Formalin, aqueous tov ntawm formaldehyde, yog xim tsis muaj xim, pob tshab thiab corrosive nyob rau hauv tsos. Vim hais tias cov formaldehyde muaj nyob rau hauv volatile heev, nws yuav muab tawm ib tug muaj zog pungent tsw tam sim ntawd tom qab qhib lub raj mis. Formaldehyde yog qhov sib xyaw ntawm carbon, hydrogen thiab oxygen. Raws li ib txwm muaj, nws yog lub xeev roj thiab muaj cov yam ntxwv ntawm kev ua kom lub qhov muag zoo nkauj thiab cov kab mob ua pa. Cov ntsiab lus formaldehyde ntawm formalin yog 35% mus rau 40% (feem ntau 37 formaldehyde). 10% ~ 15% methanol kuj tseem ntxiv los tiv thaiv polymerization.
Kev siv cov formaldehyde kev lag luam tshwj xeeb yog dav, yog li kev lag luam ntawm formaldehyde kuj loj heev.Cov ntawv thov suav nrog chemistry, kev ua liaj ua teb, nuv ntses, tshuaj thiab lwm yam.
Nyob rau hauv chemistry, formaldehyde kua yog ib tug heev irritating tshuaj lom gas nrog flammability thiab corrosivity. Nws tuaj yeem ntes cov kab hauv huab cua dav dav thiab soluble hauv dej heev. Nws yog feem ntau tau los ntawm tshuaj oxidation ntawm methanol. Formic acid tov tuaj yeem tau txais los ntawm methanol oxidation thiab formic acid tuaj yeem tau los ntawm formaldehyde oxidation.
Hauv kev ua liaj ua teb, formalin thiab formaldehyde cov khoom lag luam nrog cov ntsiab lus ntawm 40% yog siv los tswj melon anthracnose, eggplant xim av streak, Verticillium wilt, anthracnose, dib blight, Fusarium wilt, scab thiab vine blight. (2) Tswj cov kab mob angular ntawm dib (3) kab mob wilt ntawm txiv lws suav (4) Fusarium Wilt ntawm taum dav (5) liab dos ntsuab thiab dos anthracnose (6) ntxov blight, lig blight, scab, kab mob wilt, qia rot, powdery scab ntawm qos yaj ywm, anthracnose ntawm lub raum taum thiab peas thiab paus rot ntawm cabbage.
Kev siv hauv cov pas dej ntses muaj xws li (1) lub pas dej tshem tawm: cov khoom tseem ceeb ntawm ermalin yog formaldehyde, uas yog cov khoom tsis haum, yog li nws tsis muaj tshuaj lom rau hauv qab ntawm lub pas dej. Xav txog kev txuag nqi, tus nqi ntawm cov kua formalin qis dua li cov sulfur dioxide, yog li yuav cov formalin yog xaiv. (2) Immersion: formalin yog cov tshuaj tua kab mob zoo tshaj plaws rau mariculture, uas tuaj yeem tiv thaiv lub cev ulceration thiab ntau yam kab mob parasitic. Lub sijhawm noj tshuaj thiab tshuaj tua kab mob yog: formalin concentration 100 × 10-6～300 × 10-6, lub sijhawm tshuaj tua kab mob 5 ~ 30 feeb. (3) Sprinkling: feem ntau yog siv los kho cov teeb meem ntawm melon kab kab mob ntawm cov ntses thiab fungal thiab kab mob ntawm vaub kib. Nws yog ib qho tsim nyog kom nkag siab qhov concentration thiab lub sijhawm ntawm kev siv thiab ntsuas kev hloov dej txhua lub sijhawm. (4) fumigation: thaum lub sij hawm fumigation thiab tshuaj tua kab mob, chav tsev kub yuav tsum tsis txhob qis dua 15 ℃ thiab cov txheeb ze av noo yuav tsum yog 60-80%, nyob rau lub sij hawm no, poov tshuaj permanganate tuaj yeem muab ntxiv rau hauv lub thawv ua ntej, thiab tom qab ntawd cov tshuaj formalin tuaj yeem muab ntxiv. ntxiv rau cua sov thiab fumigation. Lub hom phiaj ntawm kev tua kab mob tuaj yeem ua tiav los ntawm kev sib khi lub qhov rooj thiab qhov rais rau ntau tshaj 7 teev, thiab tom qab ntawd qhib lub qhov rooj thiab qhov rais rau qhov cua kom tshem tawm cov ntxhiab tsw seem.
Sau ntawv
(l) Formalin tsuas yog siv tau los ua cov av thiab cov noob tshuaj tua kab mob, thiab tsis tuaj yeem siv tshuaj tsuag.
(2) Yog tias nag lossis daus tshwm sim, nws yuav tsum tau siv tom qab cua sov thiab yaj. Ib tug npaum li cas ntawm alkali tov yuav muab ntxiv rau precipitate ntau, thiab tag nrho stirred, muab tso rau 2 hnub, thiab siv tom qab nag lossis daus ploj. Thaum siv formalin tom qab alkali ntxiv, cov dilution ntau yuav tsum raug txo kom tsim nyog.