Tính toán phát thải và lắng ướt axit áp dụng cho vùng miền Bắc Việt Nam

Viec tinh toan du bao mua axit hien dang la mot bai toan mo phdng kha phue tap cua cac nha nghien ciiu moi trudng bdi viec tinh toan luang phat thai lit cac nguon thai eu the la het siic

MUC LUC

CHl/ONG 1 TONG QUAN CAC VAN OE VE PHAT THAI VA LANG AXIT

1.1 Khai quat thanh phan hoa hoc khong khi 5

1.2 Tien chat 6 nhiem gay axit nude mud 9

1.2.1 Nguon phat thai 9

1.2.2 Quy Udc Quoctevetien chat gay axit nt/dc mi/a [1] 12

1.2.3 Chu trinh chuyen hoa nita va iifu huynh trong tang doi luu 12

1.3 Su hinh thanh thanh phan hoa hoc nude mua 18

1.3.1 Chuyen hoa hoa hoc tang doi iifu [11 ] 18

1.3.2 Van chuyen cac chat 6 nhiSm trong tang doi Iifu 21

1.3.3 Ldngudt 22

1.3.4 L^ngkho 24

1.3.5 Thanh phan hoahoccCia nude mi/a [4] 26

1.4 Ketluan 32

CHUONG 2 PHl/ONG PHAP TINH TOAN PHAT THAI VA LANG LTCJT AXIT

2.1 PhiTdng phap tinh toan phat thai 34

2.1.1 Tinh toan li/ang phat thai theo phifOng phap tn/c tiep 34

2.1.2 Tinh toan luang phat thai theo phtrang phap gian tiep 35

2.2 PhUdng phap tinh toan ling irdt 39

2.2.1 Phi/ang phap phan tich mau nude mUa 40

2.2.2 Quan trac va tinh toan thong /ce tong luang mua thang,

nam tai tram quan trie 42 2.2.3 Tinh toan tai iugng ion tUiSng udt 43

CHUONG 3 KET QUA TINH PHAT THAI VA LANG AXIT CHO MIEN BAC VIET NAM

NAM 2001 (TLT NINH BINH T R 6 R A )

3.1 Tinh hinh so lieu 49

DANH MUC HINH

l-iinh 1.1 Chu trinh chuyen hoa cac hap chatchUa Nita 14

l-iinh 1.2 Chu trinh chuyen hoa cac hap chat Luu huynh trong l<hdng l<hi 16

Hinh 1.3 Sa do he thong cac qua thnh tu lam sach i<hi quyen bang nude mua 24

l-iinh 1.4 Cac l<ieu f<hae nhau trong l§ng l<hd (cac chat l<hi va hat) 26

l-iinh 3.1 Sa do tinh toan luang phat thai khi SO2 va NO, 50

Hinh 3 2 Sa do vi tri tram 64 Hinh 3.3 Sa do tinh toan tai luang ling ion trong khu vuc Bic Bg 72

DANH MUC BANG

•

Bang 1.1 Nong do cua chat vet trong khong khi kho gan mat dat 5

Bang 1.2 Tac hai cua eac chat vet gay 6 nhiem moi trudng khong khi 6

Bang 1.3 Phan loai cac chat thai theo tinh chat vat ly va ban chat hoa hoc 7

Bang 1.4 Phan loai cac chat thai theo loai cong nghe eo phat thai khi 8

Bang 1.5 NhUng chat thai dac trung cua mot so nganh cong nghiep 11

Bang 1.6 Nong do mot so hap chat Nita trong khong khi 12

Bang 1.7 Phat thai SO2 do hoat dong eCta con ngudi tren the gidi 15

Bang 1.8 Nguon goe phat thai tao thanh phan hoa hoe khong khi 17

Bang 1.9 Cac chat hoa hoc eo anh hudng den do axit nude mua 26

Bang 2.1 Cac phuang phap phan tich (thiet bi va tieu chuan ap dung) 41

Bang 2.2 Tieu chuan cho ^1 45 Bang 2.3 Tieu chuan cho ^2 47 Bang 3.1 Luang than cung cap cho cac nganh cong nghiep mien Bic Viet Nam 51

Bang 3.2 He so phat thai tCf cac nganh cong nghiep 52

Bang 3.3 Khoi luang hang hoa va khoi luang hanh khach luan chuyen cua

van tai mien Bic 55 Bang 3.4 Dinh mCfc tieu hao nhien lieu cho moi km dudng tren dia ban 56

Bang 3.5 He so phat thai tCfgiao thong 58

Bang 3.6 Tinh hinh san xuatkinh doanh cOa TCTthan Viet Nam 2001 61

Bang 3.7 He so phat thai tCr cac Id dot thd cong 61

Bang 3.8 Vi tri cac tram quan trac mua axit a Bic bg Viet Nam 63

Bang 3.9 Dac trung mua tai cac tram quan trie 66

Bang 3.10 MCfc sal khae giCfa luang mua theo vu ke va luang mua thu mau 68

Bang 3.11 Danh gia chat luang thu gom mau 69

Bang 3.12 So luang mau phan tich dat tieu chuan 70

Bang 3.13 T^ le so lieu miu phan tich dat tieu chuan (%) 71

Bang 3.14 Luang thai tU eac nganh cong nghiep nam 2001 74

Bang 3.15 Luang thai tUgiao thong va sinh hoat nam 2001 74

Bang 3.16 Luang thai tCf cac nguon thai nam 2001 75

Bang 3.17 Nong do trung binh ion SO/' va NO; trung binh mua tai cac

tram quan trie 76 Bang 3.18 Tong luang mua theo mua cQa cac tram quan trie nam 2001 77

Bang 3.19 Tai luang ion SO/' va NO3 tai cac tram nam 2001 78

Bang 3.20 Tai luang quy ra S va NtCfiing Udt trong toan vung nam 2001 79

Bang 4.1 Tai luang phat thai va ling udt Luu huynh va Nita nam 2001

mien Bic Viet Nam 83

CHUT VIET TAT

Khi tuang Thu^ van Tong cong ty Dong bang song Hong

TRUNG TAM HOP TAC DAO TAO VA B 6 | DUONG CO HOC

MSDAU

Dat van de

Vice thue hien cac muc tieu phat trien da va dang tac ddng den toan bo thien nhien va moi trucmg cua hanh tinh chiing ta Phat trie'n v6 mat nao do con dong nghia vdi lam can kiet tai nguyen thien nhien va giam siit chat luang moi truong song, de doa true tiep den sue khoe eon ngucri va he sinh thai

Ngay nay, bao ve moi truong khoi bi 6 nhi6m la mot nhiem vu eo tam quan trong dac biet va la m6'i quan t^m hang dau khong chi cua mot dia phuang, mot quoc gia hay mot khu vuc ma la cua ea cong dong the giai Bao

ve moi truong la mot van de mang tinh toan eau

Do phat trien kinh t6' ma hang ngay eon nguod da thai vao bau khi quyen mot luang khi thai, bui thai v6 cung Ian va eung ehinh con nguai dang phai hiing chiu hau qua do 6 nhilm moi trucmg ngay mot gia tang O nhilm moi truong da gay ra hau qua het sire nang ne: hien tuang hang tram nguai ehet a thung lung Manse (Bi) nam 1930, hoae a Niu - Yooe 6 nhidm khong khi lam ehet 200 ngucri nam 1953 va 400 ngucri nam 1963 Vu ro ri khi MIC cua Lien hiep san xuat phto bon Bhopal (An D6) da lam khoang 2 trieu nguoi

bi nhiem doe, trong do lam 5000 nguai ehet va han 50.000 nguod bi nhidm doc nang [1] O nuac ta, tham hoa do 6 nhiem moi truong chua xay ra, nhung thuc te hoat dong cong nghiep tap trung da gay 6 nhidm moi truong khong khi, nude cac khu vuc xung quanh

Nhung nam gan day the giai dang phai doi mat vai nhung van de moi truong mang tinh toan eau nhu.'hien tuang trai dat nong len, suy giam tSng ozon, mua axit Mua axit da tan pha riimg, buy hoai eac cong trinh xay dung

Lu^n van Th^c sy

Tinh toan phat thai va iang Udt axit - Ap dung ciio vung mien Bic Viet Nam

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va lam axit hoa cac nguon nude mat Th6ng qua eac hoat dong c6ng, nong

nghiep, eon ngucri thai vao bau khong khi ngay eang nhidu tien chat gay mua

axit Cac chat khi doe hai nay da v^n chuyen trong khong khi nha hoan luu

khi quyen da Ian truydn tijf vung nay sang vung khae, tiT nude nay sang nude

khac Thuc te cho th^'y, khdng chi nhung nude phat trid'n, noi ngay dem thai ra

mot luang khi thai rat Idn chiu hau qua cua mua axit ma rat nhidu nude dang

phat trien cd lugng phat thai thSp nhirng cung phai chiu tham canh nay Di6u

dd cd nghia vKn de mua axit khong eon trong khuon kho cua mot quoc gia ma

no da mang tinh qude te

Viet Nam la mot nude dang phat trien, cac hoat dong c6ng nong nghiep

va giao thong chua phat trien, nhung ket qua phan tich thanh phan hoa hoe

nude mua cho thay da xuat hien dau hieu cua mua axit Viec xac dinh nguyen

nhan hmh thanh mua axit d Viet Nam thuc su la van de m6i trudng duac eac

nha nghien euu cung nhu cac nha quan ly moi trudng quan tam Van di dat ra

la: Nguyen nhan nao din den hien tuang mua axit d mien B^e Viet Nam? Phat

thai tu: eac hoat dong phat trien kinh te trong khu vuc mien Bic dong gdp bao

nhieu trong tong lugng Idng axit d khu vuc nay? *

De gdp phan lam sang to cac eau hoi tren, luan van tap trung vao

nghien euu tinh toan luang phat thai d khu vuc mi6n Bic Viet Nam tren eo sd

phto tich cac hoat dong dan sinh kinh te va tinh toan luang Iang udt axit thong

qua nhiJng sd lieu do dac, phan tich thanh phSn hoa hoc nude mua d eac tram

quan trie nude mua trong khu vuc

Viec tinh toan du bao mua axit hien dang la mot bai toan mo phdng kha

phue tap cua cac nha nghien ciiu moi trudng bdi viec tinh toan luang phat thai

lit cac nguon thai eu the la het siic khd khan, hon niia pham vi anh hudng ciia

mua axit kha rong, khong trong pham vi mot vung hay mot qudc gia Vi v£iy,

viec su dung quy luat can bang vat chat trong tong the de xac dinh kha nang

i.M<3/i uan Th^a sy

Tinii toan piiat tiiai va iang ifdt axit - Ap dung ciio vung mien Bac Viet Nam

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va thuc trang eua mua axit trong mot khu vuc nhat dinh la mot phuang phap con tho nhung cd th6' dua ra mot sd ket lu^n huxi leh trong nghien euu v6 mua axit

Noi dung chinh ciia lu^n van la mdt phin trong d l tai nghien cuxi doc

lap cap Nha nude ''Nghien cihi, ddnh gia fiien trang dubdo xu the dien Men

vd de xuat cdc gidi phdp Iciem sodt mua axit a mien Bdc Viet Nam - giai doqn r Tac gia da true tiep thuc hien noi dung nay dudi su hudng dSn cua

chu nhiem dd tai -Tien si Nguydn Hong Khanh (Dd tai da dugc nghiem thu thang 5 nam 2003 vdi ket qua xuat sic)

PhUdng phap nghien curu

De hoan thanh cac noi dung cac luan van cac phuong phap sau da duge

ap dung:

- Lua chon phuang phap tinh toan phu hop: tren eo sd xem xet mot sd cac phuang phap tinh toan qua trinh phat thai dang ap dung d cac nude de lua chon phuang phap phu hgp vdi dieu kien Viet Nam, Lugng phat thai duge tinh toan tren ea sd phan tich cac sd lieu thong

ke ciia cac nganh kinh te"

- Phuang phap phan tich thong ke: phuang phap duge lua chon de danh gia tinh hgp ly cua cac ket qua phan tich thanh phan hoa hoc nude mua lam eo sd cho vide tinh toan lugng Iang udt axit

- Su dung quy lucit bao toan vat ch^'t trong t6ng the: phuang phap dugc

su dung de tinh toan qua trinh chuyen hoa eac chat trong khi quyen

va tinh toan tai lugng chat mang den va mang di NhiJng ket qua thu duge la eo sd de danh gia miic do ddng gdp eua qua trinh phat thai trong khu vuc va qua trinh ling axit trong khu vuc

LtA^n van Tix^c sy

Tinh toan phat thai va idng ifdt axit - Ap dung cho vung mien Bac Viet Nam

DAI HOC QUdc GIA - Vlf N CO HOC

TRUNG TAM HOP TAC D A O TAO VA B 6 | DUONG CO HOC

Cau true cua luan van

Noi dung cua luan van duge trinh bay trong 4 chuang:

Chuomg 1: Tong quan vd cac van de ve phat thai va ling udt axit

Chuang nay trinh bay khai quat ve thanh phan hoa hoc cua khong khi, cac tien chat 6 nhidm gay axit hoa nude mua, cac eo che' van chuyen va chu trinh ehuyd'n hoa hoa hoc cac chat g^y axit hoa nude mua trong ting doi luu va thanh phan hoa hoe eua nude mua

Chuomg 2: Cac phuang phap tinh toan phat thai va ling udt axit

Chuang nay trinh bay cac phuang phap gian tiep va true tiep duge ap dung rong rai tren the" gidi hien nay Dd la cac phuang phap cua WHO, USEPA, Nga

Chuang 3: Ket qua tinh toan phat thai va ling axit cho khu vuc midn

Bic Viet Nam (nam 2001)

Chuomg 4: Ket luan

l-u^t^ vay\ Tfi^c sy

Tinh toan phat thai va iang Udt axit - Ap dung cho vung mien Bac Viet Nam

DAI HOC QUdc GIA - VI$N CO HOC

TRUNG TAM HOP T A C O A O TAO VA B(3l Dt/ONG CO HOC

^

CHl/ONG 1 TONG QUAN CAC VAN DE VE PHAT THAI

VA LANG AXIT

1.1 KHAI QUAT THANH PHAN HOA HOC KHONG KHI

Khong khi khi quyen la mot hdn hgp gdm nhieu eh£t khi khae nhau Khong khi kho d khoang each mdt vai km each mat dat chiia eac thanh phin chinh sau: Nito: 78,080%, Oxy: 20,950%, Argon: 0,934%, Cacbon dioxyt: 0,035%, va mot sd chat khae chid'm ty le rat nhd (eon ggi la thanh phan vet eiia khi quydn) [13] Khong khi khi quyen con cd the chiia tu 0,1 den 5% (tinh theo the tich) hai nude Cac thanh phan vet eua khi quyen la hgp chat chua 5 nguyen to eo ban cua tu nhidn bao gdm: C, S, N, H va oxy Cac hgp chat vet nay cd thdi gian ton luu tijr mdt vai nam, mot vai ngay hoae mot vai gid Nong do eua chiing phu thuoc rat Idn vao qua trinh chuyen hoa cua chiing trong khong khi Bang 1.1 trinh bay ndng do mot sd chat vet trong khong khi kho gan mat dat

Bang 1.1 Nong do cua chat vet trong khong khi kho gan mat dat

J^upi^ van "Vixftc sy

Tinh toan phat thai va iing Udt axit - Ap dung cho vung mien Bac Viet Nam

DAI HOC QUOC GIA - VI^N CO HQC

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10-^

2 1 0 '

Ngudn phat thai

Do s^'m set, hoae cac hoat ddng eua con ngudi

Quang hoa Sinh hoc Hoat dgng cua eon ngudi

nt Hoat dgng cua con ngudi, quang hoa, niii liia

Qua trinh lam sach khdi khong khi

nt

Rua troi theo mua

nt Quang hoa

Bang 1.2 Tac hai cua cac chat vet gay 6 nhiSm moi trudng khong khi

l^u^n van ZTipc sy

Tinh toan phat thai va iang udt axit - Ap dung cho vung mien Bac Viet Nam

T

G

AHST

T T,G

T

G

AXNM

T,G T,G

T- true tiep; G- gian tiep

AHSK : anh hicdng den sUc khoe;

AHST : anh huong den sinh thdi;

AHOZ : anh huong den tang 3 zon,

HHVC : huy hoai vat chat;

AXNM : gay axit hoa nuac mUa;

AHKH : anh hudng den khi hau;

Cd hai loai ngudn gay 6 nhidm khong khi ehinh la ngudn 6 nhidm thien nhien va ngudn 6 nhiem do eon ngUdi Ngudn do eon ngudi ngay eang trd nen tac nhan ehinh gay 6 nhidm moi trudng khong khi Cac chat 6 nhidm khong khi chu yeu la nhutig hgp chat cua C, S, N, H, O, dd la SO., NO,, O3, C,H^, cac chat hat v.v Tuy thuge vao ban chat ciia tirng cong nghe dugc su dung, chat lugng thid't bi, nguydn nhien lieu su dung ma eac chft thai dugc san sinh

va that thoat bay vao khong khi nhieu hay it

De phue vu cac mue dich nghidn ciJu ma cac nha nghien cuxi moi trudng thudng phan loai cac cha't thai theo cac quan diem de phu hgp vdi cac nghidn euu hoae eac cong nghe phat thai Bang 1.3 dudi day trinh bay p h ^ loai cac chat thai theo quan diem vat ly va hoa hoc

l.u^n vdn Th^c: sy

Tinh toan phat thai va iing ifdt axit - Ap dung cho vung mien Bac Viet Nam

DAI HOC QUOC GIA - VI$N CO HQC

TRUNG TAM HOP T A C D A O TAO VA B 6 | D U O N G CO HOC 8

Bang 1.3 Phan loai cac chat thai theo tinh chat vat ly va ban chat hoa hoc

Cac cha't hat Bui

Cac chat khi Cac chat khi Cac chat hoi

Nguon: World Health Organization Tropospheric Chemistry and air pollution Geneva,

Cong Dot nhidn lieu, khi

Phun nong dugc Dot nuong ray

Phun son, muc, dung moi lam sach

Vidu San xuat da xay dung, xay dung, sua chua nha ctra v.v

Nha may nhidt dien

A,

Oto cac loai, xe may

Luydn kim den, mau

hoa dau giay, phan bdn, xi mang Thudc nong dugc

Che tao 6t6, noi that

cac tac nhan lam sach

Cac chat thai Cac hgp chat huu co

va v6 CO

SO., NO,, CO, khdi, tro, hoi hiixi co, hat oxy kim loai Hoi kim loai (Pb, As,Zn), F, SO,, H.S, hod huu CO, bui Phot phat huu co Hgp chat huu co co clo, As, Pb, khdi tro, bd hdng Hydrocacbon va hoi hiiu CO

Nguon: World Health Organization Tropospheric Chemistry and air pollution Geneva,

1982

J^u^n van TTip^ sy

Tinh toan phat thai va iing ifdt axit - Ap dung cho vung mien Bac Viet Nam

TRUNG TAM HOP TAC OAO TAO VA B 6 | DUONG CO HOC

1.2 TIEN CHAT 6 NHIEM GAY AXIT NlTdC Ml/A

1,2,1, NGUON PHATTHAI

1.2.1.1 Nguon thai tir nhien

Su tao thanh cac chat 6 nhidm trong tu nhidn rat phiic tap va da dang Chiing cd the dugc tao thanh do qua trinh phong hoa dat da, phan huy cac chat huu CO, cac chat da cd san trong tu nhidn (bui), cac san pham do hoat dgng ciia niii lua hoae cac chat phdng xa tu nhidn

Cd nhieu eo che' dgng lire dd' dua cac chat 6 nhidm vao moi trudng khong khi nhu cac qua trinh khuydch tan va doi luu Cac ch^'t hat dugc dua vao moi trudng khong khi do chuyen dgng gid hoae trong qua trinh phun trao eiia niii lua

Phan Idn cac chat d nhidm cd ngudn gdc tu nhidn deu anh hudng den moi trudng xung quanh, tuy nhidn pham vi anh hudng cua chiing thudng khong Idn vi do cao phat thai cua chiing thudng thap, ngoai trii hoat dgng cua niii lua Cac san phim cua niii lua van chuyen kha xa, trong nhieu trudng hgp chiing cd the vugt xa hang ngan km

1.2.1.2 Nguon thai nhan tao

Trong qua trinh hoat dgng va phat trien, con ngudi da thai vao moi trudng ndi chung va bau khi quyen ndi rieng hang tram loai chat thai khac nhau vdi sd lugng rat Idn Tdc do phat thai cac chat 6 nhidm nay ngay eang tang Cung vdi su gia tang dan sd va hoat dgng cong, ndng nghiep, tdc do dd dugc quy dinh bdi su phat trien dan sd va nhu cau trung binh cho mot ea the' Theo tinh toan ciia cac nha mdi trudng hang nam khi quyen tiep nhan khoang 200.10^ tan luu huynh tu cac ngudn thai, trong dd hon 90% do dot nhien lieu hoa thach (than, dau) [2]

J-u^n van TTiiftc: sy

Tinh toan phat thai va iang Uift axit - Ap dung cho vung mien Bac Viet Nam

DAI HOC QUdC GIA - VlfN CO HOC i Q

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- Cac nguon phat thai g^y 6 nhidm mdi trudng khdng khi dugc chia thanh bdn nhdm chinh ngudn thai sinh hoat, ngudn thai nong nghiep, ngudn thai cong nghiep va ngudn thai giao thong Loai chat thai, cudng do thai va tinh chat thai ciia cac nhdm ngudn tren r^'t khac nhau

Nguon tftdi sinit fioqt

Chat d nhidm duge tao ra tir nguon thai sinh hoat chu yd'u do qua trinh phan huy cac chat thai sinh hoat nhu phan, rac Ngoai ra, mot lugng Idn khi thai con dugc sinh ra trong qua trinh su dung than, cui de nau an Khi thai tu ngudn thai sinh hoat thudng la cac chat khf: CH4, NH3, SO2, NO,

Nguon tftdi nong nghiep

Nong nghiep dua chat thai vao khong khi dudi hai hinh thiic khac nhau: thai khi thai do cac san pham ndng nghiep nhu CO2, CH4 va do su dung phan bdn, thudc tru sau

Khf thai do nong nghiep duge phat thai tren mot vung rong Idn, trong mot muc do nhat dinh, tuong tu nhu phat thai tu nhien Su khac nhau co ban giua phat thai tu nhidn va phat thai do ndng nghiep la d ch6 phat thai tu nhien khdng the hien tinh chu ky ro ret, eon phat thai ndng nghiep chi tap trung vao cac thdi ky nhat dinh trong nam (cac thdi vu chinh)

Nguon tfidi cong ng/iiep

Ngay riay, vdi su phat trien san xuat, cac nganh cong nghiep da dua vao moi trudng hang nghin loai ch^'t doc hai khac nhau vdi mot tdc do ngay eang tang So vdi cac dang ngudn thai khae thi ngudn phat thai cong nghiep la loai ngudn thai quan trong nh^'t vi day la loai ngudn phat thai tap trung cd cudng

do Idn hon rat nhieu Idn eac loai ngudn khac Bdn canh dd, thanh phan chat thai trong cong nghiep cung rat da dang, mdi loai nganh cong nghiep lai thai

L-u^n van TTiiftc sy

Tinh toan phat thai va Iang ifdt axit - Ap dung cho vung mien Bdc Viet Nam

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ra nhung loai ch^'t thai r^'t khac nhau Cac ch^'t thai dac trung ciia mot sd nganh cong nghiep dugc trinh bay bang 1.5 dudi day

Bang 1.5 Nhutig chat thai dac truhg cua mot so nganh cong nghiep

Nganh edng nghiep

Luydn kim den

Luydn kim mau

Hoa chat

San xuat axit Sulfiiric

San xuat Superphosphat

San xudt xiit

San xua't p h ^ dam

San xuat cao su

Vat lieu xay dung

San xuat ximang

San xuat vdi gach

San xu^t sanh sii thuy tinh

Thanh phan ch^'t thai C,Hy, SO., NO,

Bui, SO2, CO, NO,, CO2 Muoi, SO2, CO, NO,, CO2, C,Hy

Bui, SO2, CO, NO,, Pb Bui, SO2, CO, NO,, cac kim loai nang

SOx Bui, H2SiF6, SO3

CI2 NH3 Bui, SO2, CO, NO,, CO2

Bui, SO2, CO, NO,, CO2 Bui, SO2, CO, NO,, CO2 Bui, SO2, CO, NO,, CO2

Nguon : Vien KTTV - Tong.cue KTTV Giam sat moi tru&ng khdng khi vd nuac Ha

DAI HOC QUOC GIA - VIEN CO HQC i 2

TRUNG TAM HOP T A C O A O TAO VA B(5l Dl/ONG CO HOC

thai phu thudc vao quy trinh edng nghd san xu^'t, nguydn nhidn v^t lidu, trang thie't bi va hieu qua xu ly cua he thong xu ly khf thai

1,2.2, QUY l/dC QUOC TE VE TIEN CHAT GAY AXIT Nl/6C Ml/A [1]

Theo thong Id Qudc te', phan hang cac ch^'t d nhidm khdng khf nhu sau;

- Cac tidn ch^'t tao axit: dioxyt luu huynh (SO2), Cac oxyt nito (NO,)

- Cac chat tfch tu khdng suy giam; Bui, cac hgp chat trong bui

- Cac ch^'t cd doe tfnh cao; cac hgp cha't trong bui, eac hgp chat huu CO bay hoi

- Cac tien chat dSn den chat oxi hoa; cac oxyt nito, cac hgp chat hiJu CO bay hoi

- Cac chat lam bid'n doi khf hau; dioxyt cacbon (CO-,), cac hgp chat hiru CO bay hoi

Trong cac khf thai thi SO2, va NO, la nhirng tac nhan chfnh gay axit hoa nude mua, do dd luan van nay chi tap trung vao cac van de lien quan de'n qua trinh phat thai vao khong khf va Mng udt hai yd'u to nito va luu huynh

1,2,3 CHU TRINH CHUYEN HOA NITO VA Ll/U HUYNH TRONG TANG

DOI Ll/U

1.2.3.1 Chu trinh chuyen hoa cac chat khi [10]

Cdc hap chat chica Nita

Hgp chat Nito trong khf quyen dudi dang khf (N2, N2O, NO,, HNO3, NH3), long (N03', NH4'') Bang 1,6 trinh bay dang ton tai va ndng do mot sd hgp eha't chiia nito trong khi quyen

J^u^n van Xh^c: sy

Tinh toan phat thai va iing utft axit - Ap dung cho vung mien Bic Viet Nam

DAI HOC Q U d c G»A - VI^N CO HOC

TRUNG TAM HOP TAC DAO TAO VA B6| DI/ONG CO HOC 13

Bang 1.6 Nong dp mot sohafp chat Nitaf trong khong khi

Khdng khf ndn

Ddi luu

Khdng khf nen

Khdng khf vung d nhidm

Nude mua 0 vung ndng thdn xa

Nude mua d vung d nhidm

Ghi cfiii: pp^'^'phan trieu tinh theo the tich;

ppbv: phan ty tinh theo the tich

Qua trinh phin huy cac hgp chat Nito trong dat axit, vi sinh vat da chuyen hoa Nito dudi dang hgp chat thanh N2O, khf N2O khi phat tan vao khdng khf phan iing vdi d xi tao thanh NO2 Day la qua trinh chfnh sinh ra

NO, cd ngudn gdc thidn nhien Mat khac, qua trinh dot chay nguydn nhidn hdu do hoat dgng cua con ngudi cung la mdt ngudn phat sinh ra khf NO, Khf

NO, trong khf quyen la mot trong nhiing ngudn sinh ra son khf khf quyen dang hat NH4NO3 Phan Idn cac hgp chat chiia NO, va ion NO3 dugc loai bd

Lu4n van Thfi^ sy

Tinh toan phat thai va idng Udt axit-Ap dung cho vung mien Bac Viet Nam

DAI HOC QUOC GIA - VI^N CO HQC

TRUNG T A M H O P TAC DAO TAO VA B 6 I D U O N G CO HOC 14

khdi t&g ddi luu thdng qua qua trinh Iang udt Chu trinh chuyen hoa cac hgp chat Nito dugc trinh bay trong hinh 1.1

Dinh tang ddi luu

Be mat Trai dat va sinh quyen ke ca cac hoat dong cua con nguoi

Hinh 1.1 Chu trinh chuyen hoa cac hcfp chat chufa Nitcf

(Nguon: E Meszaros Atmospheric Chemistry 1981.)

Ghi chu:

• Phat thdi vd tieu huy thien nhien

^ Phat thdi vd tieu huy nhan tao

• Chuyen hod hod hoc

I I Luu tri/ khi quyen } bieu thi bang 10^ tan bieu thi bang 10^ tan/nam

Nguon NHj tit gia siic dugc xem nhu nguon sinh hoc, khong tinh do con ngu&i

Cdc hap chat luu huynh

Trong khdng khf tang ddi liru va tang binh luu cac chat hat (son khf)

deu c&n tao tir hat sunfat amoni hoae axft Sunfuric Trong khf quyen, khi eac

hat son khf sunfat gia tang se lam anh hudng dd'n can can buc xa he thdng Trai dat - Khf quyen, de'n tfnh cha't quang hoc va kha nang tao giang thuy cua khdng khf

Lu^n van TTi^a^ sy

Tinh toan phat thai va iang ifdt axit - Ap dung cho vung mien Bic Viet Nam

DAI HQC QUdC GIA - VI$N CO HQC

TRUNG TAM HOP TAC O A O TAO VA B 6 | DUONG CO HOC 15

Nguon gdc luu huynh trong khong khi

Luu huynh cd mat trong khdng khf khf quy^n do su ph^n huy cac hgp cha't huu CO, dot chay cac nhien lidu hda thach, do phat tan cac hat mudi bien

va su hoat ddng cua nui lua Nhu v^y, ea sinh quyen ISn con ngudi ddu thai ra cac hgp chat luu huynh Bang 1.7 dudi d^y trinh bay kd't qua tfnh toan lugng

va ty Id phat thai SO2 do cac hoat ddng ciia con ngudi trdn toan thd' gidi

Bang 1.7 Phat thai SO2 do hoat dgng ciia con nguofi tren the gidi

Nguon phat thai SO2 - S

D6't than

Dot dSu

Cong nghiep (luyen va dau mo)

Giao thong van tai

Nguon: E Meszaros Atmospheric Chemistry 1981

Ngoai khf SO2, trong khf quyen con cd cac dang hgp chat khac chiia luu huynh nhu H2S (hydrosunfua), DMS (dimethinsunfua), CS2 (disunfua cacbon), DMDS (dimethindisunfua),

Ca che chuyen hod luu huynh trong khi quyen

Trong khdng khf sach, luu huynh dugc tim thay dudi dang hat sunfat Chuyen hoa luu huynh trong khf quyen la su chuyen hoa cac hgp chat luu huynh cd hda tri thap sang luu huynh cd hoa tri cao ( SO4 luu huynh cd hoa tri 6)

Lu4»^ van TTipc sy

Tinh toan phat thai va iang Udt axit - Ap dung cho vung mien Bic Viet Nam

DAI HQC QUd'c GIA - VI^N CO HQC

TRUNG TAM HOP T A C D A O TAO VA B(5l Dl/CfNG CO HOC 16

Ngoai trijf DMDS, chuyen hoa cac hgp chat luu huynh da dugc Kellogg (1972) tong kd't bang so dd dudi day:

(O, O2, O3) (hv, O, O2, O3, aldphin) X X(thudng la NH3) H,S + > SO2 + > SO3 + H2O —> H2SO4 + X —> XSO4

Gid Gid hoae ngay (*) giay

(*): nhanh hon ne'u xay ra tren bd mat chat hat hoae trong dung dich

h quyen ke ca cac hoat dgng

^ Mat bien; Uot

kho

•

cua con ngudi

Hinh 1.2 Chu trinh chuyen hoa cac hdp chat Luu huynh trong khong khi

(Nguon: E Meszaros Atmospheric Chemistry 1981.)

1.2.3.2 Phat thai chat hat - thanh phan hoa hoc chat hat [1]

Cac son khi la mot phiJc hgp gdm cac hat r^n hoae long lo lung trong khdng khf Cac son khi rat khac nhau ve tinh ch^'t vat ly ciing nhu hoa hoc, do vay ma qua trinh chuyen hoa, loai bd va thdi gian ton luu cua chiing cung r^'t khac nhau

LtA^n van Tiy^a sy

Tinh toan phat thai va iing Udt axit - Ap dung cho vung mien Bic Viet Nam

DAI HOC QUOC GIA - VI$N CO HQC

TRUNG TAM HOP T A C O A O TAO VA B 6 \ DL/ONG CO HOC 17

Cac ngudn sinh ra son khi bao gdm cac chuyen hoa khf sang hat (hat

min), cac hat cd ngudn gdc bien va cac loai bui sinh ra do gid eudn mat dat

(hat thd) Hat cd ngudn gdc tijf chuyen hoa khf sang hat la cac hat kieii ddng tu

(thudng la hat sunfat, nitrat, amoni) va cac hat tif hgp chat cac bon huu co Hat

bui da't chiia cac khoang chat chfnh nhu Si, Fe, Al, Ca, Do ngudn phat thai

khac nhau ndn tfnh chat ly hoa hoc ciia hat cung khac nhau Ngudi ta phan

biet chiing thanh 2 loai: hat min va hat thd

Hat min cd kfch thudc tir 0,1 - 2 |im, thanh ph& hoa hgc cua chiing la

sunfat va nitrat Trudc day, ngudn phat thai cac hat nay chu yd'u la tu thien

nhidn, ngay nay, phat thai do hoat ddng ciia con ngudi gia tang rat nhanh, va

dieu nay lam anh hudng rd ret dd'n tfnh chat son khf cua khdng khf

Hat thd cd kfch thudc tijr 2 - 20 |J.m va ngudn gdc phat thai chu yd'u la tu

thidn nhidn

Thdi gian ton liru ciia cac hat trong khf quyen phu thuge nhieu vao cac

yd'u to khf tugng, dac biet la mua Bang 1.8 dudi day trinh bay ngudn gdc phat

thai tao thanh thanh phan hoa hgc khdng khf

Bang 1,8 Ngudn gdc phat thai tao thanh phan hda hgc !<hdng l<hi

-Lu^n van T^h^c: sy

Tinh toan phat thai va ling udt axit - Ap dung cho vung mien Bic Viet Nam

\!'Ulur

DAI HOC QUOC GIA - VIEN CO HQC

TRUNG TAM HOP TAC D A O TAO vA B6\ DUONG CO HOC 18

Nguon Hoa khi quyen va hien doi khi hau, 1999, Oxford University Press

1.3 Sir HINH THANH THANH PHAN HOA HOC Nl/OC Ml/A

Nguon son khf Tong phat thai

(hat CO d<25)Lim)

Nguon thu cap: chuyen hod khi-hqt

DMS, H.S

SOT nui lua

NO^ sinh hoc

VOCs sinh hoc

Nguon son khf nhan tao

Nguon sa cap

Bui cong nghiep

Muoi

Dot sinh khoi

Bui gio cuon

Nguon thi( cap: chuyen hod khi-hqt cua

SO-,: luyen Idm/nhiet dien

NOx: oto/nhiet dien

1,3.1 CHUYEN HOA HOA HOC TANG DOI Ll/U [11]

Chuyen hoa hoa hoc cd mot vai trd quyet dinh trong qua trinh loai bd cac chat vet trong khong khi Sir tao thanh hat hoae giu nguyen dang khf, tiep den qua trinh loai bd hoan toan hay tung phan deu phu thuoc vao ban chat cua cac qua trinh hoa hoc xay ra trong khong khf Cac chat d nhiem so cap (bac 1) dugc giai phdng tCr mat dat va bay vao khdng khf - thdng thudng la cac hgp

J^u^n van Tiift^ sy

Tinh toan phat thai va iing udt axit - Ap dung cho vung mien Bic Viet Nam

DAI HOC QUOC GIA - Vlf N CO HOC i Q

TRUNG TAM HOP T A C O A O TAO VA B 6 I D U O N G CO HOC

chat chiia S, N, C - qua cac phan iing hoa hgc tao thanh cac hgp chat thii cap

(bac 2) - thudng la cac hgp ch^'t nitrat, sunfat, cac hat huu co, cac chat oxi

hoa, v.v Hon nOa, cac chat oxy quang hoa (qui ve O3) tuy la san pham bac 2

nhung lai cd vai trd chfnh trong cac phan ung hoa hgc pha khf trong khdng

khf O3 cd the ket hgp vdi nhieu chat khac nhu vdi cac oxit de tao thanh cac

gdc tu do, cac peroxit, cac hydrocacbon cac chat cd hoat tfnh r^'t cao

1.3.1.1 Phan ufng pha khi

Cac cha't 0 nhidm khi dugc phat tan vao khdng khf se xay ra cac tuong

tac vdi cac chat cd san trong khdng khf Thdng thudng cac phan dng xay ra

theo cac b^c khac nhau ma trong cac phan iing nay mdt sd chat cd nhung tac

dung dac biet vdi anh sang, dd ^m khdng khf v.v

TCr cac hgp chat b^c 1, kha nang xay ra cac phan iing nhu sau:

A + B ^ C + D v a A + B + M ^ A B + M Trong dd:

A, B la cac cha't tham gia phan iing

B, C la cac chat tao thanh sau phan iing,

M la chat trung tfnh

Nhung khi cd mat cac tia UV va VIS (tia cue tfm va nhin thay) thi kha

nang xay ra la AB + hv -> A+B, trong dd hv la biic xa tir ngoai Isaken (1978)

da tdng ke't t^m quan trong cua ozon trong cac phan iing pha khf de tao thanh

cac gdc tu do Cac gdc tu do sinh ra trong qua trinh quang hoa la nhirng tac

nhan quan trong cho cac phan iing pha khf Trong khdng khi sach, nong do

cac chat b^c 1 (NO^ va H^C^^) la thap, cac phan iing pha khf bat dau tit phan

ling sau:

0 +H2O -^ OH + OH (*)

LiA^n van 77i<3^ sy

Tinh toan phat thai va iing ifdt axit - Ap dung cho vung mien Bic Viet Nam

DAI HOC QUOC GIA - VI$N CO HOC 2 0

TRUNG TAM HOP TAC O A O TAO VA B(5l DUONG CO HOC

HC + O H -> cac peroxit (3 (HO., CH3O2)

va ngudn tao ra gdc OH trong tang ddi luu la phan iing (*)

1.3.1.2 Phan umg pha long

A Si/tao thanh nitrat

Phan ling OH -h NO2 ^ HNO3 trong pha khf la phan iing chfnh de chuydn hoa NO3 thanh HNO3 Do vay, tIm quan trong cua pha long chi la chuyen pha HNO3 khf thanh cac gigt va kem theo su phan ly trong dung dich theo cac phan iing sau:

HNO3 (khf) ^ HNO3 (long) va HNO3 (long) ^ H^ -f NO

3-Tai pH = 4 - ^ 5 , HNO3 bi phan ly hoan toan thanh cac ion Do vay, su cd mat ciia HNO3 chi la tac nhan cho gia tri pH trong su oxi hoa SO2

S Sir tao thanh sunphat

Su oxi hoa dioxit luu huynh (SO2) thanh sunphat trong pha long la qua

trinh chfnh cua chuyen hoa SO2 ~^ H2SO4 Cac phan iing nay xay ra cd sir

tham gia cua cac xiic tac la cac ion kim loai (Fe, Mn) chu yeu tai vung cd 0 nhilm khong khf Cac tac nhan oxi hoa quan trgng nhat la H2O2 va O3 (Penkett, 1979) SO2 bi O3 oxi hoa phu thuoc rat nhilu vao pH cua dung dich (d day la pH ciia cac gigt nude) SO2 trong khdng khf am ton tai d nhung dang sau:

J^u^n van Z / i p c sy

Tinh toan phat thai va iing Udt axit - Apdyng cho vung mien Bac Viet Nam

DAI HOC QUOC GIA - VI^N CO HQC 2 1

TRUNG TAM HOP T A C D A O TAO VA B(5t Dl/ONG CO HOC

SO2.H2O ^ HSO3+ H^ va HS03^ ^ SO3-' + H^

He sd eta btag phan iing khdng phu thudc vao ndng dd cac ch^'t khf,

ma chiing phu thudc chu yeu vao ndng do ion H"^ cd mat cd nghia la phu thudc vao pH va nhi6t do Tai pH thtfp (ndng dd H^ cao) ta cd chu yeu la HSO3' va SO3"' (Taylor, 1982) Hi6u qua cua chuyen hoa tu SO2 "^ S04^' thuc su la chuyen hoa ciia tat ca loai SO2.H2O, HS03"va S03^' Thuc nghiem chiing minh rtag pH dudi 4,2 -^ 4,5 thi hieu qua cua qua trinh nay kem, cd nghia la cac ion sunphat ft dugc tao thanh Do trong khdng khf cd mat thudng xuyen NH3, dieu

dd cd nghia la pH cac gigt khdng khf dugc NH3 kiem soat theo phan iing sau: NH3.H2O -> NH4'^ + OH" va phan iing nay cd chieu hudng v6 phfa phai nhieu hon Hon nua trong khdng khf cac hoi nude cd su phan ly sau: H2O -^ H"^ +0H' Cac nghien ciiu thay rtag neu ndng dd NH3 trong khdng khf du Idn nd

se dSn den phan iing phan ly va ion OH" dugc tao thanh Dieu nay se lam tang

pH va tdc do oxi hoa tang va ket qua la ndng do sunphat tang

1.3,2 VAN CHUYEN CAC CHAT 6 NHlilVI TRONG TANG DOI Ll/U

Miic do nguy hai ciia cac chat d nhidm phu thudc vao ndng do cac chat

dd trong khdng khf Ndng do cac chat d nhidm trong khdng khf lai phu thudc vao su khuech tan va ban ch£t hoa hgc cua chiing

1.3.2.1 Khuech tan theo phiTdng thang dufng [14]

Su thay doi nhiet do ciing vdi su thay ddi ap suat theo do cao la mot yeu

to anh hudng rat Idn den qua trinh van chuy6n theo phuong thing diing va qua trinh pha loang cac chat d nhidm Trong khdng khf ^m, bao hoa hoi nude, tdc

dd suy giam doan nhiet (F) khoang 0,6 °C/100m cao dd va dugc bieu thi bdi cdng thiic sau:

Li4^n van ZTi^i^ sy

Tinh toan phat thai va iing Udt axit-Ap dung cho vung mien Bic Viet Nam

DAI HOC QUOC GIA - VIEN CO HOC 2 2

TRUNG TAM HOP TAC D A O TAO VA B(5l Dl/ONG CO HOC

Khi -dT/dz » F thi khdng khf d dang rat on dinh (hien tugng nghich nhidt) Trong trudng hgp nay kha nang ddi luu theo chidu thang diing ciia khdng khf rat han che va miic do khuech tan cac cha't d nhidm didn ra cham chap va dieu nay cd nghia la ndng do cac ch^'t d nhidm cao hon d Idp khdng khf sat mat dat

1.3.2.2 Khuech tan theo phirdng ngang [11]

Hudng va tdc do gid anh hudng rat Idn ddh qua trinh khuech tan va van chuyen chat 6 nhidm Nhd xac dinh dugc hudng gid ma ngudi ta xac dinh dugc hudng v^n chuyen cac chat d nhidm Mat khac, dia hinh cung la mot yeu

to quan trgng trong khuech tan cac chat 6 nhidm trong khong khf Tai viing ddi niii, do su chenh lech vd nhidt do giua dinh va thung lung gay ra su bid'n ddi ve ap suat va ty trgng cua khdng khf se gay ra nhung ludng gid dia phuong Loai gid nay lam can trd su van chuyen cac chtft d nhidm di Idn de khudch tan Ian xa hon

Nhu vay, cung vdi khuech tan thing diing, khuech tan theo phuong ngang trong khdng khf da lam cac chat 6 nhidm phan tan di ra xa khdi ngudn phat thai, lam thay d6i ndng dd ciia chiing trong mdi trudng khdng khf xung quanh

Lt4^n van Tixfic sy

Tinh toan phat thai va iing Lfdt axit-Ap dung cho vung mien Bic Viet Nam

OAI HOC QUOC GIA - VIEN CO HOC 2 3

TRUNG TAM HOP T A C O A O TAO VA B(5l D L / O N G CO HOC

1.3.3 L A N G l / d T

Lang udt la qua trinh loai bd cac chat 5 nhidm ra khdi khdng khf, dua xudng mat dat b^ng giang thuy L^ng udt chia lam hai loai: Rain-out va Wash-out

Rain out la qua trinh hinh thanh, van chuyen va chuyen hoa hoa hgc

trong may va ddng vai trd quan trgng trong ling udt vi cac tfnh chat ly, hoa hgc sau nay ciia nude mua phfo Idn phu thudc vao qua trinh nay

Rain out cac chat hat dugc xay ra ngay tir thdi diem bit dau tao may Khi xuat hien su qua bao hoa hoi nude, su ngung tu xay ra tai be mat cac hat nhan ngung kd't (cac hat son khf), tuy thudc vao ban chat cau tao (tfnh chat ly, hoa hgc, kfch thudc hat son khf ) mdi hat trd ndn hoat tfnh de hap thu hoi nude (ddi vdi cac hat tan trong nude) Khi dam may tao thanh, cac hat nhan ngung kd't se tfch tu va tao thanh mot dam cac gigt nhd cd ndng do cao cac chat hat

Rain-out cac chat khf chi xay ra sau khi hinh thanh may Rain out trd ndn dac biet quan trgng trong trudng hgp cac chat khf sau khi dugc hap thu, phan ling hoa hgc khdng thuan nghich vdi cac thanh phan khac trong pha long, tao thanh cac thanh phan hoan toan khac so vdi ban dau Kieu chuyen hoa nay la dac thu ciia cac khf SO2, NO^^

Wash-out la qua trinh tu lam sach ciia khf quyen bing qua trinh mua

xay ra trong tang day may Khi mdt dam may hinh thanh se cd hai kha nang xay ra:

Dam may se bdc hoi hoan toan hay tijfng phan, khi dd cac chat chiia trong dam may lai trd ve dudi nhung dang khf va hat nhu ban dau Tuy nhidn,

khdng hkn chiing da trd lai nguydn dang cu, do trudc dd trong dam may da

xay ra cac phan iing khong thuan nghich Vf du mot vai chat khf sau khi

L-u^n van T^h^a sy

Tinh toan phat thai va iing Udt axit - Ap dung cho vung mien Bic Viet Nam

DAI HOC QUOC GIA - VI$N CO HOC

TRUNG TAM HOP T A C O A O TAO VA B(5l DUONG CO HOC 24

chuyd'n thanh mudi hoae axit, sau khi bdc hoi se trd thanh nhirng hat cd kfch thudc thay ddi Nhin chung kfch thudc trung binh ciia cac hat mdi tao thanh sau khi may bdc hoi Idn hon nhieu so vdi trudc khi tao thanh may

Trong qua trinh tfch tu, neu cac hat hoi nude dii Idn se roi xudng dat tao thanh mua Khi dd v^t ch£t chiia trong dam m^y cQng theo nude mua roi xudng mat dat Ndi each khac, lugng vat chat nay da bi loai bd khdi khdng khf khf quyen nhd qua trinh mua Su tu lam sach cua khf quyen b i n g giang thuy xay ra trong tang day may ggi la Wash-out Cac son khf (bao gdm chat khf va hat) tang dudi day may bi nude mua giir lai b i n g su ddng tu trgng trudng Cac phan tu khf thi di vdng xung quanh, cdn cac hat thi va cham vdi hat nude mua

va bi keo theo xudng mat dat Wash-out dac biet cd y nghia tai nhung viing cd miic do 6 nhidm Idn Cac qua trinh tu lam sach cua khf quydn b i n g mua (Wash-out) dugc so dd hoa trong hinh 1.3

KHI

Xao tron roi

khuech tan phan tu

Hoa tan thu^n nghic

phan ung hoa hoc

Mp thu

H A T

Hat nhin ngung tu

Chuyen dong Brao luc hut tfnh dien

Bi chan va va dap bang giang thuy

Hinh 1.3 Scf do he thong cac qua trinh tiT lam sach khf quyen bang nu'dc miTa

Nguon: World Health Organization Tropospheric Chemistry and air pollution: Geneva,

1982

Lu^n van T7i\o^ sy

Tinh toan phat thai va iing Udt axit - Ap dung cho vung mien Bic Viet Nam

OAI HOC QUOC GIA - VIEN CO HQC 2 5

TRUNG TAM HOP T A C O A O TAO VA B6\ D I / O N G CO HOC

1.3.4 LANG KHO

Ling kho la qua trinh tu lam sach ciia khf quyen thong qua Iang true tiep cac chat khf kh6 va hgp chat kho dd'n cac be mat khac nhau trdn trai dat Lang kho xay ra mgi noi, mgi liic tren trai dat (trir nhung liic xay ra mua) Cac cha't 6 nhidm trong khf quyen t6n tai dudi dang hat, dang khf (hoae hoi), co kfch thuoc rat khac nhau va ton tai 6 do cao each mat dat tir vai met dd'n vai

km PChi khuech tan trong khong khf cac chat nay da bi he tidp nhan hap thu Trong khong khf, nhung hat co dudng kfnh nho hon l|j.m thudng chuyen dgng

tuan theo chuydn dgng Brao, nhirng hat cd dudng kfnh txx l\im den 10|im

thudng chuydn dgng khuydch tan roi va nhung hat Idn hon nua thi ling dgng xudng mat dat do chiu su tac dgng ciia trgng luc Rieng ddi vdi chat khf, mot mat bi hap thu va hap phu trdn be mat, mat khac chung cdn chiu anh hudng eua cac chuyen hoa hoa hgc trong khong khf

De xac dinh qua trinh ling kho, ngudi ta dua ra khai nidm van tdc ling kho Van tdc ling kho tai mot vimg hay mot pham vi phu thuge vao nong do cac chat gay 6 nhidm trong khong khf, va dac didm khf hau (tdc do gid, nhidt

do va do am khong khf) cua viing hay pham vi dd

Co che ling kho phu thuoc vao cac yd'u to sau:

- Ndng do cac chat 6 nhidm trong khf quyen

- Cau tao, thanh phan, dac tfnh cua bd mat tiep nhan

- Kfch thudc hat chat 6 nhidm

- Loai chfl't gay 6 nhidm

Cac kieu ling kho cac chat khf va hat trong khong khf dugc trinh bay trong hinh 1.4

LiA^n van Ti\^c sy

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OAI HOC QUOC GIA - VI^N CO HOC

TRUNG TAM H O P TAC DAO TAO VA B6\ DUONG CO HOC 26

Hinh 1.4 Cac kieu khac nhau trong Iang kho (cac chat khi va hat)

Nguon: World Health Organization Tropospheric Chemistry and air pollution Geneva,

1982

1,3.5 THANH PHAN HOA HOC CUA Nl/dC Ml/A [4]

Trong nude mua, cac ion hoa hgc chu yeu bao gom: Ca""^, Mg""^, Na^, K^ NH4^ SO4-', NO3", Cr, HCO3" Nguon gdc va miic do anh hudng cua cac chat hoa hoc dd'n dd axit nude mua dugc trinh bay d bang 1.9 dudi day

Bang 1.9 Cac chat tioa hgc co anh huong den do axit nudfc mua

Miiedg anh hudng

Nho

Nguon nh^n tao

Nguon gdc

Nhidt didn, luyen kim, cong nghiep khae

Muc do anh hudng

Ldn

Tien chat

S02,H3S, COS, CH3SCH3

Li4^n van Tfi^^ sy

Tinh toan phat thai va iing Udt axit-Ap dung Cho vung mien Bic Viet Nam

OAI HOC QUOC GIA - VIEN CO HOC

TRUNG TAM HOP T A C D A O TAO VA B(5l DUONG CO HOC 27

Bien, vd Trai dat

Qua trinh sinh hgc, chat thai chan nuoi

Miic dd anh hudng

C5ng nghidp, Bui giao thong

Vira

Natri (Na^)

Canxi (Ca-^

Bien, vd Trai dat

Vd Trai dat

Xac dinh bdi sir tham gia cua cac yd'u

Cong va ndng nghidp

Nhd

Cong va nong nghiep

Xac dinh bdi su tham gia cua cac yd'u to trdn

Miic do anh hudng

Nguon: Con ngUdi va thanh phan khi quyen Dr R.F Pueschel, WMO, 1986

Lu4^ van Tix^c sy

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1-3.5.1 Cac ion co mat thudng xuyen trong hoa nude mua [4]

A Cac ion chu yeu co nguon gdc tCt thien nhien

Canxi (Ca''*')

Ion Canxi chid'm uu the trong cac ion duong ciia nude mua Ndng do cua chiing thay doi cd the lidn quan dd'n ndng do ciia ion Hydrocacbonat va Sunphat,

Nguon gdc cua Canxi trong nude mua la bui tii nham thach da voi va nham thach Sunfat Tuy nhidn nhung hat bui d tang cao ciia khf quyen (vu tru) hoae tii nhirng hien tugng thidn nhidn bat thudng, vf du nhu niii lua thuc sir ft lidn quan dd'n ndng do Canxi trong nude mua Nhu vay qua trinh phan tfch da

mang nhirng hat bui chiia Canxi til be mat trai dat va cac nha may san xuat cd

su dung quang cd chiia Canxi la nhung nguydn nhan chu yd'u anh hudng dd'n nong do Canxi trong nude mua

Magie (Mg^^)

Cac nha nghidn ciiu cho r^ng Magie trong nude mua cd ngudn gdc chu

yd'u tix bien, nhiing ngudn khac nhu khai thac quang hoae tu cac co sd san xuat

Cacbonat chi lam gia tang dang ke n6ng do d viing xung quanh cac ngudn nay Ion Magie thudng lien kd't vdi ion Clo, Sunphat va Hydrocacbonat

Natri (Na^)

Cac ion Natri cd lidn kd't nhieu hon vdi ion Q o , Hydrocacbonat va ft hon vdi Sunphat Natri trong nude mua phan ldn cd ngudn gdc tir bien, tii san xuat cong nghidp va tir bui tren mat dat do gid eudn ldn

Lu^n van ZTi^a^ sy

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OAI HOC QUOC GIA - VIEN CO HOC ^ n

TRUNG TAM HOP TAC DAO TAO VA B(5l DUONG CO HOC ^^

Kali (K^)

Trong sd cac ion duong, Kali ft phd bid'n hon Gidng nhu ion Natri, ion Kali cung lidn kd't vdi Clo va Hydrocacbonat Ngudn gdc cua chiing chu yd'u tii san xuat cdng nghiep va nong nghidp

Luu fiuynft vd Sunfat (SO/')

Trong khdng khf, cac chat hat (son khf) deu cau tao tir hat sunphat amoni hoae axit sunfuric dang gigt Gia tang cac hat son khf sunfat se lam anh hudng dd'n can can biic xa ciia he thdng Trai dat - Khf quyen, de'n tfnh chat quang hgc va kha nang tao mua cua khdng khf

Ngoai khf SO2, trong khdng khf con co cac dang hgp chat khac chiia luu huynh nhu: H^S (hydrosunfua), DMS (dimethylsunfua), CS2 (disunfua cacbon), DMDS (dimethyldisunfua), v.v

Sau cac chuyen hda hda hgc, phan ldn cac oxyt luu huynh nay bi oxy hda thanh ion sunfat va ton tai d 2 dang: kho (trong bui) va udt (trong nude mua)

Nita, Nitrat (NO/) vd Amoni (NH/)

Trong qua trinh phan huy cac hgp chat chiia Nito trong dat, vi sinh vat

da chuyen hoa Nito dudi dang hgp chat thanh N^O, khf nay phat tan vao khdng khf da bi oxi hoa chuyen hoa thanh NOo Day la qua trinh chfnh sinh ra NO^ cd ngudn gdc thidn nhien va chiing dugc chuyd'n hda thanh nitrat Phan ldn ion N03' deu dugc loai bd khdi khdng khi do ling udt Cac cac hoat dgng dot chay nhidn lieu hda thach cung sinh ra mot lugng NOx dang ke do khdng khf chiia mot ndng do kha cao Nito Ben canh dd, eac hoat dgng san xuat phan dam va qua trinh su dung phan dam trong canh tac ndng nghiep cung gdp ph^n gia tang phat thai cac hgp chat Nito tdi khdng khf

l-u^n vdn ZTi^ac sy

Tinh toan phat thai va iing Udt axit - Ap dung cho vung mien Bic Viet Nam

DAI HOC QUOC GIA - VIEN CO HOC o ^

TRUNG TAM HOP TAC DAO TAO VA B(5l DUONG CO HOC ^ ^

Trudc kia khi ndi de'n d nhidm khdng khf ngudi ta thudng de cap den cac cha't nhu SO hoae NO, ma bd qua chat khf amoniac (NH3) Cac nghidn ciiu ve hoa nude mua da chi ra r4ng chat khf NH3 nay cd tam quan trgng dac biet trong mgi van de lien quan dd'n thanh phan hoa nude mua Ling qua tai cac ion NH4'' cd the g^y axit hoa d^'t va day la kd't qua cua qua trinh d xi hoa NH4'' thanh NO3" do vi sinh vat Amoni thiic day nhanh qua trinh oxy hoa SO trong may va nude mua Cac hoat dgng san xu^'t phan bdn chiia Nito va chat thai tijr chan nuoi la nhung nguon chu yd'u sinh ra NH3

Ngudn tu nhidn ciia axit nitric trong khdng khf dugc coi la khdng dang

ke, bdi vay phan ldn nguon nitrat cua khdng khf dugc tao ra tir NO, Cac dang hgp chat Nito trong khdng khf (trong dd bao gom nude mua) dugc trinh bay d bang 1.6

Clo (cn

Su tham gia ciia ion Clo trong thanh phan hoa hgc nude mua da dugc cac nha nghidn ciiu khAng dinh chiing cd ngudn gdc tir bien, tir hoat dgng ciia niii lua va sau nay la su tham gia cua thai khf cdng nghidp Mot phan nhd ion Clo nua cd ngudn gdc tu bui mat dat do gid mang dd'n song nd phu thudc rat ldn vao dac didm dia chat noi bui phat sinh

Hydrocacbonat (HCO/)

Nguon gdc ciia ion nay chu yd'u la do dia hinh cd niii da vdi va cac loai

da khac cd chiia cacbonat Bui Cacbonat tii nhiing dia hinh nay dugc gid eudn

va tach ra khdi mat dat tham gia vao qua trinh tao may (hat nhan ngung kd't)

Su bid'n doi nong do ion HCO3 phu thudc vao ion Natri va Canxi

Z M 4 « v/a« ZTi^^ sy

Tinh toan phat thai va iing Udt axit - Ap dung cho vung mien Bic Viet Nam

TRUNG TAM HOP TAC DAO TAO VA B(5l DUONG CO HOC

S Cac Ion chu yeu do anh hudng tir hoat dong cua con ngu& [4]

ion Sunpiiat, Nitrat - Nitrit vd Amoni

Vide gia tang dot chay cac nhidn lieu hda thach dan den gia tang ndng

do SO trong khdng khf, va nd chfnh la nguydn nhan gay axit hoa nude mua Galloway va Likens, 1981 da chiing minh ring nong do cua axit nitric (hay ion nitrat) ludn tang vdi nong do cua axit sunfuric tuong iing cd trong khdng khf Mat khac, amoniac (hoae amoni) la chat trung hda (tung ph^n hay toan bg) duy nha't chung cho cac thanh phan axit khdng khf da dugc tao thanh tir cac oxit axit tuong iing, va dd bid'n doi cua do pH cua nude mua cd hdn quan dd'n xu thd' cua bid'n doi cua ion sunfat, nitrat, va amoni

1.3.5.2 Thanh phan hoa hoc nude mUa [4]

PhSn chu yd'u ciia thanh phan hoa hgc nude mua dugc hinh thanh khi di qua phan thap nhat cua khdng khf, nghia la thap hon may va d gan sat mat dat Trong thanh phan hoa hgc nude mua, cac ion chii yd'u bao gdm: Ca""", Mg""^,

N a \ K^ NH4^ S04 , NO3-, Cr, H C 0 3 - va mot sd ion khac cd ndng do thap Thanh phan hoa hoc nude mua bidu dien mdi lien he giOa ndng do "C" ciia chat d nhidm va lugng mua trong thdi gian cd mua Lugng mua dugc tfnh b^ng milimet (mm) Mot milimet nude mua ed y nghia la 1 1ft nude mua roi trdn mot m~ didn tich n^m ngang Don vi cua thanh phan hoa hgc nude mua duge bieu thi bang mg/1, ciing vdi lugng mua ta ed lugng cac thanh phSn hoa hgc phan bd la mg/m" mat dat trong thdi gian qui udc Gia tri nay dugc ggi la Idng udt, ddng bid'n vdi do tang ciia lugng mua Nhung hieu bid't ve hoa hgc nude mua cho phep danh gia miic do d nhidm khdng khf, vd nguydn nhan tieu huy hoae loai bd cac chat d nhidm khf va hat tan trong nude, ve miic do an mdn cua nude mua va tac dgng ciia nd trdn he thuc vat

J^t4pn vdn ZTi^^ sy

Tinh toan phat thai va iing Udt axit'Ap dung Cho vung mien Bic VietNam

OAI HOC QUOC GIA - Vlf N CO HOC 0 9

TRUNG TAM HOP T A C O A O TAO VA B6\ D U O N G CO HOC

Nhiing thanh phan hoa hgc ciia nude mua dugc tao ra do anh hudng eua cac didu kien tu nhidn nhu khf tugng, thd nhudng mat dat (dia hinh, dia mao nhu nhdm kim loai kidm - kiem tho hay mudi bien tu ban th^n chiing khdng giy d nhidm khdng khf) Cac tac nh^n do hoat dgng cua con ngudi ngay eang

anh hudng dd'n thanh phin hoa hgc ciia may va khi roi xudng mat dat lam anh

hudng nghidm trgng eac he sinh thai cung nhu cac thanh qua vat chat cua con ngudi

1.4 KET LUAN

Theo quy luat bao toan vat chat trong tdng the, trdn phuong dien toan cau neu quan trie va tfnh toan trong mot chu ky du ldn thi tdng lugng Nito va

Luu huynh tic mat dat do phat thai can b ^ g vdi tong lugng Nito va Luu huynh

roi xudng mat dat qua Idng khd va Iang udt

Lugng Nito va Luu huynh tii mat dat phat thai ra bao gdm tir cac ngudn:

- Cac ngudn thai tu nhidn

- Cac ngudn thai nhan tao

Lugng Nito va Luu huynh roi xudng dat la:

- Thanh phdn trong Idng kho (bui, ndng do cac chat trong khdng khf )

- Thanh phan Idng udt (ndng do cac chat trong nude mua)

- Bi hap thu do sinh thai trdn mat dat

Neu tinh trong pham vi toan eau thi tong lugng trdn phat thai va Idng se can bdng, cdn neu chi tfnh cho mot pham vi nhat dinh, do hoan luu khf quyen, v$t chat van chuyen tu noi nay dd'n noi kia trong tang ddi luu, vi the thdng thudng can can vat chat khdng can bdng ddi vdi mdi dia phuong

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Tinh toan phat thai valhg Ifdt axit-Ap dung cho vung mien Bic VietNam

OAI HOC QUOC GIA - VI$N CO HOC o o

TRUNG TAM HOP T A C O A O TAO VA B 6 I D U O N G CO HOC

Viec tfnh toan lugng phat thai tii cac ngudn thai tu nhidn rat khd khan, hien nay van dd nay chua dugc nghidn ciiu s^u trdn thd' gidi.Trong khuon kho luan van nay, chi gidi han tfnh toan lugng phat thai va Idng udt Nito va Luu huynh tu cac ngudn thai nhan tao trong mot pham vi nhat dinh Tu ket qua tfnh toan lugng phat thai do con ngudi g^y ra so sanh vdi kd't qua tfnh toan lugng Idng roi xudng mat da't, cd the dinh lugng mot each tuong ddi lugng d nhidm do ngudi dan trong khu vuc gay ra va lugng d nhidm hg phai ganh chiu

Dd cung la phuong phap lu^n de danh gia tai lugng d nhidm va la co sd cho van de d nhidm mdi trudng xuydn bien gidi va xay dung nhirng chfnh sach quan ly mdi trudng mang tfnh Qudc td'

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OAI HOC QUOC GIA - VIEN CO HOC

TRUNG TAM HOP TAC D A O TAO vA B 6 | D U O N G CO HOC 34

CHl/ONG 2 PHUONG PHAP TINH TOAN PHAT THAI

VA LANG 1 / 6 T AXIT

2.1 PHl/ONG PHAP TINH TOAN PHAT THAI

Cd nhieu phuong phap xac dinh lugng phat thai, cd th^ phan chia chiing thanh hai loai la phuong phap true tiep va phuong phap gian tiep

2.1.1 TINH TOAN Ll/ONG P H A T THAI THEO PHl/ONG PHAP TRL/C TIEP

Phuong phap true tid'p la lugng phat thai dugc tfnh toan thdng qua cac thong sd thai dugc do true tiep tai ngudn thai iTu diem cua phuong phap nay

la khdng can phai nghidn ciiu sau cdng nghe san xuat ma vdn tfnh toan dugc lugng phat thai kha chfnh xac Nhung nhuge diem ciia phuong phap la yeu cdu phai cd nhQng thid't bi do dac chuydn dung, cac ngudn thai nghien ciiu phai dugc thid't ke phu hgp vdi quy trinh ky thuat do dac ndn rat tdn kem vd mat kinh phf,

Lugng phat thai dugc tfnh theo cdng thiic sau:

Q = C x S x v (2.1)

trong dd:

Q -lugng phat thai tii nguon thai (mg/s)

S - didn tfch thie't didn ngang cua ngudn thai - tai vi tri do (m")

V - van tdc khf thai - tai vi tri do (m/s)

C - ndng do khf thai (SO2, NO,, CO, ) - tai vi tri do (mg/m')

Lu^n vdn T^i\^c: sy

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OAI HOC QUOC GIA - VI$N CO HOC ntr

TRUNG TAM HOP TAC D A O TAO VA B 6 I D U O N G CO HOC "^^

Tix cdng thiic tren, nhan thay de cd dugc lugng phat thai chfnh xac ta

can phai cd cac sd do chfnh xac 5, v, C tir nguon phat thai Lugng phat thai

thdng thudng dugc tfnh bdng don vi kg/h hoae bdng don vi ta'n/nam

2,1,2 TINH TOAN Ll/ONG PHATTHAI THEO PHl/ONG PHAP GIAN TIEP

Tfnh toan lugng phat thai bdng phuong phap gian tid'p la lugng phat thai dugc tfnh toan thong qua cac he sd phat thai, khdng qua do dac De cd nhung he so phat thai nay, ban dau ngudi ta cung phai qua do dac, sau dd khai quiit hoa de ap dung cho cac trudng hgp tuong tu

Uu diem cua phuong phap nay la khdng can phai do dac true tid'p tai dng khdi, vi vay, phuong phap nay da giai quyet dugc toan bg nhiing khuyd't didm cua phuong phap true tid'p Nhugc diem ciia phuong phap nay la qua trinh san xuat trong mdi mot nha may mot khac nhau mac du ciing mot cdng nghe san xuat, va nd'u ap dat ciing mot he sd phat thai cho cac nha may thi se gay ra sai sd

Hien tai, d Viet Nam chua cd mdt nghidn ciiu nao chuyen sau de dua ra nhiing he sd phat thai cho cac nganh san xuat cua Viet nam Phan ldn khi tfnh toan lugng phat thai cua cac nha may, cum cdng nghiep cac nha nghien ciiu thudng ap dung nhiing he sd phat thai eua nude ngoai khi khdng cd dieu kien

do true tid'p

Hien nay cd ba each tinh lugng phat thai theo cac each md phdng cua

Td chiic Y te The gidi (WHO), Lien xd cu va Cue Bao ve Mdi trudng Lidn bang My (EPA) Ca ba each tinh trdn deu dua vao cac he sd phat thai, tinh cho mdt don vi nhidn Ueu su dung

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Tinh toan phat thai va iing Udt axit-Apdyng Cho vung mien Bic VietNam

TRUNG TAM HOP TAC DAO TAO VA B<5l DUONG CO HOC 36

2.1.2.1 Tfnh toan ludng phat thai theo W H O [9]

WHO da thuc hien kha nhieu nghidn ciiu de md phdng lugng phat thai ciia cac nganh giao thdng va cong nghidp chfnh, de tii dd dua ra nhung he sd phat thai Trong tfnh toan nhanh lugng phat thai, nd'u chap nhan nhung sai sd cho phep thi vide dua vao nhirng he sd phat thai cua WHO la mdt giai phap de

cd thd' cd nhiing kd't qua ve lugng phat thai tiir mdt nha may, mdt cum nha may hay mot khu cdng nghidp, tham chi tii mdt nganh san xu^'t

Tuy nhidn, day la phuong phap tfnh nhanh ndn sai so thudng Idn, bdi vay, de giam sai so khi ap dung eac he sd can cd nhiing hieu biet nhat dinh ve cdng nghe san xuat eiia nha may de lua chgn va ap dung nhiing he so thfeh hgp ddi vdi tirng loai cdng nghe,

Theo hudng ddn cua WHO, phuong phap ap dung cac he sd phat thai de tfnh toan nhanh lugng phat thai tir cac loai ngudn thai nhu sau:

Cong thuc tinh luang phat thdi SO2

M s o 2 = B x y x S ^ (2.2)

«

trong dd:

Mso2 - Itigng phat thai SOo (kg)

B ' lugng than sir dung (tan)

y - he sd phat thai SO2 iing vdi tiing loai ngudn thai khae nhau

S^ - ham lugng luu huynh trong than (%) (d Viet nam S^ cd gia tri

0,5-1,0)

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Tinh toan phat thai va Iang i/dt axit-Apdyng cho vungmienBk VietNam