DPD spectrophotometry yog tus qauv qauv rau kev kuaj xyuas cov tshuaj dawb seem thiab tag nrho cov tshuaj chlorine seem nyob hauv Suav teb tus qauv "Water Quality Vocabulary and analytical Methods" GB11898-89, sib koom tsim los ntawm American Public Health Association, American Water Works Association thiab Water Pollution Control Federation. Hauv kev kho "Standard Test Methods for Water and Wastewater", DPD txoj kev tau tsim los txij li xyoo 15th thiab tau pom zoo raws li tus qauv qauv rau kev kuaj tshuaj chlorine dioxide.
Qhov zoo ntawm DPD txoj kev
Nws tuaj yeem cais cov tshuaj chlorine dioxide los ntawm ntau hom tshuaj chlorine (xws li cov tshuaj chlorine dawb, tag nrho cov tshuaj chlorine residual thiab chlorite, thiab lwm yam), ua kom nws yooj yim dua rau kev kuaj xim xim. Txoj kev no tsis yog qhov tseeb raws li amperometric titration, tab sis cov txiaj ntsig tau txaus rau feem ntau cov hom phiaj.
txoj cai
Raws li cov xwm txheej ntawm pH 6.2 ~ 6.5, ClO2 thawj zaug cuam tshuam nrog DPD los tsim cov xim liab, tab sis tus nqi tsuas yog nce mus txog ib feem tsib ntawm nws cov ntsiab lus chlorine tag nrho (sib npaug txo ClO2 rau chlorite ions). Yog hais tias cov qauv dej yog acidified nyob rau hauv lub xub ntiag ntawm iodide, chlorite thiab chlorate kuj react, thiab thaum neutralized los ntawm kev ntxiv ntawm bicarbonate, cov xim tshwm sim sib haum mus rau tag nrho cov muaj chlorine ntsiab lus ntawm ClO2. Kev cuam tshuam ntawm cov tshuaj dawb chlorine tuaj yeem cuam tshuam los ntawm kev ntxiv glycine. Lub hauv paus yog tias glycine tuaj yeem hloov cov tshuaj dawb tam sim ntawd rau hauv chlorinated aminoacetic acid, tab sis tsis muaj kev cuam tshuam rau ClO2.
Potassium iodate standard stock solution, 1.006g/L: Nyhav 1.003g poov tshuaj iodate (KIO3, qhuav ntawm 120 ~ 140 ° C rau 2 teev), yaj nyob rau hauv high-purity dej, thiab hloov mus rau 1000ml ntim.
Dilute lub khob ntsuas rau lub cim thiab sib tov.
Potassium iodate standard tov, 10.06mg / L: Siv 10.0ml ntawm cov tshuaj Tshuag (4.1) nyob rau hauv 1000ml volumetric hwj, ntxiv txog 1g ntawm poov tshuaj iodide (4.5), ntxiv dej rau dilute rau lub cim, thiab sib tov. Npaj rau hnub siv hauv lub raj mis xim av. 1.00ml ntawm cov txheej txheem no muaj 10.06μg KIO3, uas yog sib npaug rau 1.00mg / L muaj chlorine.
Phosphate buffer: Dissolve 24g anhydrous disodium hydrogen phosphate thiab 46g anhydrous potassium dihydrogen phosphate hauv dej distilled, thiab ces sib tov rau hauv 100ml ntawm distilled dej nrog 800mg EDTA disodium ntsev yaj. Dilute nrog dej distilled rau 1L, optionally ntxiv 20mg mercuric chloride los yog 2 tee ntawm toluene los tiv thaiv pwm kev loj hlob. Ntxiv 20 mg ntawm mercuric chloride tuaj yeem tshem tawm qhov cuam tshuam ntawm cov kab mob iodide uas yuav nyob twj ywm thaum ntsuas cov tshuaj dawb. (Ceeb Toom: Mercury chloride yog tshuaj lom, tuav nrog ceev faj thiab tsis txhob noj)
N, N-diethyl-p-phenylenediamine (DPD) Indicator: Dissolve 1.5g DPD sulfate pentahydrate los yog 1.1g anhydrous DPD sulfate nyob rau hauv chlorine-free distilled dej uas muaj 8ml1 + 3 sulfuric acid thiab 200mg EDTA disodium ntsev, dilute rau 1 liter, khw nyob rau hauv ib lub raj mis av xim av, thiab khaws cia rau hauv qhov chaw tsaus. Thaum qhov taw qhia ploj mus, nws yuav tsum tau rov ua dua. Tsis tu ncua xyuas tus nqi absorbance ntawm cov qauv dawb paug,
Yog tias tus nqi nqus ntawm qhov khoob ntawm 515nm tshaj 0.002 / cm, qhov kev hloov kho yuav tsum tau tso tseg.
Potassium iodide (KI siv lead ua)
Sodium arsenite tov: Dissolve 5.0g NaAsO2 hauv dej distilled thiab dilute mus rau 1 liter. Lus Cim: NaAsO2 yog tshuaj lom, tsis txhob noj!
Thioacetamide daws: Dissolve 125 mg ntawm thioacetamide hauv 100 ml ntawm dej distilled.
Glycine tov: Dissolve 20g glycine hauv dej tsis muaj chlorine thiab dilute rau 100ml. Khaws khov. Yuav tsum tau rov tsim kho dua thaum muaj kev kub ntxhov tshwm sim.
Sulfuric acid tov (li 1mol / L): Dissolve 5.4ml concentrated H2SO4 rau hauv 100ml distilled dej.
Sodium hydroxide tov (li 2mol / L): Nyhav 8g NaOH thiab yaj hauv 100ml dej ntshiab.
Calibration (ua haujlwm) nkhaus
Rau ib tug series ntawm 50 colorimetric hlab, ntxiv 0.0, 0.25, 0.50, 1.50, 2.50, 3.75, 5.00, 10.00ml ntawm poov tshuaj iodate standard tov, feem, ntxiv txog 1g ntawm poov tshuaj iodide thiab 0.5ml ntawm sulfuric acid tov, sib tov sulfuric acid. sawv ntsug rau 2 feeb, ces ntxiv 0.5ml sodium hydroxide tov thiab dilute rau lub cim. Cov concentrations hauv txhua lub raj mis yog sib npaug rau 0.00, 0.05, 0.10, 0.30, 0.50, 0.75, 1.00, thiab 2.00 mg / L ntawm cov tshuaj chlorine. Ntxiv 2.5ml ntawm phosphate buffer thiab 2.5ml ntawm DPD qhia daws, sib tov zoo, thiab tam sim ntawd (hauv 2 feeb) ntsuas qhov nqus ntawm 515nm siv 1-nti cuvette. Kos tus qauv nkhaus thiab nrhiav qhov sib npaug regression.
Kev txiav txim cov kauj ruam
Chlorine dioxide: Ntxiv 1ml ntawm glycine tov rau 50ml ntawm cov qauv dej thiab sib tov, ces ntxiv 2.5ml ntawm phosphate buffer thiab 2.5ml ntawm DPD qhia kev daws, sib tov zoo, thiab ntsuas qhov absorbance tam sim ntawd (hauv 2 feeb) (nyeem ntawv yog G).
Cov tshuaj chlorine dioxide thiab cov tshuaj dawb uas muaj chlorine: Siv lwm 50ml dej qauv, ntxiv 2.5ml phosphate buffer thiab 2.5ml DPD qhov taw qhia cov tshuaj, sib tov zoo, thiab ntsuas qhov absorbance tam sim ntawd (hauv 2 feeb) (qhov kev nyeem ntawv yog A).
7.3 Chlorine dioxide, dawb muaj chlorine thiab ua ke muaj cov tshuaj chlorine: Siv lwm 50ml ntawm cov qauv dej, ntxiv txog 1g ntawm poov tshuaj iodide, ntxiv 2.5ml ntawm phosphate tsis thiab 2.5ml ntawm DPD qhia daws teeb meem, sib tov zoo, thiab ntsuas qhov absorbance tam sim ntawd (hauv 2 feeb) (Nyeem yog C).
Tag nrho cov muaj cov tshuaj chlorine suav nrog cov tshuaj dawb chlorine dioxide, chlorite, cov tshuaj dawb residual thiab cov tshuaj chlorine ua ke: Tom qab tau txais cov ntawv nyeem C, ntxiv 0.5ml sulfuric acid tov rau hauv cov qauv dej hauv tib lub raj mis colorimetric, thiab sib tov Tom qab sawv ntsug li 2 feeb, ntxiv. 0.5 ml sodium hydroxide tov, sib tov thiab ntsuas qhov absorbance tam sim ntawd (qhov kev nyeem ntawv yog D).
ClO2 = 1.9G (xws li ClO2)
Dawb muaj chlorine = AG
Ua ke muaj chlorine = CA
Tag nrho cov muaj chlorine = D
Chlorite = D-(C + 4G)
Cov teebmeem ntawm Manganese: Cov khoom cuam tshuam tseem ceeb tshaj plaws hauv cov dej haus yog manganese oxide. Tom qab ntxiv phosphate buffer (4.3), ntxiv 0.5 ~ 1.0ml sodium arsenite tov (4.6), thiab tom qab ntawd ntxiv DPD ntsuas ntsuas qhov nqus. Tshem tawm qhov kev nyeem ntawv no los ntawm kev nyeem A kom tshem tawm
Tshem tawm kev cuam tshuam los ntawm manganese oxide.
Kev cuam tshuam ntawm qhov kub thiab txias: Ntawm txhua txoj kev ntsuas tam sim no uas tuaj yeem paub qhov txawv ntawm ClO2, cov tshuaj dawb dawb thiab cov tshuaj chlorine ua ke, suav nrog amperometric titration, nruam iodometric txoj kev, thiab lwm yam, kub yuav cuam tshuam qhov tseeb ntawm qhov sib txawv. Thaum qhov kub siab dua, cov tshuaj chlorine ua ke (chloramine) yuav raug qhia kom koom nrog cov tshuaj tiv thaiv ua ntej, ua rau muaj txiaj ntsig ntau dua ntawm ClO2, tshwj xeeb tshaj yog cov tshuaj dawb dawb. Thawj txoj kev tswj yog tswj qhov kub thiab txias. Nyob ib ncig ntawm 20 ° C, koj tuaj yeem ntxiv DPD rau cov qauv dej thiab sib tov, thiab tam sim ntawd ntxiv 0.5ml thioacetamide tov (4.7) kom tsis txhob muaj cov tshuaj chlorine (chloramine) los ntawm DPD. Cov tshuaj tiv thaiv.
Kev cuam tshuam ntawm lub sijhawm colorimetric: Ntawm ib sab, cov xim liab uas ua los ntawm ClO2 thiab DPD qhov taw qhia tsis ruaj khov. Qhov xim tsaus nti, qhov ceev nws ploj. Ntawm qhov tod tes, raws li cov tshuaj phosphate buffer thiab DPD qhia tau sib xyaw ua ke, lawv lawv tus kheej kuj yuav ploj mus. Tsim cov xim liab tsis tseeb, thiab kev paub dhau los tau pom tias lub sijhawm no nyob ntawm cov xim tsis ruaj khov yog qhov ua rau txo cov ntaub ntawv precision. Yog li ntawd, kev ua kom nrawm rau txhua kauj ruam ua haujlwm thaum tswj cov txheej txheem ntawm lub sijhawm siv hauv txhua kauj ruam yog qhov tseem ceeb rau kev txhim kho qhov tseeb. Raws li kev paub dhau los: cov xim kev loj hlob ntawm qhov siab tshaj 0.5 mg / L tuaj yeem ruaj khov li ntawm 10 mus rau 20 feeb, cov xim kev loj hlob ntawm qhov concentration ntawm li 2.0 mg / L tsuas tuaj yeem ruaj khov li ntawm 3 mus rau 5 feeb, thiab Kev loj hlob xim ntawm qhov siab tshaj 5.0 mg / L yuav ruaj khov rau tsawg dua 1 feeb.
CovLH-P3CLOTam sim no muab los ntawm Lianhua yog ib qho chaw nqa khoomresidual chlorine meteruas ua raws li DPD photometric method.
Lub ntsuas ntsuas tau teeb tsa lub wavelength thiab nkhaus. Koj tsuas yog yuav tsum tau ntxiv cov tshuaj reagents thiab ua colorimetry kom sai sai tau cov ntsiab lus ntawm cov tshuaj chlorine residual, tag nrho cov chlorine residual thiab chlorine dioxide nyob rau hauv dej. Nws kuj txhawb cov roj teeb lub zog thiab cov khoom siv hluav taws xob sab hauv tsev, ua kom yooj yim siv txawm tias sab nraum zoov lossis hauv chav kuaj.
Post lub sij hawm: May-24-2024
