Khoom theem extractionyog ib tug qauv pretreatment technology tsim nyob rau hauv xyoo tas los. Nws yog tsim los ntawm kev sib xyaw ua ke ntawm cov kua-khoom extraction thiab kem kua chromatography. Nws yog tsuas yog siv rau cov qauv sib cais, purification thiab concentration. Piv nrog rau cov tshuaj ua kua-kua extraction Txhim kho tus nqi rov qab ntawm cov tshuaj ntsuam xyuas, cais cov tshuaj ntsuam xyuas los ntawm cov khoom cuam tshuam zoo dua, txo cov qauv ua ntej ua ntej, thiab kev ua haujlwm yooj yim, txuag lub sijhawm thiab txuag zog. Nws yog dav siv hauv tshuaj, khoom noj khoom haus, ib puag ncig, tshuaj xyuas khoom, tshuaj lom neeg kev lag luam thiab lwm yam kev lag luam.

Extraction yog ib chav ua haujlwm uas siv qhov sib txawv solubility ntawm cov khoom hauv lub cev kom cais cov sib tov. Muaj ob txoj hauv kev los rho tawm:

Cov kua-kua extraction, ib qho hnyav uas tau xaiv yog siv los cais ib yam khoom hauv cov kua sib tov. Cov kuab tshuaj yuav tsum yog immiscible nrog cov kua sib tov sib xyaw, muaj kev xaiv solubility, thiab yuav tsum muaj cov thermal thiab tshuaj lom neeg ruaj khov, thiab tsis tshua muaj toxicity thiab corrosiveness. Xws li kev sib cais ntawm phenol nrog benzene; Kev sib cais ntawm olefins hauv cov roj av feem nrog cov kuab tshuaj organic.

Khoom theem extraction, tseem hu ua leaching, siv cov kuab tshuaj los cais cov khoom hauv cov khoom sib tov, xws li leaching cov suab thaj hauv qab zib beets nrog dej; leaching soybean roj los ntawm soybeans nrog cawv kom nce roj tawm los; leaching cov khoom xyaw nquag los ntawm cov tshuaj suav tshuaj suav nrog dej Kev npaj cov kua extract hu ua "leaching" lossis "leaching".

Txawm hais tias kev rho tawm feem ntau siv rau hauv kev sim tshuaj, nws cov txheej txheem kev ua haujlwm tsis ua rau muaj kev hloov pauv hauv cov tshuaj muaj pes tsawg leeg ntawm cov tshuaj rho tawm (lossis tshuaj lom neeg cov tshuaj tiv thaiv), yog li kev ua haujlwm extraction yog txheej txheem lub cev.
Extractive distillation yog distillation nyob rau hauv lub xub ntiag ntawm ib qho yooj yim soluble, siab boiling point, thiab tsis-volatile tivthaiv, thiab cov kuab tshuaj no nws tus kheej tsis tsim ib tug tas li boiling point nrog rau lwm yam khoom nyob rau hauv lub sib tov. Extractive distillation feem ntau yog siv los cais qee lub tshuab nrog tsawg heev lossis txawm tias sib npaug ntawm cov txheeb ze volatility. Txij li thaum lub volatility ntawm ob lub Cheebtsam nyob rau hauv cov sib tov yog ze li ntawm sib npaug, cov khoom theem extractor ua rau lawv evaporate ntawm ze li ntawm qhov kub thiab txias, thiab cov degree ntawm evaporation zoo sib xws, ua rau kev sib cais nyuaj. Yog li ntawd, cov tshuab tsis tshua muaj hluav taws xob feem ntau yog qhov nyuaj rau kev sib cais los ntawm cov txheej txheem distillation yooj yim.

Extractive distillation siv feem ntau uas tsis yog-volatile, siab kub taw tes, thiab yooj yim soluble hnyav kom sib tov nrog cov sib tov, tab sis tsis tsim ib tug tas mus li boiling point nrog lub Cheebtsam nyob rau hauv qhov sib tov. Cov kuab tshuaj no cuam tshuam nrog cov khoom hauv qhov sib tov sib txawv, ua rau lawv cov txheeb ze hloov pauv hloov. Yog li ntawd lawv tuaj yeem sib cais thaum lub sijhawm distillation. Cov khoom tawg yooj yim heev tau sib cais thiab tsim cov khoom siv nyiaj siv ua haujlwm. Cov khoom hauv qab yog sib xyaw ntawm cov kuab tshuaj thiab lwm yam khoom. Txij li cov kuab tshuaj tsis tsim ib qho azeotrope nrog rau lwm yam, lawv tuaj yeem raug cais los ntawm txoj kev tsim nyog.

Ib qho tseem ceeb ntawm txoj kev distillation no yog kev xaiv cov kuab tshuaj. Cov kuab tshuaj ua lub luag haujlwm tseem ceeb hauv kev sib cais ntawm ob lub ntsiab lus. Nws yog ib qho tsim nyog sau cia tias thaum xaiv cov kuab tshuaj, cov kuab tshuaj yuav tsum muaj peev xwm hloov pauv qhov txheeb ze ntawm qhov tsis sib xws, txwv tsis pub nws yuav yog qhov ua tsis tau zoo. Nyob rau tib lub sijhawm, xyuam xim rau kev lag luam ntawm cov kuab tshuaj (cov nyiaj uas yuav tsum tau siv, nws tus nqi thiab nws muaj). Nws kuj yog ib qho yooj yim rau cais nyob rau hauv lub pej thuam kettle. Thiab nws tsis tuaj yeem ua rau muaj kev cuam tshuam nrog txhua qhov sib xyaw lossis sib xyaw; nws tsis tuaj yeem ua rau corrosion hauv cov khoom siv. Ib qho piv txwv yog kev siv aniline lossis lwm yam khoom siv uas tsim nyog los ua cov kuab tshuaj kom tshem tawm cov azeotrope tsim los ntawm distilling benzene thiab cyclohexane.

Khoom theem extraction yog ib tug dav siv thiab nce nrov qauv pretreatment technology. Nws yog ua raws li cov kua-kua rho tawm ib txwm muaj thiab sib txuas cov txheej txheem zoo sib xws ntawm kev sib cuam tshuam nrog cov khoom siv dav siv HPLC thiab GC. Cov kev paub ntawm cov theem nyob ruaj ruaj hauv phau ntawv maj mam tsim. SPE muaj cov yam ntxwv ntawm me me ntawm cov kuab tshuaj organic, yooj yim, kev nyab xeeb, thiab kev ua haujlwm siab. SPE tuaj yeem muab faib ua plaub hom raws li nws qhov kev sib cais zoo sib xws: thim rov qab theem SPE, theem ib txwm SPE, ion pauv SPE, thiab adsorption SPE.

SPE feem ntau yog siv los ua cov qauv ua kua, tshem tawm, ua kom pom tseeb thiab ua kom huv si ib nrab thiab tsis hloov pauv hauv lawv. Nws kuj tuaj yeem siv rau cov qauv khoom, tab sis yuav tsum tau ua tiav ua kua ua ntej. Tam sim no, cov ntawv thov tseem ceeb hauv Suav teb yog kev tshuaj xyuas cov khoom siv organic xws li polycyclic aromatic hydrocarbons thiab PCBs hauv dej, kev tshuaj xyuas tshuaj tua kab thiab tshuaj tua kab hauv cov txiv hmab txiv ntoo, zaub thiab zaub mov, kev tshuaj xyuas tshuaj tua kab mob, thiab tshuaj xyuas cov tshuaj kho mob.

Cov cuab yeej SPE yog tsim los ntawm SPE kab me me thiab cov khoom siv ntxiv. SPE kem me me yog tsim los ntawm peb ntu, kem raj, sintered ncoo thiab ntim. SPE accessories feem ntau muaj xws li lub tshuab nqus tsev, lub tshuab nqus tsev twj, lub tshuab ziab khaub ncaws, ib qho roj av inert, lub peev xwm loj thiab lub raj mis tsis.

Ib qho piv txwv suav nrog cov khoom sib cais thiab kev cuam tshuam dhau los ntawm adsorbent; lub adsorbent xaiv khaws cov khoom sib cais thiab qee qhov cuam tshuam, thiab lwm yam cuam tshuam dhau los ntawm adsorbent; yaug cov adsorbent nrog cov kuab tshuaj uas tsim nyog los ua kom cov kev cuam tshuam yav dhau los tau xaiv Tom qab leaching tawm, cov khoom sib cais tseem nyob ntawm lub txaj adsorbent; purified thiab concentrated cais cov khoom yog ntxuav los ntawm adsorbent.

Kev rho tawm cov theem khoom yog ib qho kev tshem tawm lub cev uas muaj cov theem ua kua thiab cov khoom. Hauvkhoom theem extraction, lub zog adsorption ntawm cov khoom theem extractor tiv thaiv kev sib cais yog ntau dua li cov kuab tshuaj uas dissolves qhov sib cais. Thaum cov qauv kev daws teeb meem dhau los ntawm lub txaj adsorbent, cov khoom sib cais yog concentrated rau ntawm nws qhov chaw, thiab lwm yam khoom piv txwv dhau los ntawm lub txaj adsorbent; los ntawm cov adsorbent uas tsuas yog adsorbs cov khoom sib cais thiab tsis adsorb lwm cov qauv piv txwv, cov khoom muaj siab purity thiab concentrated cais tau.