Nghiên cứu khả năng hấp phụ của vật liệu FK đối với ASEN

..

TRtTONG DAI HOC AN GIANG
KHOA KY THUAT - CONG NGH^ - MOITRUONG

NGUYEN VAN CAM

nghien cutj kha nang hap phu cua
vAt lieu fk d6i v6i asen
TRUC3NG DAI HQC
AN GIANG

THtfVIEN

KHOA LUAN TOT NGHIEP

GVHD: TS. NGUYEN TRUNG THANH

An Giang, 05/2013


L01 CAM CWV
Qua bon nam hoc tap tren giang dubng trubng Dai Hoc An Giang, em da
nhan dugc su chi day va giiip da nhiet tinh ciia quy thay co khoa Ky Thuat Cong
Nghe Moi Trubng. Quy thay co da tan tinh truyen dat nhung kien thuc va kinh
nghiem vo cung quy bau, do la nen tang vung chac giiip em co the hoan thanh tot
cong viec hoc tap dac biet la khoa luan tot nghiep.
Em xin chan thanh cam an Ban Giam Hieu Trubng Dai Hoc An Giang, quy
thiy co khoa Ky Thuat Cong Nghe Moi Trubng, Ban Quan ly Khu thi nghiem da
tao dilu kien cho em thuc tap, nghien cuu va tilp xiic thuc tl dl em dugc hgc hoi
nhung kinh nghigm rat quy bau.

Em xin bay to long bilt an sau sic din Thly TS. Nguyln Trung Thanh. Thiy
da tan tinh giiip da, chi din va dong gop nhung y kiln quy bau trong suit thai gian
nghien cuu thuc hien de tai tu do giiip em hoan thanh tit khoa luan tit nghiep.
Em xin cam an Thiy Phan Phudc Toan, Co Nguyen Hbrig Nhat da tan tinh
giiip da em trong suot qua trinh thuc hien thi nghiem giiip em co thi hoan thanh tit
cong viec cua minh.

Day la Ian dau tien em co ca hoi tiep can cong viec nghien cuu khoa hoc
nhung trong khoang thai gian ngln va vln kiln thuc con han chi nen khoa luan tit
nghiep ciia em khong the khong tranh khoi nhung sai sot, em xin ghi nhan nhung
nhan xet, dbng gop y kien cua quy thay co de de tai ciia em dugc hoan thien vai
chat lugng tit han.
Mot Ian nua em xin chan thanh cam an!

Long Xuyen, ngay 17 (hang 05 nam 2013.
Sinh vien thuc hien

Nguyen Van Cam


NHAN XET CUA GIANG VIEN HirdNG DAN

Long Xuyen, ngay 17 thdng 05 nam 2013

TS. Nguyen Trung Thanh


NHAN XET CUA GIANG VIEN PHAN BIEN

Long Xuyen, ngay 17 thing 05 ndm 2013

Giang vien phan bien 1

Ths. Nguyen Thanh Hung


NHAN XET CUA GIANG VIEN PHAN BIEN

Long Xuyen, ngdy 17 thdng 05-ndm 2013
Giang vien phan bien 2

Ths. H6 Thi Thanh Tam


LOfI Md DAU
Hien nay fr mot so vung nong thon Viet Nam phan Ion sii dung nguon nude
ngam lam nguon nude chinh phuc vu cho sinh hoat va an uong nhung chua dupe
xu ly hoac chi xil ly bang cac phuang phap thu cong nhu de lang, lpc, ... nen van
de 6 nhiem kim loai nang, dac biet la Asen trong nude ngam la rat cao. Do do,

viec nghien ciiu tach Asen cung nhu cac kim loai nang khac ra khoi ngam nude
ngam bi 6 nhiem la van de quan trpng nham bao ve sue khoe cpng dong va thu
hut su quan tarn cua nhiSu nha khoa hoe. Da cd nhieu phucmg phap dupe su dung
de xii ly Asen trong nude ngam, trong do phucmg phap hap phu dupe su dung
rang rai hon vi co nhung uu diem nhu sau: tong hpp vat lieu don gian re tien,
thai gian xu ly nhanh va cd the tai su dung vat lieu hap phu.
Trong phuang phap hap phu thi cac vat lieu bien tinh tu cac phe pham nong
nghiep nhu tro trau, sa dira, vd lac, ba mia,.,.. dupe nghien cuu rat nhieu va dupe

danh gia la vat lieu hap phu cd nhieu trien vpng.
Trong de tai "Nghien cuu kha nang hap phu cua vat lieu FK doi v&i

Asen" chung toi chu yeu tap trung nghien cuu kha nang hap phu ciia tro trau tir
cac Id dot gach (tro trau se duac hoat hoa bang H2SO4) va gan hop chat hoat
dpng be mat (cd hoat tinh rieng doi v&i Asen) bang phuang phap tam va nung
lam vat lieu hap phu Asen cd trong nude ngam.


TOM TAT
Van de 6 nhiem Asen trong nude ngam va nhung anh hudng cua Asen doi
vdri sue khoe con nguai dang la van d ndng bong va dang quan tam cua nMSu
quoc gia. KM tham nhap vao ca the Asen co the gay ra hang loat tac dpng xau den

siic khoe con nguai du chi a mpt luang rat thap. Trong nghien cuu nay, vat lieu
FK dupe tong hap tren nen chat mang la tro trSu (da hoat hoa bang axit H2SO4
10%, thai gian hoat hoa la 30 phut) se duac gan cac chat hoat dpng be mat (co
hoat tinh rieng doi vai Asen) bang phuang phap tam va nung. Cac yeu to nhu: che
dp hoat hoa tro trdu, kh6i lupng vat lieu FK, ham luang chSt hoat dpng b mat, va
pH ciia nuac ngam la cac yeu to chinh anh huang den qua trinh hap phu Asen ciia .
vat lieu FK. Qua cac dieu Men thi nghiem khac nhau, chiing toi nhan thay rang
5mg vat lieu FK co kha nang hap phu gan nhu hoan toan ham luang Asen trong
50ml nude ngam (0,009 mg/1) d pH ~ 7.0 vdi thai gian hap phu la 15 phut. Qua do
xac dinh dupe tai lupng hap phu Asen ciia vat lieu FK la 0,09 (mg/g).
Qua ket qua nghien ciiu ciia de tai cho thay ldra nang hap phu ciia vat lieu FK
doi vdi Asen co hieu qua cao. VI vay co the nghien ciiu, ling dung rpng rai vat
lieu FK vao thuc te xu ly Asen trong nude ngam Men nay la rat can thiSt.


ABSTRACT
The issue of groundwater contamination from arsenic has been concerned
from many countries on the world. The reason is the arsenic will poison human

even the small amounts of the arsenic. In this study, the impregnation and
calcination methods were used to synthesize FK/rice husk ash materials. The

factors could effect to Arsenic adsorption for our materials, for example: the way
activated the rice husk ash material, mount of adsorbent and FK percent on the
support, pH value,... The experimental condition optimum is 5 mg FK/rice husk
ash material capable of almost completely adsorbed arsenic concentrations in
groundwater 50ml (0.009 mg/1) at pH ~ 7.0 with adsorption time is 15 minutes.
Thereby determine the load of material adsorbed As FK is 0,09 (mg/g).
The results showed that the arsenic adsorption capacity of our material
with 10 % FK (in the weigth) is very high. So we think that our material can
apply our material into the real system to treat the arsenic contamination from the
groundwater.


KHOA LUANTOTNGHIEPGVHD: TS. NGUYENTRUNG THANH

muc Lye
LOICAMON
NH^N XET CUA GIANG VIEN HUONG DAN
LOflMCJBAU
TOM TAT
MUC LUCi
DANH SACH BANGiv
DANHSACHHINHv
DANH MUC CACTU" VIET TATvi
Chuong 1: GICH THIEU1
Chuwng 2: LUOC KHAO TAI LIEU2
2.1. T6ng quan vIMp phu'.2
2.1.1.Hap phu2

2.1.2.Ban chat Men tuanghapphu2

2.1.3.Phdn loai cdc qua trinh hap phu3
2.1.4.Cache hap phu

5

2.1.5.Dong hoc qua trinh hap phu5
• 2.2. Tong quan ve nudcngam5
2.2.1.Hien trqng sit dung nuac ngam5
2.2.2.Vaitrd cua nuac ngam doi vai dai song6
2.2.3.Thdnhphdn vd dqc diem cua nuac ngam-6
2.2.4.Nguon goc vd nguyen nhan gay 6 nhiem nuac ngam7

2.3. T6ng quan v6 Asen (thach tin)'.7
2.3.1.Asen7
2.3.2.Tinh chat cua Asen8
2.3.3.Nguon goc vdsuphdn bo Asen trongmoi truang8
2.3.4.Nguon goc 6 nhiem Asen8
2.3.5.Hien trqng nguon nuac hi nhiem Asen10

SVTH: Nguyin Van Cam-DHIOMTi

MSSV: DMT092098


KHOA LUAN TOTNGHIEPGVHD: TS. NGUYEN TRUNG THANH

2.4.Trieu chumg nhiem doc Asen

12

2.4.1.Co che gay doc cua Asen...12
2.4.2.Nhiem doc cap tinh

13

2.4.3.Nhiem doc man tinh14

2.5.Mot so phircmg phap xit ly Asen15
2.5.1.Phuongphap keo tu - ket tua15

2.5.2.Phwongphdp oxy hoa16
2.5.3.Phuongphdp trao doi ion17
2.5.4.Phuongphdp loc17
2.6.Phuong phap hap phu xil ly Asen

19

2.7.Mot s6 nghien cum v vat lieu hip phu Asen21
2.8.T6ng quan v tro trlu23
2.8.1.Trotrdu23
2.5.2.Thanhphdn hoa hoc cua tro trdu23
2.8.3.Mot s<5 ieng dung cua tro trdu23
2.5.4.Anh hudng cua tro trdu den moi truong, sue khoe con nguoi... 24

Chuo-ng 3: PHlTONG TIEN VA PHlTONG PHAP NGHIEN CUTJ25
3.1.D6i tuomg nghien cum25
3.2.Thai gian nghien cum25
3.3.Mpc tieu nghien cum25

3.4.Npi dung nghien cum25
3.4.1.Thu mdu nude ngdm nhiem Asen25

3.4.2.Tdng hop vat lieu FK25
3.4.3.Khdo sat khd nang hap phu cua vat lieu FK doi voi Asen trong
nuocngdm25
3.5.Phuang tien va vat lieu nghien cum25
3.5.1.Phuong tien nghi&n cicu25
3.5.2.Hoa chdtvd vat lieu nghien cuu26

SVTH: Nguyen Van Cam - DH1OMTii

MSSV: DMT092098


KHOA LUAN TOTNGHIEP

GVHD: TS. NGUYEN TRUNG THANH

3.6. Phuong phap nghien cuu26
3.6.1.Tdng hop vdt lieu FK26
3.6.2.Phwongphdp thu mdu26
3.6.3.Bo tri thi nghiem27
3.6.4.Phuong phap phdn tich mdu trongphdng thi nghiem28

Chuong 4: KET QUA THAO LUAN

29

4.1.T6ng hop vat lieu FK29

4.1.1.Hoqt hda tro trdu bdngH2SO4

29

4.1.2.long hop vdt lieu hdpphu FK tic tro trdu da hoqt hoa30
4.2.Khao sdt kha nang hap phu cua vat lieu FK ctoi vdi Asen trong nuac

ngim33
4.2.1.Lap duong chudn Asen

33

4.2.2.Anh huong cuapHden hieu qua hdpphu Asen trong nude ngdrn
cua vdt lieu FK33
4.2.3.Anh huong ham lupng chat HBBMden hieu qua hdpphu Asen
trong nude ngdm cua vdt lieu FK36
4.2.4.Xdc dinh tdi lupng hdpphu Asen cua vdt lieu FK40
4.3.Mot so uu diem cua vat lieu FK hap phu Asen trong nuac ngam41

Chuong 5: KET LUAN VA K3EN NGHI42
5.1.KET LU^N42
5.2.KIENNGHI42

TAI LIEU THAM KHAO
PHU LUC;

SVTH: Nguyen Van Cam - DH10MT

MSSV: DMT092098

KHOA LUAN TOTNGHIEPGVHD: TS. NGUYEN TRUNG THANH

DANH SACH BANG

Bang 2.1: Dien tick be mat riing ciia mot so vat lieu hap phu3
Bang 2.2: Tiiu chudnphdn biet hap phu vat ly va hap phu hoa hoc4
Bang2.3: Thanhphan hoahoccua tro trdu23
Bang3.1: Thanhphdn cdc chat tonghap vat lieu FK27
Bang 4.1: Thanh phan tong hap vat lieu FK30
Bang 4.2: Kit qua duang chudn As33
Bang 4.3: Kit qua hap phu As bang vat lieu FK khipHthay doi35
Bang 4.4: Kit qua hap phu As trong nic&c ngdm cua vat lieu FKkhi ham luqng

chdt HDBM thay doi37
Bang 4.5: Kit qua xdcdinh tdi luqng hap phu As.40

SVTH: Nguyen Van Cam-DHIOMT

MSSV: DMT092098


KHOA LUAN TOTNGHIEPGVHD: TS. NGUYEN TRUNG THANH

DANH SACH HINH
Hinh 2.1: Md td hap phu vat ly vdi hai lop chat hdp phu3
Hinh 2.2: Gidn do ndng luong hoat hoa chophdn ung hoa hoc4
Hinh 2.3: So do cdng nghe xic ly As bangphuongphdp keo tu-kettua15
Hinh 4.1: So dd hoat hoa tro trdu bang H2SO429
Hinh 4.2: Tro trdu ban ddu30

Hinh 4.3: Tro trdusau hoat hoa30
Hinh 4.4: Chudn bimdu31
Hinh 4.5: Tarn chdt HDBM len tro trdu:31
Hinh 4.6: Vat lieu FK31
Hinh 4.7:Bdo qudn mdu31
Hinh 4.8: Tro trdu tuoi32

Hinh 4.9: Mdu 1 (0% HDBM)32
Hinh 4.10: Mdu 2 (5%HBBM)....,32

Hinh 4.11: Mdu 3 (10% HDBM)32
Hinh 4.12: Mdu 4 (15% HDBM)32
Hinh 4.13: Mdu 5 (20% HDBM)32
Hinh 4.14: Duong chudn Asen33
• Hinh 4.15: Thi nghiem khdo sat su dnh huong cua pH den hieu qua hdp phu As
trong nude ngdm cua vqt lieu FK.34

Hinh 4. 16: Biiu dd hieu qua xu ly As (%) cua vdt lieu FK khi pH thay ddi55
Hinh 4.17: Thi nghiem khdo sat dnh huong cua ham luong chat HDBM den hieu
qua hdp phu As trong nude ngdm cua vdt lieu FK.36
Hinh 4.18: Bieu do the Men ndng do As (ppb) sau khi hdp phu bang vdt lieu FK

khi ham luong chdt HDBM thay ddi

37

->•^'
Hinh 4.19: Bieu
do hieu qua xu ly As (%) ciia vdt lieu FK khi ham luong chdt

HDBM thay ddi38
Hinh 4.20: Thi nghiem xdc dinh tdi luong hdp phu cua vdt lieu FK40

SVTH: Nguyen Van Cam -DH10MT

MSSV: DMT092098


KHOA LUAN TOTNGHIEP

GVHD: TS. NGUYEN TRUNG THANH

DANH MUC CAC TlT VIET TAT

DBCSL

Bong Blng Song Ciru Long

HBBM

Hoat Bong B6 Mat

UNICEF

Quy Nhi Bong Lien Hop Quoc

QCVN

Quy Chuiri Viet Nam

TP.HCM

Thanh Ph6 H6 Chi Minh

TCVN

Tieu Chulh Viet Nam

WHO

T^ChiicYTSThSGioi

NST

NhiSm Sic Th6

KPH

Khong Phat Hien

NXB

Nha Xudt Ban

sr

Bien tich be mat rieng

As

Asen

N2

Nito

Cu

B6ng

Pb

Chi

Ag

Bac

SVTH: Nguyen Van Cam-DHIOMT

MSSV: DMT092098


KHOA LU4NT6T NGHIEPGVHD: TS. NGUYEN TRUNG THANH

Chuong 1

GIOI TfflOEU
Nude la mot trong nhung yeu to vo cimg quan trpng doi vdi sir ton tai va
phat trien cua con ngubi. Hien nay vdi sir bung no dan so the gidi thi van de cung

cap nude sach phuc vu nhu c^u an udng va sinh hoat cua con ngudi dang trd
thanh van de ndng bong ma xa hoi quan tarn. Trong khi cac ngudn nude mat nhu:
song, sudi, ao, ho dang ngay cang bi 6 nhiem mpt each nghiem trpng bdi nude
thai sinh hoat, nude thai tir cac nha may cong nghiep, hoat dpng ndng nghiep,...
thi hien trang bien doi khi hau toan cau lam cho trai dat ndng dan len cung la
nguyen nhan gdp phSn lam cho nguon nude ngay cang bi can kiet.
VI vay, viec tai su dung nguon nude thai tit cac nha may cong nghiep hoac
khai thac tot nguon nude cd san trong tu nhien la viec lam rat can thiet hien nay.
Trong do, viec khai thac va su dung nude ngam dupe xem nhu la mot giai phap
him hieu. Nude ngam thudng la ngudn nude dupe ua thich doi vdi cac he thong
cap nude cpng dong bdi vi cac ngudn nude ngam thudng it 6 nhidm va luu lupng
khai thac khdng phai phu thupc nhieu vao su bien dpng cua mdi trudng. Tuy
nhien, trong qua trinh. khai thac nude ngam thi su ton tai cua Asen la mot trong
nhung van de dang quan tam thdi gian gan day.
VSn de 6 nhiem Asen trong nude ngam la mot thuc trang dang lo ngai
khdng chi cua Viet Nam ma cua ca The Gidi. An Giang la tinh co mire dp d
nhiem Asen trong nude ngam rat cao, dien hinh la huyen An Phu cd tren 800
gieng khoan nhilm Asen. Ndng dp Asen trong cac ting tram tich dupe phat hien
ddn dp sau 40 m.
Nhan thuc dupe nhiing anh hudng ciia Asen den sue khde con ngudi. Vi ly
do do nen nhdm nghien cuu chiing tdi chpn de tai "Nghien cum khd ndng hap
phu cua vat lieu FK doi v&iAsen".
Trong nghien cuu nay cluing tdi su dung ngudn tro trau tir cac 16 dot (da
hoat hoa bang H2SO4) va gan cac hap chat vo ca (chat HDBM cd hoat tinh rieng
doi vai Asen) lam vat lieu hap phu Asen cd hong nude ngam.

SVTH: Nguyen Van Cam -DH10MT

MSSV: DMT092098

KHOA LUANTOTNGHIEPG.VHD: TS. NGUYENTRUNG THANH

Chmmg 2
LlTO'C KHAO TAI LIU
2.1. Tong quail ve hip phu
2.1.1.H^p phu

Hap phu la qua trinh hut cac chat len be mat cac vat lieu xop nhb cac luc be
mat. Cac vat lieu x6p gpi la chit hip phu, chit bi hut gpi la chat bi hip phu.
Hap phu dugc ling dung rpng rai trong cong nghiep hda chat thuc pham va
nhieu linh vuc che bien khac, tit viec tach triet de cac chat khi co ham lugng thap,
tiy mau, tiy mui cac dung dich din hip phu cac chat doc hai trong nude va khi
thai. Ngay nay cac chit hip phu da dugc che tao de tach cac dong phan Parafin,
tach nhiiu chit long huu ca phan hi thap thay cho qua trinh chung luyen hong
nhung trudng hop kho khan. Chit hip phu con giu vai tro quan trong hong viec
san xuat chat xiic tac. (Nguyen Bin, 2005)
2.1.2.Ban chat hien tuffng hap phu

Nhu chiing ta da biit, cac phin hi hen bi mat chat rin luon tin tai mot nang
lugng du, do la do: gidi han be mat cua vat lieu va su mat hat tu hen hong cau
tnic cua vat lieu.

Chinh nguon nang lugng du nay da giiip cac phan hi cd kha nang bit lay
cac phan hi khac nam gan vi hi do hen be mat chat ran nham giai tda nguon nang
lugng du, day chinh la ban chat ciia hien tugng hap phu. Va vi hi ciia nguon nang
lugng du nay dugc gpi la tam hap phu. Ngudi ta khong the xac dinli dugc gia hi
nang lugng du hen cac tam hap phu. Trong thuc te, de danli gia kha nang hap
phu ciia vat lieu ngudi ta thuong dung thong so bi mat rieng ciia vat lieu (la dien
tich be mat ciia chat hap phu tinh cho mot gam chat hap phu, thuong cd don vi

m2/g hoac Sr).
Dieu do cd the hieu la vat lieu nao cd dien tich be mat rieng cang ldn thi
kha nang hap phu cang ldn.
Tuy nhien, ngoai gia hi Sr thi ban chat ciia chat hap phu va yeu td hinli hoc
cung giu mot vai tro quylt dinh d6n qua hinh hap phu.
Thuc nghiem cho thay, cac vat lieu cd Sr > 200 m2/g cho kha nang hip phu
rat cao, cho nen chiing dugc su dung nhidu hon (so vdi cac vat lieu cd Sr < 200
m2/g) hong qua trinh hip phu.

SVTH: Nguyen Van Cam -DH10MT

MSSV: DMT092098


KHOA LUAN TOTNGHIEP

GVHD: TS. NGUYEN TRUNG THANH

Bang 2.1: Dien tich be mat rieng cua mot so vat lieu hap phu

Ten vat lieu

Chat bi h^p phu

1Than hoat tinh
2Silicagen
3Oxit nhom
4Zeolite

Dien tich be mat rieng

(Sr hoac mVg)

N2
N2
N2
N2

400^ 1000
200 - 500

200 - 400
200-300

(NguSn : Rice hush ash market study 2003 - UK)

2.1.3. Phan loai cac qua tririh hap phu
Dua vao ban chat qua trinli hap phu; co the chia thanh hai loai do la hap phu
vat ly va hap phu hoa hoc. Trong do:
a. Hap phu vat ly
Hap phu vat ly la qua trinh hap phu duqc thiic hien boi cac luc vat ly vi du
nhu luc Van - der - Walls. Dae diem cua qua trinh nay la:
-Xay ra a nhiet dp thucmg (co the d nhiet dp thap hon nhiet dp moi trudng).
-Nang Iupng cho qua trinh nay thudng vao khoang < 20kJ/mol.
-Khong hinh thanh lien ket hoa hoc.
-Co the hinh thanh cac Mp phu chong chat len nhau.
Luu y rang cac yeu to nhu dien tich be mat rieng (Sr), kich thuoc 16 xop,
ban chat cua chat hap phu va chat bi hap phu (tinh phan cue) se quyet dinh kha
nang hap phu.

Lop hap phu thu hai

Lop hap phu thu nliat

Hinh 2.1: Mo tct hap phu vat ly vffi hai lap chat hap phu
SVTH: Nguyen Van Cam-DHIOMT

MSSV: DMT09209S


GVHD: TS. NGUYENTRUNG THANH

KHOALUAN TOTNGHIEP
b. Hap phu hoa hoc

La qua trinh hap phu dupe thuc Men bai cac lye lien ket co ban chat hoa
hoc. Tuc la qua trinh nay co su hinh thanh cac lien ket hoa hoc. Sac diem cua

qua trinh nay la:
-Dugc thuc Men a nhiet do cao.

-Qua trinh dugc tiSn hanh cham hon so vdi cac qua trinh phan ling hoa hoc
va hap phu vat ly.
-Chi tao hip phu dan lop.
-Phu thuoc vao pH va ban chit axit - baza giua chat hap phu va chat bi hap
phu.

A+B

Hinh 2.2: Gian dd nang luvng hoat hoa cho phan wig hoa hoc

c. Tieu chuan phan biet hap phu vat ly va hap phu hoa hoc
Bang 2.2: Tieu chuan phan biet hap phu vat ly va hap phu hoa hoc

Hap phu vSt ly

Hap phu hoa hoc

Entanpy hip phu8-20 kJ/mol

40 - 80 kJ/mol

Nang luo'ng hoat hoa E

Bang khong

Thuang nho

Nhiet do hip phu

Phu thuoc vao nhiet dp Phu thupc nang lugng
soi nhung thuang rat thap hoat hoa nhung thuang
khong cao

So lop hip phu

Co the nhieu lap

SVTH: Nguyen Van Cam-DHIOMT

MSSV: DMT092098

Chi mot lap


KHOA LUAN TOTNGHIEPGVHD: TS. NGUYEN TRUNG THANH
2.1.4.Co1 chi hip phu
Co1 che hip phu trong moi truang nude phu thupc vao ban chat hoa hoc cua
chat bi hap phu, chat hap phu ya yeu to ngoai canh cua moi truang nhu pH, nhiet
do, curing do ion, su co mat chat la ...

Co 3 tuong tac chinh trong qua trinh hap phu: chat hap phu - chat bi hap
phu, chat hap phu - dung moi nude, chat bi hap phu - dung moi. Luc nao tuong

tac manh hon se dong vai trd quyet dinh co che.
2.1.5.Bong hoc qua trinh hap phu
Qua trinh hap phu tu pha (long hay khi) len be mat xop cua chat hap phu
gom ba giai doan:
-Chuyen chit long tu pha long den be mat ngoai cua cac hop chat hap phu.
-Khuyen tan vao cac mao quan ciia hat.

-Hip phu: qua trinh hip phu lam bao hoa dan timg phln khong gian hap
phu, ding thai lam giam dp tu do cua cac phan til bi hap phu, nen luon kem theo
su toa nhiet. Hieu ling nay rat dang ke doi vdi hap phu khi. (Nguyen Bin, 2005)
2.2. Tong quan vl nu'6'c ngam
2.2.1. Hien trang su- dung nude ngam

Bong bang Song Cieu Long:
DBSCL hien co hon 400.000 gieng nude ngam cimg hang tram tram cap
nude tap trung khai thac nude ngim vdi quy mo ldn. Mot sd tinh nhu Tra Vinh,
Sdc Trang, Bac Lieu, Ca Mau gan nhu su dung 100% nude ngam phuc vu sinh

hoat va cac hoat dong san xuat kinh doanh. Hien tai Ca Mau dang la dia phuang
dan dau BBSCL ve khai thac nude ngam vdi 137.988 gieng dang su dung. Tuy
nhien BBSCL hien co hang ngan gieng khai thac nude ngim dang bj bo phi,
khong dupe tram va lap dung ky thuat dan den nguy ca sup, lun tang khai thac,
suy thoai tang nude, nhiem man, 6 nhiem nguon nude ngam rat ldir. Trong do,

Ca Mau co 3.238 giing, Bac Lieu 1.700 giing, Tra Vinh 1.600 giing... (Vu Thi
Dan Thanh, 2011)
Tinh An Giang:
Theo so lieu tur Trung tam Quan trie va Ky thuat Tai nguyen Moi trudng
tinh An Giang cung cap, hifn nay toan tinh co 7133 gieng, trong do chi co 6466
gieng la dang su dung, con 667 gieng con lai dang trong tinh trang khong dupe
su dung va bi hu hong, chiim ty le la 9,35%, do la mot ty le kha cao. Tu trudc
SVTH: Nguyin Van Cam-DHIOMT

MSSV: DMT0920985


KHOA WANTOT NGHIEP 'GVHD: TS. NGUYENTRUNG THANH

den nay chua co ca quan nao co trach nhiem xd ly nude gieng bi 6 nhiem hoac
gieng bi hu hong nen nguy ca gay nhiem ban ngudn nude ngam kha cao. Cac dia
phuOng co sd lugng giSng nhi^u nhat cua tinh la Tri Ton, An Phu, Chg Mdi, Tan
Chau...

0 tinh ta s6 lugng gi6ng phuc vu cho cac muc dich khac nhau co su chenh
lech rat ldn. S6 luong gieng phuc vu cho nhu cau sinli hoat chiem ty le cao nhat
92,12%. Trong khi do, so gieng phuc vu cho san xuat nong nghiep chi chiem
7,3% va so gieng con lai chiem ty le chua tdi 0,6% (mot ty le rat thap) nhung vua
phuc vu cho cong nghiep (0,26%) vita cung cap nude cho cac tram bom cap nude

cua tinh (0,32%). (Vu ThiDan Thanh, 2011)
2.2.2.Vai tro cua nu-dc ngSm d6i voi doi sfing
Doi vdi cac he thong cap nude cong cong, nude ngam luon la nguon nude
dugc ua thich han. Vi nude mat thudng de bi 6 nhiem va co tru luong kliai thac
khong on dinh, thay doi theo mua. Trong khi do, nude ngam it chiu anh hudng
bdi cac tac dpng ciia con ngudi va ham lupng chat ran la lung, rong tao la rat
thap, gan nhu la khong co. Cac chi tieu vi sinh vat gay benh trong nude ngam
cung tot hon nude mat. Th6 nhung vi tru lugng ldn va dl khai thac nen nguon
nude mat tren trai dlt dang dugc khai thac va su dung qua muc nen ngay cang bi
hao hut ve so lugng, suy giam ve chat lugng. Do do, hien nay nude ngam dong
vai tro het sue quan trong va can thiet doi vdi cupc song ciia con ngudi. Nude
ngam thudng dugc sd dung phuc vu cho sinh hoat, cac nganh cong nghiep, y hoc,
du lich.v.v... Doi vdi mot sd vung ven bien, nhiem phen, kho han nude ngam
con dung de san xuat hoa mau va nuoi trong thuy san. Ben canh do nude ngam

con ddng gdp rit ldn cho ddng chay song ngdi cua nhi6u con song.
2.2.3.Thanh phSn va dac diem cua nude ng^m
Trong nude ngam thudng ton tai cac anion va cation, ma chu yeu la Na+,
Ca2+, Fe2+, Mg2+, NH4+, HCO3", SO42", Cl". ThS nhung Fe2+, Mn2+ la thanh ph^n

luon dugc quan tarn, chu trong trong qua trinh xd ly nude cap, vi su hien dien
thudng xuyen cua chung trong nude ngam vdi ham lugng kha cao. Thuc te nude
ngam con chua rat nhieu Io^i muoi nhu: Na2CO3, MgCO3, Na2SO4, Fe2(SO4)3,
, A12(SO4)3, NaHCO3... NaCl, NaBr. Thanh phln chit lugng cua nude ngim phu
thupc vao nguon goc cua nude ngam, cau true dia tang cua khu vuc va chieu sau

dia tang nai khai thac nude. Ngudi ta chia nude ngam ra lam hai loai khac nhau:
-Nude ngam hieu khi (co oxy).
-Nude ngam yem khi (khong co oxy).
SVTH: Nguyin Van Cam -DH10MT

MSSV: DMT092098'6


KHOA LUANTOTNGHIEPGVHD: TS. NGUYEN TRUNG THANH

+ Nworc ngam hieu khi (co oxy): thong thuong nude co oxy co chat lupng
tot, co trudng hop khong can xu ly ma co the cap true tiep cho ngudi tieu thu.
Trong nude co oxy se khong co cac chat khu nhu H2S, CKL)r, NH4+...

+ Nw&c ngam yem khi (khong co oxy): trong qua trinh nude tham qua cac
tang dat da, oxy bi tieu thu. Khi lupng oxy hoa tan trong nude bi tieu thu het, cac
chit hoa tan nhu Fe2+, Mn2+ se dugc tao thanh. Mat khac cac qua trinh khu NO3"

=> NH4+; SO42' => H2S; CO2 => CH4 cung xay ra. (Nguyin Thi Thu Thuy, 2006)
2.2.4. Ngu^^n g6c va nguyen nhan gay 6 nhiem nude ngam
>Ngudn tw nhien:
Lu hit, han han, xdi mdn, rua troi cac hop chat huu ca va vo co tu qua trinh

phan huy xac dong thuc vat va qua trinh theo nude mua tham vao nude ngam.
^Ngudn nhan tao:
Day la nguyen nhan chinh gay 6 nhiem nude ngam, bao gom cac van de
sau:

-T6c dp phat triln kinh tl cung vdi sir bung no dan s6 keo theo nhu cau su
dung nude gia tang. Dan den tinh trang khai thac nude ngam qua muc va bira hai
khong theo qui dinh va lam suy giam ve so lupng va suy thoai ve chat lupng
nude. Muc nude ngam ha thap se de bi nhiem man, tao dieu kien de cac chat doc,
chat ban xam nhap va lam 6 nhiem nude ngam.

-Nude thai tu cac khu cong nghiep, khu che xuat, khu chan nuoi, benh
vien, khu dan cu va nude ri tu cac bai rac, be phan hoa hoc.
-Du lupng thuoc trir sau, thuoc diet co, thuoc bao ve thuc vat, phan bdn
hoa hoc... ttr cac canh dong.

-Nan khai thac rung bua bai lam giam kha nang giu dat, gift nude, din din
lupng nude thlm vao dat cung giam theo, do do tru lupng nude ngam se bi ha
thlp.
2.3. Tong quan ve Asen (thach tin)
2.3.1. Asen

Asen (As) la nguyen to hinh thanh tu nhien trong vd trai dat. As nguyen
chat la kim loai mau xam, nhung dang nay ft ton tai trong thien nhien. Ngudi ta
thudng tim thay As ton tai dudi dang hop chat vdi mot hay mot so nguyen to
khac nhu oxy, clo, luu huynh,... Asen kit hop vdi nhung nguyen td tren tao thanh
cac hop chat Asen vo ca nhu cac khoang vat: Da thien thach, Orpiment (As2S3),
Arsenplite (As2O3),... hop chit cua Asen vdi carbon va hydro gpi la hop chit As
SVTH: Nguyin Van Cam -DH10MT

MSSV: DMT0920987


KHOA LUAN TOTNGHIEPGVHD: TS. NGUYEN TRUNG THANH

huu ca. Cac dang hpp chat him ca cua As thudng it doc hai so vdi cac hop chat
As vo co. (Le Huy Ba, 2006)
Qua cac tai lieu nghien ciiru cho thay doc tinh cua As phu thupc rat Ion vao
hinh thiic ton tai, trang thai oxy hoa va do tan (hay ham lupng) ciia no trong moi
tnrdng, cu the la cac dang hop chat As hoa tri III co doc tinh cao hon dang hoa tri
V.

2.3.2.Tinh chSt cua Asen

Asen va cac hop chat vo ca ciia no la nhung chat rat doc, chiing ton tai pho
bien trong thien nhi^n va cung co mat trong san xuat cong nghiep. Asen la mot a
kim mau xam triing, mui toi, ty trong la 5,7 (ty trong cua nude la 1). Khi lam
ndng As chay ra va thang hoa d nhiet dp 613 C. (Le Huy Ba, 2006)
As tinh khiet dupe xem la khong doc, nliung trong dieu kien binh thuong
As khong bao gid a trang thai tinh khiet vi khi tiep xuc vai khong khi mot phan
As da bi phan hoa oxit rat doc. Asen chay trong khong khi tao thanh khoi tring
gpi la trioxit asen rat doc. (Le Huy Ba, 2006)
2.3.3.Ngu6n goc va su phan b6 Asen trong moi trudng
As la nguyen to kha pho bien tren trai dat. Trong thien nhien As co the ton
tai trong moi txudng dat, nude, khong khi, sinh hoc... va lien quan chat che tdi
cac qua trinh dia chat, dia hoa, sinh dia hoa. Trong lap vo trai dat As chiem
khoang 0,001%, t6n tai chu yeu dudi dang cac loai quang nhu: quang arsenite
cua Cu, Pb, Ag hoac quang sunfua: As2S2; As2S; As2S3,... As cung cdthS co

trong than da vdi ham luong cao. Dong thai ngtrdi ta con tim thay sir hien dien
cua As trong da, quang; dat, vo phong hoa; tram tich bdi rdi; khong khi, nude va
trong ca the sinh vat. Trong khi quyen ton tai ca As vo ca va huu ca, ngirdi ta
con phat hien su co mat cua As trong nude mua dudi dang arsenit. Ngoai ra As
con ton tai trong rau qua, thuc pham, trong ca the dpng vat va ngudi vdi nong dp
rat nhd, gpi la vi lupng. Dudi tac dpng cua cac qua trinh tu nhien va nhan sinh
khac nhau As co thd di chuyen trr cac hop phan moi trudng nay sang hop phan
moi trudng khac dan den su phan bo phiic tap ciia cac nguyen to trong tu nliien.
2.3.4.Nguon goc 6 nhiem Asen

Cac qua trinh phong hoa da chua As va cac hoat dpng cua con ngudi thai
As vao moi trudng dat, nude va khong khi.

SVTH: Nguyen Van Cam -DH10MT

MSSV: DMT092098


KHOA LUANTOT NGHIEPGVHD: TS. NGUYEN TRUNG THANH

Qua trinh tu nhien:
Qua trinh nhiet dich, tao quang sulfua, da kim, vang; hoat dong nui lira; qua
trinh phong hda...dien ra d cac vung nui vdi cac da bien ddi nhiet dich, quang
vang, da kim.

Qua trinh xdi mon, phong hoa lam giau As trong quang oxyhydroxit sit sau
do la nhung qua trinh bdi dip phu sa, trim tich hoa dan tdi hinh thanh tram tich
chua As trong cac dia tang.

Qua trinh kku hoa, hoa tan cac khoang chat giau As trong dat vao nguon
nude ngim. Do do, nhung vung co nhidu khoang giau As thi kha nang gay 6
nhiem nguon nude cang cao.

Hoat dpng cua con ngucti:
As dugc sii dung nhieu trong cong nghiep va dugc su dung han che trong
thuoc trir sau, chat phu gia trong thuc an gia sue va trong cac dugc pham.

>Trong cong nghiep:
- As xam nhap vao moi trudng qua nguon nude thai cong nghiep, khi thai,
xii ly cac khoang As, sir dot chay cac nhien lieu hoa thach, cac chat thai ran trong
cong nghiep...

- Cac nganli cong nghiep khai thac va che bien cac loai quang, nhat la
quang sunfua, luyen kim tao ra nguon 6 nhiem As.
, - Che tao, san xuat cac hoa chat bao ve thuc vat.

>Trong nong nghiep
As co mat trong thanh phin cua cac loai thuoc trir sau, thuoc diet cd, chit
diet con trung...

Theo dieu tra cua UNICEF, As cd trong tat ca dat, da, cac tram tich, dugc
hinh thanh tir hang nghin nam trudc tai Viet Nam vdi nong do khac nhau. As tir
da tan vao cac mach nude ngam; vi vay, mach nude ngam d moi noi tren lanh tho

Viet Nam deu cd nguy ca nhiem As. Ngoai ra, cung khong loai trir kha nang
nhiem doc As tu cac nguon nhan tao nhu gan cac nha may hoa chat, cac khu khai
thac quang, nhung khu vuc nong nghiep sir dung hoa chat bao ve thuc vat, nhung
khu vuc dan tu dpng dao va lip giing khong dung tieu chuin ky thuat khoan
gieng cua UNICEF khien chat ban, chat doc hai bi tham thau xuong mach nude
ngam.

SVTH: Nguyen Van Cam-DHIOMT

MSSV: DMT092098


KHOA WAN TOT NGHIEPGVHD: TS. NGUYEN TRUNG THANH

2.3.5. Hien trang nguon mrdc bj nhiem Asen

a.Tinh hinh nhiem Asen tren the gidi
Cl Lien xo trudc day viec ddt than lam nhiet nang da thai vao khdng khi

khoang 3000 tin As/nam. Ngucri ta da phat hien nhieu vimg 6 nhiem dat, nude,
thitc vat bdi As d Bawngladet, An Dp, My, Italia, Nhat,... LTdc tinh cd tdi hang
chuc trieu ngudi tren thd gidi dang sdng trong nhung vung moi trudng giau As ed
nguy ca de dpa sue khde va tinh mang. Tai Bangladet cd khoang 2-4 trieu
gidng khoan khai thac nude. Thu nghiem 8000 gidng khoan d 60 trong 64 tinh ca
nude cho thay cd 51% so mau nude cd ham lupng As vupt qua 0,05 mg/1
(nguong quy dinh cua to chuc WHO la 0,01 mg/1).
Su 6 nhiem Asen trong nude dudi dat d vung Ronphiboon d Thai Lan lai cd
nguyen nhan do nude thai giau arsenopyrit tu nhung khu vuc khai thac che bien
quang thiec - volfram da ngam vao long dat.

Hien tuong 6 nhiem Asen trong moi trudng da dupe phat hien d nhieu noi
tren th8 gidi, trong do cd nhung khu vuc ham lupng ham lupng Asen rat cao nhu:
d Anh trong dit tdi 2%, d My trong nude tdi 8 mg/1, Chile - 800mg/l, Gana 175 mg/1,...(LeHuy Bd, 2006)
b.Tinh hinh nhiem Asen d Viet Nam
Theo bao cao chua day du cua Chuong trinh nude sach (Bp Ndng nghiep va
Phat trien nong thon), d nude ta hien cd 10 - 15 trieu dan dang su dung mach
nude ngam. Qua k^t qua kiem tra 1 trieu gieng khoan cua chuong trinh nay cho
thay: ty le nhiem As len ddn 26% - 46%, nham khu vuc cd ndng dp As cao gap
20 - 50 lan tieu chuan cua WHO, bao gom vimg trung du (khoan sau) va ca vimg
dong bang, thanh phd (khoan nong hem) nhu Ha Noi, TP. Ho Chi Minh, Ha Nam,
Ha Tay, Hung Yen, Nam Dinh, An Giang, Ddng Thap.
Ha Noi nam trong danh sach 10 tinh, thanh cd nguon nude ngam bi nhiem
As vupt qua muc cho phep va anh hudng den sue khde ngudi dan (Ha Noi, Ha
Nam, Ha Tay, Hung Yen, Nam Dinh, Ninh Binh, Thai Binh, Hai Duong, Ddng
Thap va An Giang). Muc dp d nhilm As trong nude ngam tai Ha Ndi phan bd
khong deu theo dien tich va chieu sau cac tang chira nude, thudng tap trung d
mot so khu vuc cd dia hinh thap va trung, nhat la khu cdng nghiep tap tmng. VS
mat.phan vimg d nhiem As thi khu vtrc Nam Ha Noi bi 6 nhiem nang hon so. vdi
cac khu vuc khac. Hai huySn Thanh Tri va Tir Liem ciia Ha Ndi la nhung vimg bi

nhiem nang nhat.

SVTH: Nguyen Van Cam -DH10MT

MSSV: DMT09209810


KHOA LUANTOTNGHIEPGVHD: TS. NGUYENTRUNG THANH

DBSCL co cau tao dia tang teong to nhu1 Bangladesh, do do co nguy co 6
nhiem As la rat cao. Qua mot nghien cuu cua Vien Ve sinh — Y te cong cpng (Bo
Y te) ve khao sat, danh gia Men trang 6 nhiem As trong nude ngam tai 4 tinh
BBSCL la Long An, B6ng Thap, Kien Giang va An Giang cho thay, mtic dp
nhiem As d ham lupng kha cao, de dpa sue khoe cua ngudi dan. Tai mot so
huyen cua Bdng Thap va An Giang, tinh trang nay r&t dang bao dpng khi phan
ldn cac mlu khao sat d6u bi riMim vdi ham lupng vupt nguong 100 ppb, ca Met
co nhung mau len tdi 1.000 ppb, trong khi theo quy chuan Viet Nam QCVN
09:2008/BTNMT, ham lupng As trong nude ng^m khong dupe ldn hon 50 ppb.
Tai Long An, trong tong so 4.876 mau nude ngam dupe khao sat co 56% so
mSu nhilm As.
Tai B6ng Thap, tinh hinh cung dang bao dpng, khi co tren 67% so mlu
trong tong so 2.960 mau nude ngam dupe khao sat da phat Men nhiem As. Trong
do, huyen Thanh Binh co ty 16 nhiem As cao vdi 85% so mau thu co ham lupng
tren 50ppb.
Tren 51% s6 mlu thu trong tdng so hpn 3.000 mau dupe khao sat phat Men
da nhiem As taiKien Giang.
c. Tinh hinh nhiem Asen tren dia ban tinh An Giang
Tong so mau khao sat tai tinh An Giang la 2.699 mau vdi ti le nhiem As la
20,18%, tap trung nhigu tai mot s6 huyen nhu: An Phu 97,3%, Phu Tan 53,19%,
Tan Chau 26,98% va Chp Mdi 27,82%. Ham lupng As trong nude ng^m tai cac

huyen nay khi phan tich deu tir 100 ppb trd len, dupe tim thay d cac gieng tang
nong, dp sau chua tdi 60m va dupe dung cho sinh hoat pho bien trong ngudi dan.
Bac biet theo thOng ke vao nam 2005, huyen An Phu co 257 tren t6ng s6 450
gieng tren dia ban tinh co ham lupng As cao hon QCVN, cM6m ty le la 57,11%.
Trong thang 11/2006, Vien Y hoc lao dpng va moi trudng TP.HCM da t6
chuc kham sue khoe cho ngudi dan tai 2 huyen Tri Ton va An Phu, kgt qua co
den 10 ca nghi nhiem As vdi nhung bieu Men cua benh As d giai doan dau nhu
sung hda da, tang giam sac to da, xu^t Men cac dom sam mau tren ca the.

Tinh An Giang da khuyn cao cac to chuc, ca nhan khong khoan lip gi^ng
mdi, tien hanh lap 112 gi^ng khoan bi nhilm nang thach tin; d6ng thai khin
truang trien khai ke hoach xay dung cao tram cap nude sach vdi quy mo nhd.

SVTH: Nguyin Van Cam -DH10MT

MSSV: DMT09209811