51. Dab tsi yog cov cim qhia ntau yam uas qhia txog cov tshuaj lom thiab cov organic teeb meem hauv dej?
Tsuas yog qee qhov me me ntawm cov tshuaj lom thiab tsis zoo hauv cov dej phwj tuaj (xws li cov phenols tsis zoo, thiab lwm yam), lawv feem ntau nyuaj rau biodegrade thiab ua rau muaj kev phom sij rau tib neeg lub cev, xws li roj av, anionic surfactants (LAS), organic Chlorine thiab organophosphorus tshuaj tua kab, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), high-molecular hluavtaws polymers (xws li yas, hluavtaws roj hmab, hluavtaws fibers, thiab lwm yam), fuels thiab lwm yam organic tshuaj.
Lub teb chaws tus qauv tso tawm tag nrho GB 8978-1996 muaj cov kev cai nruj heev ntawm cov dej phwj tuaj uas muaj cov tshuaj lom neeg saum toj no thiab cov teeb meem organic tawm los ntawm ntau qhov kev lag luam. Cov ntsuas dej tshwj xeeb suav nrog benzo(a) pyrene, roj av, tsis muaj zog phenols, thiab organophosphorus tshuaj tua kab (xws li P), tetrachloromethane, tetrachloroethylene, benzene, toluene, m-cresol thiab 36 lwm yam khoom. Cov kev lag luam sib txawv muaj cov ntsuas dej khib nyiab sib txawv uas yuav tsum tau tswj hwm. Txawm hais tias cov ntsuas dej zoo ua tau raws li cov qauv kev tso tawm hauv lub tebchaws yuav tsum tau saib xyuas raws li qhov tshwj xeeb ntawm cov dej khib nyiab tawm los ntawm txhua qhov kev lag luam.
52.Puas muaj pes tsawg hom phenolic tebchaw nyob rau hauv dej?
Phenol yog hydroxyl derivative ntawm benzene, nrog nws pawg hydroxyl txuas ncaj qha rau lub nplhaib benzene. Raws li tus naj npawb ntawm pawg hydroxyl muaj nyob rau ntawm lub nplhaib benzene, nws tuaj yeem muab faib ua cov phenols (xws li phenol) thiab polyphenols. Raws li seb nws puas tuaj yeem volatilize nrog dej vapor, nws muab faib ua cov phenol tsis hloov pauv thiab tsis hloov pauv phenol. Yog li, phenols tsis tsuas yog xa mus rau phenol, tab sis kuj suav nrog lub npe dav dav ntawm phenolates hloov los ntawm hydroxyl, halogen, nitro, carboxyl, thiab lwm yam hauv ortho, meta thiab para txoj haujlwm.
Phenolic compounds xa mus rau benzene thiab nws cov fused-ring hydroxyl derivatives. Muaj ntau hom. Nws feem ntau suav hais tias cov neeg uas muaj qhov kub siab tshaj 230oC yog cov phenols tsis hloov pauv, thaum cov uas muaj qhov kub siab tshaj 230oC yog cov phenols uas tsis yog-volatile. Volatile phenols hauv cov qauv dej zoo xa mus rau phenolic tebchaw uas tuaj yeem hloov pauv nrog dej vapor thaum lub sijhawm distillation.
53.Dab tsi yog cov kev siv feem ntau rau kev ntsuas cov phenol tsis haum?
Txij li thaum tsis muaj zog phenols yog ib hom kev sib xyaw es tsis yog ib qho kev sib xyaw, txawm tias phenol yog siv raws li tus qauv, cov txiaj ntsig yuav txawv yog tias siv cov kev tshuaj ntsuam sib txawv. Txhawm rau ua kom cov txiaj ntsig sib piv, yuav tsum siv txoj kev sib koom ua ke uas tau teev tseg los ntawm lub tebchaws. Cov kev ntsuas feem ntau siv rau cov phenol volatile yog 4-aminoantipyrine spectrophotometry teev nyob rau hauv GB 7490–87 thiab lub peev xwm bromination teev hauv GB 7491–87. Txoj cai.
4-Aminoantipyrine spectrophotometric txoj kev muaj tsawg cuam tshuam yam cuam tshuam thiab ntau dua rhiab heev, thiab tsim nyog rau kev ntsuas cov dej huv huv nrog cov ntsiab lus phenol volatile<5mg>Txoj kev bromination volumetric yog qhov yooj yim thiab yooj yim rau kev khiav lag luam, thiab tsim nyog rau kev txiav txim siab tus nqi ntawm cov phenols volatile hauv cov dej khib nyiab> 10 mg / L lossis cov dej ntws tawm los ntawm cov chaw kho dej khib nyiab. Lub hauv paus ntsiab lus yog tias nyob rau hauv ib qho kev daws nrog ntau tshaj bromine, phenol thiab bromine tsim tribromophenol, thiab ntxiv tsim bromotribromophenol. Cov bromine ntxiv tom qab ntawd ua rau cov poov tshuaj iodide tso tawm iodine dawb, thaum bromotribromophenol reacts nrog potassium iodide los tsim tribromophenol thiab dawb iodine. Cov iodine dawb yog ces titrated nrog sodium thiosulfate tov, thiab cov volatile phenol cov ntsiab lus nyob rau hauv cov nqe lus ntawm phenol yuav xam raws li nws noj.
54. Dab tsi yog kev ceev faj rau kev ntsuas cov phenol tsis haum?
Txij li thaum yaj cov pa oxygen thiab lwm yam oxidants thiab cov kab mob tuaj yeem oxidize lossis decompose phenolic tebchaw, ua rau cov phenolic tebchaw nyob rau hauv dej tsis ruaj tsis khov, txoj kev ntxiv acid (H3PO4) thiab txo qhov kub yog feem ntau siv los inhibit qhov kev txiav txim ntawm cov kab mob, thiab ib tug txaus. tus nqi ntawm sulfuric acid ntxiv. Txoj kev ferrous tshem tawm cov teebmeem ntawm oxidants. Txawm hais tias cov kev ntsuas saum toj no raug coj los ntsuas, cov qauv dej yuav tsum tau soj ntsuam thiab kuaj hauv 24 teev, thiab cov qauv dej yuav tsum tau muab cia rau hauv lub khob iav es tsis yog cov thawv yas.
Txawm hais tias txoj kev bromination volumetric los yog 4-aminoantipyrine spectrophotometric txoj kev, thaum cov qauv dej muaj oxidizing los yog txo cov tshuaj, hlau ions, aromatic amines, roj thiab tars, thiab lwm yam, nws yuav muaj kev cuam tshuam rau qhov tseeb ntawm qhov ntsuas. kev cuam tshuam, kev ntsuas tsim nyog yuav tsum tau ua kom tshem tawm nws cov teebmeem. Piv txwv li, oxidants tuaj yeem raug tshem tawm los ntawm kev ntxiv ferrous sulfate los yog sodium arsenite, sulfides tuaj yeem raug tshem tawm los ntawm kev ntxiv tooj liab sulfate nyob rau hauv acidic tej yam kev mob, roj thiab tar yuav raug tshem tawm los ntawm extraction thiab sib cais nrog organic solvents nyob rau hauv muaj zog alkaline tej yam kev mob. Txo cov tshuaj xws li sulfate thiab formaldehyde raug tshem tawm los ntawm kev rho tawm nrog cov kuab tshuaj organic nyob rau hauv acidic tej yam kev mob thiab tawm hauv cov tshuaj txo nyob rau hauv dej. Thaum txheeb xyuas cov dej phwj tuaj nrog cov khoom siv ruaj khov, tom qab sib sau ua ke ntawm qee lub sijhawm ntawm kev paub, hom kev cuam tshuam cov khoom tuaj yeem raug qhia meej, thiab tom qab ntawd cov khoom cuam tshuam tuaj yeem raug tshem tawm los ntawm kev nce lossis txo qis, thiab cov kauj ruam tshuaj ntsuam tuaj yeem yooj yim npaum li ntau. raws li qhov ua tau.
Kev ua haujlwm distillation yog ib kauj ruam tseem ceeb hauv kev txiav txim siab ntawm phenol volatile. Yuav kom evaporate tag nrho cov volatile phenol, tus nqi pH ntawm tus qauv yuav tsum tau distilled yuav tsum tau hloov mus rau li ntawm 4 (qhov discoloration ntau ntawm methyl txiv kab ntxwv). Tsis tas li ntawd, txij li cov txheej txheem volatilization ntawm volatile phenol kuj qeeb, lub ntim ntawm cov distillate sau yuav tsum sib npaug rau qhov ntim ntawm cov qauv qub uas yuav tsum tau distilled, txwv tsis pub cov txiaj ntsig ntsuas yuav raug cuam tshuam. Yog hais tias cov distillate pom tias dawb thiab turbid, nws yuav tsum tau evaporated dua nyob rau hauv acidic tej yam kev mob. Yog hais tias cov distillate tseem yog xim dawb thiab turbid rau zaum ob, nws yuav yog tias muaj roj thiab tar hauv cov qauv dej, thiab kev kho mob yuav tsum tau ua.
Tag nrho cov nqi ntsuas siv txoj kev bromination volumetric yog tus nqi txheeb ze, thiab cov kev ua haujlwm tau teev tseg los ntawm lub teb chaws cov qauv yuav tsum nruj me ntsis raws li cov kua ntxiv, cov tshuaj tiv thaiv kub thiab lub sij hawm, thiab lwm yam. Tsis tas li ntawd, tribromophenol precipitates yooj yim encapsulate I2, yog li nws yuav tsum tau shaken ceev thaum mus txog qhov taw tes titration.
55. Yuav ua li cas ceev faj txog kev siv 4-aminoantipyrine spectrophotometric los txiav txim siab cov phenols tsis haum?
Thaum siv 4-aminoantipyrine (4-AAP) spectrophotometry, tag nrho cov kev khiav hauj lwm yuav tsum tau ua nyob rau hauv lub fume hood, thiab cov neeg kho tshuab nqus ntawm lub fume hood yuav tsum tau siv los tshem tawm cov kev tsis zoo ntawm cov tshuaj lom benzene rau tus neeg teb xov tooj. .
Qhov nce ntawm cov reagent dawb paug tus nqi yog feem ntau yog vim muaj tej yam xws li paug nyob rau hauv distilled dej, iav thiab lwm yam khoom siv kuaj, raws li zoo raws li lub volatilization ntawm extraction hnyav vim nce chav tsev kub, thiab feem ntau yog vim 4-AAP reagent. , uas yog nquag nqus dej, caking thiab oxidation. , yog li cov kev ntsuas tsim nyog yuav tsum tau ua los xyuas kom meej qhov purity ntawm 4-AAP. Kev loj hlob xim ntawm cov tshuaj tiv thaiv yog yooj yim cuam tshuam los ntawm tus nqi pH, thiab pH tus nqi ntawm cov tshuaj tiv thaiv yuav tsum nruj me ntsis tswj ntawm 9.8 thiab 10.2.
Cov txheej txheem diluted phenol tsis ruaj khov. Cov txheej txheem tshuaj uas muaj 1 mg phenol ib ml yuav tsum muab tso rau hauv lub tub yees thiab siv tsis tau ntau tshaj 30 hnub. Cov txheej txheem tshuaj uas muaj 10 μg phenol ib ml yuav tsum tau siv rau hnub ntawm kev npaj. Cov txheej txheem tshuaj uas muaj 1 μg phenol ib ml yuav tsum tau siv tom qab kev npaj. Siv li ntawm 2 teev.
Nco ntsoov ntxiv cov reagents nyob rau hauv kev txiav txim raws li cov txheej txheem kev khiav hauj lwm, thiab co zoo tom qab ntxiv txhua reagent. Yog tias qhov tsis tau shaken tusyees tom qab ntxiv nws, cov ammonia concentration hauv cov kev sim tshuaj yuav tsis sib npaug, uas yuav cuam tshuam rau cov tshuaj tiv thaiv. Impure ammonia tuaj yeem ua rau tus nqi dawb paug ntau dua 10 npaug. Yog tias tsis siv ammonia ntev ntev tom qab qhib lub raj mis, nws yuav tsum tau distilled ua ntej siv.
Lub generated aminoantipyrine liab dye tsuas yog ruaj khov rau li 30 feeb nyob rau hauv aqueous tov, thiab yuav ruaj khov rau 4 teev tom qab extraction rau hauv chloroform. Yog tias lub sijhawm ntev dhau lawm, xim yuav hloov ntawm liab mus rau daj. Yog tias cov xim dawb paug tsaus dhau vim qhov tsis huv ntawm 4-aminoantipyrine, qhov ntsuas 490nm wavelength tuaj yeem siv los txhim kho qhov ntsuas qhov tseeb. 4-Thaum cov aminoantibi tsis huv, nws tuaj yeem yaj hauv methanol, thiab tom qab ntawd lim thiab recrystallized nrog cov pa roj carbon activated los ua kom zoo dua.
Post lub sij hawm: Nov-23-2023
