Sử dụng sét chứa chất hữu cơ trong việc xử lý tách dầu ra khỏi nước vỉa

Tuyin tap bao cao Hgi nghj KHCN "30 nam DSu khi Vift Nam: Cff hgi mdi, thach thde mdi" 181<br /> <br /> <br /> <br /> Sir DUNG SET CHlTA CHAT HLTU CO TRONG VIEC<br /> Xif LY TACH DAU RA KHOI NlfOC VIA<br /> <br /> Pham Thj Le Minh<br /> Vien Ddu Khi<br /> Cao Anh Dung<br /> Cdng ty Dung dich khoan vd Hod phdm Ddu khi<br /> <br /> TOM TAT<br /> Di tdng hi sd thu hdi ddu, mpt phuang phdp hay dugc ung dung Id tdi xir ly nuac<br /> (nuac via, nuac da duac xir ly) bam ep lgi vdo trong via. Cdc logi nuac thdi ndy diu cd<br /> ldn ddu vd cdc nguyen hiu khdc nhu kim logi, ddt da, v.v.. Di hgn chi tdi da su ket miit<br /> giing khoan, diiu quan trgng nhdt Id phdi xu ly logi bd dugc ddu vd cdc kim logi ndng<br /> khdc ra khdi nuac via.<br /> Bdo cdo gidi thieu mpt phuong phdp xir ly nude via cd hiiu qud kinh ti khd cao<br /> (dang duac irng dung tgi My) [2j. Phuong phdp ndy su dung set chira chdt him ca cd kit<br /> hgp than hogt tinh di tdch logi bd ddu ra khdi nuac via.<br /> Trong trudng hap mudn logi bd cdc kim logi ndng, cdc nguyen lieu khdc thi thiit bi<br /> xic ly phdi dugc thiit ki ddc biet, cdn than, cd tinh todn chat che cho mdi mpt trudng hgp<br /> sic dung.<br /> Logi set chira chdt hiru ca duac yeu cdu sir dung la set bentonit dugc trao ddi bdi<br /> cdc cation cua cdc amin bgc bdn.<br /> Nhiing nguai van hdnh cd the xir ly set chica chdt hieu ca mpt cdch di ddng tren ddt<br /> liin, ngay tgi giing khoan hay cd thi chuyin set ndy sang cdc tdu di sdn xudt atphan hodc<br /> cdc mdy trpn nhien lieu.<br /> <br /> G l d l THIEU CHUNG<br /> Rat nhieu nha khoa bgc da dua ra cac ly thuyet ve sy tuomg tac giua eae amin vdi<br /> ldp silieat eua set [1]. Mdi lien ket cua amin (cac amin bae 1, bae 4, mach dai, mach ngan<br /> hoae cac polyamin) vdi ldp silieat (montmorillonit, mica, vermieulit, v.v...) tao thanh<br /> phirc chat cd cac tinh chat rieng biet, do vay khi ung dung set ehua chat hiru co phai quan<br /> tam den eau true va tinh chat ciia ehiing. Cac cation trao ddi cd mat trong set cd the duge<br /> thay the bang cae cation amoni bae 4 mach dai, khi dd set se ed kha nang truong nd va<br /> phan tan dugc trong cae dung mdi hum co khae nhau [4]. Set chua chat hum co cd img<br /> dyng rdng rai trong cdng nghiep. Vi du, set chua chat hdu co la cau tir quan trgng trong<br /> dung djch khoan gdc dau, trong son, nhya deo, cac chat bdi tron, trong ITnh vyc my pham,<br /> myc in, sac ky, v.v... Set chua chat biha co cdn duge diing lam chat phan tan cua cac<br /> polyme ua nude trong dau va lam cac chat xue tac [4].<br /> Set ehua chat bijru co da duge cac nha khoa hgc nghien cuu trong khoang 50 nam<br /> nay, nhung cau true, co che truang nd va sy phan tan cua chiing trong cac dung mdi huru<br /> CO vin chua dugc hieu rd. Sau day chiing tdi se dua ra mdt sd thuat ngir, khai niem lien<br /> quan din eau true va tinh chat cua set chua chit him co.<br /> Set chua chit hiru co dugc dilu ebl tir set dang smectit (bentonit) da duge tinh ebl<br /> 182 Sd dung set ehda chat hdu co trong viec xd Iv tach d;iu ra khoi nuoc \ ia<br /> <br /> <br /> udt de loai bo cac thanh phan khoang phi set thd. Vira set na> cd thanh phan khoang<br /> montmorillonit Na. Ca. Mg. Cac ion Na*. Ca"". Mg" dugc coi nhu la cac ion trao ddi.<br /> Dung tich trao ddi ion cua set na)- phai dat it nhat la 75mcq'10()g set khd. Set nen dugc su<br /> dung tdt nhit a dang montmorillonit - Na (set na>' cd kha nang truomg no' rat tdt). Trdn sin<br /> vdi hgp chit amoni bae 4 hoae hdn hgp amoni cua chimg (2M2irf: dimethyl<br /> bihydrogenated tallow ammoniumchloride; ammoni di (CislL,-') dimcth\l; ammoni di<br /> (C1XH37) benzyl methyl va ammoni di (Ci^Hj?) benz> 1 dimeth\l. \.\...) ciing vdi mgt chat<br /> pha loang (metanon. axeton. propylen carbonat. prop) len gl)col. di cl) len ghcol. \'.\'...).<br /> chit nay la chit phan cyc dugc cho vao nham tang cudng kha nang truang na cua set<br /> trong cac dung mdi huu ca. Khi dd trong huyen phii set xa)' ra su trao ddi ion nhanh<br /> chdng va hoan toan theo phuang trinh sau:<br /> Mont - Na^ + R,R2R3R4N*CI ^ Mont - N^ R,R2R3R.i + NaCI<br /> Mont= Montmorillonit<br /> R= Hydrocarbon<br /> San pham thu dugc d dang keo va cd tinh chat ky nude, ggi la set chira chat hiru ca<br /> dugc dem Igc. lam khd va nghien den kich thudc mong mudn [6. 7].<br /> <br /> 1. Cau true ciia set chira chat huu co'<br /> 45niii<br /> <br /> Da ttuirc xii ly<br /> \i'yi chat phan<br /> <br /> <br /> <br /> <br /> chira xir ly si'd<br /> chai phan cue<br /> <br /> <br /> <br /> <br /> 10 X<br /> <br /> <br /> <br /> <br /> Hinh 1: Sy thay doi ctia khoang each dodi khi co chat phan cue<br /> Cac cation cua cac amin nhu di (HT) dimeth)! ammoni se khuyech tan \a hip phu<br /> bao phii tren be mat hat set cd dien tich khoang 2nm". trong khi vimg trao ddi cation cua<br /> montniorillonit chi khoang l,4nm^ Do dd, khoang each ldp ben trong (d,,,,,) phai dugc<br /> lam day them bai it nhat la 3 mach hydrocarbon (HC). Xac dinh quang phd .X mau bdt set<br /> huu CO cho thay dinh pic cd be rdng tir 2.6 - 2.9nm (Hinh 1). Dieu nay tuang ima \'di 4<br /> mach HC khi nam det cd khoang each S = 4 x 0,4nm + 0,96nm = 2,56nm hoae tuong<br /> duong vdi mdt mach octadecyl khi nam nghieng mdt gdc 54"44' so vdi ldp silieat (S =<br /> Tuyen tap bao cao Hgi nghj KHCN "30 nam Dgu khi Viet Nam: Co hgi mdi, thach thde mdi" 183<br /> <br /> 2.9nm). Khoang each d,,,)] rat de bi tha) ddi khi cd sy hap phu cua cac phan tu phu trg cd<br /> cyc hoae khdng cd cyc. Tren Hinh 1 ciing cho thay khoang each do,,! thay ddi tu 2.8nm<br /> den 3,45nm. Su thciy ddi nay la do cd sy hgp nhat cua mdt vai phan tram cac phan tu dac<br /> trung nao dd trung hda vao trong bdt set. Ciing vdi viec tang khoang each di,,,!. su .xuat<br /> hien ciia chat phan cyc se lam dn djnh cau triic va khoang each cua cac dinh pic se hep va<br /> sac net hon. Sir tuang tac ciia set chira chat huu co^ vdi phan tir phan cyc trung hda ddng<br /> vai trd quan trgng nhu la cac chat keo tu trong cac dung mdi huu ca [5].<br /> <br /> V<br /> <br /> <br /> <br /> <br /> (a) (b)<br /> <br /> Hinh 2: Minh hoa kha nang ciia cac ion amoni ci) the sap xep<br /> vao khoang each ben trong dom ciia montmorillonit<br /> Cd nidt quan niem khae ve sy hinh thanh cau tnic cua phirc chat. Cac trat tu duge<br /> sap xep trong can tnic ciia set chira chat huu co phu thudc rat nhieu vao ban chat ciia dung<br /> mdi (nude hoae hgp chat hiru co). De nghien ciru va dua ra cac thdng sd chinh xac ve cau<br /> tnic ciia phiic chat ngudi ta phai diing phuong phap nhieu xa tia Ranghen (X - ra)) |3].<br /> 2. Tinh chat truong nd ciia set chua chat hiiu co'<br /> Set chiia chat huu co rat de bi tam udt boi cac dung mdi huu ca. Tuv' nhien, de<br /> irng dung cd ich dugc trong cdng nghiep thi set phai cd kha nang phiin tan tdt thanh<br /> cac hat nhd rieng re va cd the tao gel trong cac dung djch huyen phii rat loang (dung<br /> dich 1% trgng lugng). Trong bat ky ITnh vyc irng dung nao thi he dung mdi ciia set<br /> chii'a chat hCru co phai dugc xem xet can than vi kha nang tao gel cua set rat khiic nhau<br /> trong cac dung mdi khae nhau. Cac dung mdi lam cho set chira chat huu co' cd kha<br /> nang truong nd tdt thdng thudng cd chira cac nhdm hoae cac phan tir ua nude va ky<br /> nirdc. Vi vay. cac hgp chat HC khdng phan cue tinh khiet se khdng lam cho set chira<br /> chat hiru co truang nd dugc vi cac HC nay khdng cd kha nang sonvat hda cac HC ciia<br /> cac amin cd trong set chira chat hiru ca. Trong khi dd, cac dung mdi phan cyc nhu<br /> nitrobenzen tham chi ngay ca styren cting cd the lam cho set chii'a chat hu'u co truong<br /> no rat tdt. Dieu nay cd the la do cac nhdm phenyl cd kha nang hap phu manh Ircn be<br /> mat silieat va nd ddng vai trd nhu la mgt chat hoat hda phan cue. Cac chat hoat hda<br /> dugc irng dung rdng rai la MeOH, EtOH. Me2C03 hoae prop) len carbonat dugc them<br /> vao vdi ham lugng tir 10 - 50% theo trgng lugng ciia set huu co. Mdt sd nghien cii'u<br /> cho tha)' cac chat na)' cd the tham nhap sau vao trong cac ldp. hap phu len be mat<br /> silieat \'a bat dau qua trinh truang nd.<br /> Kha nang keo tu cua set chira chat huu ca tha)' ddi rat nha) theo l) le cua amin va<br /> set. Hinh 3 cho thay anh hiro'ng cua ty le amin/set din do nhdt bieu kiln cua dung dich<br /> hu)'en phii set chira chat hiru co trong dau khoang nhe. Thanh phin cua hu)'en phii na)<br /> gdm: 93,33 % dau khoang nhe, 1.67 % propylen carbonat, 5 % set chira chit huu co.<br /> 184 Sd dung set chij-a chat hdu cff trong vifc xd ly tach dau ra khdi nude via<br /> <br /> <br /> AV(Pa.sx 10')<br /> <br /> <br /> 1.2 H<br /> <br /> 1.0-<br /> <br /> 0.8 H<br /> <br /> 0.6-<br /> <br /> 0.4<br /> <br /> 0.2 H<br /> <br /> <br /> <br /> 80 85 90 95 100 105 110<br /> Ty le amin/set (meq/lOOg)<br /> <br /> Hinh 3: Anh hirdng cua ty le amin/set den do nhdt bieu kien AV<br /> Tai ndng do amin thip thi set khdng truang nd, cd the la do ehudi mach amin hap<br /> phu ldp mdng tren bl mat silieat, ndng do amin qua cao thi kha nang tao gel eiing bj uc<br /> chi. Nguyen nhan ciia dilu nay cung chua duge biet rd. Cac chat boat hda phan eye ciing<br /> ddng gdp vao viec tao ciu tnic gel bang eae lien ket mach hydro canh - canh vdi cac hat<br /> set phan tan.<br /> Mdt dilu luru y la vdi mdt lugng nude rit nhd (1%) - 2 % trgng lugmg so vdi trgng<br /> lugmg eiia set chua chit him co) cdng rat can thiet trong qua trinh hinh thanh gel. Vai tro<br /> eua nude eiing chua duge biet ehinh xac nhung cd mdt dieu chac chan rang ehi vdi mdt<br /> lugng rat nhd ciia nude ciing lam cho do linh ddng eiia cac ion amoni bae 4 tren be mat<br /> hat set tang len. Mat khae, nude eiing ed anh hudng den the zeta cua set chua chat hum co<br /> khi phan tan trong cac dung mdi hiru co. Ngudi ta cho rang nude gay ra trang thai ludng<br /> cyc d tren be mat hat set va tao nen lye day ludng cyc gdp phan vao thiie day qua trinh<br /> truomg nd eua set chira chat biju co sau khi ket thuc vai trd cua chat boat hda phan cue.<br /> Ddi khi nude ciing duge chu ddng eho them vao trong qua trinh san xuat chat bdi tron ma<br /> cd sir dyng set chiia chat hum co, dac biet trong trudng hgp ed su dyng dau ndng. Vi du<br /> nhu trong san xuat som thi viec sir dyng ket hgp metanol/nudc cho hieu qua eao hon la chi<br /> diing metanol.<br /> Nude cd mat trong thanh phan set chiia chat hiru co se tao ra cac lien ket hydro canh<br /> - canh, canh - mat tren cac phien set phan tan va do dd cai thien dugc cudng do gel. Trong<br /> hau het cac trudng hgp, de pha vd cac td hgp hat set va de dam bao eho mdi td hgp phan<br /> tan deu, rieng re trong dung mdi thi can phai cd mdt lye eat xen. Dieu nay rat quan trgng<br /> trong nhiimg dung mdi cd do nhdt cao nhu cac dung mdi dugc dimg trong san xuat chat<br /> bdi tron.<br /> Ngay khi gel dugc hinh thanh, thdng thudng thi gel se dn djnh rat ben virng, nhung<br /> ddi khi su tuomg tac eiia eae eau tir khae trong thanh phan se gay ra su keo ty va lam giam<br /> cudng do gel. Vi dy nhu trong hdn hgp chat bdi tron va trong nhya polyeste/styren cd tdn<br /> tai cac bgt xa phdng kim loai. Dieu nay duge coi nhu la mdt djnh de rang: cac bgt xa<br /> Tuyin tap bao cao Hgi nghj KHCN "30 nam DSu khi Vift Nam: Cff hgi mdi, thach thde mdi" 185<br /> <br /> <br /> phdng lien kit phdi tri tai cac canh eua cac phien set va do dd lam eho lien ket canh - canh<br /> yeu di. Hieu img bit lgi nay cd the dugc xir ly bang each cho them mdt sd cac cau tu khae<br /> nhu amin dl cho amin tao lien kit hydro vdi cac bgt xa phdng kim loai. Mgt hieu img ed<br /> hai tuomg ty cung dugc quan sat khi cho du chat boat hda phan cyc.<br /> Ciing cd mdt djnh dl khae eho rang: cac chat bap phy du tai cac canh cua phien set<br /> se lam pha vd cau true canh - canh va tao cac lien ket song song tren cac phien set. Kha<br /> nang tang the tich eua set chua chat hiru co se tang len khi ndng do ciia chat hoat hda phan<br /> cue tang. Dieu nay cd the gay khd khan neu ban than dung mdi la cac chat phan eye nhu<br /> este hay alcohol [3].<br /> 3. Su" tuomg tac gifra set vdi cac hop chat hiru co" (cac mudi amin dac trirng)<br /> Cac anion hum eo dugc hap phy tai cac canh eua cac hat set, nguge lai cac cation cua<br /> phan tir hiru co lai dugc hap phy len cac be mat tich dien am cua cac hat set thay the cac<br /> cation Na"^, K"^ hoae Ca^"", v.v... Rd rang dieu nay cho thay kha nang hap phy cua set ddi<br /> vdi cac cation manh hom va khi dd khdng gian day (khoang each dooi) cua cae hat set<br /> montmorillonit tang len sau khi duge xir ly vdi eae cation hum co.<br /> Khi mudi amin (vi dy nhu mudi R - NH3^Cr hoae mudi amoni bae 4, hoae bazo<br /> (R4N^Cr hoae R4N"^0H")) dugc them vao trong dung djch huyen phii set thi cac cation<br /> hum CO se thay the cac cation gdc cd mat tren cac be mat hat set hay ndi each khae khi dd<br /> cd sy trao ddi hap phy xay ra. Cd sy hap phy chgn lge cua hat set ddi vdi cac cation hum<br /> CO (hap phy djnh lugmg) cho den khi tat ca cac vi tri trao ddi duge eae cation bum eo thay<br /> the vao.<br /> Cac nhdm amoni lien ket rat manh vdi cac be mat set. Ddng thdi cac ehudi mach<br /> hydrocarbon ty chung se lien ket vdi be mat set va thay the cac phan tir nude da duge hap<br /> phy trudc. Phiic hum co - set duge bieu dien tren Hinh 4a. Trong hinh nay ngudi ta gia<br /> thiet rang khoang khdng gian tren be mat set du de cho mach HC nam vao. Neu mach nay<br /> qua dai thi chiing se nam nghieng hoae 2 Idp cation hum co se nam chdng len nhau neu set<br /> cd do truang nd cao. Be mat trao ddi eua phiic luc nay bj che phu bdi cac mach HC, do dd<br /> nd khdng bj lam udt bdi nude va set se ket tua (tuy nhien gan day ngudi ta quan sat thay<br /> vai phuc hum eo - set eua montmorilllonit bj truomg nd d cac ldp ben trong, nghTa la cd<br /> cac ldp nude hap phy d ben trong phiic hum co - set). Ddng thdi tren be mat phuc set duge<br /> lam udt bdi dau va do dd set bj phan tan khdng ddng nhat trong cac chat ldng hum co.<br /> Phuc trao ddi cua set ciing se xue tien nhd hda.<br /> <br /> <br /> ffl I (^ I ffl I ffl"<br /> (a)<br /> <br /> o o o o<br /> 1 (+) 1 ffl 1 ffl<br /> l^+^sl<br /> ffl 1 c+^ 1 (+)<br /> 1 (+)<br /> <br /> (b)<br /> <br /> Hinh 4: Cach sip xep cac phan tir amin len be mat hat set<br /> Kha nang hap phu cua cac cation hiru co khdng cd gidi ban din dung tich trao ddi<br /> 1 86 Sd dung set ehda chat hdu co trong vice \ d Iv tach diiu rajvhoi nude via<br /> <br /> <br /> cation cua set. \'i du. \'di cac hgp chat amoni bae 4 mach dai cd 3 nhdm met) 1 thi kha<br /> nang hip phu se gap 2.5 lan so vdi dung tich trao ddi cation cua set. Muoi hiiu eo' du dugc<br /> hip phu \'at ly bang luc lien ket Van - dec - Van. Cac ion cua cac phan tu' bi hap phu \at<br /> ly cd xu hudng tien \'e phia pha nude. Cac cation hiru ca cimg \ di anion cua nhdm ionic<br /> se tao thanh Idp dien tu kep. cd the dugc khu)'ech tan nhieu hoae it \ a phire hap phu liic<br /> na) dugc coi la cd tich dien duang nhu trong Hinh 4b.<br /> Caeh sap xep na) dugc nit ra tir thuc te. khi tien hanh thi nghiem dien di cho tha)<br /> set bi giai keo va cac hat set trd nen tich dien duong. Liic na) set khdng edn cd kha nang<br /> ua diu nira do dd khdng cd kha nang de dieu che nhii tuang ha) phan lan \ ao trong cac<br /> dung mdi h)drocarbon. Kha ncing tao nhu cua phiic hiru ca - set dugc the hien tai diem<br /> tiro'ng du'O'ng cua qua trinh trao ddi cation. Viec dinh hudng cua cac cation \ao ldp ben<br /> trong \'a khoang each da)' dooi cua cac phirc ludn duge xac dinh. Be mat dy kien cua cac<br /> cation trong \'iing djnh hudng nen dugc can bang hoae nho hon \'di \ img be mat trao ddi<br /> sin cd. Mdt phuo'ng phap dua ra de danh gia mat dd dien tich be mat la dya tren viec do<br /> khoang each dom cua phirc chat vdi cac cation mono dialk) 1 amoni \di cac chieu dai nicich<br /> khae nhau. Cac cation tho'm cd the nam a vi tri song song hoae thang diing giua cac ldp<br /> phu thudc \ ao khoang each dooi san cd [3J.<br /> <br /> 4. Do on dinh ctia set chiia chat huu co'<br /> Ion amoni bae 4 dugc hap phu rat manh len vung trao ddi cation cua montmorillonit.<br /> Vi vii). chiing se khdng bi cac dung mdi hda tan \a cau tnic cua phiie huu co' - set dugc<br /> dn dinh mac dii trong dung dieh cd mdt lugng ldn cac cation kim loai. Do ben cua phirc<br /> hiru CO - set mdt phan la do luc hut Van - dec - Van giua cac mach I IC \ a giua mach I IC<br /> vdi be mat hat set (hieu img nay tang len nhanh chdng khi chieu dai mach I IC lang) \a<br /> mgt phan khae la do do ben nhiet ddng hgc cua cac ion amoni biic 4 tren be mat eiic hat<br /> set so vdi do ben nhiet ddng hgc ciia chiing dugc h)'drat hda. Do vay, keo tu set huu ca la<br /> tuong ddi dn djnh nhiet. nd cd the dugc sir dung a nhiet do len tdi 250"C. Dieu nay cho<br /> phep sir dung set chira chat hiru co trong dung dich khoan. trong so'n luu hda niiiet va<br /> trong chat bdi tron [3].<br /> Qua mdt sd khai niem tren, chiing tdi cd the nit ra mgt sd ket luan sau 11 |: Co che<br /> truong no cua set chira chat hiru co trong cac dung mdi hii'u ca hien na) \'an chua dugc<br /> hieu rd. Cd mdt sy can bang giira luc hiit Van - dec - Van (luc nay cie giii cac td hgp set<br /> lien ket vdi nhau) va luc dien (trg giiip cho qua trinh truang no). Cac bang chimg dua ra<br /> cho phep chimg ta hieu set truong no chii yeu theo co che sau: khi set chira chat hiru co<br /> dang khd dugc khuii)' \'di dung mdi hiru co. cac phan tu phan cue nho han cd kha nang ai<br /> lye \'di be mat silieat se tham nhap vao khoang khdng gian giua cac ldp. Cac mach HC<br /> cua cac amin hap phu Idp mong nhung cong tren be mat silieat. bit dau tang len. Su cd<br /> miit cua mdt lugng nho nude rat can thiet de cai thien tinh linh ddng cua eiic ion amoni<br /> bcic 4 \ a cho phep cd nhieu ho'n cac dung mdi va cac phan tu phan eye tham gia vao phan<br /> img. Cudi eiing la cau tnic tactoit ciia set bj pha vd va set \'an tiep tuc truang no do cd luc<br /> da)' lirdng circ. Dung dich hu)'en phii dugc phan tan hoan toan do sy chuyen dich cit xen<br /> va cau true gel dugc dn dinh nhd cac phan tu phan cue do hinh thanh cac cau noi lien kit<br /> h)dro. Cac phan tu nude ddng vai trd quan trgng trong qua trinh truang na cua set \'a dn<br /> dinh ael.<br /> Tu>cn tap biio ciio Hgi nghj KHCN "30 nam D3u khi Viet Nam: Cff hgi mdi, thach thuc moi" 1 87<br /> <br /> <br /> UNG DUNG SET CHUA CHAT HUU CO TRONG VIEC TACH DAI RA KHOI<br /> NUOC VIA<br /> 1. Cac quy tac trong xii' ly nude thai<br /> 0 My vice cap giay phep cho xu ly nude thai cd chira diiu. md bdi li'on \ii ciic kim<br /> loai nang niio dd la nit nghiem ngat. Viec dua nude thai den noi xu ly riit tdn kem tir 0.1 -<br /> I USD/gal (3,785 lit) [2J. dieu nay lam tang them mdt khoang ehi phi dang ke eho \iee xu<br /> ly. Cue bao ve mdi trud'ng d My (EPA) da phan loai khai thac diiu mo thiinh hai loai: khai<br /> thac ngoiii khoi va khai thac ven bd. BAT (Best Available Technolog) ) qu)' dinh rd ehilt<br /> phe thai dugc gidi ban tdi da cd chira 29mg/l dau kin trong nu'dc. tinh trung binh tren 30<br /> nga)'. cdn Offshore BCT (Best Conventional Technolog)) ehi qu) dinh khoang 48mg''l.<br /> tinh trung binh tren 30 ngiiy [9]. Nhung qu)' dinh nil) ed the dat duge khi xu ly nude \ la<br /> being hda chat, nhung cung chua thoa man dugc yeu cau cua My. Vi du nhu khdng chi de<br /> loai bd dau ra khdi nude via ma cdn xir ly dugc cac loai nude bi nhiem ban bo'i diiu nhien<br /> lieu, xang gasoline, nhien lieu diing trong cdng nghiep himg khdng. \ .\.. Lugng diiu cd<br /> trong nude thai khdng qua lOmg/1.<br /> Dc thiet lap mdt tieu chuan cho nude udng tir nude ngam vii nude be mat ngudi ta<br /> dya theo tieu chuan ciia BAT, edn EPA thi dua ra cac gidi han ve hiim lugng kim loai<br /> nang cho phep trong nude via nhu ddng (Cu), arsen (As), kem (Zn), hiim lugng HC thom<br /> tdng va loan bd cac chiit ddc phe thai. Dieu nay cd nghTa lii phuo'ng phiip liim sach bao<br /> gdm ca carbon boat tinh dang hat va nhua can trao ddi ion cung deu dugc xu ly tai ehd. Sir<br /> ket hgp giua Chinh phii My va EPA se liim cho nude via tai \ img ven hd nit sach.<br /> Khi nude via hay nude bo'm ep cd dang polyme thi lirgng dau trong nirdc chi cho<br /> phep den 50ppm [9]. Nude thud'ng dimg de sinh hoat cung ed the bi nhiem biin boi dau. 0<br /> Cdoet, nude sinh boat riit hiem, chiing bi nhiem diiu d mdt dien riit rdng sau chien tranh<br /> vLing Vinh.<br /> 2. Phuong phap xii' ly<br /> De xir ly lam sach nude via cd the ngirdi ta se bom viio trong binh tiich dau'nu'dc<br /> mdt he dung djch nhu tuong ldng (axit hoae demulsifier) hoiic cd the su dung ciic tiii Igc.<br /> binh Igc cd set chira chat hiru co dang hat hoae than boat tinh dang hat de loai bo ciic HC<br /> tho'm bay ho'i va cac can nhya trao ddi ion (cac kim loai nang). Tiit ca cac thiet bi nil)' deu<br /> cd the dat tren ciic xe mode di ddng de di chuyen den ciic no'i xu ly mdt each de dang.<br /> Set chira chiit hu'u co thdng thudng dang hat cd kich thiidc 8 x 3()US mesh size<br /> (75ym) dugc trdn lan vdi antraxit (than boat tinh cao cap) cd cimg kich thudc \ ii cimg t)'<br /> khdi (0.896g/cnr') nhu set ehira chat huu co.<br /> Hdn hgp set chira chat huu co dugc sii' dung khi ndng do cua dau lan trong nude via<br /> khoang 70ppm hoae it ban. chiing ddng vai trd la chat lam sach giai doan cudi trong bd<br /> phiin tiich diiu/nudc. Neu trong he thdng nay cd sir dung than boat tinh thi hdn hgp set<br /> chira chiit hiru co dirge diing d giai doan trirdc khi cho qua than boat tinh.<br /> Set chira chat hiru co cd the loai bd mdt khdi lugng diiu biing 50% trgng lugng cua<br /> nd tire lii gap 7 lan so vdi than boat tinh. chinh vi the ma nd dirge su dung rdng nii thii)<br /> eho than boat tinh.<br /> Trong mdt thai gian dai, nganh cdng nghe khoan da sii dung set chira chiit hiru co<br /> dang bdt de lam chiit tiiy do nhdt, chat phu gia cho dung djch khoan goc diu. Dung dich<br /> chira set chira chit huu co cd the chju dugc nhiet do len tdi 175"F (97"C) trong ciie thiet bi<br /> 188 Sd dung set chu-a chat hdu co trong vifc xd ly tach dau ra khdi nude via<br /> <br /> <br /> dun sdi d cac nha may Igc dau.<br /> Qua trinh tach la mdt qua trinh hda hgc xay ra giura set chiia chit hum co va cac gigt<br /> dau. Cae amin bae 4 trong set chua chat hum co lam eho set cd tinh ua chit bum co (dau)<br /> va ky nude do dd nd se phan bd hoae hda tan phan tan vao trong diu va lam cho cac gigt<br /> dau bam viu vao eae hat set bang lye Coulombic [2].<br /> Khi cho set chiia him co vao phan tan trong cae dung mdi hiiu co (HC) thi set se<br /> trucmg nd va lam cho dung djch dam dac len va cd tinh bdi tron eho mui khoan va bit nhet<br /> vao cac Id xdp trong gieng khoan.<br /> 3. Van de kinh te trong viec xu ly nu'dc via<br /> Lgi ich kinh te ciia viec su dyng set ehiia chat hum co cho thay rat rd tai trung tam<br /> Michigan, d day, trong eae gieng bom ep, nhumg ngudi van hanh da xu ly khoang 3.500<br /> thung nude via tren mdt ngay, trong dd cd chua 500ppm can dau. Nude via da dugc xu ly<br /> dugc diing lai de bom ep vao via. Do lugmg dau edn lai qua nhieu sau khi xu ly, nen tdc<br /> do bom nude giam manh vi nd gay ra hien tugng bit nhet be chua va do dd cac gieng<br /> khoan phai dugc bao dudng, nia gieng cu hai, ba thang mdt lan. Cdng viec nay ddi hdi<br /> phai lap dat them cac thiet bj khoan kem theo de bom axit HCI va cac dung mdi xylen dl<br /> dan dan phye hdi lai do tham thau cua via.<br /> Cdng viec bao dudng cac thiet bj khoan phai mat 3 ngay kem theo viee su dyng axit<br /> va dung mdi de bom, do dd da lam tang chi phi len 7.500USD cii sau mdi 2 - 3 thang.<br /> Chinh vi dieu nay ma phuomg phap loai bd can dau ra khdi nude via da dugc ap dung<br /> ngay tu dau.<br /> Thiet bj tach dau/nude nhd ggn duge lap dat tai diu giing. Nude thai tir thilt bj tach<br /> duge bom vao binh lge cd dudng kinh 3ft (0,9m) cd chua sin 1.2001b (544 kg) set ehiia<br /> chat hdu co Biomin's EC-100. Sau khi eho qua xir ly, ham lugmg diu trong nude chi cdn<br /> 5ppm, giam 100 lan so vdi nude chua xu ly. Tde do bom nude vin dugc gid nguyen. He<br /> thdng mdi nay khdng ein phai bao dudng be thong giing khoan. Thilt bi tach/lgc dugc<br /> lap dat dom gian, gia thanh thip va dl dang sir dyng. Gia thanh lip dat cua cac thilt bj nay<br /> khoang 5.900USD (thilt bj tach 2.000USD, bd Igc 3.000USD, bom 400USD va thiing vdt<br /> dau 500USD). Set hum co Biomin's EC-100 cu 3 thang mdi phai nap lai mdt lin, chi phi<br /> cho viec nay khoang 1.200USD. Ap dyng he thdng mdi nay cu 2 - 3 thang cd thi tilt kiem<br /> dugc khoang 6.000USD.<br /> <br /> KET LUAN<br /> • Bao cao gidi thieu mdt phuomg phap mdi trong ITnh vyc xir ly nude via, dd la<br /> phuomg phap su dyng set ehua chit bum co dl tach diu ra khdi nude via. Day la<br /> phuomg phap xu ly cd hieu qua kinh tl kha eao dang dugc ung dyng rdng rai tai<br /> cac nude tren thi gidi.<br /> • Mgt sd khai niem vl set chiia chit hum co, tuy chua dugc nghien cuu ky va hilu<br /> rd nhung ciing gdp phan nao dd giup tac gia ed thi hinh dung duge vai trd eua<br /> chung. Chung tdi hy vgng se cd dilu kien dl nghien cuu ky them dl hoan thien<br /> nhiimg kien thuc vl set chiia chit hiim co.<br /> • Ngudn nguyen lieu de san xuat set chira chat hum co d nude ta eiing rit sin ed<br /> eiing da cd mdt sd noi dang nghien cuu va san xuat thu set ehua chit hum co. Hy<br /> vgng trong vai nam tdi chiing ta cd the mua duge set chua hum co duge san xuit<br /> Tuyin tap bao cao Hgi nghj KHCN "30 nam D5u khi Vift Nam: Cff hgi mdi, thach thde moi" 189<br /> <br /> <br /> trong nude vdi gia thanh re, chat lugmg cao, nham giam bdt chi phi nhap khau va<br /> nang cao hieu qua kinh te.<br /> <br /> TAI LIEU THAM KHAO<br /> 1. Cao Anh Diing, 2004. Bdo cdo nghien cim cdng nghe sdn xudt set hieu ca phuc vu<br /> khoan thdm dd khai thde ddu khi.<br /> 2. George Alther, 1997. Organoclay cost effectively removes oil from produced water.<br /> Oil and Gas Joumal, Apr. 14, 1997.<br /> 3. Swelling and oder versus disorder ofdimethyl-dioctadecyl-ammoniwn montmorUlonite<br /> in the presence of water and methanol. Clay Minerals, 1994, 29, p. 401 - 404.<br /> 4. T.R. Jones, 1983. The properties and uses of clays which swell in organic solvents.<br /> Clay Minerals, 1983, 18, p. 399 - 410.<br /> 5. US Patent No. 4081496. Thixotropic polyester compositions containing an<br /> organophillic clay gellant. March 28/3/1978.<br /> 6. US Patent No. 4116866. Organophillic clay gellant. September 26, 1978.<br /> 7. US Patent No. 5634969. Organoclay composition. March 6, 1997.<br /> 8. Vasily N. Moraru, 2001 Structure formation of alkylammonium montmorUlonite in<br /> organic media. Applied Clay Science 19, 2001, p. 11 - 26.<br /> 9. Veil J.A., 1994. Npdes permits have increased emphasis on control of toxic pollutants.<br /> OGJ,Jan. 6,1994, p. 46-52.<br />