Nghiên cứu áp dụng kiểm toán chất thải tại xí nghiệp chế biến thủy đặc sản xuất khẩu Hà Nội

Trong cong trinb nay chung toi tien hanh nghien ciiu ap dung kiem toan chat thai tai xi nghiep Che bien Tbuy dac san xuat khau Ha Noi F37 vdi muc dich ap dung cong cu kiem toan vao viec

NGHIEN CAU AP DUNG KIEM TOAN CHAT THAI

TAI XI NGHIEP CHE BIEN THUY DAC SAN XUAT KHAU HANOI

N g u y e n T h i H a , B u i T h i L u a n

Khoa Moi trudng, TrUdng DHKHTN, BHQGHN

TOM TAT

Kiem toan moi trUdng noi chung va Kiem toan chat thai cong nghiep ndi rieng la mot cong cu quan ly mdi dUdc ap dung d nUdc ta trong mot vai nam gan day Mac du day la cong cu mdi nhung qua cac ket qua ap dung kiem toan tai nhieu cd sd san xuat cho thay cong cu nay mang lai Idi ich kbong nbd ca ve moi trUdng va hieu qua kinh te Trong cong trinb nay chung toi tien hanh nghien ciiu ap dung kiem toan chat thai tai xi nghiep Che bien Tbuy dac san xuat khau Ha Noi (F37) vdi muc dich ap dung cong cu kiem toan vao viec giam tbieu chat thai tai xi nghiep n b i m tim ra nhiing khau ton that nUdc, nguyen lieu

de tix do diia ra nhiing phUdng an cho'ng that thoat, giam tbieu chat

thai, tang hieu qua cua qua trinb san xuat, dong tbdi cai thien chat lUdng moi trUdng cho xi nghiep va nang cao hieu qua kinh te trong san xuat kinh doanh Cac noi dung cu the dudi day se dUdc nghien ciiu: 1) Tim hieu day chuyen cong nghe che bien, miJtc do tieu thu nUdc, nguyen lieu va cac chat thai phat sinh

2) Tinb toan can b^ng nUdc, can b^ng chat thai r^n

3) Xac dinh cac khau gay lang phi nUdc va cac nguon gay 6 nhiem moi trUdng

4) Xem xet, danh gia cac phUdng an xii ly, giam tbieu lang phi nUdc cua xi nghiep,

5) De xuat cac giai phap c6 tinb kha thi nh^m tiet kiem nUdc,

giam CTR, xii ly nUdc thai nh^m cai thien moi trUdng va tang cUdng hieu qua kinh te cho xi nghiep

I KIEM TOAN CHAT THAI CONG NGHIEP

Kiem toan chat thai la mot loai hinh cua KTMT la cong cu c6 gia tri de cac doanh nghiep kiem tra lai kha nang tuan thu cac tieu chuan moi trUdng, giam cac vi pham ve moi trUdng, giam thieu chat thai va tang cUdng kha nang quan ly moi trUdng

Kiem toan chat thai la budc d^u tien de giam chat thai va ciing lam giam 6 nhiem moi trUdng N6 la qua trinb kiem tra khach quan cac qua trinh san xuat va chat thai nh4m muc dich giam nguon thai

tang s\i dung lai boac loai bo boan toan chat thai Qua kiem toan cac

phUdng an giam thieu chat thai dUdc nhan dang, dUdc danh gia, dUdc lUa ebon, dUdc thUc hien va dUdc giam sat

Viec thUc h i e n kiem toan giam thieu chat thai cho xi nghiep F37 dUdc thUc hien theo hudng d^n gom 9 bUdc theo 3 giai doan [Trinb Thi Thanh, Nguyen Thi Ha, 2003] Nghien ciiu dUdc thUc hien tai xi nghiep sau hdn 4 thang khao sat hien trang va tinb toan thUc hien cac budc kiem toan vdi trong tam kiem toan la day chuyen che bien torn va 2 chat thai chinh la nUdc thai va chat thai r^n

II CAC VAN Dfi MOI T R U 6 N G CUA NGANH C H ^ BIEN THUY SAN

Qua trinb san xuat che bien thuy san c6 anh hudng Idn tdi moi trUdng dac biet la moi trUdng nUdc va moi trUdng khong khi

Kbong kbi trong cac khu vUc san xu^'t va khong khi xung quanh thUdng cbiu tac dong cua cac yeu to gay 6 n b i i m nhu mui hoi thoi, mui tanh, khi HgS, boa chat nhu clo, mercaptan, ure do qua trinh phan buy cac chat c6 trong nUdc thai va phe thai r4n thai trong qua trinh san xuat Ngoai ra trong qua trinh san xuat che bien con su( dung pho bien cac thiet bi lanb de duy tri boat dong cua cac may nen lanh va day CO the la nguon gay 6 n b i i m moi trUdng khong khi (khi NHg, freon, )

Khdi lUdng chat thai ran thai bd trong qua trinh san xuat la rat Idn bao gom cac t h a n h phan nhU: dau; v6 tom; noi tang cac loai ca, mUc; mai mUc; ong mUc; xUdng vay, vay ca Day la cac chat giau chat hiiu cd de p h t o buy sinh hoc c6 tiem nang gay 6 nhiem moi trUdng neu

khong cd bien phap thu gom, xcL \i kip tbdi se anh hUdng dang ke den moi trUdng va sxic khoe con ngUdi

Van de dang quan tam hdn ca trong san xuat che bien thuy san

la van de suf dung nUdc va nUdc thai Qua trinh che bien can mot lUdng nUdc tUdng do'i Idn Nudc thai che bien thuy san cd ham lUdng cac chat ran, cac chat huEu cd de phan buy sinh hoc cao Cac chat nay ton tai trong nUdc d dang keo, dang boa tan, dang phan tan min lam cho nude thai c6 mau va do due Idn Qua trinh phan buy cac chat nay trong nUdc tao ra cac miii khd chiu va doc hai Ngoai ra nUdc thai con c6 mat cac boa chat khii trung nhU clo, javen; cac chat tay riia, chat boat dong be mat dung trong hoat dong ve sinh nha xUdng

Hien nay van de moi trUdng mdi dUdc quan tam trong eac cd sd che bien c6 quy mo Idn Con lai trong hau bet cac cd sd che bien c6 quy

mo viia va nhd van de moi trUdng con it dUdc quan tam

III KET QUA KIEM TOAN CHAT THAI

Nhin chung moi trUdng trong xi nghiep luon dUdc giiJ thong thoang va sach se Trong khu vUc san xuat che bien van de moi trUdng cung da dUdc quan tam Xi nghiep c6 ba cong n h a n chuyen quet don

va thu gom do chat thai ran (khu vUc xung quanh xi nghiep) va chat thai ran san xuat Cong tac ve sinh moi trUdng da dUdc xi nghiep tbUc hien mot each nghiem tuc

3 1 N g u y e n n h i e n l i e u , nvtdc v a h o a c h a t sxi d u n g

Nguyen, nhien lieu

Nguyen lieu chinh ciia xi nghiep la tom, mUc, ca cac loai dUdc thu mua tiif cac vung khac n h a u nhU: Quang Ninb, Hai Phong, Thai Binh, Thanh Hoa, Nghe An, Ha Tinb Trung binh moi nam xi nghiep thu

mua khoang 450 tan nguyen lieu, lUdng nguyen lieu mdi loai thay doi theo tiing nam va phu thuoc vao tbdi tiet Nguyen lieu thu mua trong nam 2002 dUdc chi ra trong bang sau

Bang 1 - Li^dng nguyen lieu thu mua trong n a m 2002

STT

1

2

3

4

5

6

N g u y e n , n h i e n lieu sijf dung

Tom cac loai (Tan/nam)

Muc (Tan/nam)

Ca cac loai (Tan/nam)

Tong nguyen lieu (Tan/nam)

Dien (kWh)

Dau DO (Lit)

So litdng

302,7 171,9 23,7 498,3

700 000

400

[Nguon: Phong Ke toan Tai chinh cua xi nghiep F 37]

Hod chat

Hoa chat svL dung chu yeu la chlorin vdi khoi lUdng khoang 30 kg/

nam Chlorin diing kbit trung nguyen vat lieu, dung cu thiet bi, tiep xuc vdi san pham, ngan chan su phat trien cua vi sinh vat va khong lam anh hudng tdi chat lUdng san pham Ngoai chlorin xi nghiep con dung H2O2 de ngam va tay tr^ng mUc tuy nhien lUdng dung khong dang ke

Ni/dc

Nguon nude sii dung cua xi nghiep la nUdc gieng khoan da qua he thong xd li bao gom: Nude'diing cho sinh hoat, nUdc d u n g cho san xuat da, nUdc diing ve sinh n h a xudng va nUdc dung cho cac cong doan san xuat

Hien nay trong tat ca cac cong doan san xuat cua xi nghiep deu

chua lap dong ho do nudc do d6 viec tinb toan lUdng nUdc sd dung chi

mang tinb chat tUdng do'i Xi nghiep c6 hai may bdm:

* May bdm cong suat 30 m /b lam viec trung binh 4h/ngay

* May bdm cong suat 12m /h lam viec trung binh 8h/ ngay

Tong ludng nUdc bdm trong mot ngay la: 30 x 4 + 12 x 8 = 216 (m'^), tinb trung binh trong mot nam tong so'ngay lam viec cua xi nghiep

la 200 ngay do do lUdng nude khai thac trong mot nam c6 the Udc tinb nhu d bang 2

Bang 2- Li^tfng nUdc suf d u n g cho cac muc dich k h a c n h a u t r o n g

Xi nghiep

S T T

1'

2

3

4

5

L o a i nvtdc svt d u n g

Nude sinh boat

Nude san xuat da

Nude ve sinh cong nghiep

Nude cho cac cong doan san xuat

T o n g

hxidng (m^/nam)

3120

1000

1348

25732

31200

3 2 Q u i t r i n h c o n g n g h e c h e b i e n

Cac loai san pham torn, mUc, ca dong lanh deu dUdc che bien theo quy trinh chung nbu d hinh 1 Tuy nhien, tuy theo loai san pham ma

cd the bdt di mot boac mot so* cong doan

Tren cd sd tbdi gian nghien cdu tai xi nghiep, quy trinh che bien torn thit dong lanh dUdc lUa chon la doi tUdng cho kiem toan vdi t r o n g

t a m k i e m t o a n la moi trUdng nUdc bao gom cac noi dung sau: (1) Tinb

toan lUdng nUdc thUc te sxi dung; (2) Tinb toan can b§ng nUdc cho qui

trinh che bien tom de xac dinh cac khau gay t h a t thoat nUdc; (3) Tinb

can b^ng chat thai vkn de xac dinh lUdng chat thai di vao dong thai; (4) Tinb toan chi phi cho viec sii dung nUdc vUdt dinh mvic va dUa ra

cac bien phap n h i m tiet kiem nUdc cho xi nghiep; (5) De xuat giai phap tiet kiem nUdc sii dung, giam thieu lUdng nUdc thai va xii ly nUdc thai d cong doan cd dac tinb 6 nhiem cao

Nudc da—>

Nudc da—•

Nude—•

D a _ >

Nude—•

D a - >

Nudc—^

Nudc—•

T h i i n g - >

carton

Nang lUdng—^

Ngu3'en lieu: Tom mUc, ca

i

Tiep nhan, rda nguyen lieu,

bao quan

1

Xiily

+

Riia Ian 2

1

Nhat tap chat

+

Rua Ian 3

1

Phan cd hang

i

Riia Ian 4

i

De rao nUdc, can, xep khuon

i

Chd cap dong

i

Tach khuon, ma bang, dong tui PE

i

May do kim loai

i

Bao goi, dong tbung carton

i

Bao quan kho lanh

— • N u d c thai

Nudc thai, CTR

— • N u d c thai

Nudc thai,

n h a t tap chat

— • N u d e thai

— • N u d c thai

Nude thai, bao bi thai bd

^ Thiing phe thai

Hinh 1: Quy trinh cong nghe che bien

3.3 T i n h t o a n c a n b ^ n g nxidc v a c h a t t h a i r a n

Binh mite ni/dc sti dung

Nham dap ling cac yeu cau ve ve sinh thUc pham, hien nay xi nghiep dang tien h a n h san xuat theo mot so'tieu chuan kiem soat chat lUdng thuy san nhu GMP (He thong san xuat to't), HACCP (He thong phan tich rui ro va kiem soat gia tri tdi ban) De thUc hien tot cac tieu chuan tren dong tbdi nham giam cbi phi cho san xuat xi nghiep da dUa

ra dinh mute nUdc sii dung cho nguyen lieu torn nhU sau;

Tom cac loai: 20 m^/TNL; Dinh miic da sii dung la 2 tan da/TNL

Tuy nhien, dinh miic xi nghiep dUa ra mdi chi dUdc thUc hien trong mot so' cong doan con trong thUc te lUdng nUde sii dung cua xi nghiep cao hdn dinh miic r^'t nhieu

Can bang nitdc trong qud trinh san xuat tom

* Ludng nude sii dung trong cac cong doan san xuat:

Ta so' lieu bang 2, ta thay rang lUdng nUdc dung trong cac cong

doan san xuat la 25.732m2/nam Theo bo phan ki t h u a t cua xi nghiep

ti le sii dung nUdc so sanh vdi dinh mdc de san xu^'t 1 TNL torn, mUc,

ca t r o n g thUc te tUdng iing la 2: 3: 3 Tii ti le n a y va c a n cii vao lUdng n g u y e n lieu t h u m u a moi loai n a m 2002 c6 tong so' p h a n nUdc sii d u n g la:

(302,5 tan tom x 2) + (171,9 tan mUc X 3) + (23,7 tan ca x 3) = 1192,2 (phan) LUdng nUdc dung cho qui trinh che bien tom:

Wt5^ = 25732 : 1191,8 x 2 ^ 43,18 (m^)

* LUdng nUdc diing de ve sinh nha xudng (nam 2002):

LUdng nUdc dung de ve sinh nha xUdng:

1348m3 : 498,3 TNL = 2.7 ( m W N L )

Vi vay, tong lUdng nUdc sii dung (gom ve smh nha xUdng) cho 1 TNL

(tom) la:

43,18 + 2,7 = 45,88 m^

Nhu vay lUdng nUdc sii dung vUdt dinh miic tinh tren 1 T N L doi vdi nguyen heu dau vao la tom rat Idn (gap hdn 2-3 Ian), tUdng iing la:

45,88 - 20 = 25,88 m^/TNL

Nhu vay tong lUdng nUdc sd dung vUdt dinh mdc n a m 2002 (W^^^j^) la: WvDM(tdm) = 25,88m3/TNL x 3 0 2 , 5 T N L / n a m = 7 8 2 8 , 7 m 3 / n a m

C a n b ^ n g nUde dUdc t i n h t o a n cho tufng cong d o a n , cac k e t q u a dUdc cbi r a d b a n g 3

Bang 3: Lifdng nUdc suf d u n g va nifdc t h a i t r o n g

c a c c o n g d o a n s a n x u a t

TT

1

2

3

4

5

6

7

8

C o n g d o a n c h e b i e n

Tiep nhan nguyen

lieu, riia, bao quan

Sd che nguyen lieu

Rijta Ian 2, nhat tap

chat

Phan cd bang

Ru[a Ian 3, de rao, can

Xep khuon

Tach khuon, ma bang,

dong PE

T o n g

D a u

Nxidc

(m^/TNL) 3,04

33,6 1,5

2,1 0,123 1,717

42,08

v a o

Da (Tan/TNL) 0,5

1 0,25 0,25

2,0

Nvidc t h a i

( m ^ / T N L )

3,54+ Aw

34,6+ Aw 1,75+Aw 0,25± Aw 2,l±Aw

1,717+Aw

43,975±Aw (*)Ghi ehu:

A^ - LUdng nLf6c chenh lech do that thoat (bay hoi, ng^'m, ) hoac do con lai tii cong doan trxidc

^WT{*)" ^^^^ Lutdng nUdc chenh lech do that thoat (bay hdi, ngam, ) hoac do con

lai tCt cong doan trU6c

Trong cac cong doan eiia qui trinh che bien tom chi c6 cong

doan xep khuon la nUdc dUdc di vao san pham con lai t a t ca cac cong doan khac nUdc va nUde da tan deu theo eac mang thoat nUdc thai ra ngoai Ngoai ra trong qua trinh san xuat con mot lUdng nUde bi t h a t t h o a t do bay hdi, do tham vao san nha va eac dung eu thiet bi Do d6 qua so lieu tong ket d bang 3 tren thUe te lUdng nudc thai ra la: Wj^^ = 43,795± AWT(*) (m'VTNL)

Dinb mde da sU dung cua xi ngbiep vdi torn la: 2 tan/TNL NhU vay CO the thay lUdng da sii dung trong cae eong doan la phii hdp vdi dinh mile dat ra

TU cac ket qua tinh toan tren ta c6 the dUa ra sd do can bang nUdc nhu trong hinh 2

Nguyen nhan dan den sii dung ni/dc vUOt dinh mdc

Cac ket qua tinh toan can bang nUdc ket hdp vdi qua trinh khao sat eac dieu kien san xuat trong xi nghiep nguyen nhan dan den lUdng nUde sii dung vUdt hdn nhieu so vdi dinh mUc la do:

- Nudc dUdc sii dung ehUa hdp ly cho cong doan sd che nguyen lieu Trong cong doan nay torn dUde boe v6, bd dau, rut ruot dUdi vdi nUdc ehay nhe Tuy nhien qua thuc te nhan thay khong phai luc nao cong nhan ciing de tay dUdi voi nUde NhU vay se c6 nln2ng khoang tbdi gian nUdc ehay ma khong dUdc sii dung do do se gay lang phi rat nhieu nUdc

- Xi nghiep mdi ap dung dinh miic nUdc sii dung trong mot so eong doan nhu riia nguyen lieu, ban thanh pham, xep khuon Tuy nhien, do

d moi cong doan doi khi tuy thuoc vao loai nguyen lieu, miJc do saeh ban eiia nguyen lieu, ma lUdng nUdc dinb mdc c6 the thay doi, va khi

do rat kho xac dinh lUdng nUdc sii dung do viec thay nUdc phu thuoe vao mau nUdc va mUe do cam quan cua ngUdi eong nhan

- Xi ngbiep ebUa c6 dong ho do nUde eho ttfng eong doan san xuat

do do chUa xac dinh dUdc chinh xac lUdng nUdc sii dung cho tiing eong

doan la bao nhieu, cong doan nao vUdt hdn so vdi dinb mdc

- Mot so van nUdc moi noi bi hu hong lam nude bi ro that thoat

ra ngoai

- Y thUc tiet kiem nUdc eiia cong nhan cbUa cao

- Ngoai ra viee dung 6'ng nhUa mem de ve sinh thiet bi nha xudng,

ve sinh cac dung cu san xuat nhU thiing difng nguyen lieu, ro ra, thau chau cung la nguyen nhan lam tang lUdng nUdc sU dung

Nude:

3.04m-Da: 0.5 tan

2,lm;i+0,123m;!

Nudc

0,9mH0.817m'^

Tom nguyen lieu: 1000kg

Tie]D nhan nguyen lieu Rua Ian 1 Bao quan

Nirdc: 33,6m'^

Da: 1 tan

NUdc: l,5m^

Da: 0,25 tan

Da: 0,25 tan

Nudc:

— •

Nudc thai 3,04 ± Aw(m-J)

Da: 0,5 tan

^ V Nudc thai: 3,36± A ^ (m-) S'^i ehe nguyen lieu |Nudc da tan: 1.5+ A\v

Nude thai: 1,5± A^y (m*')

Riia lim 2, nhat tap chat [Nudc "dd ta"nro"25±2?u,

Phan cd hang

Rua Ian 3, de rao, can, xep khuon

Nude thai 2,1 ± Awta'O

Chd dong, cap dong

tach khuon, ma bang, dong PE

Nude thai 1,777 ± Aw(m'^)

Bao goi carton

Bao quan

Hinh 2: Sd do can b^ng nUdc trong qua trinh san xuat torn

Can bang chat thai ran trong qud trinh che bien tom

* Q u a k e t q u a t h e o doi cua bo p h a n ky t h u a t ciia xi nghiej) cho t h a y :

- 1000 kg n g u y e n lieu (XL) d a u vao sau khi ciua sd che khoi ludng

B T P t h u dUdc t r u n g binh la 500 kg Khdi ludng p h e t h a i t h u dude la

470 kg

N h u vay lUdng p h e t h a i r a n di vao dong thai t r o n g eong d o a n na>- la:

P h e t h a i r a n di vao dung t h a i - N L - B T P - P h e t h a i r a n t h u gom

= 1000 kg- 5 0 0 k g - 470 kg = 30 kg

500 kg B T P s a u khi (lua cae cong doan riia Ian 2, n h a t t a p c h a t ,

p h a n cd b a n g , riia kin 3 de t a o den t h a n h p h a m (TP) cudi c u n g t r u n g

b i n h cd kbo'i lUdng la 490 kg LUdng p h e t h a i r a n di vao d o n g t h a i long

t r o n g eac eong d o a n n a y la: P h e thai r a n di vao dong t h a i long = B T P

- T P = 500 - 490 - 1 0 k g

Tii ket (jua t r e n ta eo sd do can b a n g chat thai r a n nhU s a u (hinh 3):

Tom nguyen lieu 1000kg

Xiily

Phe thai ran Ihu gom: 470kg Phe thai r^n di vao dong thai: 30kg

BTF: 500kg

1

RUa n h a t tap chat

p h a n cd h a n g

I

Phe thai r^n di vao dong thai: 10kg

T h a n h pham 490kg

Hinh 3: Sd d o c a n b a n g c h a t t h a i r a n

Tu! sd do c a n b a n g c h a t t h a i r a n ta t h a y t o n g lUdng p h e t h a i di vao

d o n g t h a i t r o n g q u a t r i n h s a n x u a t torn la: 30 + 10 = 40 (kg/TNL)