p chi Khoa hoc Tnnmg Dgi hoc Can Tha Phdn A: Khoa hoc Tu nbien. Cdng nghe vd .Mdi mr&ng- 28 <20l3i: 73-79
Tap chi Khoa hoc Tru'dng Dai hoc Can Thd
•^^^V' website: sj. ctu. edu. vn
KHAO SAT HAM LlTONG As, Cd, Cu, Zn TAI VUNG BAO DE KIEM SOAT LU TINH AN GIANG
Tran Anh Thu', Nguyen Hoang Oanh* va Tnrong Thi Nga"
' Sa Tdi nguyen & Mdi trucmg.4n Giang
- Khoa Mdi trudng &. Tdi nguyen Thiin rdiiin, Truang Dgi hoc Cdn Tha Thdng tin chung:
Ngdy nhdn: 05 05/2013 .Xgdy chdp nhgn: 29/10/2013 TUle:
Survey of Arsenic, Cadmium, Copper, Zinc content with dike contruction for flooding control in .4n Giang province Tu khda:
Arsen (As), Cadimi (Cd).
ddng (Cu), kem (Zn), di bao.
An Giang Keywords:
Arsen (As). Cadmium (Cd).
Copper (Cu). Zinc (Zn). Dike.
An Giang
ABSTRACT
Study of 'Survey of Cu, Zn, CdandAs content inside dyke-systems in An Giang province' was carried out lo assess heavy metal conienis in different existing dyke-systems in An Giang province. Soil sample were collected inside full-dyke system (Kien An village), flood-flush practice dyke systems (Tan Hoa and Phu My village) and non-dyke system (Tan Trung village) in Autumn-Winter and Winter-Spring crop in .4n Giang province and were analysed Cu. Zn, Cd and As contents. The results showed that total and dissolved Cu contents were not different amongst the dyke systems and were 10.5~-22.74 mg/Kg and 4.26- 15.30 mg/Kg respectively for the both crops. The total Zn contents were not different the amongst dyke systems, while the dissolved Zn inside the the non- dyke system were higher (10.46-13 23 mg/Kg) (p<0.05) than other dyke sysnnes. especially jlood-jlushpractice dyke systems (7.07-10.40 mg/Kg}. The full-dyke system had the total Cd (0 48-0.63 mg/Kg) higher (p<0 05) than the jlood-jlush practice and non-dyke systems (0.29-0.51 mg/Kg). There was not different total As amongst the dykes (0.87-3.77 mg/Kg) in Winter-Spring crop and this As conients were not detected injull-dyke system. The embankment oj thejull-dyke systems has accumulated the total Cd conients in the soils.
TOIVl TAT
"Nghien citu 'Khdo sal lidm lugng Cu. Zn. Cd vd As a cdc vitng de bao kiim sodt lu tmh An Giang" dugc thuc hien nhdm ddnh gid hiin trang kim logi ndng a cdc vimg di bao khdc nhau. Cdc mdu ddt dugc thu dugc thu & vimg di bao khip kin (Kien An), de bao xd lH (Phu My vd Tdn Hda) vd vung khdng de bao (Tdn Trung) d vu Thu Ddng vd Dong Xudn d tinh An Giang vd phdn tich hdm lugng vdphdn lich Cu, Zn, Cd vd As. Kit qua cho hdy hdm luang Cu tdng sd vd hda tan khdng khdc biit giiia cdc logi di bao ldn lugt 10,57- 22 ~4 mg/Kg vd 4.26-15.30 mg/Kg d cd hai i-y Ida. Hdm lugng Zn tdng s6 cUng khong khdc biit giira cdc logi de bao (82,81-105.24 mg/Kg). trong khi Zn hda tan a vitng khong de bao (10,46-13,23 mg/Kg) cao han (p<0.05) vitng cd de bao khdc, dgc biel Id vitng de bao xd 15 (7.07-10,40 mg/Kg) Vitng di khep kin cd hdm lirgng Cd Idng sd (0,48-0,63 mg/Kg) cao han viing de bao xd 15 vd khdng de bao (0,29-0.51 mg/Kg). Khdng cd su khdc biit hdm lirgng As tdng sd giua cdc logi de bao (0,8:'-3. 77 mg/Kg) d vu Ddng Xudn vd khdng phdt hien hdm lugng As ndy & vimg de bao khep kin Qud trinh khip kin de bao ldm tich lay hdm luang Cd tdng sd trong cdc ldng ddt.
Tap chi Khoa hgc Tru&ng Doi hgc Cdn Tha PhdnA Khoahgc Tunhien. Cong ngh? vd Moi Iru&ng: 2812013): 73-79 1 GIOfITHI$U
O Dfing bang sdng Ciiu Long ndi chung vd tinh An Giang ndi rieng, vin dk d nhilm mfii truong ddt tir sdn xudt nfing nghiip dugc quan tdm hem nhimg nguyen nhdn khic vi ddy li noi tap trung cfaii yeu sdn xudt nfing nghiep. Nganfa nay dang frong tinh frang tham canh cung vdi su ting nhanh vdng quay eiia dat, gia tdng ddu tu ndng dugc yd phan bdn, cd khd ndng gay hai din mfii trudng song ciia sinh vat chung quanh nlu nhu viec sir dung cac logi phin bdn va ndng dugc khdng hgp ly (Sd Tai nguyin vi Mdi tnrdng An Giang, 2008). Mgt khic, bao dl tgi An Giang da dem lgi nfaiiu lgi ich cho nhdn ddn vd chinh quyln cic mdt kinfa li - xa hdi nhu chdng tu, tang vu. Tuy nhiin, ngoai cac mat tich cyc, bao dl cd nhiing inh hudng bit lgi din mfii trudng dgc bilt la mfii trudng ddt. Theo nghien ciiu ciia Pham Ngpc Xuan (2004) da cd su hipn diln cua kim loai nang ttong dat vimg tham canh lua khu vyc cd de bao. Dl tii "khao sat ham lugng As, Cd, Cu, Zn tgi viing dl bao kiem sodt lij tinh An Giang'" dugc thyc hiln nhim gop phan xay dung co sd dO' lieu cho cfaiin lygc quin Iy tai nguyin dit vung ngap lii tinfa An Giang.
2 PHU'CfNG PHAP NGHIEN c i r u 2.1 Thfi"! gian va dja diim nghiin ciin Dl tii dugc tiln hinh t£r thdng 9/2011 din tfadng 10/2012. Tai bdn khu vyc sau
Khu vyc 1: bao de ttilt di xd Kiln An, huyen Chg Mdi (dl bao dugc xiy tir nim 1996, din nay khdng xa lii) san xuat 3 vy liia/ndm.
Khu vuc 2: bao de cd xd lu xa Tan Hda.
huyen Phu Tan (vira moi xi lu ndm 2011) sin xudt 8 vu lua/3 ndm.
Khu vyc 3: bao de co x i lii tai thi ttan Phii My, sdn xuat 8 vu liia/3 nam nhung tir nam 2006 den nay chua xa lu, sdn xudt 3 vy lua/nim.
Khu vyc 4: khdng dl bao xi Tin Tmng huyen Phu Tin. sin xuit 1-2 vy liia/nam hodc 1- 2 vu mau/nim.
2.2 Thfil gian thu mau
Dgt 1: thdng 12/2011. sau lii nit ddi vdi khu vyc khfing bao de, vao cudi vy Thu Dfing ndm 2011 doi vdi vimg cd bao dl.
Dgt 2' thing 5/2012. vdo cufii vy Dfing Xuan ndm 2012 doi vdi khu vyc trdng liia thupc khu vyc bao dl va cufii vu bap hoic giii-a vy oi thufic khu vyc khong bao dl.
2.3 Phuong phdp thu mau
Mdu ddt dugc liy 5 diim theo hmh Ziczic 2 dp sau: 0-20 cm va 20-40 cm. Trpn mdu theo timg dp sau. Trpng lupng moi mau ddt luong duang 1 kg.
Vi tri dygc gfai nhin bang GPS dl lay mdu cfainfa xdc cho lan sau.
Tdng mdu thu hai dot la 40 x 2 = 80 mau. Cic chi tiiu Cd, Cu, Zn tfing sfi va hoa tan dugc phan tich 80 miu. Dfii vdi As tfing so va hoa tan miu ddt ehi do d tang mat vd dugc chpn ngiu nhiin 3 frong 5 rudng dugc thu fren. Sd mau phdn tich As la 3 mdng X 4 dja diim x 2 dgt = 24 miu.
2.4 Thu thap tfadng tin, phong van nong hp Thu thdp thfing tin tir cac sd. ban nginh cd liln quan, cdn bfi phy trach nfing nghiip xd vl cdc tdi lieu vd sd lieu lien quan din khu vuc nghien ciiu vl thyc frgng he thdng dl bao, quy mfi. di|n tfch de bao, ning suit liia.
Phfing vin 100 hfi dan co hoat dpng san xuat ndng ngliiep tuong ty nhau tgi 4 khu vyc nghiin cim. Moi viing phong vin 25 ho co thdi gian canh lac lau nim trong viing, cdc hfi dugc chpn cd di|n tich dit fren 0,1 ha. Dilu fra bang cdch hdi tryc liip ndng din theo raau cau hfii di in san.
2.5 Phuong phap phin ticfa
Him lugng cadmium, ddng, kem dugc do tai phong thi nghiem bp mfin Khoa hpc Dat thufic Vien Liia Dfing bdng sfing Cuu Long. Cadmium, ddng, kim tdng sd do bdng phuong phdp cdng phd mau bdng hon hgp xiic tac (HiSO^ dd va Se).
Ham lugng As tdng s6 vi hoa tan dugc do tai Phdng thi nghiim Chuyen sau Tnrdng Dgi hpc Cdn Tho. Theo phuong phdp: Soil analysis procedures-Wageningen Agricultural University LOD = 0,04 ppb. Soan dieo Part5B soil analysis procedures - department of soil science and nufrition wageningen agricultural university V.J.G. Houba va cfing sy.
2.6 Xir ly sfi lilu
Sfi tieu phfing vin, diiu fra duge xu ly bdng phan mem Excel 2003.
Cac kit qua As. Cd, Cu. Zn frong mau dit dugc xir ly thfing kl voi phdn mem thdng ke SPSS 18.0, dimg phep thii ANOVA - one way (Duncan) de kiim dinh khac bilt As, Cd, Cu, Zn giu'a cac khu vyc va phep thii' Independent samples T-Test dl kiim djnh kfaac biet As, Cd, Cu, Zn giiia hai vu va hai dfi sdu.
Top cbi Kboa boc Tnr&ng Dai boc Cdn Tha Plidn .4: Kboa boc Tu nhien, Cdng nglie vd Mdi tru&ng' 28 <20I3i: ~i-*9 3 KET QUA VA THAO LUAN
3.1 Tinfa fainfa nang suit va sir dung phan bdn tai cdc khu vuc kfaao sat
Kit qua diiu fra cho tfady ndng sudt frfing liia tai khu vyc khfing bao dl tuong duong vdi ndng tua tmdc khi bao de. Tgi khu vyc bao dl trilt dl xd Kiin An sau khi bao de nang sudt giim tir 7,37 tin/ha, faien nay 5,59 tdn/ha, Ddi vdi khu vuc bao dl cd xa lu Tin Hda va Phii My nang sudt hiln tai vdn cao hon Kiin An nhimg van co chieu hudng giim so vo'i trudc kfai bao dl. Mac dii, nang suit cd_
xu hudng gidm nhung phdn bdn sti dung cdc khu vuc cd bao dl tgi tdng. Tai cdc kfau vyc cd bao de sir dung lucmg phdn bdn tang cao so vdi trudc khi bao de, ttong dd khu vyc bao dl friet de Kien An ldng cao hon faai kfau vuc bao de cd xd lii. Kfau vyc khdng bao dl xd Tan Tmng sir dung pfadn bdn cfao frdng Ilia tuong duong vdi cdc kfau vuc khdc tiudc khi cd bao dl. Tuy nhien. lugng pfadn bdn sii dyng cfao frfing miu cao faon nhilu so vdi lugng phin bdn sii dung frong liia. Lugng pfaan bon sii dui^
trudc va sau kfai bao dl dugc tfal faien d Hinfa I.
Hiin Iai
TMICC lie bao a V y 3 • V u 2 OVy 1
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200 400 600 800 1000 1200 Luomgphan bon kg/ha/vu
Hinb 1: Lugng pfadn bdn sii dung tai cac kfau vuc Cdc logi phan bdn chinh dugc sir dyng d bdn
khu vyc khdo sat la Ure Vilt Nam, DAP (18-46-0) cua My. Thai Lan. Trang Qufic. phan NPK tfaeo ti II 16-16-8 (13S), 20-20-15, 20-15-7 ciia Viet Nam, Phap, Thai Lan, Vilt - Nhat, lupng it kali vd phdn tin. Sau khi xa> bao de, nhu cau phin bdn eac khu vyc ngay cing cao, nhit la cic loai phan hdn hgp
Bang 1: Ket qua do ham lugng Cu tong so trong dat (mg/kg) tai cac kfau vuc kfaao sdt
NPK (20-20-15 vi 16-16-8) dugc su dur^ nfaieu nhit chiim ti 1179,01% - 88,89%.
3.2 Ham lugng Cu tong sd trong dat it cac vung de bao
Kit qud d Bing 1 cho thay him lugng Cu tong sd khdng cd sy khac bill cd >' nghTa tfadng ke gifla cac khu vyc nghiin ciiu.
Kien An Phii My Tan Hoa Tan Trung
Tbu Dong Ocm - 20cm 22,74' ± 4,48
22.3" ±5,20 19,65'= 4,10 17,95'±2,37
20cin - 40CII1 18,74'±1,73 18,50'±O,88 16,94'±3,67 18,57" ±2,69
Song Xuan Ocm-20cm 13.80'±2.35 11,10'= 4.65 10,68'= 3.52 13,64'±1.92
20cm - 40cm 11,40'±1.42 l l , i r ± 3 . 2 4 10,57'±2.00 12,65" ±3,24 Ghichu: Cdc gid tri trong citng mgi col cd cimg ki tu ( a. b. c. d) thi khdng cd khdc biel cd y ngbia thdng ke (p>0.05) qua phep thu Duncan
Ham lugng Cu tdng sfi cd sy khac bill cd y nghia (/7<0,05) giiJa hai dp siu vi hai vu. Tdng mat (dfi sau 0-20 cm) (I0.68±3.52 mg/kg din 22,74±
4.48 mg/kg) cao han so vdi tdng dudi (10.57±2,00 din t8.74±1.73). vy Thu Dfing (I6.94±3.67 mg/kg
din 22.74±4.48 mg/kg) cao hon vu Ddng Xudn (10.57±2,00 mg/kg din 13.80±2.35mg/kg).
Ham lugng cic nguyen td vi lugng trong ddt Viet Nam biln thien ttoi^ khoing pfaam vi rgng ve ham lugng tdng sd. hda tan va phy thugc chu \'lu
'^'^P chi Khoa hoc Tnr&ng Dai hgc Cdn Tha Phdn A- Khoa hgc Tunhien. Cong nghe va Moi Inrang. 28(2013): 73-79 vao di me va thinh phdn co gidi ddt (Nguyen Nfau
Ba, 2006). Him lugng Cu tfing sfi do dd kfaac nhau phu thudc vdo da me vdo thdnh phin co gidi dat d tmig dja diim. Theo Ngd Nggc Hung (2005) frich dan tir Dierolf and ei al. (2001) tfal dit thiiu ddng khi cd hdm lugng Cu nhfi hen 4mg/kg ddt khd. Dit huyen Chg Moi, An Giang thufic nhdm dat phu sa tuong dfii mdi vd miu md (Duong Minh Viin vd Vfi Thi Guong, 2008). Theo gidi han hdm lugng tong sfi cua mdt sd kim logi ning trong cdc nhdm dat ndng nghiip dfii vdi ting mat cua Viin Thfi Nhudng Nfing Hda da xay dyng thi hdm lugng Cu Bang 2: Ket qud do ham lupng Cu hda tan trong
tdng sfi trong dat phii sa d miic trung binfa tfadp 13,0 mg/kg - 22,4 mg/kg, frung binfa cao 22,5 mg/kg - 31.8 mg/kg (Ll Thj Thiiy, Pham Quang Ha, 2008). Ham lugng Cu d bin khu vuc nghiin cmi chi d nguong rit thip den ttung binh cao. Vi vay, nguy ca vl d nhilm Cu chua xay ra.
3.3 Ham lugng Cu hda tan trong ddt d l bao Tuong ty Cu tfing sfi, ham lugng Cu hda lan tgi ciing khu vyc cd sy tdiac bill giua hai dp siu vi hai vu. Gia tri Cu hda tan dupe the hien cy thi d Bdng 2.
dat (mg/kg) tai cic khu vyc kfaao sat
Kien An Phu My Tan Hoa Tan Trung
Thu Dong 0 cm - 20 cm
15,30'±2,31 13,64'±1,95 13,34"'±1,79 10,31'±2,87
20 cm - 40 cm 10,56'±2,59 11,48'±1,94 10,78'±3,05 8,91"±2,52
DdngXuar O c m - 2 0 cm
7,80" ±1,95 7,36" ±2,23 7,75" ±2,10 7,38'±1,50
1
20 cm ~ 40 cm 4,89'±1,93 4,26'±1,60 6,67" ±1,61 5,18"±1,98 Gbi chu: Cdc gid Iri irong cimg mot col co cung ki tu (a. b. c
phep Ihu Duncan
Tir Bdng 2 cfao thdy vio vy Thu Ddng ham lupng Cu hda tan cao nfadt tai Kiln An 15,30±
2,31 mg/kg vd tfadp nfait tai Tan Trung 10,31±
2,87 mg/kg. Ham lugng Cu hoan tan, d ldng dudi vu Thu Ddng va hai tang vu Dfing Xudn tai bon khu vyc khao sit khdng cd su khic bi|t co y n^hTa thing ke (p>0,05).
Phdn bon vd nfing duge la mdt trong nhiing ngudn dua cdc nguyen td vi luong nhu Cu, Zn vao ddt (Ngfi Ngpc Hung, 2012). Theo Ll Vdn Khoa (2004) ham lugng Cu cd trong phdn lan la 1- 300 mg/kg, phan dgm li 1-15 mg/kg. Tdng tren cd ham lugng cao hon tang dudi, sy khac biet nay cd y nghia thong kl theo kiem dinh T - test. Cd thi giii thich, trong dit ludn cd qud trinh chuyin hda giiia Cu hfia tan vi Cu khfi lieu trong nhung dieu kiln thugn lgi ddng khd tiiu chuyin hda thinh Cu Bang 3: Kit qua do ham lugng Zn tdng so trong
d) thi khdng CO khdc biet cdy nghia thdng ke (p>0,05) qua hda tan va ngupc lai (Chu Thi Thom va ctv., 2006).
Tgi cic khu vyc nghien cuu dilu ki|n tang tren thich hgp chuyen faoa thanh Cu hfia tan hon, cd thi do hdm lugng Cu trong phan bdn vd nfing dugc tilp xiic voi dat tang mat trudc. Mil khac, vy Thu Dfing, khu vyc khfing dl xd Tan Trung kfadng canh tdc, du nhdn dugc lugng Cu hda tan tir phu sa bfii ling nhung vin cd ham lugng thip ban cac khu vyc cd dl, nfait Id Kiln An vi cung cap cfao dat lugng Cu tir pfaan bon va ndng dugc cao hon phii sa ty nhiin. 6 Kiln An lupng phan sir dung trung binli Id 275 kg/ha/tfaang.
3.4 Ham lupng Zn tfing so
Cac khu vyc nghiin ciiu khfing cfi sy kfaac bilt vi ham lupng Zn tfing sfi. Gid trj Zn tdng sfi dugc thi hiln trong Bdng 3.
dat (mg/kg) tai cac khu vyc khao sat Khu virc
Kien An PhiiMJ Tan Hoa Tan Trung
Thu Dong
0 cm - 20 cm 20 cm - 40 cm 96,51"± 14,70 84,45'±7,00 105,24'±12,68 87,01 "±3,59
97,98'±9,60 82,81'± 11,46 92,78'±6,19 86,13'±7,75
Dong 0 cm - 20 cm 79,26" ± 5,48 69,60'±13,45 70,46'±7,10 79,07' ± 2,64
Xuan
20 cm - 40 cm 65,05'±7,14 69,41'±4,97 60,06 "± 13,06
70,28 "±9,49 Ghichu Cdc gid [ri trong citng mpl egt CO citng ki lir (a. b. c. d) thi khong co khac biel co y nghTa thong ke (p> 0.05) qua phep thir Duncan
Gii trj ham lugng Zn tfing sfi dao dfing 60,06±
13.06 mg/kg din 105,24±12.68 mg/kg. Him lugng Zn tdng sfi thdp hon nhlu so vdi ham lugng qui
dinh frong qui chuan Viet Nam 2008 la 200 mg/kg.
Theo Ngd Ngoc Himg, 2005 trich dan tir Dierolf vd cir nim 2001 thi ddt thieu Zn khi cd ham lugng
Tap chi Khoa hoc Tru&ng Dgi hgc Cdn Tho PhdnA. Khoa hoc Tu nbien. Cong ngh? \d Moi trudng: 28 (2013): 73-79 tfing sd < 20 mg/kg. Theo gioi hgn ham luong tdng
sd ciia mdt sfi kim logi ning ttong cac nhdm ddt ndng ngfailp ddi voi tdng mat ciia Vien Tfad nfauong Ndng hda da xiy dung thi ham luong Zn tdng sd ttong dat phii sa d miic trung binh tfadp 45.0 mg/kg - 76.6 mg/kg, trung binfa cao 76,6 mg/kg - 21.65 mg/kg (Ll Tfai Tfauy vi Pham Quang Hi, 2008). Vay d cic kfau vyc nghien ciiu xet d hai dp sdu vd hai vy tfai hdm lugng Zn tfing sfi cao hem ngudng thilu nhieu Ian, nhung da sfi cac Bang 4: Kit qud do ham lugng Zn hoa tan trong dat
mdu cfi hdm lupng ehi d miic trung binfa cao nen nguy CO vi d nhiem Zn chua xdy ra.
3.5 Ham lugng Zn boa tan
Zn hda tan khfing khac bill gii^a hai ting, md CO kfadc biet giiia hai miia Thu Dong vi Ddng Xuin. Tai Tan Trung cd ham lugng Zn hda tan cao hon ba khu vuc cdn lgi.
Gii tri Zn hda tan dugc ghi nhdn tai Bdng 4.
(mg/kg) tai cac kfau vyc khao sdt
Kien An PhiiMJ Tan Hoa Tan Trung
Thu Dong 0 cm - 20 cm
8,74" ±1,44 9,90'±1,69 10,40'±1,50 13,23'±1,45
20 cm - 40 cm 11,29"'±0,47 10,40' ± 2,03 9,81'±0,80 12,43'±0,82
Dong 0 cm - 20 cm 7,61'±0,79 7,45'±0,94 7,62'±1,85 11,63" ±2,45
Xuan
20 cm - 40 cm 8,65" ±1,19 8,41'±1,20 7,07'±1,01 10,64'±2,31 Ghi chu- Cdc gid tri trong cung mot cot co cimg ki tu (a, b. c, d) thi khong co khdc biet cd y nghia ihdng ke (p>0.05) qua phep thu Duncan
Nfaieu kit qui ngfailn ciiu dd ket lugn dat thilu kem kfai ham lucmg kem hiiu hieu < 0,6 ppm (Chu Thi Thom va ctv., 2006). Voi him lugng Zn hiiu hieu nhu frln cd thi ddnh gid ddt tai cac khu vyc nghiin cim kfadng tfaieu kem. Ben canfa dd, theo nghien cim cua Duong Minh Vien vd ctv. (2010) d dit cd nfain vd kfadng cd nfaan phii sa ttong bdn ndm thi sy suy gidm ban diu ciia K frao dfii ciing nhu vi lugng Zn hda tan trong ddt ciing la tin hieu cho thdy nhinig bdt loi cd thi mang lgi cho dl bao Bang 5: Ket qua do ham lugng Cd tdng si trong dat
ngan lu. Do do. ham lugng kem hfia tan cao nhat d khu vyc khdng de bao xa Tdn Trang do sau vy lu dat nhdn dugc phii sa lam tdng lugng kem hiiy hi|u frong dat.
3.6 Ham lugng Cd tdng sfi
Ham lugng Cd tfing sfi tai khu vyc dl bao ttilt de xa Kiln An cao nfadt, kl tiep la khu vyc kfafing dl xa Tdn Trang vd tfadp nhat li khu vyc bao de vita xd to xa Tan Hda.
(mg/kg) tgi cac khu vyc kfaao sat Khu virc
Kien An Phii My Tan Hoa Tan Trung
Thu Dong
0 cm - 20 cm 20 cm - 40 cm 0,50" ±0,06 0,63" ±0.08 0,34'«±0,06 0,40 " ± 0 , 0 2 0,29' ± 0,03 0,35' ± 0,05 0,39' ± 0,04 0,48' ± 0,07
Dong 0 cm - 20 cm 0,48" ±0,02 0,51'±0,01 0,50'±0,01 0,49" ±0,02
Xuan
20 cm - 40 cm 0,51'±0,02 0,50'' ± 0,02 0,47'' ± 0,02 0,46'±0,01 Ghi chii Cdc gid In trong citng mot col cd citng ki lu (a. b. c. d) thi khdng co khdc biet cd y nghta thong 1^ (p>0.05) qua phep thu Duncan
Theo gidi hgn faim lugng tdng sd ciia mdt sfi kim logi ndng trong cdc nfadm dit nong ngfailp dfii vdi tdng mat ciia Vien Tfafi nfauong Nfing hfia xiy dyng thi him lugng Cd tdng sfi ttong ddt phii sa d miic thip < 0.5 mg/kg, frung binh thap 0.5 mg/kg - 1 mg/kg (Ll Thj Thiiy vd Pham Quang Ha. 2008) thi ham lugng Cd trong khu vyc nghiin ciiu chi d miirc trang binh thip. Ben canfa dd. him tugng Cd tfing sfi phit hiln dugc thip ban nfaiiu lin so voi qui chudn Viet Nam nam 2008 li 2 mg/kg. Ham lugng Cd tai kfau vyc nghien ciiu dao dfing lir 0.29 mg/kg - 0.63 mg/kg chua vugt qua 1,1 mg/kg.
Ham lugng Cd van chua vugt nguong thi hiln dnh hudng ciia con ngudi. Tuy hdm lupng Cd d khu vyc nay vdn chua d nhiem nhung ciing cin luu y vi ngodi ham lugng Cd tdng sd con phat hiln ham lugng Cd hda tan trong hiu hit cic mlu phin tich.
3.7 Ham lupng Cd hda tan
Ham lupng Cd hoa tan trung binh vu Thu Dong CO gii fri tir 0,020 mg/kg - 0,036 mg/kg. Chi co sy khic biet gitra hai dp sau tai khu vyc bao dl vira xd lu xa Tan Hda. Kit qua do Cd hda lan dupe the hien frong Bdng 6.
T(.ip chi Kboa hoc Tru&ng Dai hgc Cdn Tha Phdn A Khoa bpc Tu nhien. Cong ngbe vd -Moi Inr&ng- 28 (2013/ 73-79 Bing 6; Kit qua do faim lugng Cd hoa tan trong dat (mg/kg) tgi eac khu vyc khao sdt
Kien An PhiiMJ Tan Hoa Tan Trung
Thu Dong 0 cm - 20 cm
0,02'±0,00 0,04" ±0,01 0,02'±0,01 0,03'±0,00
20 cm - 40 cm 0,02'±0,00 0,04'±0,01 0,03" ±0,01 0,03''±0,01
Dong 0 c m - 2 0 c m
0.11" ±0,01 0,06' ± 0,02 0,13" ±0,01 0,12" ±0,02
Xuan
20 cm - 40 cm 0,11'±0,01 0,09'±0,01 0,13'±0,00 0,04' ± 0,01 Ghi chir. Cdc gid iri trong cimg mgt egt eg ciing ki lu (a, b, c. d) thi khong co khac biet ca y nghTa thdng ki (p>0.05) qua phep thir Duncan
Ty 1| phdn fram frTing binh cua Cd hda lan so Tdn Trung li dit frfing mau cd hira lupng Cd hda vdi Cd tdng sd tai cdc khu vyc vao vu Thu Dfing ^^n tdng fren cao hon tdng dudi. Theo Ngo Ngpc dao dpng tir 3,17% din 11,19%. Trong dd, Phii My hung (2012) trich dan tii Geniste yd Driel (1984) cd ti 11 cao nhit. Vdo vy Dfing Xuan ti 11 nay tang *hi ham lugng chit hiru co dit thip dua den khd tin, dao dpng ttong kfaoang tir 7.83% din 25,20%. "^ng hap phy rat it kim logi ndng frong ddt, ddt Trong dd, cao nhit la khu vyc Tin Hda. Theo Hd trfing mau chiia it thanh phdn chit huu co se ldm Thi Lam Tra, 2005 cac dang liln kit cda Cd khdng tang tinh sdn sang sinh hpc ciia Cd.
phy thupc vio ham lugng tdng sd cua Cd trong ddt. 3.8 Ham Imnig As
Tai cac khu vyc nghien ciiu. hini lugng Cd hoa tan ^ s chi duoc do 6 ting m^t (0 cm - 20 cm), chi do dugc sovoi Cd long so co t. 1? kha cao nen can ^it hiln As tdng sd, khfing phit hien As hda tan.
luu y kha nang gay dpe cua Cd doi voi smh vgt. QJ^ t^ g^j ^han tai Bing 7.
Nhin chung, hdm lugng Cd hda tan cd xu Vy Thu Ddng tchu vyc bao de trill di xa Kiin huong vy sau cao faon vy frudc do sir dung phan An vd khu vyc bao de chua xa lu Phu My khdng lin (trong phan hdn hop) NPK mfit thoi gian dai. phit hiln As tfing so. Khu vyc Tan Hoa va Tan Ham lugng ting dudi cao hon ting trin cd thi do Trang co phat hien nhung chi d him lugng thdp trong dat fring lua dieu kien ngdp nudc din din khoang 1,30 mg/kg - 4,75 mg/kg. Vy Dong Xuin trgng thdi ciia hgp chat CdS trong ddt liia yIm khi, ca bin khu vuc diu co phat hi|n As tdng sfi vdi khi dang sulfite bi oxi hoa frd nen acid hoa tir do him lugng dao dgng 1,00 mg/kg - 5,4 rag/kg. thdp gdp phan lam linh dfing Cd (Ngd Ngpc Hung, hem nhilu lin so vdi qui djnh ve ham lupng As 2012). Dieu ndy da ldm Cd hfia tan dting duoi cao ttong dit ndng nghiep ciia qui chuin Viet Nam hon ting tren. Ddi vdi khu vyc khdng bao dl xa nim 2008 la 12 mg/kg.
Bang 7: Ket qua do ham lirgng As tong so d tang mgt (mg/kg) tgi bon kfau vyc khao sat Vw
Thu Ddng Dfing Xuin
Bien dong ham lirgng As tfing so d dp sau 0 cm - 20 cm Kien An Phii My Tan Hoa Tan Trung
KPH KPH 1,25^ ±2,17 ' 2.02''±2,45 2,55 ± 2.32 0.87± 1,50 1,92'' ± 1,98 3,77= ± 2,41 Ghi chu: Trong mot hang cd chii cai (a. b, c. dj giong nhau thi khong cosu khdc biet co y ngiiTa thdng ke a mitc 3% qua phep thu Duncan
Khu vuc khong bao de xa Tan Trung hau khu vuc khong bao de xa Tan Trung phat hien ham het tr6ng mau, co ham lirgng As cao hon cac khu lugng As cao hon cac khu virc con lai nhimg sir virc khac do khu vuc nay su dung lugng phin khac biet nay khong co y nghTa thong ke.
b6n cao hon trung binh khoang 283,34 kg - Kit qua khong phat hiSn As hoa tan tai cac khu 458,06 kg/lOOOm'/thang. Song thai khu vuc nay y,,c „gi,ien ciiu, As vo CO c6 thi nhanh chong sir dyng nuoc ngam de tucri ti«u nen trong dat co chuyin thanh bit dgng trong hSu hit cac loai 6k do ham lugng As cao hon ba khu virc con Iai. Dieu j ^ i,)ni, ,],anh mu6i sjt va nhom khong hoa tan nay phii hgp vgi ket qua nghien cilu cua Tran Anh mile dg bit dong nay phu thugc vao ndng do cac Thu, 2009 ket qua phan tich mau dat canh tac cho ^^id Fe, Al trong dit (Ngo Nggc Hung, 2012). Vi thiy khong phat hien Arsen ttong dat 6 nhiJng ,,jy ,aj (.jc it|,u vuc nghien ciiu chi phat hien As viing khong sil dung nuoc ngam de turn. Tuy tai ,j„g j j A ; hoa tan khong phat hien.
Tap cbi Khoa hgc Tnr&ng Dgi hoc Cdn Tha PhdnA. Khoahgc T[r nbien. Cong nghe vd Mdi tnrdng- 28 (2013): 73-79 4 KET LU4,N VA BE XUAT
4.1 Kit luan
Khu vyc bao de trill dl xa Kiln An su dung lugng phdn bdn cao nhit nhimg ndng suit liia thdp nhit trong bdn kfau vuc. Khu vyc Pfaii My vd Tdn Hda cd ning suit cao han Kiin An nhung vdn cd chieu hudng gidm du tugng phdn bon va ndng dupe ting.
Ham lygng Cu tdng sd vd Zn tfing sfi d miic thap din trang binh, kfadng cd sy khac bilt cd y nghTa tgi eac khu vyc nghiin cuu, cd xu huong gidm theo dp sau, vy Dfing Xudn thdp han vu Thu Ddng. Vy Thu Dfing, ting mil, Cu hda tan cao nhit khu vyc dl bao triet de xa Kien An (15,30±
2.31 mg/kg), thap nhat khu vuc khfing 6e xa Tan Trung (10,3I±2,87mg/kg), mic du ham lugng Zn hoa tan tai Tan Trang cao nhdt (10,64±
2,31 mg/kg - 13,23±1,45 mg/kg). Ngugc lai vdi Cu, Zn; Cd tdng sd cd khuynh hudng tip trang d tang dudi, vy Ddng Xuin cao hon Thu Dfing. Tgi khu vyc dl bao ttilt dl xd Kiln An. Cd tfing sfi cao nhit (0,48±0,02 mg/kg - 0.63±0,08 mg/kg), him lupng thip nhit dugc ghi nhin tgi khu vyc vira xi lu xd Tin Hoa (0.29±0,03 mg/kg - 0,50±
0.01 mg/kg). Vu Thu Dfing, hdm lupng Cd hoa tan khu vyc chua xa lu thi ttin Phii My cao nhat (0,04
±0,01 mg/kg), khu vyc khdng bao dl xa Tdn Tnmg do dugc ham lupng Cd hda tan (0,03±0,0l mg/kg - 0,12±6.02 mg/kg), frong dd vy Ddng Xudn Cd hda tan tdng mdt cao han nfaieu so vdi tdng dudi. Hdm lugng As tong sd do duoc d tang mil thap, tham chi khfing phat hien d mfit vdi vi fri. Khu vyc khdng bao de xa Tan Trung As tdng sfi cao nhat ttong bfin khu vyc. nfaimg khong co khic bi|t cd y nghia gi&a cdc khu vuc. Kit qui ciing cho thiy khdng phat hi|n As hda tan trong dat d cdc vimg dl bao.
4.2 De xuat
Nghiin cim ddi ban hon vl him lugng cic chat cd the giy dfic. tgi cdc khu vyc cd dl vd khdng de ciia tinh An Gigng dl dinh gid todn diln dugc tinh hinh tich luy dfic lgi cic logi fainfa bao dl tgi tinh An Giang.
TAI U $ U THAM KHAO
1. Chu Thi Tham, Phan Thi Lai. Nguyin Vin Td. 2006. Phan vi lugng vdi cay ttdng.
NXB Lao dfing Ha Ndi.
2. Duong Minh Viin vi Vd Thi Guong, 2008.
San xuit phin hihi eo vi sinh tii ba bCm mia.
Dh tii yam tgo cdng nghe. Bd mdn Khoa hpc Ddt - Khoa Ndng nghiep & SHUT) - Tnrdng Dai hgc Can Tfaa.
3. Duong Minh Viin, Vd Vdn Binh, Huynfa Tfai Thu Huong, Vd Thj Guong, 2010. Anh hudng ciia phii sa len ndng sudt liia vi mdt sd tinh chat ciia dit. Ki yeu Hdi nghi khoa hpc phdt frien ndng nghiip ben virng thich irng voi bien ddi khi hdu. NXB Ndng nghiip.
4. Hfi Thi Lam Trd, 2005. Sy ticfa luy kim loai ning ttong ddt ndng ngfaiep vd nudc ogim d xa Dai Ddng. huyen Vdn Lam, Hung Yin.
Tap chi Khoa hpc Dit sd 21. Liln hiep eic Hfii Khoa hpc vi Ky thugt Vi?t Nam. Hdi Khoa hpc Dal Viet Nam. Trudng Dgi hpc cin Tho.
5. Ll Thi Thiiy, Pham Quang Hi, 2008. Danh gii thyc trgng Cu. Pb, Zn, Cd trong dit ndng nghiep Viet Nam giai doan 2002 - 2007. Tap chl khoa hpc ddt sd 29. Lien hiep cac Hpi Khoa hpc va Ky thugt Viet Nam.
Hpi Khoa fapc Dat Vilt Nam. Trudng Dgi hpc Cdn Tho.
6. Ll Vdn Khoa, 2004. Sinli thai va mfii truong ddt. NXB Dai hpc Qudc gia Ha Npi.
7. Ngfi Ngpc Hung, 2005. Thyc tap tfafi nfauong. Tnrong Dgi hpc Can Tha.
8. Ngd Ngpc Hung. 2012. Gido ttinh Dfic chit hpc mdi tmdng dat. NXB Dgi hpc Can Tho.
9. Nguyin Nhu Bd. 2006. Thd nhudng ndng hda. NXB Ha Ndi.
10. Phgm Ngpc Xuan, 2004. Luin vdn thgc sT khoa hpc mdi trudng "Chat lugng mfii trudng ddt d cic viing de bao kilm soat IQ thudc huyen An Phii - Chg Mdi tinh An Giang". Trudng Dai hpc Cin Tha.
11. Sd tai nguyen mdi tradng An Giang. 2008.
Bio cio tdng hgp quan fric hiln ttgng mdi truong tinh An Giang nim 2008.
12. Trin Anh Thu, Trin Kim Tinh, Vd QuMig Minh, 2009. Nghiin ciiu nguon gay 6 nhilm Arsen trong nudc ngdm tai An Phii, tinh An Giang. Hdi nghi khoa hpc - cong nghe nam 2009. Tnrdng Dai hpc Cdn Tha.
