Xử lý khí thải trại chăn nuôi gia cầm ở quy mô công nghiệp

Tiiu ban: Moi tru&ng vd Ndng lugng ISBN: 978-604-913-013-7<br /> <br /> <br /> Xtr LY KHI THAI TRAI CHAN NUOI GIA CAM 6 QUY IMO CONG<br /> NGHIEP<br /> <br /> Pham Hoang Long, Nguyen Hoai Chau<br /> Vien C6ng Nghe M6i Truong<br /> 18 - Hoang Qu6c Viet, Cau Giay, Ha Noi<br /> Email: longphamhoangvs@vahoo.com<br /> Tom tat:<br /> Su d nhiim khdng khi trong mdi trudng chdn nudi tdc ddng din con ngudi trudc<br /> hit vd chit yeu la qua mill Miii hdi ciia chudng trgi chdn nudi la mot trong nhirng yiu<br /> td gdy d nhiim mdi trudng d ndng thdn vd cd tdc ddng cdn trd viec phdt triin vd tdng<br /> quy md cdc trgi chdn nudi<br /> Bdo cdo trinh bdy kit qud nghien cieu vd thuc hien xit ly mui trong khi thdi trgi<br /> chdn nudi gia cdm a quy md cdng nghiep bdng qud trinh hdp thu (sir dung dung<br /> dich kiim, dung dich axit) kit hpp vdi qud trinh hdp phu (su dung than hogt tinh).<br /> Khi thdi sau xie ly da gidm duac trin 90% mui hdi (thi hien qua hdm luong NH3,<br /> H2S) vd cd hdm luong bui Idng dgt yiu cdu theo QCVN 05:2009/BTNMT vd<br /> QCVN 06:2009/BTNMT.<br /> Abstract:<br /> The air pollution from environmental animal husbandary impact of human first<br /> and primarily through odor. The odor of the cages is one of the factors that cause<br /> environmental pollution in rural areas and obstacles affecting the development<br /> and scale livestock farms.<br /> The report presents the results of research and implementation odor treatment<br /> in exhaust gas poultry farms in industrial scale with the absorption process (using<br /> alkaline solution, acidic solution) combined with the adsorption process (using<br /> activated charcoal). Exhaust gas after treatment is over 90% had reduced odor<br /> (represented by the concentration ofNHs, H2S) and deposited dust levels meet the<br /> QCVN 05:2009/BTNMT and QCVN 06:2009/BTNMT.<br /> <br /> <br /> 1. NHU CAU Xlf LY MUI TlT KHI THAI TRAI CHAN NUOI GIA CAM<br /> Trong nhiirig nam gan day riganh chan nu6i gia cim a nuac ta da co nhiing buac tang truang<br /> rnanh me ca ve sl lugng va chit lugng. Theo sl lieu cua T6ng Cue tiling ke, Viet Nam hien co<br /> ting dan gia cim khoang 260 trieu con. Phuang thiic chan nu6i tinyln thing theo kilu chuing<br /> nu6i ha da tiing buoc chuyin dich sang chan nu6i cong nghiep vai kilu chuing khep kin dl phu<br /> hgp vai gilng ga c6ng nghiep rit min cam voi dilu kien m6i trucmg, kh6ng dl tiiich nghi voi<br /> ning n6ng m6i tnrang nhiet do thay dli a Viet Nam. Do la phuang thiic lam chuing kin hoan<br /> toan, benti-ongchuing lip dat he thing giai nhiet, he tiling hai nuac, quat hiit, quat tiili... dl In<br /> dinh nhiet do thich nghi vod gi6ng ga. Dilu nay giiip cho ga khong bi anh huong bai m6i truang<br /> ben ngoai, each ly dugc vai chim choc la nguln gay benh, nhit la dich ciim gia cim xay ra tiong<br /> thod gian vua qua.<br /> <br /> <br /> <br /> 214<br />  Hgi nghi Khoa hgc ky niem 35 ndm Vien Khoa hgc vd Cong nghe Viet Nam - Hd Noi 10/2010<br /> <br /> Tuy nhien neu khi thai chu6ng nu6i cua cac trai chan nu6i gia cam a quy m6 c6ng nghiep<br /> kh6ng dugc thu gom xir ly ma phat tan true tiep ra m6i truong xung quanh thi se gay 6 nhiem ve<br /> miii tren mot viing rgng, tac dgng manh den nhung nguod s6ng each hang tram met. Vi vay xir ly<br /> mui tir khitiiaitrai chan nu6i gia cam quy m6 cong nghiep la nhu ciu tit ylu dli vod cac trai nam<br /> gan khu dan cu.<br /> Su 6 nhiem kh6ng khi trong m6i truang chan nu6i tac dgng din con nguod truoc hit va chu<br /> yeu la qua miii. Neu nhu 6 nhiem khong khi trong nhieu nganh san xuit khac thuong gay bod cac<br /> boa chat dgc the khi lam t6n hai den he ho bap, than kinh va da cua con nguod, co the lam nguoi<br /> ta bi ngat va tir vong tai ch6 thi 6 nhiem khong khi trong m6i truong chan nu6i anh buong den<br /> tinh mang va siic khoe con nguoi 6 miic do thap hon, nhung tac dgng lien tuc cua n6 tod con<br /> nguod la dieu kh6ng the xem nhe.<br /> Hartung va Philips [1] da the hien sir anh huong toi m6i truong khong khi cua boat dong chan<br /> nu6i qua mo hinh phat thai khi duod day:<br /> <br /> Vat nu6i - ^ ^ CO2 (Carbon dioxide)<br /> H2S (Hydro sulphide)<br /> CH4 (Methane)<br /> Chat bai tiet . . = = = £zr^hrKV;'_'_^ NH3 (Amonia)<br /> (phan, nuoc giai...) """ ~"" - - --Tt>*. NO2 (Nitrous oxide)<br /> Thiic an • Nhirng chat khac: aldehydes,<br /> amines, phenols...<br /> <br /> Hinh 1: Md hinh phdt thdi khi tir hogt ddng chdn nudi<br /> Trong khu vuc chan nu6i co cac diem gay mui la chu6ng nu6i va nod luu gift chat thai ran,<br /> nuac thai chan nuoi. Vat the gay mui la nhung nod dinh chat thai chan nu6i va ngay ca co the ciia<br /> vat nu6i. Lugng miii sinh ra Ion nhat la tu qua trinh phan buy chat thai chan nu6i, lam phat sinh ra<br /> cac khi doc hoac cac khi c6 mui h6i th6i kh6 chiu. Trong mot s6 dieu kien nhu mat do vat nuoi<br /> cao, su th6ng thoang kem, nhiet do va do am kb6ng khi cao, cac khi nay co the gay bai den sue<br /> khoe cua nguod va vat nu6i.<br /> Khi thai chan nu6i bao g6m h6n hgp nhieu loai khi trong do co tren 40 loai gay miii - Hartung<br /> [2]. De danh gia tac dgng cua miii can phai xac dinh cac chat khi gay mui va n6ng do cua n6 trong<br /> kh6ng khi. Tuy nhien thuc hien dinh tinh va dinh lugng cac chat gay miii trong kh6ng khi la viec<br /> rat phuc tap. M6i loai khi gay mui tao ra cho con nguod cam giac ve mgt mui song cac nghien cim<br /> ve miii da chiing to h6n hgp cac khi gay mui se gay cho con nguoi cam giac ve miii mod nen viec<br /> diing giac quan cua nguod de phan biet va xac dinh cac chat gay mui la viec kho kha thi. Viec xac<br /> dinh sir co mat cua cac khi gay mui bang phuong tien ky thuat nhin chung la viec rat kh6 khan va<br /> t6n kem. Viec danh gia n6ng do cua chat gay mui cho den nay chi co the thuc hien dugc vod mgt<br /> s6 chat, va cu6i ciing thi ciing van phai dua vao giac quan cua con nguod. Vi vay trong cac nghien<br /> ciiu so bg ve miii trong chan nu6i nguod ta thuong chi nhac den la NH3, H2S la cac khi c6 nong do<br /> cao ban nhieu cac khi gay miii khac va tuong d6i de xac dinh. Sir phan buy yem khi cua cac chat<br /> thai trong chu6ng nu6i con sinh ra lugng Ion khi CH4, tuy nhien tiong m6i truong thoang khi no<br /> CO kh6ng nhieu.<br /> <br /> <br /> <br /> <br /> 215<br /> Tieu ban: Moi tru&ng vd Ndng lugng ISBN: 978-604-913-013-7<br /> <br /> <br /> 2. KHAI QUAT VE DOI TUOfNG THU'C HIEN XU" LY MUI TtT KHI THAI<br /> Trai chan nu6i gia cam dugc chiing t6i lira chgn thuc hien nam 6f tinh Phii Thg co quy m6 chan<br /> nu6i tren 60.000 con ga. Day la trai nu6i dugc thiet ke theo c6ng nghe chan nuoi khep kin, vod 2<br /> day chu6ng nu6i, moi day chu6ng nu6i g6m 4 chu6ng nu6i vod nang suat m6i chu6ng khoang<br /> 8.000 con. Tai dau m6i chu6ng nu6i dugc lap 11 quat hiit gio c6ng nghiep vod t6ng cong suat<br /> 36.000 m , kh6ng khi ben ngoai truoc khi dua vao trong chu6ng nu6i dugc xu ly qua he th6ng<br /> tam tan nhiet dang song ket hgp phun nuac. Nhiet do ben trong chu6ng nu6i dugc dieu chinh<br /> bang bien tan de thay d6i t6c do vong quay quat biit khi co sir chenh lech nhiet do so vod ben<br /> ngoai chu6ng nu6i.<br /> Voi quy trinh chan nu6i khep kin nay, ga dugc nu6i voi tongtiiodgian 68 tuan. Trong su6t thoi<br /> gian nay, ga dugc each ly hoan toan voi m6i truong ben ngoai. Toan bg lugng phan va nuoc thai<br /> trong suot qua trinh nu6i kh6ng dugc thu gom ra ben ngoai ma dugc trgn vod mim cua, mat trau sau<br /> do day xu6ng day chuong nuoi ngan each bod san nu6i due lo. Dinh ky hang tuan, lop phan trgn nay<br /> se dugc c6ng nhan trong trai nu6i phun che pham EM nham giam miii h6i. Tuy nhien, theo kit qua<br /> khao sat cua chiing t6i do lop phan trgn trong chu6ng nu6i kh6ng dugc thu gom dinh ky va u diing<br /> quy each da dan tod viec phat tan mui h6i kho chiu ra m6i truang dan cu xung quanh. D I giai quylt<br /> van de nay, C6ng ty da lap dat he th6ng dan phun suong co che bat nham giam thieu bui va miii hoi<br /> phat tan ra khu vuc dan cu xung quanh. Ket qua phan tich, danh gia chit lugng khi thai sau xir ly<br /> bang he th6ng dan phun suong co che bat dugc trinh bay a bang 1 duoi day:<br /> Bdng I: Kit qud phdn tich chdt luang khdng khi xung quanh trgi chdn nudi gia cdm<br /> Ket qua phan tich<br /> STT Ten chi tieu Don vj TCCP<br /> KKl KK2 KK3 KK4 KK5<br /> 1 Bui lo limg |ag/m^ 203 190 199 205 187 300<br /> 2 H2S \iglvci 18 21 24 11 23 42<br /> 3 NH3 l^g/m^ 290 260 240 270 180 200<br /> Vi tri lay man: KKI ^ KK4 - mdu khi lay a cdc ddy chudng sd 1 -;-4 (phia sau<br /> qugt gid); KK5: Bin ngodi tudmg rdo Trgi gd, gdn cdc hd ddn<br /> TCCP: Quy chuan ky thuat qu6c gia ve chat lugng khong khi xung quanh (trung binh 1 gio) -<br /> QCVN 05:2009/BTNMT dli vai bui lo limg; Quy chuin ky thuat quIc gia vl mgt sl chit doc<br /> hai trong kh6ng khi xung quanh (trung binh 1 gia) - QCVN 06:2009/BTNMT doi voi NH3,<br /> H2S.<br /> Ket qua cho thay, tai thod diem kiem tra khu vuc chan nu6i boat dgng binh thuang, m6i truong<br /> kh6ng khi khu vuc xung quanh ve culi huong gio chu d^o trong pham vi 100m co mui thii, kho<br /> chiu. So sanh vod Quy chuin ky thuat cjulc gia vl chit lugng kh6ng khi xung quanh (trung<br /> binh 1 gia) va Quy chuan ky thuat quIc gia vl mgt sl chit dgc hai trong kh6ng khi xung<br /> quanh (trung binh 1 gia) co till tiiiy: chi tieu NH3 cua cac mSu KKl, KK2, KK3, KK4 cao hon<br /> TCCP. Cac chi tieu phan tich con lai nam trong gioi ban cho phep.<br /> Nhu vay, viec lip dat he thing dan phun suong c6 che bat tai C6ng ty da giam dugc ham lugng<br /> bui lo lung phat tan ra m6i tiuong xung quanh, ban cbl dugc dong khi tiiai tiiai tiuc tilp sang Idiu<br /> vuc dan cu, song kh6ng xu ly dugc khi NH3, H2S la nguyen nhan gay ra miii h6i, tiiii vi chi su dung<br /> nuoc de phun. Ben canh do, viec dong khitiiaikh6ng dugc tiiu gom cung se la nguyen nhan gay 6<br /> nhiem m6i truang kh6ng khi trong khu vuc khi xay ra cac su cl tiong chuing nu6i.<br /> <br /> <br /> <br /> 216<br />  Hgi nghi Khoa hgc ky niem 35 ndm Vien Khoa hgc vd Cong nghe Viet Nam - Hd Noi 10/2010<br /> <br /> <br /> 3. PHLTONG PHAP DANH GIA MOT SO CHI TIEU GAY MUI CUA KHI THAI<br /> De danh gia muc do 6 nhiem miii va hieu qua xu ly mui tu khi thai trai chan nu6i gia<br /> cam quy m6 c6ng nghiep da ap dung cac phuong phap sau: Phuong phap lay mau, phan<br /> tich mau bui lo limg theo TCVN 5067:1995; Phuang phap lay mau, phan tich mau H2S va<br /> NH3theo 10 TCN 676:2006 va 677:2006.<br /> <br /> <br /> 4. DE X U A T CONG NGHE XU* LY KHI THAI TRAI CHAN NUOI GIA CAM<br /> Co nhieu each de giam boi mui nhu cac bien phap thu dgng trong xu ly mui nhu che chan, xir<br /> ly mui vod boa chat khir mui, xay dung ham chua phan, ham Biogas, ii phan compost. Mgt s6 nod<br /> da ap dung bien phap tich cue hon nhu su dung thiic an can d6i, hgp ly, b6 sung cac chat ch6ng<br /> tao mui... tuy nhien vi gia thanh cac bien phap nay con cao nen it co so co the ap dung dugc. Mgt<br /> each khac la dung che pham EM, che pham nay dugc san xuat theo c6ng nghe vi sinh len men cac<br /> vi sinh vat co ich : vi khuan quang hgp, vi khuan lac-tic, nam men, xa khuan va nam sgi (cong<br /> nghe Nhat Ban). Che pham nay co tac dung khu mui hoi chuong trai gia cam, phan buy cac chat<br /> hiru CO, thuc an du thua va cac chat dgc hai nhu NH3, H2S,... Tuy nhien voi cac trai chan nu6i<br /> c6ng nghiep do co dan vat nu6i Ion, nguoi ta thuong ban che su dung cac che pham phun ben<br /> trong chu6ng nu6i de tranh cac tac dgng bat Igi d6i voi dac tinh sinh hgc nhay cam cua con ga.<br /> Vi vay de xu ly mui trong truong hgp cu the trai nu6i ga c6ng nghiep c6 cac dac diem da neu<br /> tren da lira chgn c6ng nghe xu ly khi thai bang qua trinh hap thu va qua trinh hap phu qua he th6ng<br /> thiet bi ket hgp bu6ng phun va thap dem. Nguyen ly cua phuong phap dugc the hien a Hinh 2.<br /> Nguyen ly ket hgp bu6ng phun va thap dem thuong dugc ap dung de xir ly khi thai c6ng<br /> nghiep [3]. Thiet bi loai nay co mgt bu6ng phun a phia tren va mgt thap dem o phia duoi. Khi<br /> thai di tu duoi len qua thap dem va qua bu6ng phun, sau do dugc dua qua mgt lop vat lieu<br /> r6ng khac de tach lai cac hat nuoc phun. Thap dem thuang la mgt thap chua lop vat lieu r6ng<br /> nhu cac loai khau bang su, kim loai hay plastic. Khi thai dugc dan vao a day thap va thoat ra<br /> o dinh thap. Dung dich hap thu dugc tuoi deu len dinh lop dem va chay dgc theo cac be mat<br /> vat lieu. Phan img hap thu xay ra tren be mat uot cua lap dem. Van t6c dong khi di qua lop<br /> dem trong khoang v = 1-1,5 m/s. Chieu day lop dem h = 0,4-3 m. Dung dich hap thu dugc<br /> phan ph6i deu tren toan mat cat ngang thap bang voi phun hay 6ng khoan 16. Cuong do tuoi<br /> dung dich hap thu |j. = 1,5-4 kg/kg kh6ng khi. Tro lire cua thap cho dong khi thai p = 60 x<br /> (li/0,4) kg/m^. Dung dich hip thu dugc thu b6i dua qua thiet bi lang can va xu ly boa truoc<br /> khi dugc phun tro lai. Sau mgt khoang thai gian lam viec, dung dich phun dugc thai vao be<br /> th6ng xu ly nuoc thai [4-8].<br /> <br /> <br /> Lap tach hat long Cua dan khi thai ra<br /> <br /> <br /> Lop vat lieu r6ng Dan voi phun<br /> <br /> Cua dan khi vao<br /> <br /> <br /> Ong dan dung dich phun<br /> Cua thai dung dich phun<br /> <br /> Hinh 2: So dd nguyin ly kit hpp budng phun vd thdp dim<br /> <br /> 217<br /> Tieu ban: Moi tru&ng vd Ndng lugng ISBN: 978-604-913-013-7<br /> <br /> 5. XAY DUNG HE THONG XIJ^ LY MUI TlT KHI THAI TRAI CHAN NUOI GIA C A M<br /> Tai trai nuoi gia cam quy m6 c6ng nghiep vod kieu nu6i khep kin theo c6ng nghe de xuat o tren<br /> da che tao, lap dat va van hanh he th6ng xu ly khi thai cho 4 chu6ng nu6i. He th6ng xu ly khi tiiai<br /> bao gom 2 thap xu ly, m6i thap co duong kinh 2,2m. Ben trong thap bl tri 2 lop vat lieu dem hip<br /> thu bang vong g6m rasig, moi lap day 0,5m. Phia tren lop dem hip thu la he thing buIng phun.<br /> Tren cimg la lop dem tach nuac va lop dem hap phu bing than boat tinh co chieu day tijong<br /> duong la 0,3m va 0,2m. Tong chieu cao cua toan bg thap la 15m, trong do phan than thap cao 5m.<br /> Khi thai tu 4 chu6ng nuoi sau khi dugc lang bui qua he thing phun suong dugc dan tod he thing<br /> 6ng thu gom khep kin nha 2 quat hiit vod c6ng suit mli quat la 70.000m^/h va dugc nli vod than<br /> thap. Khi thai dugc dan vao day thap qua hetii6nghuong dong, dugc va dap vao lop vat lieu dem<br /> hap thu va dugc xu ly bang dung dich Na2C03 voi nIng do l-5%> qua he thing buIng phun, khi<br /> thai sau do dugc dan qua lop vat lieu r6ng bang plastic de tach lai cac hat dung dich hip thu va<br /> dugc hap phu qua than hoat tinh truoc khi thoat ra ngoai. Dung dich hip thu dugc thu bli xuIng<br /> daytiiap,din tod be lang can va phun tuan hoan tra lai thap. Kit qua phan tich chit lugng khi thai<br /> sau xu ly dugc trinh bay a bang 2 duoi day.<br /> Bdng 2: Kit qud phdn tich chdt lupng khi thdi sau xir ly bdng thdp hdp thii - hdp phu<br /> <br /> Ket qua phan tich<br /> STT Ten chi tieu Don vi TCCP<br /> KKl KK2 KK3<br /> <br /> 1 Bui lo limg fxg/m^ 196 198 192 300<br /> <br /> 2 H2S |4g/m^ 8 9 17 42<br /> <br /> 3 NH3 |4g/m^ 17 18 24 200<br /> <br /> Vi tri lay mau: KKl, KK2: Mdu khi ldy tgi cira thdm thdp xic ly sd I vd sd 2;<br /> KK3: Bin ngodi tuong rdo Trgi gd, gdn cdc hd ddn<br /> Kit qua cho thiy, khi tiiai sau xir ly da dat theo Quy chuin ky thuat quIc gia vl chit lugng<br /> kh6ng khi xung quanh (trung binh 1 gio) dli voi ham lugng bui lo limg va Quy chuin ky<br /> thuat quIc gia vl mgt s6 chit dgc hai trong kh6ng khi xung quanh (trung binh 1 gio) dli voi<br /> ham lugng NH3 va H2S.<br /> <br /> <br /> <br /> <br /> Hinh 3. Anh hi thdng xit ly miii tie khi thdi trgi chdn nudi gia cdm<br /> <br /> 218<br />  Hgi nghi Khoa hgc ky niem 35 ndm Vien Khoa hgc vd Cong nghe Viet Nam - Hd Noi 10/2010<br /> <br /> <br /> <br /> 6. KET LUAN<br /> C6ng nghe xu ly khi thai trai chan nu6i gia cam a quy m6 c6ng nghiep bang qua trinh hap<br /> thu va qua trinh hap phu qua he th6ng thiet bi ket hgp bu6ng phun va thap dem da dugc van<br /> hanh thanh c6ng tai trai chan nu6i gia cam a tinh Phii Thg. Vod c6ng nghe nay, khi thai sau xu<br /> ly da dugc loai bo tien 90% thanh phan miii h6i the hien qua ham lugng NH3, H2S va dam<br /> bao kh6ng gay anh buong toi dac tinh sinh hgc cua dan ga ben trong chu6ng nu6i. Day la<br /> c6ng nghe dugc ap dung lan dau tien a Viet Nam d6i voi trai chan nu6i gia cam va hoan toan<br /> CO kha nang ling dung rgng rai tren toan quoc.<br /> <br /> <br /> TAI LIEU THAM KHAO<br /> 1. Hartung J, Phillips V.R., (1994), "Control of gaseous emissions from livestock<br /> buildings and manure stores", Journal of Agricultural Engineering Research 57, 173-<br /> 9.<br /> 2. Hartung J., (1999), '^Airborne emissions from animal production and its impact on<br /> environment and man". In proceedings of the International Congress 'Regulation of<br /> Animal Production in Europe'.<br /> 3. Duong Due H6ng, Hoang Kim Co, Luong Due Pham, Ly Kim Bang, Tran Hiru Uyen<br /> (2001),''Ky thudt mdi trudng", Nha xuat ban khoa hgc va ky thuat.<br /> 4. Hoang Thi Hien (2000), "Thiit ke thdng gid cdng nghiep ", Nha xuat ban xay dung.<br /> 5. Nguyin Van Xuan (2005), "Nhid ky thudt", Truong dai bgc Nong Lam TP. H6 Chi<br /> Minh<br /> 6. Tran Nggc Chan (1999), "O nhiem khdng khi vd xie ly khi thdi tap 1,2,3", Nha xuat<br /> ban khoa hgc va ky thuat.<br /> 7. Trin Nggc Chin (1998), "Ky thudt thdng gid ", Nha xuat ban xay dung.<br /> 8. Hoang Kim Co (1999), "Ky thudt Ipc bui vd lam sgch khi thdi", Nha xuat ban Giao<br /> Due.<br /> <br /> <br /> <br /> <br /> 219<br />