Koj puas to taub tiag tiag cov khoom no, koj puas paub nws lub hom phiaj? Cov khoom zoo li no tuaj yeem coj mus rau qhov twg? Cov hauv qab no yuav coj koj mus tshawb.
Raws li ntau hom oxidants, nws muab faib ua CODCr thiab CODMn.
(1.) Cov txheej txheem poov tshuaj permanganate raug xa mus rau CODMn, vim tias oxidation tus nqi kuj tsawg, tsuas yog li 45 feem pua, yog li nws feem ntau yog siv los ua cov ntsiab lus ntawm COD hauv hom dej saum npoo av, uas tau qhia los ntawm cov poov tshuaj permanganate index.
(2.) CODCr yog hais txog txoj kev potassium dichromate, uas yuav tsum tau zom ntawm qhov kub ntawm 165 degrees rau 20 feeb ua ntej ntsuas. oxidation tus nqi yog siab dua 95 feem pua. Kev kuaj pom tseeb yog qhov siab. Yog li ntawd, lub teb chaws tus qauv yuav tsum tau txiav txim siab ntawm COD nyob rau hauv cov dej phwj tuaj, thiab cov poov tshuaj dichromate txoj kev yuav tsum tau siv.
Feem ntau siv COD detectors nyob rau hauv txoj kev poov tshuaj dichromate yog reflux titration thiab sai digestion photometry. Lub hauv paus ntsiab lus ntawm reflux titration txoj kev ntawm COD ntes: nyob rau hauv ib tug acidic nruab nrab ntawm sulfuric acid, poov tshuaj dichromate yog siv raws li ib tug oxidant, nyiaj sulfate yog siv raws li ib tug catalyst, thiab mercury sulfate yog siv los ua ib tug masking agent rau chloride ions. yog lub digestion kub. Siv dej txias thiab reflux kom sov cov tshuaj tiv thaiv rau 2H. Tom qab cov kev zom zaub mov yog txias lawm, ntxiv dej kom dilute nws. Siv ferrous ammonium ua qhov taw qhia kom titrate cov poov tshuaj dichromate ntxiv nrog ferrous ammonium sulfate tov. Raws li kev noj cov tshuaj ferrous ammonium sulfate suav cov nqi COD ntawm cov qauv dej. Cov oxidant yog poov tshuaj dichromate, thiab cov cuab yeej oxidizing yog hexavalent chromium, yog li nws yog hu ua txoj kev dichromate.
Lub hauv paus ntsiab lus ntawm kev zom sai sai photometric txoj kev ntawm COD ntes:
1.) Ntxiv ntau cov poov tshuaj dichromate rau cov qauv, siv cov poov tshuaj dichromate li oxidant, sulfuric acid li cov tshuaj tiv thaiv nruab nrab, nyiaj sulfate li catalyst, mercury sulfate li shielding agent, ntawm 165degreeThaum tshav kub kub thiab zom rau 20min nyob rau hauv qhov xwm txheej, ntsuas cov ntsiab lus ntawm hexavalent chromium los yog trivalent chromium los ntawm spectrophotometric, thiab txiav txim siab tus nqi COD. Qhov zoo ntawm kev zom sai sai photometry:
Lub sij hawm: los ntawm 120 feeb mus rau 20 feeb.
Kev Ua Haujlwm: Cov txheej txheem tedious ua haujlwm tsuas yog siv ob peb kauj ruam tam sim no.
Reagents: Cov txheej txheem reflux ib txwm yuav tsum tau haus ntau ntawm cov poov tshuaj dichromate, nyiaj sulfate tov, dej kuaj, thiab ntau cov kais dej rau reflux.
Tam sim no txoj kev zom sai sai tsuas yog xav tau ib qho me me ntawm cov tshuaj reagents thiab cov qauv dej, thiab tsis tas yuav tsum muaj cov dej ntau npaum li qhov reflux.
