Persulfate Oxidation rau Cyanide Wastewater Treatment: Kev Tshawb Fawb

Introduction

Cyanide, cov tshuaj lom neeg muaj zog heev, yog siv dav hauv ntau yam kev lag luam xws li electroplating, mining, thiab hlau tiav. Yog li ntawd, loj ntim ntawm cyanide-muaj cov dej khib nyiab tsim tawm, ua rau muaj kev hem thawj rau ib puag ncig thiab tib neeg kev noj qab haus huv. Ib txwm Cyanide dej khib nyiab txoj kev kho mob, xws li alkaline chlorination, muaj ob peb qhov tsis zoo. Cov no suav nrog kev tsim cov tshuaj lom neeg los ntawm cov khoom lag luam, kev siv tshuaj lom neeg siab, thiab kev tshem tawm qis rau cov hlau-cyanide complexes. Raws li qhov tshwm sim, muaj kev xav tau ntau ntxiv rau kev kho kom zoo dua qub thiab ib puag ncig zoo.

Nyob rau hauv xyoo tas los no, cov txheej txheem oxidation siab heev (AOPs) tau tshwm sim los ua kev cog lus rau kev kho cov dej khib nyiab cyanide. Ntawm cov no, cov Persulfate oxidation Cov txheej txheem tau nyiam cov xim zoo nkauj vim nws muaj peev xwm oxidation muaj zog, kev siv pH dav dav, thiab kev ua haujlwm yooj yim. Qhov kev tshaj tawm blog no yog tsim los muab cov ntsiab lus nthuav dav ntawm persulfate oxidation txoj kev rau kev kho dej khib nyiab cyanide, npog nws cov txheej txheem, muaj feem cuam tshuam, thiab kev siv tswv yim.

Mechanism ntawm Persulfate Oxidation

Persulfate, uas muaj xws li peroxydisulfate (PDS) lossis peroxymonosulfate (PMS), tuaj yeem qhib tau los ntawm ntau txoj kev, xws li tshav kub, UV teeb, hloov hlau, lossis alkalinity, los tsim cov tshuaj sulfate radicals heev. Cov sulfate radicals no muaj peev xwm oxidation siab, ua rau lawv oxidize ntau yam organic thiab inorganic pollutants, nrog rau cyanide.

Cov tshuaj tiv thaiv mechanism ntawm persulfate oxidation ntawm cyanide yog complex thiab koom nrog ntau kauj ruam. Feem ntau, sulfate radicals hnov ​​​​mob nrog cyanide ions los ua cyanate ua cov khoom nruab nrab. Cov cyanate tuaj yeem raug oxidized ntxiv los yog hydrolyzed los tsim cov khoom tsis muaj tshuaj lom, xws li nitrate, ammonium, thiab nitrogen gas. Txoj kev tshuaj tiv thaiv tshwj xeeb sib txawv nyob ntawm seb cov tshuaj tiv thaiv zoo li pH, qhov kub thiab txias, thiab muaj lwm yam tshuaj. Hauv qhov nruab nrab acidic, cov tshuaj tiv thaiv ua raws li ib ntus, thaum nyob rau hauv nruab nrab nruab nrab, cov tshuaj tiv thaiv kev hloov pauv, thiab hydroxyl radicals kuj tuaj yeem koom nrog hauv cov txheej txheem oxidation. Hydroxyl radicals tuaj yeem tsim los ntawm cov tshuaj tiv thaiv ntawm sulfate radicals nrog dej lossis los ntawm kev ua kom cov persulfate los ntawm alkalinity, thiab lawv cov tshuaj tiv thaiv nrog cyanide yog txoj hauv kev tseem ceeb rau kev tshem tawm cyanide.

Muaj feem cuam tshuam

1. Persulfate Concentration

Qhov concentration ntawm persulfate yog ib qho tseem ceeb heev rau kev kho cov dej khib nyiab ntawm cyanide. Feem ntau, nce cov tshuaj persulfate tuaj yeem txhim kho cov cim ntawm sulfate radicals, yog li txhawb kev oxidation ntawm cyanide. Txawm li cas los xij, ntau dhau persulfate tuaj yeem ua rau nws tus kheej quenching cov tshuaj tiv thaiv sulfate radicals, txo cov oxidation tag nrho. Ntxiv mus, siab persulfate ntau tuaj yeem ua rau cov nqi kho mob thiab ua rau muaj teeb meem ib puag ncig vim muaj cov persulfate seem hauv cov dej kho. Yog li, qhov tsim nyog persulfate concentration yuav tsum tau txiav txim siab los ntawm kev sim raws li cov yam ntxwv ntawm cov dej khib nyiab.

2. Tus nqi pH

Cov pH ntawm cov dej khib nyiab cuam tshuam rau persulfate oxidation txheej txheem. Cov xwm txheej pH sib txawv tuaj yeem cuam tshuam rau kev ua kom muaj zog, hom thiab kev ua haujlwm ntawm cov radicals generated, thiab daim ntawv ntawm cyanide. Nyob rau hauv acidic tej yam kev mob, sulfate radicals yog lub ntsiab reactive hom thiab qhia siab reactivity ntawm cyanide. Raws li pH nce, qhov kev faib ua feem ntawm hydroxyl radicals tsim los ntawm cov tshuaj tiv thaiv ntawm sulfate radicals nrog dej los yog los ntawm persulfate activation los ntawm alkalinity nce. Hauv cov xwm txheej alkaline, hydroxyl radicals tuaj yeem ua lub luag haujlwm tseem ceeb hauv cyanide oxidation. Txawm li cas los xij, qhov pH siab heev lossis qis qis tuaj yeem cuam tshuam tsis zoo rau cov tshuaj tiv thaiv. Piv txwv li, thaum pH tsawg heev, kev ruaj ntseg ntawm persulfate yuav raug cuam tshuam, thaum pH siab heev, solubility ntawm qee cov hlau ions hauv cov dej khib nyiab tuaj yeem hloov pauv, uas tuaj yeem cuam tshuam rau persulfate activation thiab cov txheej txheem oxidation.

3. Ntsig Kub

Qhov kub thiab txias tuaj yeem ua kom lub zog ntawm persulfate thiab cov tshuaj tiv thaiv ntawm cov radicals thiab cyanide. Kev kub siab dua feem ntau ua rau muaj kev tsim cov sulfate radicals sai dua thiab ua kom zoo dua cyanide oxidation. Txawm li cas los xij, nce qhov kub thiab txias yuav tsum muaj zog ntxiv, uas ua rau cov nqi kho mob. Tsis tas li ntawd, yog tias qhov kub thiab txias dhau lawm, nws tuaj yeem ua rau decomposition ntawm persulfate thiab lwm yam kev xav tsis zoo. Yog li ntawd, thaum xaiv qhov tsim nyog qhov ntsuas kub, qhov sib npaug yuav tsum raug ntaus ntawm kev kho mob thiab kev siv lub zog.

4. Muaj cov hlau ions

Cov hlau ions feem ntau pom nyob rau hauv cov dej khib nyiab, xws li Cu²⁺, Zn²⁺, Fe²⁺, thiab Ni²⁺, tuaj yeem muaj qhov sib txawv ntawm cov txheej txheem oxidation persulfate. Qee cov hlau ions, zoo li Cu²⁺, tuaj yeem ua raws li cov khoom siv los ua kom cov persulfate, tsim cov sulfate radicals ntau dua thiab txhim kho cyanide tshem tawm. Ntawm qhov tod tes, qee cov hlau ions tuaj yeem tsim cov complexes nrog cyanide, ua rau nws ruaj khov thiab nyuaj rau oxidize. Tsis tas li ntawd, cov hlau ions kuj tseem tuaj yeem koom nrog kev cuam tshuam sab nraud nrog persulfate lossis radicals, cuam tshuam rau tag nrho cov tshuaj tiv thaiv txoj hauv kev thiab kev ua haujlwm. Kev nkag siab txog lub luag haujlwm ntawm cov hlau ions hauv persulfate oxidation system yog qhov tseem ceeb rau kev ua kom zoo rau kev kho cov txheej txheem ntawm cyanide - muaj cov dej khib nyiab.

5. Lub Sijhawm Tawm Tsam

Lub sij hawm txaus cov tshuaj tiv thaiv yog tsim nyog los xyuas kom meej oxidation ntawm cyanide. Raws li cov tshuaj tiv thaiv zoo zuj zus, cov cyanide concentration maj mam txo. Txawm li cas los xij, tom qab qee lub sijhawm, cov tshuaj tiv thaiv tus nqi yuav qeeb vim qhov depletion ntawm reactants los yog tsub zuj zuj ntawm cov tshuaj tiv thaiv cov khoom. Lub sijhawm zoo tshaj plaws yog nyob ntawm ntau yam, suav nrog qhov pib cyanide concentration, cov tshuaj tiv thaiv kab mob (xws li persulfate concentration, pH, thiab kub), thiab hom dej khib nyiab matrix. Kev ncua sij hawm cov tshuaj tiv thaiv tsis tas yuav ua rau muaj feem cuam tshuam ntawm kev tshem tawm cyanide thiab kuj tseem tuaj yeem ua rau muaj zog siv zog thiab cov nqi kho mob.

Daim ntawv thov nyob rau hauv txawv Industries

1. Kev lag luam electroplating

Nyob rau hauv cov txheej txheem electroplating, cyanide feem ntau yog siv los xyuas kom meej qhov zoo ntawm cov hlau plating. Cov dej khib nyiab tsim los ntawm electroplating muaj cov ntsiab lus siab ntawm cyanide thiab hlau - cyanide complexes. Persulfate oxidation tau pom muaj peev xwm zoo hauv kev kho cov dej khib nyiab electroplating cyanide. Piv txwv li, cov kev tshawb fawb pom tau hais tias nyob rau hauv lub xub ntiag ntawm cov nqi tsim nyog ntawm Cu²⁺ (raws li ib tug activator) thiab peroxydisulfate, mus txog 99% ntawm cyanide tuaj yeem raug tshem tawm hauv 20 feeb. Txoj kev no tuaj yeem ua rau cov hlau tsis zoo - cyanide complexes thiab hloov cyanide rau hauv cov tshuaj lom neeg tsawg, ua tau raws li cov qauv tso tawm nruj rau cov dej khib nyiab electroplating.

2. Kev lag luam Mining

Kev lag luam mining, tshwj xeeb tshaj yog kub mining, tsim ib qho loj ntawm cyanide - muaj cov dej khib nyiab thiab cov khoom seem. Cyanide yog siv rau hauv kev rho tawm kub los ua cov kub soluble - cyanide complexes. Persulfate - cov txheej txheem oxidation siab heev tuaj yeem siv los kho cov dej khib nyiab thiab cov khoom seem. Piv txwv li, nyob rau hauv kev kho mob ntawm kub cyanide residues, ultrasonic - tshuab txais persulfate oxidation tau kawm. Los ntawm kev siv 2.0 wt.% potassium persulfate ntawm pH 10.0 rau 60 feeb, qhov kev tshem tawm cyanide tuaj yeem ncav cuag 53.47%. Nrog rau kev ua kom sov ntawm 60 ° C, qhov ua tau zoo nce mus rau 62.18%, thiab nyob rau hauv kev ua haujlwm ultrasonic nrog 100% lub zog, qhov kev tshem tawm tuaj yeem ncav cuag siab li 74.76%. Tom qab ultrasonic - activated persulfate - advanced oxidation kev kho mob, cov ntsiab lus cyanide nyob rau hauv cov tshuaj lom leaching cov residue tuaj yeem ua tau raws li lub teb chaws tus qauv, ua kom pom qhov ua tau ntawm txoj kev no hauv kev lag luam mining.

3. Kev lag luam hlau tiav

Hauv kev lag luam hlau tiav, cyanide yog siv ntau yam txheej txheem kho saum npoo. Cyanide tshwm sim - muaj cov dej khib nyiab yuav tsum tau kho kom zoo kom tsis txhob muaj kuab paug ib puag ncig. Persulfate oxidation tuaj yeem ua ke rau hauv cov dej khib nyiab ntawm cov nroj tsuag hlau tiav. Los ntawm optimizing cov tshuaj tiv thaiv, xws li kho cov persulfate concentration, pH, thiab cov tshuaj tiv thaiv lub sij hawm, high-efficiency cyanide tshem tawm yuav ua tau tiav. Qhov no tsis tsuas yog pab cov hlau tiav kev lag luam ua raws li kev cai ib puag ncig tab sis kuj txo cov kev pheej hmoo uas cuam tshuam nrog cyanide paug.

Case Kev tshawb fawb

Case 1: Kev kho cov dej khib nyiab tiag Electroplating

Kev tshawb fawb tau ua tiav ntawm cov dej khib nyiab tiag electroplating uas muaj cyanide, kho nws nrog cov txheej txheem oxidation persulfate. Thaum ib qho tshwj xeeb ntawm persulfate tau ntxiv, ib qho tseem ceeb ntawm cyanide hauv cov dej khib nyiab tuaj yeem raug tshem tawm tag nrho hauv 20 feeb. Cov txiaj ntsig ntawm ntau qhov kev sim qhia tau hais tias ob qho tib si hydroxyl radicals thiab sulfate radicals yog lub luag haujlwm rau kev tshem tawm cyanide, thiab lawv cov txiaj ntsig tau sib piv. Cyanate thiab nitrite tau kuaj pom los ntawm cov khoom tseem ceeb. Cov ntaub ntawv kawm no tau qhia txog qhov ua tau zoo ntawm persulfate oxidation hauv kev kho cov dej hauv ntiaj teb electroplating cyanide.

Case 2: Kev Kho Mob Kub Cyanide Residues

Hauv kev ua haujlwm kub mining, kub cyanide residues raug kho nrog cov persulfate - cov txheej txheem oxidation siab heev. Cov residues muaj cov cyanide siab uas yuav tsum tau txo kom tau raws li cov qauv pov tseg. Los ntawm kev sim, nws tau pom tias los ntawm kev siv cov poov tshuaj persulfate thiab optimizing cov tshuaj tiv thaiv, nrog rau pH, qhov kub thiab txias, thiab ua kom txoj kev (xws li ultrasonic activation), cov ntsiab lus cyanide nyob rau hauv cov tshuaj lom leaching ntawm cov residues yuav txo qis. Tom qab ultrasonic - activated persulfate - advanced oxidation kev kho mob, cov ntsiab lus cyanide nyob rau hauv cov tshuaj lom leaching tov tau raws li lub teb chaws tus qauv ntawm Tuam Tshoj. Cov ntaub ntawv no qhia txog kev ua tiav daim ntawv thov ntawm persulfate oxidation hauv kev kho cov kub cyanide residues, muab cov tswv yim daws teeb meem rau kev nyab xeeb pov tseg ntawm cov khib nyiab pov tseg.

Cov kev sib tw thiab cov kev xav yav tom ntej

1. Cov nqi sib tw

• Nqi - kev ua tau zoo: Txawm hais tias persulfate oxidation qhia tau hais tias muaj peev xwm zoo hauv kev kho cov dej khib nyiab cyanide, tus nqi ntawm persulfate thiab lub zog xav tau rau kev ua kom muaj zog (xws li cua sov lossis ultrasonic ua kom sov) tuaj yeem siab heev. Tsim kom muaj nqi ntau dua - txoj hauv kev zoo los tsim thiab qhib persulfate yog qhov tsim nyog los ua kom cov thev naus laus zis no siv tau ntau dua.

• Complexity ntawm Wastewater Matrix: Muaj cyanide - muaj cov dej khib nyiab feem ntau muaj cov sib xyaw ua ke ntawm ntau yam tshuaj, suav nrog cov hlau sib txawv, cov organic tebchaw, thiab ntsev. Cov khoom no tuaj yeem cuam tshuam nrog persulfate thiab radicals, cuam tshuam rau cov tshuaj tiv thaiv mechanism thiab kev ua haujlwm. Kev nkag siab thiab tswj cov kev sib cuam tshuam nyuaj no yog qhov nyuaj hauv kev siv tswv yim.

• Residual Persulfate thiab By - khoom: Cov residual persulfate nyob rau hauv cov dej kho tej zaum yuav ua rau muaj teeb meem ib puag ncig, thiab ib co los ntawm - cov khoom, xws li nitrite, kuj yuav tsum tau kho ntxiv kom tau raws li ib tug nruj tshaj plaws cov qauv. Txhim kho txoj hauv kev kom zoo tshem tawm cov residual persulfate thiab tswj kev tsim kev puas tsuaj los ntawm - cov khoom yog ib qho tseem ceeb rau kev tshawb fawb ntxiv.

2. Yav Tom Ntej Kev Pom Zoo

• Novel Activation Methods: Kev tshawb fawb tseem tab tom tsim kho tshiab thiab ua kom muaj txiaj ntsig zoo rau persulfate. Piv txwv li, siv cov catalysts tshiab xws li nanomaterials lossis hlau - cov txheej txheem organic (MOFs) los qhib cov persulfate tuaj yeem muab cov tshuaj tiv thaiv ntau dua thiab xaiv. Tsis tas li ntawd, kev tshawb nrhiav kev sib xyaw ua ke ntawm ntau txoj kev ua kom muaj zog, xws li siv cov cua sov thiab cov catalyst ib txhij, tuaj yeem txhim kho kev ua tau zoo ntawm cov txheej txheem oxidation persulfate.

• Kev koom ua ke nrog lwm yam kev kho mob: Kev sib xyaw persulfate oxidation nrog rau lwm yam kev kho mob technologies, xws li kev kho mob lom, membrane filtration, los yog adsorption, yuav ua tau zoo tag nrho cov kev kho mob. Piv txwv li, kev kho ua ntej nrog persulfate oxidation los rhuav tshem cov cyanide complex tuaj yeem ua rau cov dej khib nyiab zoo dua rau kev kho mob lom tom ntej.

• Nyob rau hauv-site Kev Saib Xyuas thiab Kev Ua Haujlwm Zoo: Txoj kev loj hlob ntawm in - situ xyuas cov txheej txheem rau persulfate oxidation txheej txheem, xws li real - lub sij hawm nrhiav tau ntawm radical concentrations thiab cyanide degradation khoom, yuav pab tau kom nkag siab zoo txog cov tshuaj tiv thaiv kev nce qib thiab optimizing cov txheej txheem kho. Qhov no tuaj yeem ua rau muaj txiaj ntsig zoo thiab txhim khu kev qha cyanide cov dej khib nyiab.

Hauv kev xaus, txoj kev persulfate oxidation qhia tau hais tias muaj kev cog lus zoo hauv kev kho cov cyanide - muaj cov dej khib nyiab. Nrog kev tshawb fawb txuas ntxiv thiab kev txhim kho los daws cov teeb meem uas twb muaj lawm, cov cuab yeej no muaj peev xwm los ua txoj hauv kev tseem ceeb rau kev kho cov dej khib nyiab cyanide hauv ntau qhov kev lag luam, pab txhawb kev tiv thaiv ib puag ncig thiab kev txhim kho kom ruaj khov.