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Phgm Vdn Chuong', VQ Mgnh Tudng'
T6MTAT
Tinh on djnh kich thudc cua gd sau khi xii ly chdm chdy tiiudng b] giam xudng. Nham khac phyc nhupc di^m trfin, nghidn ciiu ndy da tidn hdnh dp dyng cdng ngh^ xu ly nhidt do cao dd xii ly gd Keo la tram (/icada aunculiiornvs) d& qua xu 1^ vd khdng qua xir 1^ chdm chdy bdng mono amoni phdt phat (MAP).
Dong thdi phdn dch dnh hudng cua xu ly nhidt d^'n tinh chdt vdt ly cua gd Keo Id tram duc^c xd !y d cac che do khac nhau bao gdm: khdi lupng tlid tich. ti 1$ hiit nudc, hidu sulit chdng hiit nudc vd hd sd chong truong nd. K^'t qua xac djnh cdc tinh chdt vdt ly cua gd Keo Id trdm sau khi xu ly nlii^t cho thdy, khd nang ^n d(nh kich thuoc cua gfi dupc ndng Idn khoang 6-32%, hi^u sufit chdng hiit nudc tang khoang 12-35%, tuy nhidn khoi lupng thd tich cua gd giam di tir 2-10%. K^t qua phdn tich phuong sai th^ hi^n, hai nhdn td la thdi gian xu ly nhi^t va vide xu ly chdm chdy bang MAP d^u c6 dnh hudng rd rdt ddn cac tinh chat ciia go, . ^ dung cfing nghd xii ly nhidt cd thd cdi thidn duoc tinh 6n djnh kich thudc ciia go Keo la tram da qua xii ly ch|ini chay bdng MAP md trong qud trinh xd ly khdng cdn phdi cho tiidm b^t ky hda chdt nao. Day la mpt trong nhQng gidi phdp hidu qua viia khde phMC dupc nhupc di^m ciia go xu ly cham chay bang mudi v6 co ndi chung va MAP noi rifing \^ vira gidm thidu tdc nhSn gay d nhi^m mdi trudng.
Tiikhda: Hi^u sudt chdng hiit nudc (WRE), h$ sd chdng truong n& (ASE), keo la tram, khdi luong thd tich g6, xdly ch$m chay, xuly nhiit.
LMOBAU
Cdng nghd xii Iy nhidt dupc dp dyng rat rpng rai trong Imh vuc bidn tinh gd nhdm nang cao dp ben sinh hoc cung nhu Idm giam dd am thdng bdng, giam tinh hiit nudc vd tdng tinh dn dinh kieh thudc ciia gd (Esteves, B. vd Pereira, H., 2009). Qud trinh xu ly nhiet lam pha vd mdi Udn kdt tinhin-polysacarit trong Cctti tnic gd do cde axit hiru eo dupc phan gidi tii hemixenluloza, lam cho go vdn la Ioai vat lidu cd tinh hiit am manh frd thanh loai vat lidu ky am (Kosikova, B.etal., 1999; Wikberg, H. vd Uisa Maunu, S., 2004).
Siifliay ddi tinh hut dm cua gd sau khi xu Iy nhidt ed quan hd mat tiiidt vdi su thay ddi cdc thdnh phan hda h^ic cua gd, dde bidt Id hemixenluloza va dp kdt tinh trong gd. Tinh hiit dm eua go sau khi xii ly nhidt giam xuong la do mdt Iupng Idn cdc nhdm hdo nudc trong go, ddc bidt Id cdc nhdm hydroxyl (-0H) cua cac hop chat hydro cdc bon giam xudng (Nakano, T.
v4 Miyazaki, J., 2003; Phuong, L. X. et al., 2007).
T^ong, V. M. va Li, J. (2011) dd nghidn ciiu si; bidn 36i cdu tnic hda hpc vd mpt sd tinh chat eua gd keo
!ai sau qua tiinh xir ly nhi^t trong mdi tiudng ed khi N2 bao vd vdi nhidt dp xu \^ tir 210''C ddn 230"C. Kdt qua cho thdy, go keo Iai sau khi dupc xii ly nhidt mOt '"?ng nhat dinh cdc nhdm hydroxyl giam xudng.
ciing vdi dd la tinh hut nudc eua gd ciing giam xudng, va tinh dn dinh kieh thudc gd dd dupc cai thidn. Chuong, P. V. (2011) da nghidn ciiu anh hudng eua edng nghe xu ly thuy nhiet den tinh chat vat ly eua gd Keo Id trdm. Ket qua cho thay, nhiet dd va thdi gian xir Iy da dnh hudng rat ro den khdi lupng the tieh, hidu suat chdng hiit nudc vd hd sd chdng truong nd eua gd. Cu the, khdi lupng the tich ciia gd giam xudng nhung tinh dn dinh kieh thudc cua gd dupc eai thidn thdng qua ket qua phan tich tinh hut nudc vd tinh truong nd cua gd.
Mono amoni phdt phdt (MAP - NH4H2PO4) la chdt ehdng chdy dupc dp dung khd rdng rai trong xu Iy chdm chdy eho gd vd ed the tao ra dupc Ioai gd ed hidu qua chdm chay rat rd (Terzi, E. et al., 2011). Tuy nhidn, do ban than Id loai mudi vd co ndn MAP cd khd ndng tan trong nudc ddng thdi cung ed tinh hut dm nhat dinh (Zhi-jun, Z. et al., 2007). Vi tiie, khi dupc tam vao go sd ldm tdng kha ndng hut dm eiia gd ddn ddn dp am tiidng bdng trong mdi tiudng ciia gd tdng ldn vd kdt qua la lam giam tinh dn dinh kieh thudc cua go xu ly chdm chay bdng MAP.
Nghidn cuu nay sd ldm rd khd ndng ndng cao tinh dn djnh kieh tiiudc eua edng nghd xu ly nhidt ddi vdi gd Keo Id ti-dm (.Acacia auricuUformis) cung nhu mdi quan hd cua didu kidn xic ly nhidt vdi tinh dn dinh kich thudc cua gd da qua xii 1^ chdm chdy bdng MAP.
' Tnrftng D^i hpc Lam nghi?p
IONG NGHIEP V A PHAT TRIEN N C N G T H 6 N - KY 2 • THANG 1/2013 87
KHOA H p C C d N G N G H i ~
I. VATU^I VA PHUDNG PHAP NGfliN CUU
1. Vdt Udu
G6 Keo Id trdm (Acacia auricuUfomu's) 10-12 tudi khai thdc t^ Ldm trudng Luong Son, Hda Binh;
dudng kinh tioing binh 18 em.
Hda chdt chdm chdy mono amoni phdt phdt (MAP),ddUnhkhi^t98%.
2. Phirong phdp nghidn ciiu
a. T^o mdu thinghiim: Mdu diing trong nghidn ciiu dupc gia cdng theo quy djnh ciia tidu chudn qude td ISO 3129-1975 vd ydu cdu vd phuong phdp tgo mdu kidm tia tinh chdt co ly ciia gd, sd Iupng mdu Id 10 mdu cho mOt cdng thiic tiii nghidm.
b. Phuong phip xir ly chim chiy cho gd Ap dung phuong phap tam dp lire vdi cdc thdng sd chd do tdm sau:
Dd dm gd khi tdm: mdu gd thi nghidm sau khi gia edng theo kich thudc quy dinh trong tidu chudn sd dupc ddt trong mdi trudng ed nhidt dO 20"C vd dd dm tuong ddi cua khdng khi Id 65% dd didu ehinh ddn dp dm tiieo ydu edu Id 12-15%; ndng dO hda chdt (MAP): 10%; dp sudt tdm: 0,7 Mpa; tiidi gian duy tri dp sudt max: 2 gid.
Nhidt dd tdm: nhidt dp tiiudng.
c. Phuong phip xu ly nhiit cho gd dd qua xir ly chim chiy bing MAP: sii dyng phuong phdp xu ly nhidt dp cao tiong mdi trudng khdng khi vdi quy trinh xii Iy nhu hinh 1.
Thdng sd chd dd xir ly nhu sau: Dp dm nguydn Udu dau vdo: 15-18%; mdi trudng xu ly: khdng khi;
thdi gian xii ly ddu flam ndng vd say): 6 gid; nhidt dd xu Iy ban dau: 110°C; nhidt dp xii Iy: 180°C; thdi gian duy til nhidt dp max: 2 gid, 4 gid vd 6 gidf.
Thidt bi xit ly nhidt: sir dung thidt bj t^ TVung tdm tiu nghidm thyc hdnh ciia Khoa Chd bidn Ldm sdn -Trudng Dgi hpc Ldm nghidp. Md hi$u: Sumpot vdi hd tiidng didu khidn PLC, nhi^t dd max 230°C, sdn xudt tgi Trung Qudc.
Quy trinh xii If:
(1) Giai dogn Idm ndng: tdc dO tdng nhi^t c dinh san cho chdnh l$ch giCta nhidt dd gd vd nhidt d mdi trudng xu 1^ khdng qud 30°C nhdm hgn ch khuydt tdt xdy ra ti-ong qud tiinh xir Iy;
(2) Giai dogn sdy: nhi^t dd lua chpn cho giai dogi ndy Id 110"C vd dupc duy tii trong thdi gian 6 gid;
(3) Giai doan bidn tinh: nhi$t dd lua chpn ch(
giai dogn ndy Id 180"C (tiiam khdo tdi U^u lidn quai vd xem xdt ddn nhidt dO ndng chdy ciia MAP Ii 190"C); thdi gian cua giai dogn ndy dupc lira chpn theo 3 muc Id 2 gid, 4 gid vd 6 gid;
(4) Giai doan Idm nguOi: do sau khi xir Iy, nhi^l dd gd va nhidt dd mdi trudng bdn ngodi chdnh I^b rdt Idn; nhdm han chd khuydt tat sau qud tiinh xii Iy, sau khi kdt thuc giai doan bidn tinh cdn thidt phdi dd gd ngudi tv nhidn trong mdi truong xu ly ddn khi cd nhidt do chdnh Idch vdi mdi trudng bdn ngoai khdng qud 30"C mdi ed tiid ldy mdu ra dd tiiuc hidn cdc budc thi nghidm tidp theo.
d. Cic chi tiiu chu ydu cdn kidm tra Trudc khi tidn hdnh kidm tra, mdu dd qua xii Iy nhidt theo quy frinh trdn dupc ddt trong mdi tiudng cd nhidt do 20°C vd dd dm tuong ddi eua khdng khi Id 65% trong tiidi gian 2 tiidn. Cdc chi tidu kidm tia gdm:
Tlii tdn hao khdi lugng miu sau khixuly (M£J:
Id ti Id phdn trdm giiia khdi lupng mau sau khi xii 1^
so vdi khdi Iupng mdu sau giai doan say (khdi lupng gd khd ki$t), ti Id tdn hao khdi Iupng dupc tinh tiieo edng thiic (1):
ML = ^ ! ^ . i m % ) (1) Khdi lupng thi tiidi: Ip dung titu chuin ISO
3131-1975 ii xic djnh khdi lu(mg ttii tich cua mau gd trudc vl sau khi xit Ij?,
Hiiu suit chiing hiit nudc vi tiii hiit nudc Trln cot sd tham khio tii U$u dia Rowell, R. M, (2005), thi nghidm sii dung phuong phip xic djnh ti 1? hiit nudc vi hi^u suit chdng hut nudc nhu sau:
miu gd ddi chiing vi miu gd xii 1^ dm:ic sly d^n khd ki^t, sau dd nglm nudc d nhi^t dO mdi budng tiong Uidi gian 8 ngiy, Trong qui binh nglm s« xic djnh li 1$ hut nudc ciia miu sau khi nglm tai cic ttidi dito 6 gid, 1 ngiy, 2 ngiy, 4 ngiy vl 8 ngiy. Hi^u sui.
chdng hut nudc dugc xic djnh Uieo cdng tinic (2):
» ' « g = " ' ' ' ; r ; ^ ^ ' - ' < 1 0 0 ( % ) (2)i
NdNG NGHlfP vA PHAT TRI^N N O N G T H O N - K t 2 - T H A N G 1/2013^
9 10 11 12 13 14
ThU,lach
Hinh 1. So dd cdng ngh^ bi6i tinh nhi^t dO cao cho gi Keo 11 trim da qua xir ly ch|m chiy
88
KHOA H p c C 6 N G N G H I
Trong do: WA^, vk WA^ ldn lupt Id ti Id hut nudc cua mau go xu ly vd mau gd ddi ehiing. T\ Id hut nuoc (iW^ dirpc xac djnh theo cdng thiic (3):
"Hk = • W2 - W,
IVi i X 1 0 0 ( % ) (3) Trong dd: W^ vd Wj Idn lupt Id khdi lupng eua mau go sau khi ngdm vd mdu go dupc sdy khd kidt d nhiet dp 103±2"C.
He sd chdng truong na (ASE):
Hd so chdng truong nd dupc tinh todn dua trdn CB sd sir tiiay ddi kieh thudc cua mdu khdng xir ly nhiet vd mau xii ly nhidt sau 8 ngdy ngdm nudc. Hd s6 chong truong nd ASE dupc xdc dinh theo cdng thiic (4):
" - 5 , , __
ASE = • - X 100 (%) (4)
IVong dd: 5„ va S^, Idn lupt Id ti Id truong nd ciia g6 trudc va sau khi xir Iy nliidt. Ti Id truong nd (Si ciia mau gd sau 8 ngay ngdm nudc dupc tinh theo cong thiic (5):
5 = • - X100 (%) (5)
Trong dd: l^vd V^ Ian lupt la thd tich cua go sau khi ngSm nudc va the tieh cua go duoc say khd kidt d nhi?tdpl03±2"C.
1 x f l QUA VATHAO LUAN
1. Anh hudng cua chd dO xu 1^ ddn khdi lupng th^ lich gd Keo Id tiim
Anh hudng eiia xii Iy cham chay va xii Iy nhidt d^n khoi lirpng the ti'ch eiia gd Keo Id trdm dupc xdc ijnh thdng qua phuong phdp phdn tich phuong sai liai nhdn td ed Idp. Kdt qua phaji tich phuong sai
% th^ hidn ti-ong bang 1.
Bang 1. Kdt qud phdn tich phuong sai 2 nhdn td cd
^
Nguon
MiSnt^A B t o t J B , TuDiig"tic i^is6f5|_
5?!!g_fc_
cia khdi lirgrng t b i tich gd da Tong
buih phuong
(SS) 0,006 0,025 0,0007 0,051 0,083285
Dd do (dfl 1 9.
2 ,54 59
Trung binh binh
phuong (MS)
0,006 0,012 0,0003 0,0009
xirly F hnh toan 6,37 13,30 0,38
F«, 4,01 3,16 3,16
Kdt qua phan tich trong bang 1 cho thay, gia tri.
F tinh todn ciia ed hai nhan td ddu ldn hon so vdi gia til Fo5, do dd ed thd kdt ludn Id xii ly eham chdy va tiidi gian xir Iy nhidt ddu anh hudng den su tiiay doi eua khdi Iupng tiid tich gd Keo la tram, Tuy nhien, su tuong tac giiia XLT ly eham chay bdng MAP va tiidi gian xir ly Id khdng rd (F tinh toan nhd hon F05).
Su bidn ddi ciia khdi lupng tiid tieh gd tiieo thdi gian xir Iy nhidt vd xi; ly ehdm chay dupc tiie hidn trdn hinh 1.
MAP ' No MAP Hmh 1. Str bidn ddi khdi Iupng (hd tich cua gd
Keo Id trdm theo cde chd dp xir ly Hinh 1 eho thay, ddi vdi gd da xu ly eham chay va khdng xir Iy ehdm chdy-thi sau khi xir ly nhidt khdi lupng thd tieh deu thdp hon so vdi go ddi ehiing (go khdng qua xu ly bdng bat ky hinh thiie ndo). Khi keo dai thdi gian xii ly nhidt thi khdi lugng the tieh ciia gd eiing giam tiieo ddi vdi ca gd da qua xii ly va khdng qua xir Iy eham chay bdng MAP. Dieu ndy hodn toan phu hop vdi kdt qua nghien eiiu eua cdc cdng trinh da dupc edng bd.
Nguydn nhdn ldm gidm khdi lupng thd tich gd ed thd dupc giai thieh nhu sau: trong qua trinh xir ly nhidt, dudi tde dung ciia nhidt dp eao, mot ham lupng nhdt dinh hembcenluloza bi phan gidi do nhidt, tgo ra axit axdtic (Esteves, B. va Pereira, H., 2009), sau dd ket hpp vdi hoi nudc do gd thodt ldm eho go tid thdnh mdi trudng axit ydu, tiep tue Idm cho ede phan iing thuy phdn vd nhidt giai eua hembcenluloza va mpt phan xenluloza ti-ong viing vd dinh hinh xay ra mdnh lidt hon. Ket qua Id hdm lupng cdc tiianh phdn nay gidm xudng, dan ddn ldm gidm khdi lupng gd.
Ngodi ra, kdt qua tiii nghidm cdn the hidn, khdi lupng tild tich cua gd khdng xii ly vdi MAP sau khi xir ly nhidt nhd hon so vdi go cd xu ly vdi MAP. Kdt qua ndy cd tiie Id do hdm lupng MAP tiidm vdo trong go dd ldm tdng khdi lupng man, nhung khdng lam tdng kieh tiiudc ciia mdu. Chinh vi tiid ma khdi lupng
^^chu:Nhin tdA:Xul]^ch$m chiy; nhin tSB:
'^^.gianxulynhi$t
^6NGNGHlfP vA PHATTRIEN N C N G T H O N - Kt 2 -THANG 1/2013
89
KHOA H p C CONO NONE
Ul^ tich ciia mau gd cd xil ly MAP liVii hon so vdi miu go khdng XLf ly MAP.
2. Anh hudng cua ch^ dd xd 1^ d^n ti 1^ hiit nudc ( W/S) v i hi«u suit chdng hiit nudc ( WRE)
B4 dinh gii tinh hiit nui'ic ciia g6 Keo li trim sau khi xu ly d cic ch^ do khic nhau so vdi tinh hiit nudc c i a gd diii chiing, thi nghif m da ti^n hinh tiieo ddl diJn bi^n ciia dd am gd sau thiVi gian ngim nuiic d nhidt do thudng hong 8 ngiy. Hinli 2 bi^u hifn ditn bien tiiay ddi do Im ctia mau go xu ly d cic ch^
do khac nhau trnng thdi gian 8 ngiy.
tuong tic giua xii Iy chtai chay bing MAP vi tiidi gian xd ly li khdng rd (F tinh toin nhd hon F«i).
Bing 2. W t q u i phin tich phuong sai 2 nhin td cd l}p ciia hi^u suit chdng hiit nudc ( WKQ cua gd d i
''>'
J
TbiriKliiiBtiiniit^.b
Doi cliiniK - » - 2 l i - M A P - . Jh-M-AP - * - 6 h . M A P
21i-NoM\P Jli-NoM-VP 6I1-N0 NWP
Ngudn
Nlifiii 10 A Nli.'in lo B Tinmg t i c AB Sai so Toiig
T o n g binh p h u o n g
(SS) 115,91 3240,(XI 13,17 151,20 3.520.30
Dd tu do (dn 1 2 2 54 59
T r u n g binh binh
p h u o n g (MS)
115,91 1620,00 6,58 2,80
F U n h toan
41,39 578,56 2,35
F «
4,01 3,16 3,16
Ghi chli: Nhin tdA: Xirly chim chiy; nhin tdB:
Thdi gian xirly nhiit
Su bidn ddi cua hidu sudt chdng hiit nudc (WXQ tiieo thdi gian xii Iy nhidt vd xu Iy chdm chdy dugc tild hidn trdn hinh 3.
Hmh 2. Tl Id hiit nudc eiia gd Keo Id trdm d cdc chd dd xu I]^ sau 8 ngdy ngdm nudc Tir hinh 2 cd thd thay, cdc mau go dd qua xir ly ddu cd ti Id hut nudc thap hon so vdi mau ddi chimg, hon nira eac mau go dd xir Iy vdi MAP sau khi xir ly nhiet ed kha ndng hut nudc eao hon so vdi mdu gd khdng qua xir ly vdi MAP. Nguydn nhdn ehinh dd Id do su ed mdt eua MAP 6 trong gd dd lam cho kha ndng hut nudc eiia go tdng ldn. Kdt qua nghidn cuu da thd hidn dupc hidu qua ciia vide xu Iy nhidt, vi thdng thudng ddi vdi ede logi go dd qua xii ly bdng cdc logi mudi vd co thudng cd khd ndng hiit nudc cao hon.
Nhdm xae dinh dupc hidu qua eiia v i ^ xu ly nhidt den tinh hiit nudc, trong nghidn ciiu dd tidn hanh tinh todn hidu suat chdng hut nudc cua gd (WRE) sau khi xir ly. Ap dung phuong phap phdn tieh phuong sai dd xem xet miic dd anh hudng cua hai nhdn td Id v i ^ xir Iy ehdm chay vd thdi gian xit ly nhi$t Kdt qud phdn tieh phuong sai dupc tiid hi^n trong bang 2.
Kdt qua phdn tich trong bang 2 cho thdy, gid tii F tinh toan cua ea hai nhdn td ddu Idn hon so vdi gia til Fo5, do dd ed thd kdt luan Id xu ly ehdm chdy va thdi gian xu ly nhidt ddu anh hudng rdt rd ddn su thay ddi ciia hi$u sudt chdng hiit nudc (WRE) eiia g6 Keo Id tidm sau khi dd qua xu Iy nhi$t. TUy nhidn, su
Hinh 3. Sv bidn ddi ciia hi^u sudt chdng hiit nudc (WRE^ ciia gA Keo Id ti:dm theo cdc ehd dd xii 1^
Qua bidu dd trong hinh 3 ta thdy. mdu xir Iy vdi thdi gian dai thi kha ndng hut nudc ciia gd giam xudng rd rdt Do kha ndng hut nudc cua gd phu thupc vao cdu tgo va cde thanh phdn trong gd- Nguydn nhdn la khi go dd qua x u ly nhiet dp eao, thdi gian xii ly dai lam ham lupng cdc chat chi^t suat giam xudng; ngoai ra, mpt thanh phdn rat quan trpng cd kha ndng hut nudc mgnh nhat trong go dd la cac nhdm hydroxyl ti^ do (-0H), cdc nhdm ndy thdng thudng nam trong edu tnic cua xenluloza va hemixenluloza, trong qua trinh xii ly nhidt, do qua trinh nhidt giai, phan img thiiy phdn vd su hinh thanh cde Udn kdt ngang dd lam ham lupng cua hembcenluloza va mOt phan xenluloza tiong viing v6 dinh hinh giam xudng, dan ddn sd lupng eac nhdm hydroxyl ty do giam xudng, kdt qud la lam giam khd ndng hut nudc cua gd, tii dd hidu sudt ehdng hiit
90
NONG NGHllP vA PHAT TRI^N N 6 N G T H O N - KV 2 - THANG 172012nuoc cua gd xu ly nhi^t duoc nang Idn. Hdm lupng nhom hydroxyl (-0H) ti-ong go giam xudng do xir Iy nhiet da dirpc nhi^u cdng trinh nghidn ciiu chung minh (Nakano, T. va Miyazaki, J., 2003; Phuong, L X, etal., 2007).
3. Anh hudng ciia chd dd xir \^ ddn hd sd chdng tnroognd(ASQ
Vdi muc dich ddnh gid anh hudng eua xii ly nhi^tden tinh on dinh kich tiiudc eiia gd Keo Id tidm da qua xir ly ehdm chdy bdng MAP, trong thi nghidm da ti^n hanh xae dinh hd so chdng tinjong nd (ASE) m mau gd da qua xir ly d cdc chd dd khde nhau.
can Cli vao kdt qud tinh todn tidn hdnh phdn tich phuong sai hai nhdn td ed Idp ddi vdi hd sd chdng truong nd. Kdt qua phdn tieh dupc thd hidn trong bang 3.
Bing 3. Kdt qud phdn tieh phuong sai 2 nhdn td cd lipdiah^
Ngufin
Nhan to A Nhan to B Tiwngtac AB Sai so Tong
sd c h d n g Tdng
binh phuong
(SS) 1177,96 2537,70 12,55 36,72 3764,945
truong Do
tu do (dO 1 2 2 54 59
nd (AS£) cua gd da Tmng binh binh
phuong (MS) 1177,96 1268,85 6,27 0,68
Ftinh toan 1732,16 1865,81 9,23
xiily
F„
4,01 3,16 3,16
Ghi chli: Nhan td A Xu ly chim chiy; nhin td B:
Thai gian xirly nhiit
Ket qua phan tieh trong bang 3 cho thay, gid tri Ftinh tiian ciia ca hai nhan td ddu ldn hon so vdi gid trj Eos, do dd ed tiid kdt ludn Id xii ly ehdm chdy vd thoi gian xii Iy nhidt ddu anh hudng rat rd den si;
thay d6i cua hd sd chdng truong nd (ASE) ciia gd Keo Id tram sau khi da qua xir Iy nhidt. Ngodi ra, cdn c6 anh hudng tuong tae giiia xu Iy chdm chdy bdng MAP va tiidi gian xii ly nhidt (F tinh todn nhd hon
^tiviASE.
MAP No MAP . ^ . 4. Sitbidn ddi cua h ^ s d chdng truong ndCAS©
[ cia gd Keo Id trdm tiieo cdc chd dd xir 1^
Su bi^n ddi eiia hd so ehdng truong nd (ASQ theo tiidi gian xii ly nhidt vd xii Iy chdm chay dupc thd hidn tidn hinh 4.
Qua bidu dd hinh 4 cd thd thdy, kha ndng truong nd ciia gd giam xudng khi thdi gian xir ly tdng len.
Ndi cdch khde khi keo dai thdi gian xii ly nhidt tiii tinh dn djnh kich thudc ciia gd tdng len rd ret. Ket qua ndy hoan toan phii hpp vdi kdt qua xae dmh ti Id hiit nudc eua mdu gd dupc trinh bay trong phan trdn eung nhu kdt qua nghidn ciiu vd tinh dn dinh kich thudc eiia eae cdng trinh nghidn eiiu ddi vdi cdc loai gd khde dd dupc cdng bd.
Ngodi ra, kdt qua tidn bidu dd cdn thd hidn su khde bidt vd tinh dn dinh kieh thudc giira mau cd xii Iy chdm chdy va mau khdng xii ly chdm chdy. Mau gd khdng qua xii Iy ehgm chdy cd tinh dn dinh kieh thudc eao hon. Nguydn nhan la do ban than chat chdm chdy MAP Id mdt dgng mudi ed khd ndng hut nudc tuong ddi tdt, vi vay mau da qua xir ly cham chdy tlie dd ehua mdt Iupng nhat dinh MAP, chinh vi thd md dd Idm tdng ede thdnh phdn cd kha ndng hut nudc, ddn ddn lam tdng dp am gd. Ket qua Id kieh thudc gd kem dn dinh hon. Tuy nhidn, qua ket qud trdn cd the kdt ludn, dp dung cdng nghe xii ly nhidt dd cao, d miic dp nhat dinh cd the eai thidn dupc tinh on dinh kieh thudc eua gd Keo Id tram dd qua xii ly cham chay bdng MAP.
N.KnLUAN
Vide xu ly chdm chdy vdi MAP vd xir ly nhidt cd dnh hudng rat rd ret ddn su bidn doi cua khdi lupng thd tieh gd, tinh hiit nudc va tinh dn dinh kieh tiiudc eua gd Keo la tram dupc the hien qua ket qua phan tieh phuong sai hai nhdn td cd Idp. Khdi lupng tiie tich va tinh hiit cua gd gidm khi tdng thdi gian xu Iy;
ngupe Igi dd dn dinh kich thudc cua gd tdng khi tdng tiidi gian xu ly nhidt eho go.
Go Keo Id ti-dm khdng xii ly chdm chay vdi MAP va gd dd qua xu Iy chdm chay sau khi xir Iy nhiet cd khd ndng dn dinh kich tiiudc cao hon so vdi mdu gd ddi chiing khoang 6-32%. Tuy nhien, cimg vdi dd khdi lupng thd tieh gd cdng hi giam xudng khoang 2-10%.
Ap dung cdng nghd XLT ly nhidt do cao cd tiid ndng cao dugc tinh dn dinh kich tiiudc cua gd dd qua xii ly chdm chay. Do gd xir Iy ch$m chdy bdng mudi vo eo tiiudng cd tinh dn dinh kich tiiudc kem ndn, vide nghien oiu xay dung chd dd xu Iy nhidt dp cao hpp Iy cd tild khde phuc dupc nhupc diem cua gd da xu ly chdm chdy bdng MAP ndi ridng, mudi vo co ndi chung.
! NONG NGHllP VA PHAT TRIEN NONG THON - Kt 2 - THANG 1/2013
91
KHOiV H 9 C C O N O N G H i
T«U(UnUMHHAO
1. Chuong, P. v., 2011. Influences of the hydro- tiiermal treaUnent on physical properties of Acacia auricuUformis yiooA. 2011 International Symposium on Comprehensive Utilization of Wood Based Resources. Zhejiang A&F University, Lm'an, Zhcjiang. Pp. 105-110.
2. Esteves, B., Pereira, H., 2009. Wood modificaUon by heat treahnent: A review, Binrcsourct's 4:370-404.
3. ISO, 1975. Wood - Sampling mrtiiods and general requirements for physicnl and mechanical tests. International organization tor shindardizaUon Information Handling Services. International standard (1975) ISO 3129-1975.
4 Kosikova, B., Hricovuii, M., CoscnUno, C , 1999. Interaction of lignin and polysaccharides in beech wood ff'agus sylvaUca) during drying processes. Wood Science and Technology 33:373-380.
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Holzforschung 57:289-294.
6. Phuong, L. X., Takayama, M., Shida, S., Matsumoto, Y., Aoyagi, T , 2007. Determination of tiie accessible hydroxyl groups in heat-beated Styrax
tonkinensls (Pierre) Craib ex Hartwich^ wood by hydrogen-deuterium exchange and 'H NMR spccboscopy. Holzforschung 61:488491.
7. Rowell, R. M. Handbook of wood chemisby and wood composites. CRC Press, Boca Raton, Florida, 2005.
8. Terzi, E., Kartal, S. N., White, R , Shinoda, K., Imamura, Y., 2011. Fire performance and decay resishince of sohd wood and plywood b-eated witii quaternary ammonia compounds and common fire retardants. European Journal of Wood and Wood Products 69:41-51.
9. Tuong, V. M., Li, J., 2011. Changes caused by heal treatment in chemical composition and some physical properties of acacia hybrid sapwood.
Holzforschung 65:67-72.
10. Wikberg, H., Uisa Maunu, S., 2004.
Characterisation of thermally modified hard- and softwoods by "C CPMAS NMR. Carbohydr. Polym.
58:461-466.
11. Zhi-jun, Z„ Cheng, C , Qmg-wen, W., 2007.
Study on Hygroscopicity of Watcrbome Fhe Retardants for Wood fTidng Trung). China Forest Products Industry 34:28-30.
EFFECTS OF HEAT TREATMENT ON SOME PHYSICAL PROPERTIES OF FtRE RETARDANT-TREATED Acacia auriculifomu's WOOD
Pham Van Chuong, Vu Manh Tuong Summary
Dimensional stability of fireretardant tre,ited wood was often reduced. In order to overcome the above disadvantages, this study was conducted to apply high-temperalure technology to treat Acacia auriculifonnis wood, that was treated by mono ainnioniuin phosphaste (MAP ). Analyze the effects of heat treatment on physical properties of Acacia aunculi/ormlswood were treated in different conditions, such as: Oven dned density, water absorption, water repellency effecUveness and anu-swellmg efficiency.
Results revealed that, the dimenlional stability of wood was increased: 6-32%, water repellency effectiveness was increased: 12-35% however, the oven dried density was decreased: 2-10%. Results of analysis of variance, two factors was tiie beat UeaUiient time and the fire-retardant treatment by MAP have significant influence on tiie properties of wood. Apphcation of heat treatinent technology can improve the dimentional stability of Acacia aitnculifdrmis treated wood by MAP, and during processing do not need to add any chemicals. This is one of tiie effective solution has overcome the disadvantages of fireretardant beated wood wiUi inorganic salts in general and MAP particular, and to minunize environmental pollution.
Keywords: Acacia auriculifonnis, and swelling efSciency (ASE), tire retardant treatment, beat treatment, water repellent effectiveness (WEE), wood density.
Ngudi phin bifn: TS. Nguyin Thj Bich Ngge Ngiy nh|n bii: 6/11/2012
Ngiy ttidng qua phin bi$n: 03/01/2013 Ngiy duy*t ding: 10/01/2013
92 NdNG NGHllP vA PHAT TRI^N N O N G T H O N - K t 2 - T H A N G 1/201!
