua cac cdng nghe xir ly nudc d nhilm Trong sd cac chat gay d nhilm, kim loai nang (trong dd cd As) la ddi tugng dugc quan tam dac biet Theo cac sd lieu da cdng bd thi d mot sd nai cua Viet Nam , ham lugng kim loai nang cac ngudn nudc da vugt qua gidi han cho phep Chinh vi vay, viec xii ly tach kim loai nang khdi cac ngudn nudc la mot nhu cau can thiet va cap bach De tach kim loai nang tii dung dich cd the sir dung nhieu phuang phap khac Song , phuang phap diing chat hap phu thudng dugc sii dung nhieu han ca Axit humic cd chiia nhieu nhdm chiic khac nhu: cacboxyl, phenolic hydroxyl, cacbonyl, nita di vdng, aliphatic va amino tham Do tfnh chat hap phu, kha nang trao doi cation, kha nang tao phiic khd tan vdi cation da hoa tri va cation ciia kim loai nang, cung nhu kha nang trao ddi electron cao ma axit humic dugc xem nhu la chat hap phu ly tudng cac tap chat vd ca va hiru ca nudc Ben canh dd, axit humic cdn dugc xem la tac nhan lam dich chuyen kim loai nang d cac ngudn nudc Trong dl tai nay, chiing tdi nghien ciiu phan ling ciia axit humic vdi cac kim loai Pb, Cu, Zn, Cd, As va kha nang sii dung nd de tach kim loai nang khdi cac nguon nudc khac Chuong I AXIT HUMIC VA VAI TRO CUA NO TRONG MOI TRUCtNG l.l.Sir ton tai cua axit humic tu nhien Axit humic la mot axit hiiu ca yeu.Nd la hgp chat cd phan tu lugng Idn, cd chiia nhilu nhdm tham.Nd la chat kem tan, thudng tdn tai dudi dang rdn d nudc va da't.Trong tu nhien, axit humic tdn tai nhilu d cac loai than va bun Song, chi cd than mim la chiia axit humic vdi ham lugng ldn(tir 30-90% thugc vao md than ) Than biin, biin, cac chat humat cung chiia mot lugng dang ke axit humic (tii 5-60% thudc vao tuoi cua than) O Viet Nam, cd the tim thay than biin d hau het cac tinh tii B^c vao Nam nhu Quang Ninh, VTnh Phiic, Ha Tay, Ha Nam, Bdc Ninh, Bac Giang, Thanh Hoa, Nghe An, Hue va dac biet cd rat nhilu d viing ddng bang sdng Cuu Long Tdng trii lugng than bun ciia Viet Nam la khoang 1.033.355.000 m\ O nudc ngam, cac chat humic thudng tdn tai vdi ndng tir 10 ppb den 100 ppm 1.2.Thanh phan va cau tao cua axit humic Axit humic dugc hinh tii qua trinh phan huy ddng thuc vat Tuy thuoc vao dilu kien chuyen hoa va ban chat cua ddng thuc vat ma qua trinh chuyen hoa se tao nen cac axit humic cd ca'u tnic, trgng lugng phan tu va phan hoa hgc khac Axit humic cd khdi lugng phan tu tii 2.000-600.000 dan vi caebon Tuy thugc vao nguon gdc ma axit humic cd phan khac Tuy nhien, phan chfnh ciia axit humic la cac nguyen td C, H, O, N va mdt lugng nhd cac nguyen td khac nhu S, P, Al, Fe Ham lugng cac nguyen td chu yeu thudng chiem ty le nhu sau: Ham lugng C : tii 55%-65% Ham lugng H: til 3%-10% Ham lugng O : tii 25%-35% Ham lugng N:tir6%-7% Ham lugng cac nguyen td khac : tu 6%-7% Cung cSn phan biet vdi axit fuvic Day la axit cd khdi lugng phan tir tir 5002.000 don vi caebon va cd cau tnic phan tir gan tuang tu axit humic Axit humic cd ca'u tao khdng xac dinh Theo cac ke't qua nghien ciiu gan day thi axit humic la mdt hgp chat tham cd c^u tnic polyme vdi nhilu lien ket giiia cac nhdm tham Cac hgp chat khac lien ke't axit humic la amino axit, amino dudng, peptit axit ali phatic.Axit humic cd chiia cac nhdm chiic khac nhu -COOH, phenol, ali phatic, enolic hydroxyl, C=0 Axit humic la mdt td hgp cac phan tir hinh nhilu sgi dai d pH tha'p va cau tnic linh ddng cd nhilu Id hdng d pH cao Chfnh cac Id hdng cd the giii va hap phu cac cha't vd ca va huu ca mang dien tfch trai dau Phan tir axit humic cd dang polyme, dd cd chiia nhiing hgp chat nhan tham kieu phenol va cac hgp cha't chiia nita dang vdng va di vdng (indol; purin; primidin) va cac axit amin Cac hgp chat tham tao nhan tham ciia axit Humic Cac cSu ndi cd the la nhOng phan tir rieng biet (-0-) hoac la nhdm ( -NH2-; -CH2-) cung cd the lien ket true tiep qua nguyen tu Caebon (-C-) [1,2] Trong cau tao ciia axit humic cd : - Nhdn tham oxy hoa axit humic bdi HNO3, kilm hoac KMn04 ngudi ta thay xuat hien nhiing nhan tham Dd la nhung dan xuat cua phenol, quinon va axit benzoic Theo W Conell cau tnic mdt sd nhdm nhu sau: OH OH OH OH OCH CH 3O OH OCH OCH OCH COOH COOH Nita axit humic HO COOH KfiT LUAN Tir ket qua nghien d tren cd the nit mdt sd ket luan sau day ve kha nang phan dng ciia axit humic vdi cac kim loai Cu, Zn, Pb, Cd, As : Axit Humic cd kha nang phan ling manh vdi cac ion kim loai Cn^\ Pb^\ Zn'\ Cd^-'.Trong mdi trudng axit cd pH tir 1- 6, neu pH cang cao thi kha nang phan ling cang tdt Kha nang hap giii kim loai nang bdi axit humic phu thugc manh vao pH Phan ling dat hieu qua tdt chi khoang pH rat hep tir 4,4 den 5,5, ngoai khoang kim loai cd the bi thuy phan va kha nang hap giir khdng cao Ben canh yeu td pH thi thdi gian phan ling cung anh hudng dang ke de'n kha nang ha'p giii kim loai ciia axft humic Vdi thdi gian tii 120 den 180 phut thi hau het cac phan ling giira kim loai va axft humic dudng nhu dat den can bang Kha nang hap giii ciia axft humic Viet Nam cd phan kem han nhung khdng dang ke so vdi axit humic Wako ( Nhat Ban) Dieu cd the la su khac ve ngudn gdc cua timg loai axit.Cac cha't dien ly it anh hudng de'n su hap phu ciia axit humic vdi kim loai nang Cd the sir dung cdt chiia axit humic dugc tach tir than biin ciia Viet Nam de tach loai cac ion Pb^"", Cu^"", Zn^"", Cd^"" khdi nudc thai cd mdi trudng axit Hieu suat tach d mdi trudng pH = 4,6 ^ 4,8 dat 98 ^ 99% Bang phuang phap cho nudc d nhiem qua cdt chiia axit humic cd the giam nong cua Pb^^ Cu^"", Zn^^ Cd^"" tir 20 mg/1 xudng cdn 0,004 mg/1 49 TAI LifiU THAM KHAO l.Claudio Pereia Jordao, Cesar Reis Adsorption of Cu^^on humic acids Revista Escola de Minas.Wolumt 54, Issue 2, (2001) E.M Logan, L.O Pulford, G.T Cook & A.B Mackenzie Complexation ofCu^^ and Pb^""by peat and humic acid.The European Journal of Soil Science Volume 48, Issue 4,(1997) pages 685-690 3.Martin A.Glaus, Wolfgang Hummel, Luc R Van loon Trace metal - humate interaction I - Experimental determination of conditional stability constants Applied Geochemistry volume 15,(2000), pages 953-973 Pandey A.K, Pandey S.D, Misra V Stability constants of metal - humic acid complexes and its role in environmental detoxification Ecotoxicology and Environmental Safety Volume 47, Issue 2,( 2000), pages 195-200 Ray Von Wandruszka Decontamination of Acid Mine Drainage by Treatment with Solid Humic Acid Water Resources Research Grant Proposal USA (1999-2002) Yates, Leland M.III, Von Wandrszka, Ray Decontamination of Polluted water by treament with a Crude humic acid blend Environmental Science and Technology, Volume 33, Issue 12, (1999), page 20762080 50 DAI HOC QUOC GIA HA NOI TRUONG DAI HOC K H O A HOC TLfNHIEN KHOA HOA HOC Liru THI THANH THUY NGHIEN CUU KHA NANG TACH As TIT DUNG DICH NirOC BANG MOT SO VAT LIEU HAP PHU KHAC NHAU KHOA LUAN TOT NGHIEP DAI HOC HE CHINH QUY Chuyen nganh: Hoa vd ca Can bd hiri'mg clan: P(iS.TS Bui Duy Cnm TS Pham Van linh HA NOI - 2005 DAI HOC QUOC GIA HA NQI TRI/ONG DAI HOC KHOA HOC TU NHIEN NGUYEN BAO CHAM '- T w -) *- NGHIEN Cl/U KHA NANG XU LY NL/OC N H I I M K I M LOAI NANG BANG COT AXIT HUMIC Chuyen nganh: Moi trirdng Ma so: LUAN VAN THAC SY KHOA HOC Ngudi hu'dng dan khoa hoc: PGS.TS Biii Duy Cam L HA N O I - N A M 2004 NGHIEN CLTU KHA N A N G X U LY NL/CIC O N H I £ M KIM LOAI NANG BANG AXIT HUMIC Biii Duy Cam, Nguyin Bdo Cham - Trudng Dgi hgc Khoa hoc Tvr nhien - DHQGHN Pham Vdn Tinh - Vien Hod hpc, Vien Khoa hgc vd Cong nghe Viet Nam SUMMARY Humic acids are used most effectively in the stage subsequent to chemical treatment of water Due to their outstanding properties of adsorption of liphophilic substances, their high cation exchange capacity, their ability to form hardly soluble complexes with polyvalent cations and heavy metals and their high electron exchange capacity, humic acids are ideal as sorption medium for heavy metals and liphophilic substances We have studied decontamination of Pb^"", Cu""', Zn-^ Cd-^ As^*, As'^from acidic water with solid humic acids Two kinds of humic acids are used One is commercial humic acid of Wako Company (Japan) and the other is extracted from peat of Vietnam The influences of pH and shaking time on the adsorption of these metal ions are reported The percent of adsorption increased with increasing of pH (range from to 6) and shaking time (from 20 lo 360 minutes) About 70 % - 98 % of these metal have been adsorbed at pH 4.5 5.0.We have shown that humic acid packed column (0.15 - 0.45mm particle diameter) can remove 98 % these metals at pH 4.6 - 4.8 The extraction effiencies were highest for Pb(II),Cu(II) and lower for Zn(II) ,Cd(II) I DAT VAN DE Sir gia tang manh cac nha may, xi nghiep ciing vdi su tang truong dan so da lam cho nhu cau nudc sinh hoat cua cac quoc gia mot gia tang Song chinh didu da la mot nhiJng nguyen nhan gay nhiem cac nguon nudc ngam, nudc hi mat, nudc sinh hoat, nudc thai Van di bao ve va xir ly cac nguon nudc bi nhidm da duoc nhidu nudc quan tam, dd cd Viet Nam Trong nhiJng chat gay nhi6m, cac kim loai nang nhu Cu, Pb, Zn Cd, As, Hg la mot nhirng ddi tugng dirge dac biet chii y De tach cac kim loai khoi nguon nudc cd the sir diing nhieu phuang phap khac nhu ket liia, hap phu, s^c ky trao ddi ion, xir ly sinh hoc Trong dd, phuang phap hap phu thudng dugc diing nhieu han ca Axit humic cd chiia nhieu nhdm chiic khac nhu: cacboxyl, phenolic hydroxyl,cacbonyl, niter di v6ng,aliphatic va amino thom [1,3] Do tinh chat hap phu, kha nang trao ddi cation, kha nang tao phiic khd tan vdi cation da hoa tri va cation cua kim loai nang, ciing nhu kha nang trao ddi election cao ma axit humic dugc xem nhu la cha't hap phu ly tudng cac tap chat vo ca va hiru ca nudc Axit humic la cha't cd hi6u qua nhat dd xir ly nude bang phuang phap hoa hgc sau dung phep ket tua hydroxyt Phuang phap dac biet cd hieu qua xir ly Pb, Hg, Cd, Zn, Ni, Cr Nong kim loai ddc sau xir ly cd thd thap hon 0,03 mg/1 [4] Trong cong trinh nay, chung tdi nghien ciiu kha nang tach cac kim loai Pb, Cu, Zn, Cd, As khoi moi trudng nudc bang che ph^m axit humic khac IL HOA CHAT THIET BI Hoa chat - Cac hoa chat Pb(N03) H20, Zn (N03) H.O, Cu(N03)., CdC1 2.5 H.O, CH3COOH, HNO3, HCl, A l A deu la loai tinh khiet phan tich PA - Cac che pham axit humic: sir dung loai chd' pham, mot loai la san pham thuang mai Hang Wako - Nhat Ban san xua't (dugc ky hieu la mSu HAI) va mot loai la san pham dugc tach tiJ than bun ciia Viet Nam (dugc ky hieu la mau HA2).' Thiet bi may mdc - May pH DENVER-BASIC - May quang JENWAY 6400 - May phd ha'p thu nguyen tir GA 900 - Cot trao ddi ion bang thuy tinh dudng kinh 12mm III THl/C NGHIEM Trudc het chiing toi nghien ciiu mot sd yeu to anh hudng den qiia trinh hap giir cua axit humic ddi vdi timg kim loai nhu pH, thdi gian phan ling, su cd mat ciia chat dien ly Giai doan dau thuc hien diiu kien tinh de tim dieu kien tdi uu cho qua trinh tach Sau dd ap dung tach tren cot vdi hdn hgp kim loai - Khao sat anh hudng cua pH: Chuan bi 50 ml dung dich cd chua 40 mg kim loai can khao sat va cd gia tri pH can nghien ciiu Chuyen toan bo 50ml dung dich vao binh tam giac cd chiifa 0,lgam axit humic cd kich thudc hat < 0,45 mm Tien hanh lac deu, sau dd lgc dung dich qua gia'y lgc bang xanh O i l Phan tich ndng kim loai cd phan dung dich de tinh hieu suat knn loai dugc ha'p giir - Khao sat anh hudng ciia thdi gian phan ling: Tien hanh thi nghiem tuang tu nhung lac dung dich d nhiing thdi gian khac Cac dung dich ban dau cd pH=5 - Khao sat anh hudng cua chat dien ly: Tien hanh thf nghiem dieu kitn dung dich ban dSu cd pH=5, thdi gian lac 120 phiit, Cd(II) dugc chgn lam dai dien dd nghi6n ciiu, - Khao sat kha nang tach qua cot chiia axit humic: Tien hanh khao sat vdi dung dich hdn hgp chiia Pb^"-, Cu2^ Zn^^ Cd^Vdi loai che phim axit humic cd kich thudc hat va tdc dd chay qua c6t khac IV KET QUA VA THAO LUAN •J Anh hudng cua pH den kha nang hap giii kim loai cua axit humic Mdt sd tai lieu cho tha'y, viec tach kim loai dgc khdi mdi trudng nudc bang axit humic cd hieu qua d mdi trudng axit [4,5] Vi vay, chiing tdi khao sat pH ciia dung dich kim loai ban dau d pH tir -^ Ke't qua dugc chi tren bang Bangl Anh hudng cua pH den kha nang hap giiir kim loai cua Axit humic Luong kim loai duoc ha'p giii (mg) Luong kim loai ban dau (mg) Ddi vdri miu HAI Pb-^ Cu^Zn^Cd-^ Doi vdi mSu HA2 Pb-^ Cu^^ Zn^^ Cd-^ pH 40 40 40 40 40 40 0,69 20,48 24,36 20,20 7,45 21,76 25,17 23,70 11,00 27,20 26,14 28,00 21,28 28,06 28,29 34,10 24,71 30,08 30,09 34,70 28,56 34,88 31,76 38,00 1,5 20,01 25,30 21,40 7,45 22,46 25,47 12,20 25,90 27,00 28,70 20,50 27,89 28,80 32,79 24,30 29,50 30,06 35,70 27,50 33,57 31,30 39,22 24,60 Khi pH cang cao thi kha nang ion kim loai dugc hap phu len cac mSu axit humic cung tang theo viing pH thap, cd su canh tranh giira ion kim loai va ion H"" dung dich ddi vdi cac trung tam hoat ddng mang dien am ciia axit humic Khi pH tang kha nang phan ling cua ion kim loai vdi axit humic cung tang [2,4] Ca ion kim loai d6u cd kha nang lien ket cao vdi axit humic qua cac nhdm cacboxyl va phenolic hydroxyl Sau phan ling, ion H"" dugc giai phdng da lam giam gia tri pH cua dung dich so vdi thdi diem trudc phan ling Ca che hap giii trudng hgp cd le la phan ling trao ddi ion va phan irng tao phiic giiia ion kim loai vdi axit humic Hi6u sua't h^p giii ciia axit humic vdi cac ion kim loai Pb"^, Cu"^, Zn'^, Cd^"^ ciing khac vi nd phu thudc vao ban cha't cua ion kim loai Mat khac, axit humic vdi ngudn gdc khac se cd phdn khac va vi the kha nang phan ling cua chiing vdi kim loai ciing khac Neu so sanh hieu suat ha'p giii Cd^"*" ciia hai loai che phim HAI va HA2 chiing tdi nhan thay cd su khac bi6t khdng dang kd (hinh 1) 120 ^ 100 80 60 •a 40 U Lucmg Cd(n) duac ha'p phu tren HAI Luang Cd(Il) duac ha'p phu tren HA2 20 0 pH cua dung djch Hinh Kha nang hap phu Cd(II) cua axit HAI vaHA2 Nghien curu anh hudng ciia thdi gian den kha nang ha'p phu Thi nghiem dugc tien hanh vdi dung dich kim loai cd pH=5 Khao sat thdi gian phan ling ttr 20 phiit d6'n 360 phiit d nhiet phdng Ke't qua dugc bieu thi tr6n hinh va hinh 100 90 ^ 3J3 80 a 70 Pb(n) Cu(n) Zn(n) Q '< W £ 60 u o(^ a^ 50 cd(n) 40 E 30 ^ &X) Đã a HJ 20 10 0 100 200 300 Thcri gian phan urng (phut) 400 Hinh Anh hudng cua thdi gian phan ung den hieu suat hap phu kim loai tren axit humic HAI Nhin chung, sau 20 phiit hieu suat hap giir dd'i vdi cac ion kim loai Cvr\ ?\y\ Zn^", Cd-^ da dat tit 50 den 70% ddi vdi ca loai axit humic Sau dd, neu thdi gian phan irng tang, hieu suat hap giir cung tang theo nhung chi ddi vdi Cd"^ la tang kha rd ret Dieu cho phep cd thd thuc hien tach hieu qua ion kim loai tren cot chiia axit humic Tiep theo, Chung tdi da khao sat kha nang ha'p giii As(III) va As(V) cua axit humic d pH=5 Ke't qua cho thay ca dang As(III) va As(V) hau nhu khong bi hap giu (hieu suat hap giir khoang 6-7%) ^ I Pb(II) Cu(II) Zn{n) Cd(II) o 100 200 300 Thcri gian phan ung (phut) 400 Hinh Anh hudng cua thdi gian phan ling den hieu suat hap phu kim loai tren axit humic HA2 Nghien cun anh hudng cua mot sd dien ly den qua trinh hap giu Cd'* Tie'n hanh nghien cu\i anh hudng cua mdt sd chat dien ly nhu (NH4).S04, K2SO4, NaCI, KCI den qua trinh ha'p giir Cd'^bang axit Humic d pH = Ket qua duac bieu didn tren hinh C6matK2S04 Co mat KCI Co mat NaCI C6mat(NH4)2S04 20 40 60 Lucmg chat dien ly dung dich (mg) Hinh Anh huong cua chat dien ly den hieu suat hap phu kim loai tren axit humic HAI Su cd mat ciia (NH4)2S04 va NaCI khdng lam giam rd ret hieu suat hap giir Cd^"" Ngugc lai, K2SO4 va KCI lai cd anh hudng kha rd den qua trinh tach Cd-\ Lugng K2SO4 hoac KCI dung dich cang tang thi hieu suat tach cang giam Vai trd d day cd le la ion Kali Tach cac ion kim loai tren cot chira axit humic Tir ket qua nghien cun tach cac didu kien tinh, chiing toi chuyen sang ap dung dieu kien tdi uu da tim dugc de nghien ciiu tach tren cot cd chiia axit Humic HA2 Tien hanh pha dung dich hdn hgp ion kim loai Cu-^ Pb-^ Zn-^ Cd-"' dd mdi ion deu cd ndng 20 mg/1, pH ciia dung dich dugc didu'chinh den gia tri tir 4,6 - 4,8 Dudng kinh cua cot la 12 mm chieu cao Idp axit Humic HA2 la 55 mm ung vdi lugng 4g, kich thudc hat axil humic tiJ 15 - 45 mm Cho dung dich hdn hgp kim loai chay qua cot vdi tdc 34ml/ phut Sau chay qua cot axit humic, ndng tirng kim loai mdi phan doan (500 ml) duac xac dinh bang phuang phap phd hap thu nguyen ttr Ket qua phan tich cac phan doan dugc chi d bang Bang Kha nang tach giu cac ion kim loai tren cot axit humic % kim loai dugc ha'p phu trdn phan doan M, M, Pb-^ 99,95 99,87 99,96 99,99 99,87 99,88 99,70 99,95 M3 M4 M3 Me M7+M8 M9+M,o ion kim Cu^" 99,98 99,99 99,99 99,98 99,98 99,97 99,99 99,98 loai Zn-^ 99,95 99,96 99,98 99,90 99,61 98,92 67,83 9,38 Cd-" 99.99 99.98 99.96 99,94 99.84 99,74 99,40 85,23 Ke't qua tir bang cho ta tha'y kha nang ha'p giu cua axit humic Viet Nam ra't tdt ddi vdi kim loai khao sat d phan doan dau cua qua trinh nghien ciiu dong Hau het cac kim loai ddu dugc hip giii, den phan doan cudi kha nang hap giir Cu^"', Pb^'^ cua axit Humic van rat cao, nong hai ion sau khdi cdt cung chi nhd han hoac xap xi nhu mSu trang la nudc rira axit humic sach ban dau Nghia la ion kim loai nghien ciiu, hai ion Cu""" va Pb""' cd lire tao phiic td't nha't vdi axit humic Cdn luc tao phiic ciia Cd"'', Zn"^ cd le yeu han, dac biet ye'u nha't la Zn""" nen chiing dan bi the day rdi dugc rira giai khdi cot [1,2,3,4] Vdi phan doan - 10 (tiic la cd lit dung dich da chay qua cot), ndng Zn-"" dung dich sau qua cot len tdi 18,4 mgA gan bang ndng Zn""" ban dau dua vao la 20 mg/l.Trong dd, ndng dd cua ion Cu""" da giam xudng cdn0,004mg/^l Nhu vay, neu diing cdt trao ddi chiia axit humic dd tach cac kim loai Pb, Cu, Zn, Cd se cho hieu qua tdt han nhieu so vdi phuang phap tinh Tiv ket qua dd, cd thd nhan xet rang axit humic nhu la mdt cationit IV KET LUAN Axit Humic cd kha nang phan ling manh vdi cac ion kim loai Cu"^, Pb"^, Zn""^ Cd""^.Trong mdi trudng axit cd pH tir 1-6, neu pH cang cao thi kha nang phan ling cang tdt Su cd mat ciia cac chat dien ly gay anh hudng khdng dang kc den kha nang hap giii ion kim loai nang ciia axit humic Q r^- tud ^ir dune cdt chiia axit humic dugc tach tir than biin ciia \'ILM Nam J L.O m e M J *- cr • T-,, ->+ ^ ->+ r^ ^+ /"'J''+ U •• ' • A^^ t" h loai cac ion Pb" , Cu , Zn , Cd" knoi nuac thai co moi truong T^Hieu suat tach d mdi trudng pH = 4,6 - 4,8 dat 98 - ^N^ < Bang ^^* nhao cho nUdc d nhi^m qua cdt chira axit humic cd thc^ iziam ndns phuang p i F Zir\Cd-^ tir 20 mgl xudng cdn 0,004 me/1 ^ ciia Pb ,Cu ,^1 ' ^ ^ TAI LIEU THAM KHAO Claudio Pereia Jordao, Cesar Reis Adsorption of Ci^^on humic acids Revista Escola de Minas.Vohime 54, Issue 2, (2001) E M Logan, L O Pulford, G T Cook & A B Mackenzie Complexation of Cu^* and Pb^*by peat and humic acid.The European Journal of Soil Science Volume 48, Issue 4,(1997) pp 685-690 Pandey A K, Pandey S D, Misra V Stability constants of metal - humic acid complexes and its role in environmental detoxification Ecotoxicology and Environmental Safety Volume 47, Issue 2,( 2000), pp 195-200 Ray Von Wandruszka Decontamination of Acid Mine Drainage by Traatment with Solid Humic Acid Water Resources Research Grant Proposal USA (1999-2002) Yates, Leland M.III, Von Wandrszka, Ray Decontamination of Polluted water by treament with a Crude humic acid blend Environmental Science and Technology, Volume 33, Issue 12, (1999), pp 2076-2080 PHIEU DANG KY KET QUA NGHIEN CUU KHOA HOC I CONG NGHE Ten de tai( hoac dU an): Nghien cihi dnh huong cua axit humic den sudi chuyen cua mpt so kim loai nang cdc ddi tuong moi trudng Ma sd: QT r 03 27 Co quan chu tri de tai(hoac du an): Dai hpc Qudc gia Hd Npi Dja chi: 144 - Duong Xudn Thuy II Hd Npi Tel: 04,8340.564 Ca quan quan ly de tai(hoac du an): Trudng Dai hpc Khoa hpc Tu nhien Dia chi: 334 L Nguyin trdi Thanh Xudn Hd Npi Teh 04,5,583,001 Tong kinh phi thuc chi : 20.000.000.d Trong do:- Tdngdn sdch Nhd nu&c : 20,000.000 d - Kinh phi cua trudng : d - Vay tin dung : d - Vdn tuco : d - Thu hoi : d Thoi gian nghien ciru: 7* thdng Thdi gian bat dau: 10/2003 Thdi gian ket thuc: 06/2005 Ten cac can bp phdi hgp nghien cufu TS, Pham vdn Tinh ThS Nguyin Bdo Chdm So dang kyde tai j Sd chirng nhan dang ky ket qua nghien ciiu: Ngay: Bao mat: Pho bien rpng rdi TOM TAT KET QUA NGHIEN CLTU: Axit Humic co kha nang phan ling manh vol cac ion kim loai Cu"\ Pb"\ Zn""^, Cd^^.Trong moi tnrcmg axit co pH tuf - 6, neu pH cang cao thi kha nang phan ihig cang tot Kha nang hap giu* kim loai nang boi axft humic phu thuoc manh vao pH Phan ung dat hieu qua tot chi khoang pH rat hep lix 4,4 den 5,5 Ban canh yeu to pH thi thoi gian phan ung cung anh huong dang ke den kha nang ha'p giu" kim loai cLia axit humic Vdi thcri gian tu 120 den 180 phut thi hau het cac phan ung giu'a kim loai va axft humic duong nhu dat den can biing Kha nang hap giu cua axft humic Viet Nam co phan kem hon nhung khong dang ke so vol axft humic Wako { Nhat Ban) Dieu co the la su khac vt nguon goc cua tung loai axit.Cac chat dien ly ft anh huong den su hap phu cua axit humic voi kim loai nang Co the su diing cot chiia axit humic d\sgc tach tu than bun cua Viet Nam de tach loai cac ion Pb'", Cu'", Zn"", Cd~" khoi nuoc thai co moi truong axit Hieu suat tach moi trucmg pH = 4,6 - 4,8 dat 98 - 99% Bang phuong phap cho nudc nhiem qua cot chua axit humic co the giam nong cua Pb"", Cu"*, Zn"", Cd'" tu 20 mg/ xuong 0,004 mg/1 Kien nghi ve quy mo va doi tuomg ap dung nghien curu Day la ket qua ban dfiu mo kha nang su dung nguyen lieu siin co nudc dc xir ly cac ngudn nudc thai nhidm kim loai nang co moi tiucyng axit