Kev Txheeb Xyuas Txog Kev Txo Chrome Hauv Cov Dej Pov Tseg Electroplating Hauv Kev Lag Luam
Hexavalent chromium (Cr(VI)) yog ib qho tshuaj lom neeg tseem ceeb hauv cov txheej txheem electroplating hauv kev lag luam. Nws feem ntau yog nkag los ntawm kev da dej chromic acid thiab cov kauj ruam ua kom tiav qhov chaw chromate. Cov dej khib nyiab uas tshwm sim yuav muaj Cr(VI) ntau ntawm kaum mus rau pua pua milligrams ib liter, uas yog qhov siab dua li cov kev txwv tso tawm thoob ntiaj teb.
Cr(VI) yaj tau zoo heev, nyob tau hauv dej, thiab raug cais ua Pawg 1 carcinogen. Kev pheej hmoo rau kev noj qab haus huv ntawm tib neeg suav nrog kev ua rau tawv nqaij khaus, mob qog, teeb meem ua pa, kev hloov pauv caj ces, thiab kev pheej hmoo ntawm mob qog noj ntshav. Hauv kev cuam tshuam ntawm ecology, Cr(VI) cuam tshuam kev ua haujlwm ntawm enzyme hauv cov nroj tsuag thiab lom rau cov tsiaj txhu hauv dej ntawm qhov concentration qis li 0.05 mg/L. Nws txoj kev txav mus los ua rau nws tsiv mus rau hauv av thiab dej hauv av, ua rau muaj kev ua qias tuaj tas mus li thiab dav dav.
Vim Cr(VI) muaj tshuaj lom thiab kev cai nruj heev, cov txheej txheem txo chrome yog ib kauj ruam tseem ceeb hauv kev kho dej khib nyiab electroplating. Cov txheej txheem no suav nrog kev hloov pauv tshuaj lom Cr(VI) mus rau trivalent chromium (Cr(III)), uas tsis muaj kev phom sij ntau thiab tuaj yeem ua kom sai thiab tshem tawm tau zoo. Cov kua sodium bisulfite yog ib qho tshuaj txo qis uas siv ntau zaus, qhov twg nws cov concentration nquag raug saib xyuas kom zoo tshaj plaws. Kev ntsuas qhov tseeb yog ua tiav los ntawm kev ntsuas cov kua sodium bisulfite ceev; kev ntsuas qhov ceev inline, siv cov thev naus laus zis xws li oscillating density meters, ua kom muaj kev tswj hwm cov txheej txheem raug thiab txo cov tshuaj pov tseg.
Kev ua raws li ib puag ncig rau cov chaw electroplating xav kom txo qis hexavalent chromium kom qis dua qhov kev cai lij choj ua ntej tso dej khib nyiab tawm. Cov cai los ntawm US EPA thiab EU feem ntau txwv tsis pub muaj Cr (VI) concentration tsawg dua 0.05 mg / L hauv cov dej khib nyiab. Kev ua raws li cov qauv no xav tau kev saib xyuas chromium ion tiag tiag, kev ntsuas qhov ceev tsis siv neeg, thiab cov txheej txheem kho mob zoo. Kev ntsuas qhov ceev tsis tu ncua rau cov voj voog electroplating yog qhov tseem ceeb, vim tias qhov concentration ntawm bisulfite tsis raug lossis kev txo qis tsis tiav ua rau Cr (VI) theem siab dua qhov kev ua raws li qhov yuav tsum tau ua, ua rau muaj kev lav phib xaub rau ib puag ncig thiab tej zaum yuav raug nplua los ntawm cov cai.
Cov kev coj ua ntawm kev tswj cov khib nyiab electroplating suav nrog cov khoom siv saib xyuas los ntawm cov chaw tsim khoom xws li Lonnmeter, uas tshwj xeeb hauv cov ntsuas qhov ceev hauv kab. Cov khoom siv no muab cov ntaub ntawv tiag tiag, tsis siv neeg rau kev saib xyuas sodium bisulfite concentration thiab pab txhawb kev tswj hwm cov txheej txheem txo chrome. Kev suav nrog hauv kabviscositythiabqhov ceevkev saib xyuas txo qhov kev pheej hmoo, txhim kho kev nyab xeeb hauv kev ua haujlwm, thiab ua tiav kev ua raws li kev tso dej khib nyiab. Qhov no yog lub hauv paus rau kev tswj hwm kev ua qias tuaj ntawm hexavalent chromium niaj hnub no thiab kev kho dej khib nyiab rau chromium hauv cov chaw ua haujlwm.
Kev Kho Mob Dej Khib Nyhiab Chrome Plating
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Kev Hloov Tshuaj: Hexavalent mus rau Trivalent Chromium
Txoj Kev Siv thiab Chemistry
Kev hloov hexavalent chromium (Cr(VI)) mus rau trivalent chromium (Cr(III)) yog ib kauj ruam tseem ceeb hauv cov txheej txheem txo chrome rau cov txheej txheem electroplating hauv kev lag luam thiab kev kho cov dej khib nyiab electroplating. Cov kua sodium bisulfite thiab cov kua sodium bisulfite yog cov neeg sawv cev txo qis uas siv los tshem tawm hexavalent chromium, uas muaj tshuaj lom heev, yaj tau, thiab txav tau, ntawm cov dej khib nyiab. Kev txo qis tshwm sim feem ntau nyob rau hauv cov xwm txheej acidic, nrog kev ua tau zoo tshaj plaws ntawm pH qis (<4).
Sodium bisulfite nyiam dua li sulfur dioxide vim nws yooj yim dua rau kev tuav, tsis xav tau cov tshuab siab, thiab nws tsim nyog dua rau kev tswj hwm cov koob tshuaj zoo. Sulfur dioxide ua haujlwm tau zoo ua tus neeg sawv cev txo qis; txawm li cas los xij, nws muaj teeb meem kev tswj hwm vim nws lub xeev roj thiab lom. Hauv kev tshawb fawb hauv chaw kuaj mob thiab kev lag luam, sodium bisulfite ua tiav kev tshem tawm Cr (VI) tas mus li thiab ua tau zoo, muab pH thiab kev tswj hwm koob tshuaj kom meej, thaum sulfur dioxide yuav muab cov nqi txo qis zoo sib xws tab sis nrog rau kev ua haujlwm thiab kev nyab xeeb ntxiv.
Qhov ua tau zoo ntawm kev txo qis nyob ntawm pH ntau heev. pH nyob rau hauv qhov ntau ntawm 2-3 yog qhov zoo tshaj plaws los ua kom qhov nrawm thiab tiav ntawm Cr (VI) hloov pauv thiab txo qis kev siv bisulfite ntau dhau thiab kev tsim cov sulfate theem nrab. Thaum pH nce siab dua 4, qhov nrawm ntawm cov tshuaj tiv thaiv thiab kev ua haujlwm poob qis, ua rau kev txo qis tsis tiav thiab cov nqi tshuaj ntau dua. Yog li ntawd, kev ntsuas qhov ceev hauv kab thiab cov cuab yeej ntsuas qhov ceev oscillating, xws li tsim los ntawm Lonnmeter, tau siv ntau dua rau kev saib xyuas qhov ceev ntawm cov tshuaj sodium bisulfite, kom ntseeg tau tias qhov concentration reagent raug ntxiv kom ua tau raws li cov hom phiaj tshem tawm hexavalent chromium thaum ua kom zoo dua tus nqi thiab txo cov khib nyiab.
Kev saib xyuas qhov concentration ntawm Sodium bisulfite kuj tso cai rau kev hloov kho qhov nrawm ntawm kev pub thiab txo qis kev siv ntau dhau, uas yog qhov tseem ceeb rau kev tswj hwm kev ua raws li kev tso dej khib nyiab thiab txo qhov hnyav ntawm cov dej khib nyiab uas muaj sulfate ntau.
Nag thiab Tshem Tawm
Thaum hexavalent chromium raug txo qis rau trivalent chromium, cov kauj ruam tom ntej yog precipitation. Cr (III) tsim cov insoluble chromium hydroxide thaum pH ntawm cov tshuaj nce, feem ntau yog los ntawm kev ntxiv cov alkali xws li sodium hydroxide.
Kev ua kom cov dej nag zoo yuav tsum tau tswj hwm pH kom zoo. Qhov pH zoo tshaj plaws rau kev ua kom cov dej nag chromium hydroxide nag feem ntau yog nyob rau hauv 7.5 txog 9.0. Yog tias pH qis dhau, cov hydroxide yuav tsis tsim lossis yuav yaj dua; yog tias pH siab dhau, kev yaj amphoteric yuav tshwm sim, ua rau muaj chromium ntau ntxiv hauv cov kua. Kev sib xyaw ntawm trivalent chromium kuj cuam tshuam rau kev tsim cov khoom me me thiab kev sib xyaw; cov Cr (III) siab dua txhawb kev loj hlob ntawm cov khoom me me, txhim kho cov khoom sludge thiab yooj yim ntawm kev sib cais.
Rau kev tswj cov sludge zoo tshaj plaws hauv kev tswj cov khib nyiab electroplating, kev sib cais cov chromium hydroxide precipitate kom zoo yog qhov tseem ceeb heev. Cov txheej txheem xws li gravity sedimentation, clarification, thiab filtration yog siv. Cov kev coj ua zoo tshaj plaws suav nrog kev tswj cov pH sib xws, kev ua kom zoo dua ntawm flocculant ntxiv, thiab siv kev ntsuas qhov ceev tsis siv neeg los saib xyuas cov sludge sib xws, uas khi rov qab rau kev ua raws li thiab kev ruaj khov ntawm cov txheej txheem hauv kev kho cov dej khib nyiab rau chromium.
Kev ntsuas qhov ntom ntom hauv kab rau electroplating, siv cov cuab yeej zoo licov oscillating density meters(lub hauv paus ntsiab lus ntawm lub ntsuas qhov ceev), muab cov neeg teb xov tooj nrog cov lus teb tiag tiag ntawm cov khoom khov thiab pab kho cov txheej txheem kom ntseeg tau tias tshem tawm cov sludge zoo yam tsis muaj dej ntau dhau lossis cov chromium ions tsis txo qis. Kev sib cais thiab kev tswj hwm cov av noo kom zoo txo qhov kev ua qias tuaj thib ob thiab pab ua kom muaj kev ua raws li ib puag ncig nruj rau cov chaw electroplating.
Hauv kev xaus lus, kev sib xyaw ua ke ntawm kev siv sodium bisulfite kom raug hauv electroplating, kev tswj hwm pH nruj, thiab kev saib xyuas cov txheej txheem tiag tiag - pab los ntawm cov cuab yeej siab heev xws li cov los ntawm Lonnmeter - tsim cov txha nqaj qaum ntawm cov txheej txheem txo chromium niaj hnub hauv electroplating thiab ua kom muaj kev ruaj ntseg thiab ua raws li kev kho dej khib nyiab.
Kev Tswj Xyuas Txheej Txheem thiab Kev Siv Cov Khoom Siv
Cov Kev Ntsuas Tseem Ceeb ntawm Kev Saib Xyuas
Kev saib xyuas tas mus li ntawm kev txo cov hexavalent chromium yog qhov tseem ceeb rau kev ua raws li cov txheej txheem electroplating hauv kev lag luam thiab kev tiv thaiv ib puag ncig. Cov yam ntxwv tseem ceeb ntawm kev ua haujlwm suav nrog pH, oxidation-reduction potential (ORP), thiab chromium ion concentration. Kev tswj pH kom nyob rau hauv qhov zoo tshaj plaws ntawm 2.0–3.0 ua rau qhov ua tau zoo ntawm kev txo cov hexavalent chromium ntau tshaj plaws thiab tso cai rau kev tswj hwm meej ntawm kev hloov mus rau trivalent chromium, txo qis kev pheej hmoo ntawm kev ua qias tuaj thiab ua kom muaj kev ua raws li cov cai hauv kev ua raws li kev tso dej khib nyiab.
Kev saib xyuas ORP muab cov lus teb sai sai rau lub xeev redox, ua haujlwm ua lub cim qhia thaum ntxov rau kev tshem tawm cov chromium hexavalent tsis tiav. Cov electrodes kub, nyiam rau lawv cov tshuaj lom neeg tsis muaj zog thiab ruaj khov, muab kev ua tau zoo dua hauv cov dej khib nyiab uas xav tau. Tsis zoo li lwm yam hlau, kub tiv taus kev ua qias tuaj thiab tswj cov cim ORP raug, tshwj xeeb tshaj yog qhov twg cov chloride ntau, cov hlau hnyav, lossis cov organic contaminations yuav ua rau lwm cov khoom siv electrode puas tsuaj. Piv txwv li, thaum lub sijhawm txo cov txheej txheem chrome siab, cov electrodes kub tswj kev ntsuas dhau kev ua haujlwm ntev thiab xa cov txiaj ntsig rov ua dua txawm tias nyob rau hauv cov tshuaj lom neeg hloov pauv.
Kev soj ntsuam Chromium ion, ua nrog cov cuab yeej ntsuas lub sijhawm tiag tiag, ntsuas qhov kev nce qib ntawm kev txo qis thiab ua kom tiav kev hloov pauv. Cov kauj ruam no yog qhov tseem ceeb vim tias cov chromium hexavalent uas nyob ntev ua rau muaj kev pheej hmoo loj rau kev noj qab haus huv thiab kev ua raws li txoj cai hauv kev kho thiab tswj cov dej khib nyiab electroplating.
Cov Cuab Yeej Ntsuas Inline thiab Automated
Kev saib xyuas qhov concentration ntawm sodium bisulfite kom raug yog qhov tseem ceeb rau kev tswj cov txheej txheem txo qis, vim tias sodium bisulfite feem ntau siv ua tus neeg sawv cev txo qis rau kev tshem tawm hexavalent chromium. Kev ntsuas sodium bisulfite ua kua yuav tsum sib phim nrog cov khoom qias neeg, ua rau kev ntsuas qhov ceev ntawm inline tseem ceeb rau kev kho cov dej khib nyiab hauv kev lag luam.
Lub ntsuas qhov ceev oscillating muab kev ntsuas tsis siv neeg, inline los ntawm kev txiav txim siab qhov ceev ntawm cov kua los ntawm lub hauv paus ntsiab lus ntawm qhov ntsuas qhov ceev oscillation. Raws li sodium bisulfite cov kua concentration sib raug zoo ncaj qha nrog qhov ceev, cov cuab yeej no muab kev ntsuas tas mus li, tsis cuam tshuam. Piv txwv li, Lonnmeter's oscillating density meters ua haujlwm tau zoo.kev hloov pauv ntawm qhov ceev ntawm txoj kev, pab txhawb kev hloov kho sai ntawm cov tshuaj kom zoo dua rau kev siv sodium bisulfite hauv cov xwm txheej electroplating.
Cov ntsuas qhov ceev niaj hnub no, suav nrog cov los ntawm Lonnmeter, tso tawm cov teeb liab 4–20 mA uas tau teeb tsa, ua kom muaj kev sib koom ua ke nrog cov txheej txheem tswj hwm tsis siv neeg. Thaum ua ke nrog cov khoom siv pH thiab ORP hauv kab, lawv tsim cov txheej txheem teb rov qab kaw. Lub kaw lus no kho cov tshuaj thiab cov txheej txheem ua haujlwm hauv lub sijhawm tiag tiag, tiv thaiv kev siv ntau dhau, kev noj tshuaj tsawg dhau, lossis kev ua txhaum cai hauv cov txheej txheem txo chrome. Cov ntaub ntawv los ntawm cov cuab yeej no kuj tseem siv rau kev sau ntawv tas mus li thiab kev tshaj tawm rau cov tub ceev xwm tswj hwm.
Cov txheej txheem kev ntsuas thiab kev saib xyuas yog qhov tseem ceeb rau kev ntsuas kom ntseeg tau. Cov cuab yeej ntsuas qhov ceev hauv kab yuav tsum tau ua qhov ntsuas xoom thiab qhov ntsuas dav dav siv cov qauv paub ntawm cov kua sodium bisulfite lossis dej demineralized. Cov ntsuas ORP yuav tsum tau lees paub nrog cov redox buffers uas tau ntawv pov thawj, thiab cov khoom siv pH tau ntsuas nrog cov kua pH NIST-traceable ua ntej txhua qhov kev hloov pauv ua haujlwm, tshwj xeeb tshaj yog hauv kev kho dej khib nyiab rau chromium.
Rau kev ua raws li ib puag ncig zoo rau electroplating thiab hexavalent chromium kev tswj hwm kev ua qias tuaj, cov khoom siv ntsuas no txhawb nqa:
- Kev ntsuas qhov ceev tsis siv neeg kom ntseeg tau tias kev siv tshuaj sib xws
- Kev saib xyuas qhov ceev ntawm lub sijhawm tiag tiag rau kev kho cov txheej txheem kom ruaj khov
- Cov lus teb ncaj qha rau PLC lossis SCADA systems siv 4-20 mA tso zis
Cov txheej txheem pom zoo kom kuaj xyuas txhua hnub, ntxuav lub sensor txhua hli, thiab txheeb xyuas tsis tu ncua nrog cov txheej txheem titration hauv chav kuaj kom tswj tau qhov tseeb thiab txo qhov kev hloov pauv. Txoj hauv kev nruj no yog tsim los tswj kev ruaj khov ntawm cov txheej txheem, tiv thaiv kev ua raws li txoj cai, thiab ua kom zoo dua cov txheej txheem txo chromium hauv cov chaw dej khib nyiab electroplating.
Kev Ua Kom Muaj Kev Tshem Tawm Hexavalent Chromium Zoo Thiab Ua Raws Li Ib Puag Ncig
Cov kev pab cuam kho dej khib nyiab electroplating yog tsim los ntawm kev ua raws li cov qauv kev tso tawm rau hexavalent chromium (Cr (VI)). Cov txheej txheem ua haujlwm feem ntau pib nrog kev sib cais ntawm cov kwj deg uas muaj chromium thiab ua raws li ntau theem kev txo qis thiab kev saib xyuas.
Ib qho kev kho mob ib txwm pib los ntawm kev kho qhov pH ntawm cov dej khib nyiab, tom qab ntawd ntxiv cov tshuaj txo qis xws li cov kua sodium bisulfite. Cov kauj ruam txo qis hloov cov tshuaj lom hexavalent chromium mus rau trivalent chromium (Cr(III)), uas tsis muaj tshuaj lom thiab tuaj yeem ua rau muaj hydroxide. Kev saib xyuas qhov concentration ntawm sodium bisulfite yog qhov tseem ceeb kom ntseeg tau tias muaj kev txo qis txaus thiab kom tsis txhob siv ntau dhau, uas ua rau muaj nqi reagent tsis tsim nyog thiab kev ua qias tuaj ntxiv.
Kev tswj cov txheej txheem siab heev vam khom kev ntsuas qhov ceev hauv kab, uas muab los ntawm cov thev naus laus zis xws li cov ntsuas qhov ceev oscillating los ntawm Lonnmeter. Lub ntsuas qhov ceev oscillation ntsuas qhov concentration ntawm cov kua sodium bisulfite hauv lub sijhawm tiag tiag, kom ntseeg tau tias muaj kev ntsuas kom raug thaum lub sijhawm txo chrome. Kev ntsuas qhov ceev inline rau electroplating ua rau muaj kev taug qab tsis siv neeg, txuas ntxiv mus ntawm cov zog reagent, txo qis kev cuam tshuam ntawm tus neeg teb xov tooj thiab qhov yuam kev.
Tom qab txo qis, tom qab ntawd ua kom meej thiab lim dej tshem tawm cov chromium trivalent uas tau tso tawm. Txhawm rau kom paub tseeb tias cov dej khib nyiab ua tau raws li cov qauv tswj hwm rau chromium ion concentration, cov txheej txheem tso dej khib nyiab raws li kev cai yuav tsum tau saib xyuas kev soj ntsuam kom meej. Atomic absorption spectrophotometry (AAS) yog ib txoj kev ntsuas kub rau kev ntes cov qib me me ntawm ob qho tib si Cr (VI) thiab tag nrho chromium; nws qhov tshwj xeeb txhawb nqa kev tshaj tawm kev cai lij choj txhim khu kev qha. Kev tshuaj xyuas xim, raws li diphenylcarbazide reaction, muab cov cuab yeej tshuaj ntsuam sai rau cov seem hexavalent chromium, ua rau muaj kev soj ntsuam ntau zaus, ntawm qhov chaw nrog kev nkag siab siab.
Kev ua kom muaj kev ua raws li ib puag ncig rau kev ua haujlwm electroplating nyob ntawm lub peev xwm los saib xyuas thiab tswj cov hom chromium thoob plaws hauv kev kho dej khib nyiab rau chromium workflow. Kev ntsuas qhov ceev tsis siv neeg muab cov lus teb tam sim ntawd rau kev siv sodium bisulfite hauv electroplating, txhawb kev tswj hwm cov nqi dosing. Cov txiaj ntsig saib xyuas los ntawm AAS thiab kev ntsuas xim yog sib piv nrog cov kev cai tswjfwm - feem ntau ≤0.1 mg / L rau Cr (VI) - los lees paub qhov ua tau zoo ntawm kev tswj hwm kev ua qias tuaj thiab sau cov ntaub ntawv ua raws li cov tub ceev xwm.
Yog tias cov txheej txheem kho pom cov hexavalent chromium seem ntau dhau, cov tswv yim hloov kho xws li kev ntxiv cov tshuaj reagent ntxiv, pH rov ua kom zoo dua, lossis lub sijhawm khaws cia ntev dua yuav raug ua. Qhov kev hloov kho dynamic no, ua ke nrog kev soj ntsuam qhov ceev ntawm inline los ntawm Lonnmeter meters, ua kom muaj kev tshem tawm hexavalent chromium zoo. Los ntawm kev koom ua ke cov ntsiab lus no, cov txheej txheem txo chrome sib haum nrog cov qauv tso tawm uas hloov pauv thiab txo qis kev pheej hmoo ntawm ib puag ncig thiab kev noj qab haus huv hauv chaw ua haujlwm uas cuam tshuam nrog kev raug hexavalent chromium.
Cov Tswv Yim Txhim Kho Rau Kev Ua Haujlwm Hauv Kev Lag Luam
Kev saib xyuas qhov concentration ntawm sodium bisulfite kom meej yog qhov tseem ceeb rau kev txo cov tshuaj siv thiab tus nqi hauv cov txheej txheem txo chrome thaum lub sijhawm kho cov dej khib nyiab electroplating. Cov kua sodium bisulfite ua haujlwm ua cov tshuaj reagent tseem ceeb los ntawm kev hloov cov tshuaj lom hexavalent chromium (Cr(VI)) ions mus rau hauv cov trivalent chromium (Cr(III) uas muaj kev nyab xeeb dua), yog li ua rau ua raws li cov cai tswjfwm kev tso tawm ib puag ncig.
Kev ntsuas qhov ceev hauv kab—siv cov cuab yeej xws li cov ntsuas qhov ceev oscillating—ua lub luag haujlwm tseem ceeb hauv kev saib xyuas thiab tswj cov sodium bisulfite theem. Lub ntsuas qhov ceev hauv kab Lonnmeter txuas ntxiv mus saib xyuas qhov ceev ntawm cov tshuaj, muab cov lus teb tam sim ntawd uas cov neeg ua haujlwm tuaj yeem siv los txiav txim siab qhov concentration ntawm cov kua sodium bisulfite hauv cov txheej txheem. Cov ntaub ntawv ncaj qha no ua rau muaj kev hloov kho qhov kev ntsuas sai sai, txo cov khib nyiab reagent thiab txo cov nqi tshuaj. Kev ntsuas qhov zoo tshaj plaws tsis yog tsuas yog tiv thaiv kev siv sodium bisulfite ntau dhau xwb tab sis kuj txo qhov kev pheej hmoo ntawm kev txo cov chromium ion tsis tiav, uas yuav ua rau muaj kev ua txhaum cai lossis qhov xav tau kev them rov qab kim heev.
Piv txwv li: Hauv ib lub tshuab kho cov dej khib nyiab uas siv electroplating, kev siv density meter oscillation los saib xyuas bisulfite tiag tiag ua rau cov reagent txo tau txog li 15% thaum tswj cov hexavalent chromium qib qis dua cov kev cai lij choj. Kev saib xyuas density tiag tiag pab txhawb kev ua haujlwm ruaj khov los ntawm kev kuaj pom cov txheej txheem hloov pauv tsis tau xav txog thaum ntxov, xws li kev hloov pauv sai sai ntawm cov dej khib nyiab lossis cov sludge. Qhov kev teb no txo lub sijhawm tsis ua haujlwm kim thiab txo cov kev pheej hmoo ntawm kev ua raws li ib puag ncig.
Kev tswj cov sludge oxidation thiab cov dej khib nyiab zoo kuj cuam tshuam ncaj qha rau kev ua haujlwm thiab tus nqi. Hexavalent chromium tshem tawm ntawm cov txheej txheem electroplating kev lag luam effluent tsim sludge, uas yog tias over-oxidized, tuaj yeem cuam tshuam tom qab trivalent chromium sedimentation thiab kev lim dej. Kev saib xyuas zoo - siv kev ntsuas inline density rau electroplating daim ntawv thov thiab kev tshuaj xyuas tsom - ua kom ntseeg tau tias cov sludge lub cev zoo tshaj plaws rau kev tuav thiab pov tseg. Kev tswj hwm kom zoo ntawm cov xeev oxidation thiab cov dej khib nyiab muaj pes tsawg leeg tuaj yeem pab txo cov dej tom qab ua tiav, txo cov nqi pov tseg, thiab txo qhov kev pheej hmoo ntawm kev ua raws li cov dej khib nyiab tshaj qhov txwv.
Kev soj ntsuam Chromium ion, ua ke nrog kev ntsuas qhov ceev hauv kab, muab cov kev nkag siab ua tau rau kev txhim kho kev ua haujlwm. Piv txwv li, kev kos duab qhov ceev nrog rau cov nqi txo chromium ua rau cov pab pawg tuaj yeem sib piv cov kev hloov pauv dosing nrog cov txiaj ntsig tiag tiag. Ib qho kinetic tshem tawm nkhaus qhia tau hais tias kev tswj hwm sodium bisulfite concentration ntawm qhov zoo tshaj plaws ua rau Cr (VI) hloov pauv sai dua 35%, piv rau kev ua tiav batch yam tsis muaj kev tawm tswv yim tas mus li:
------------------------------
| Lub Sijhawm (min) | Kev Tshem Tawm Cr(VI) (%) | Qhov Ceev (g/cm³) |
|------------|-------------------|-----------------|
| 0 | 0 | 1.02 |
| 15 | 60 | 1.06 |
| 30 | 90 | 1.10 |
| 45 | 98 | 1.13 |
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Cov ntaub ntawv txheej txheem thiab kev tshuaj xyuas ntxiv txhim kho cov txheej txheem txo chrome hauv electroplating los ntawm kev ua kom muaj peev xwm kwv yees tau dosing thiab kho qhov sib txawv thaum ntxov. Kev saib xyuas tas mus li ntawm cov khoom siv tshuaj - xws li qhov ceev ntawm cov oscillating density meters - txhawb nqa kev kuaj pom sai ntawm cov tshuaj tsis sib npaug. Cov txheej txheem tshuaj xyuas siab heev siv cov kev ntsuas tiag tiag no los coj cov sodium bisulfite siv hauv electroplating, txo qis ob qho tib si reagent nqi thiab cov khoom tsim tawm, uas ua kom yooj yim electroplating pov tseg kev tswj hwm thiab txhim kho tag nrho cov txheej txheem ua haujlwm zoo.
Kev ntsuas qhov ceev ntawm inline rau electroplating tsis yog tsuas yog txhawb nqa kev tswj hwm kev ua qias tuaj ntawm hexavalent chromium xwb, tab sis kuj txhawb nqa kev ua raws li ib puag ncig rau kev ua haujlwm electroplating. Nrog rau thev naus laus zis Lonnmeter koom ua ke ntawm cov ntsiab lus tseem ceeb hauv cov txheej txheem, cov chaw tuaj yeem tswj hwm cov chromium concentration, ua tau raws li cov qauv kev cai, thiab tswj hwm kev ua haujlwm hauv kev lag luam ruaj khov yam tsis muaj kev siv tshuaj lom neeg ntau dhau lossis kev pheej hmoo ib puag ncig.
Kev daws teeb meem thiab kev txij nkawm
Cov Teeb Meem Ib Txwm Muaj: Kev Lom Zem Los Ntawm Sensor, Kev Siv Tshuaj Reagent Tsis Zoo, Kev Siv Cov Khoom Siv Tsis Tau Zoo
Hauv kev kho cov dej khib nyiab uas siv cov txheej txheem txo cov chrome, kev saib xyuas lub sijhawm tiag tiag ntawm sodium bisulfite concentration thiab chromium ion txo qis yog nyob ntawm cov sensors uas raug rau cov chaw ib puag ncig uas muaj kev kub ntxhov heev. Kev lom sensor, feem ntau yog los ntawm kev tso cov hexavalent chromium, trivalent chromium, thiab lwm yam khoom tsis huv, cuam tshuam kev ntsuas qhov ceev ntawm inline thiab kev saib xyuas cov kua sodium bisulfite. Cov khoom tso rau ntawm cov probes thiab electrodes, ua rau txo qis kev rhiab heev, nyeem tsis meej, lossis poob tag nrho kev ua haujlwm. Cov hlau hnyav ions thiab cov khoom seem tuaj yeem thaiv cov nto ntawm sensor, thaum cov kua qaub lossis oxidative tej zaum yuav ua rau cov khoom sensor lwj, ua rau cov cuab yeej siv tsis ruaj khov thiab cov teeb liab tsis ruaj khov.
Kev siv tshuaj reagent tsis raug, tshwj xeeb tshaj yog nrog cov kua sodium bisulfite, ua rau kev tswj hwm cov txheej txheem nyuaj dua. Kev siv tshuaj tsis txaus tuaj yeem ua rau kev txo qis ntawm hexavalent chromium tsis tiav, ua rau tsis ua raws li cov cai ntawm kev tso dej khib nyiab. Kev siv tshuaj ntau dhau ua rau cov nqi tshuaj lom neeg nce ntxiv thiab yuav ua rau muaj cov pa phem tsis tsim nyog. Kev hloov pauv ntawm cov cuab yeej siv - kev hloov pauv hauv kev teb thawj zaug vim yog hnub nyoog ntawm lub sensor, kev ua qias tuaj, lossis kev puas tsuaj ntawm cov khoom - ua rau kev saib xyuas sodium bisulfite concentration tsis txhim khu kev qha thiab yuav tsum tau rov kho dua ntau zaus kom tsis txhob muaj qhov yuam kev hauv kev siv tshuaj lossis cov txheej txheem tawm tswv yim. Cov teeb meem no ua rau kev ntsuas kev hloov pauv chromium ruaj khov, tas mus li tseem ceeb rau kev ua raws li ib puag ncig hauv cov txheej txheem electroplating hauv kev lag luam.
Cov Lus Qhia Txog Kev Txij Nkawm Rau Cov Probes, Electrodes, Thiab Cov Density Meters
Kev saib xyuas tsis tu ncua yog qhov tseem ceeb heev rau kev txo cov teebmeem ntawm kev lom ntawm lub sensor thiab kev hloov pauv ntawm cov cuab yeej. Cov probes thiab electrodes yuav tsum tau kuaj xyuas tsis tu ncua rau qhov pom kev qias neeg, kev hloov pauv xim, lossis kev puas tsuaj rau lub cev. Cov txheej txheem ntxuav nyob ntawm hom sensor thiab cov txheej txheem. Kev ntxuav tshuab (piv txwv li, txhuam mos lossis cov ntaub so) tuaj yeem tshem tawm cov khoom me me thiab cov zaj duab xis saum npoo. Kev ntxuav ultrasonic tsis siv neeg uas koom ua ke rau hauv lub rooj sib dhos probe pab tshem tawm cov deposits hauv lub sijhawm tiag tiag yam tsis tas yuav tsum tau ua haujlwm tsis ua haujlwm.
Cov kev ntxuav tshuaj lom neeg—siv cov kua qaub dilute, cov hauv paus, lossis cov kuab tshuaj tshwj xeeb—tshem tawm cov nplai uas nyob ntev, cov txheej hlau oxide, thiab cov organic fouling. Tom qab ntxuav, cov sensors yuav tsum tau ntxuav kom huv si nrog dej deionized kom tiv thaiv kev ua qias tuaj ntxiv. Cov probes thiab electrodes ua los ntawm PTFE, platinum, lossis lwm yam khoom siv tiv taus xeb feem ntau qhia tau tias muaj kev tiv taus fouling zoo dua thiab xav tau kev ntxuav tsawg dua.
Cov ntsuas qhov ceev oscillating, xws li cov uas Lonnmeter tsim, yuav tsum tau calibrated siv cov kua dej uas tau ntawv pov thawj ntawm lub sijhawm teev tseg los ntawm kev ruaj khov ntawm cov txheej txheem thiab cov lus pom zoo ntawm cov chaw tsim khoom. Kev txheeb xyuas tsis tu ncua ua kom ntseeg tau tias qhov drift lossis fouling tsis cuam tshuam rau qhov tseeb ntawm kev ntsuas qhov ceev inline, uas yog qhov tseem ceeb rau kev tswj hwm sodium bisulfite concentration thaum lub sijhawm tshem tawm hexavalent chromium. Txhua lub cim ntawm suab nrov lossis tsis ruaj khov hauv lub teeb liab oscillation ntawm lub ntsuas qhov ceev tuaj yeem qhia txog fouling lossis kev puas tsuaj ntawm cov khoom siv thiab yuav tsum tau ua kom sai sai tshuaj xyuas thiab ntxuav.
Hloov cov gaskets, cov seals, thiab cov khoom ntub dej ntawm lub sijhawm pom zoo kom tiv thaiv kev xau thiab xyuas kom lub sensor siv tau ntev hauv cov dej khib nyiab uas siv tshuaj lom neeg ntau. Khaws cov ntaub ntawv qhia txog kev pabcuam uas sau txog kev ua txij nkawm, kev kho dua tshiab, qhov tsis ua haujlwm uas tsis tau xav txog, thiab lub sijhawm teb los pab txheeb xyuas cov teeb meem uas rov tshwm sim thiab ua kom zoo dua kev txij nkawm yav tom ntej.
Kev Teeb Tsa Ceeb Toom thiab Kev Teeb Tsa Kom Muaj Kev Nyab Xeeb
Cov tshuab ceeb toom thiab cov tshuab tiv thaiv kev puas tsuaj yog lub hauv paus rau kev ua raws li txoj cai thiab tiv thaiv kev ua tsis tiav ntawm cov txheej txheem hauv kev kho dej khib nyiab electroplating. Cov yam ntxwv tseem ceeb - suav nrog sodium bisulfite concentration, inline density, reduction potential, thiab processed flow rates - yuav tsum muaj cov thresholds ceeb toom programmed rau hauv cov nroj tsuag cov txheej txheem tswj. Cov tshuab ceeb toom tseem ceeb yuav tsum qhib yog tias kev ntsuas inline density qhia txog kev hloov pauv ntawm cov ntsiab lus teeb tsa rau sodium bisulfite kua lossis yog tias cov hom phiaj txo chromium ion tsis tau mus txog.
Cov kev sib txuas lus ceeb toom los ntawm cov sensors tseem ceeb, xws li Lonnmeter inline density meters, yuav tsum txuas ncaj qha rau cov txheej txheem interlocks uas dais cov twj dosing lossis hloov cov dej khib nyiab tsis ua raws li txoj cai mus rau cov thoob dej tuav. Kev xav tsis ua haujlwm yuav tsum xyuas kom meej tias, yog tias lub sensor tsis ua haujlwm (xws li lub teeb liab xoom tas li lossis nyeem tawm ntawm qhov ntau), lub kaw lus rov qab mus rau hom kev ua haujlwm nyab xeeb tshaj plaws - piv txwv li, nres kev txo cov chromium dosing lossis cais cov kab kho mob cuam tshuam.
Kev qeeb ntawm lub tswb ceeb toom thiab cov kab tuag txo cov kev ceeb toom tsis zoo uas tshwm sim los ntawm kev hloov pauv me me ntawm cov txheej txheem, tab sis cov chaw teeb tsa ceeb toom yuav tsum qhia txog cov kev txwv ntawm kev tso tawm rau chromium thiab lwm yam khoom txaus ntshai. Hauv kev teeb tsa uas tau lees paub, kev rov ua dua - siv cov sensors sib luag lossis cov ntsuas qhov ceev thaub qab - tuaj yeem tiv thaiv cov ntaub ntawv poob los ntawm kev lom sensor lossis kev ua tsis tiav ntawm cov cuab yeej. Kev sim ua haujlwm tsis tu ncua ntawm cov tswb ceeb toom thiab cov interlocks, uas tau lees paub raws li qhov kev ua haujlwm tiag tiag, yog qhov yuav tsum tau ua kom lav lub sijhawm teb ntawm tus neeg teb xov tooj thiab tiv thaiv kev ua txhaum cai hauv kev tso tawm cov dej khib nyiab hauv kev lag luam.
Kev saib xyuas tsis tu ncua, kev teeb tsa lub tswb ceeb toom raws sijhawm, thiab kev teb rov qab zoo yog lub hauv paus ntawm kev saib xyuas qhov concentration ntawm sodium bisulfite, kev tswj hwm kev ua qias tuaj ntawm hexavalent chromium, thiab kev tswj hwm cov khib nyiab electroplating uas ruaj khov.
Kev txo cov chrome zoo hauv cov txheej txheem electroplating hauv kev lag luam yog nyob ntawm txoj kev tswj hwm tshuaj lom neeg, kev saib xyuas, thiab kev ua raws li ib puag ncig. Lub hauv paus ntawm kev tshem tawm cov chromium hexavalent txhim khu kev qha yog tswj cov xwm txheej acid zoo - feem ntau ntawm pH 3 - rau kev siv sodium bisulfite zoo tshaj plaws, xyuas kom meej tias hloov pauv tag nrho ntawm cov hexavalent chromium (Cr (VI)) txaus ntshai mus rau trivalent chromium (Cr (III)) muaj kev nyab xeeb dua raws li cov koom haum tswj hwm pom zoo thiab txhawb nqa los ntawm kev coj ua hauv kev lag luam. Kev khaws cov tshuaj sodium bisulfite dosed ntawm 3-5 zaug ntawm cov ntsiab lus molar Cr (VI) pab lav qhov kev txo qis sai, tag nrho thiab kwv yees tau chromium nag lossis daus thaum lub sijhawm kho tom ntej.
Kev saib xyuas qhov concentration ntawm sodium bisulfite tiag tiag yog qhov tseem ceeb rau kev ua haujlwm kom raug. Cov thev naus laus zis ntsuas qhov ntom ntom hauv kab, xws li cov uas ua raws li cov ntsiab cai ntawm lub ntsuas qhov ntom ntom oscillating, muab rau cov neeg ua haujlwm txoj hauv kev los taug qab lub zog thiab kev ruaj khov ntawm cov kua sodium bisulfite pub. Kev koom ua ke ntawm cov ntsuas qhov ntom ntom tsis siv neeg rau hauv cov txheej txheem ua rau muaj kev hloov kho qhov ntau thiab tsawg, txo qis kev siv tshuaj ntau dhau, thiab sai sai ntes tau txhua qhov kev tawm ntawm cov xwm txheej pub zoo tshaj plaws. Qib siab ntawm kev tswj hwm no txhawb nqa kev txo qis chromium thiab ua raws li cov qauv kev tso tawm sab hauv thiab cov luag haujlwm raug cai rau kev ua raws li kev tso tawm dej khib nyiab.
Kev soj ntsuam chromium ion kom raug kuj txhawb nqa kev ua raws li ib puag ncig zoo rau cov chaw electroplating. Kev ntsuas qhov ceev hauv kab rau electroplating tsis yog tsuas yog taug qab cov neeg sawv cev txo qis xwb tab sis kuj qhia lwm cov ntsiab lus tswj hwm tseem ceeb hauv kev kho dej khib nyiab rau chromium, pab cov neeg ua haujlwm ua tiav cov nqi tshem tawm cov pa phem txhim khu kev qha thiab txo cov kev pheej hmoo tswj kev ua qias tuaj ntawm hexavalent chromium. Kev siv kev soj ntsuam qhov ceev tiag tiag, lub sijhawm tiag tiag thoob plaws hauv cov txheej txheem txo chrome txwv tsis pub tus neeg ua haujlwm ua yuam kev thiab txo qis kev cia siab rau kev kuaj tes siv sijhawm ntau, txhawb nqa kev ua haujlwm zoo thiab kev ua raws li cov cai ib puag ncig.
Kev koom ua ke ntawm kev siv tshuab, uas muaj cov cuab yeej siv siab heev xws liqhov ceev hauv kabthiabcov ntsuas viscositylos ntawm cov tuam txhab xws li Lonnmeter, ua kom ntseeg tau tias cov txheej txheem txo chrome tseem ntseeg tau thiab ua haujlwm tau zoo thoob plaws kev hloov pauv thiab cov dej khib nyiab sib txawv. Kev ntsuas txhim khu kev qha ua rau cov kws ua haujlwm teb sai rau kev hloov pauv, ua tau raws li cov txheej txheem txo chromium hauv kev coj ua zoo tshaj plaws electroplating, thiab hloov kho cov tswv yim dosing raws li qhov xav tau rau kev ua raws li ib puag ncig. Txoj hauv kev no txhawb nqa kev tswj hwm cov khib nyiab electroplating ruaj khov thiab tso cai rau kev sib ntsib rov ua dua ntawm cov kev txwv tsis pub tawm yam tsis muaj kev siv tshuaj tsis tsim nyog lossis kev pheej hmoo ib puag ncig.
Kev sib xyaw ua ke ntawm kev saib xyuas qhov concentration ntawm sodium bisulfite kom raug, kev ntsuas qhov ceev hauv kab, thiab kev tswj hwm cov txheej txheem ua tiav yog lub hauv paus ntawm kev siv chromium tshiab, raws li txoj cai, thiab ua haujlwm tau zoo. Kev saib xyuas zoo thiab kev koom ua ke ntawm thev naus laus zis tsis yog tsuas yog kev txhim kho xwb - tam sim no lawv yog qhov yuav tsum tau ua kom tiav kev ua haujlwm zoo, pob tshab, thiab muaj lub luag haujlwm rau ib puag ncig.
Cov Lus Nug Feem Ntau
Cov kua sodium bisulfite pab tshem tawm hexavalent chromium ntawm cov dej khib nyiab electroplating li cas?
Cov kua sodium bisulfite yog ib qho tshuaj txo qis uas siv rau hauv cov txheej txheem txo chrome los hloov hexavalent chromium (Cr(VI)), uas yog ib qho carcinogen thiab muaj kuab lom heev, mus rau hauv trivalent chromium (Cr(III) uas muaj kev nyab xeeb dua.
Cov txheej txheem no tshwm sim zoo tshaj plaws hauv cov xwm txheej acidic (pH 2–5), nrog rau cov chromium txo qis ua chromium hydroxide thaum pH hloov kho mus rau qib alkaline, pab txhawb nws tshem tawm ntawm cov dej khib nyiab. Txoj hauv kev no ua rau cov chaw ua haujlwm ua tiav kev tso dej khib nyiab raws li kev cai nruj los ntawm kev txo qis Cr (VI) concentration hauv qab qhov txwv kev kuaj pom, txo cov kev pheej hmoo ib puag ncig thiab kev noj qab haus huv.
Qhov tseem ceeb ntawm kev ntsuas qhov ceev hauv kab hauv cov txheej txheem txo chrome yog dab tsi?
Kev ntsuas qhov ceev hauv kab yog qhov tseem ceeb rau kev tswj cov kua sodium bisulfite dosing thaum lub sijhawm txo cov hexavalent chromium hauv cov txheej txheem electroplating kev lag luam. Cov ntsuas qhov ceev oscillating, xws li cov uas tsim los ntawm Lonnmeter, xa cov sijhawm tiag tiag, kev saib xyuas tsis siv neeg ntawm sodium bisulfite concentration. Qhov no ua kom ntseeg tau tias qhov piv zoo tshaj plaws ntawm reductant ntxiv, ua kom Cr (VI) txo qis kev ua haujlwm thaum txo cov reagent pov tseg. Cov zaus oscillation ntawm cov ntsuas no yog sib npaug ncaj qha rau qhov ceev ntawm cov kua, muab cov lus teb tam sim ntawd uas tswj hwm cov txheej txheem tswj hwm, txo cov nqi ua haujlwm, thiab tiv thaiv kev ua tsis tiav.
Vim li cas kev soj ntsuam chromium ion tas mus li thiaj li tseem ceeb rau kev ua raws li ib puag ncig hauv electroplating?
Kev soj ntsuam tas mus li ntawm cov chromium ion concentration—feem ntau yog los ntawm spectrophotometry lossis colorimetry—yog qhov tsim nyog los xyuas kom meej tias cov dej khib nyiab electroplating tseem nyob hauv cov kev cai tswjfwm rau hexavalent chromium. Kev tswj hwm nruj ntawm lossis qis dua 0.1 mg / L feem ntau yog qhov yuav tsum tau los ntawm cov tub ceev xwm ib puag ncig kom tiv thaiv kev ua qias tuaj ntawm hexavalent chromium. Kev ntsuas tiag tiag tso cai rau kev hloov kho cov txheej txheem sai, txo qis kev pheej hmoo ntawm kev ua txhaum cai, kev nplua, thiab kev puas tsuaj rau ib puag ncig los ntawm kev txo qis tsis tiav lossis cov txheej txheem tsis zoo.
Lub luag haujlwm ntawm pH ua si li cas thaum lub sijhawm hloov pauv ntawm hexavalent mus rau trivalent chromium?
Kev tswj pH yog qhov tseem ceeb rau ob qho kev txo cov tshuaj lom neeg thiab cov kauj ruam tom ntej ntawm chromium precipitation. Cov xwm txheej acidic (feem ntau pH 2–5) yog qhov tsim nyog thaum lub sijhawm txo qis, vim tias lawv tswj hwm hexavalent chromium hauv nws cov ntawv ionic reactive feem ntau. Tom qab txo qis, cov kua pH raug tsa (feem ntau > 8.5) kom precipitate Cr (III) ua chromium hydroxide. Kev kho pH kom zoo ua kom muaj kev cuam tshuam sai, ua kom muaj txiaj ntsig zoo tshaj plaws, txo qis kev siv tshuaj, thiab ua kom cov dej khib nyiab sib cais thiab pov tseg yooj yim dua.
Cov ntsuas qhov ceev ntawm oscillating tuaj yeem txhim kho kev soj ntsuam qhov concentration ntawm sodium bisulfite li cas?
Cov ntsuas qhov ceev ntawm cov oscillating yog siv rau kev saib xyuas qhov concentration ntawm sodium bisulfite vim tias lawv ua rau muaj kev meej,kev ntsuas hauv kabtsis tas yuav tsum tau kuaj tes. Lub hauv paus ntsiab lus ntawm lub raj vibrating ncaj qha cuam tshuam qhov zaus oscillation hloov pauv mus rau qhov kev hloov pauv ntawm qhov ceev ntawm cov tshuaj, tso cai rau kev tawm tswv yim tsis siv neeg rau cov txheej txheem dosing tshuaj. Kev saib xyuas qhov ceev tiag tiag kom raug tiv thaiv ob qho tib si overdosing, uas ua rau cov nqi khiav lag luam thiab cov khoom sulfate byproducts nce ntxiv, thiab underdosing, uas muaj kev pheej hmoo ntawm kev txo chromium tsis tiav thiab tsis ua raws li txoj cai. Los ntawm kev koom ua ke ntawm Lonnmeter cov khoom siv, kev ruaj khov ntawm cov txheej txheem thiab kev tswj hwm dosing rau sodium bisulfite daim ntawv thov hauv electroplating tau txhim kho zoo heev, ua kom ntseeg tau tias kev txo chromate tseem ua haujlwm tau zoo thiab txhim khu kev qha.
Lub sijhawm tshaj tawm: Lub Kaum Ob Hlis-10-2025
