Nrog rau kev nrawm ntawm qhov hloov tshiab ntawm cov khoom siv hluav taws xob, tus naj npawb ntawm cov pov tseg luam tawm hauv Circuit Court board (PCB), qhov tseem ceeb ntawm cov khoom pov tseg hluav taws xob, kuj nce ntxiv. Cov pa phem ib puag ncig los ntawm pov tseg PCBs kuj tau ua rau muaj kev mloog ntawm ntau lub tebchaws. Hauv cov khib nyiab PCBs, cov hlau hnyav xws li txhuas, mercury, thiab hexavalent chromium, nrog rau cov tshuaj lom neeg xws li polybrominated biphenyls (PBB) thiab polybrominated diphenyl ethers (PBDE), uas yog siv los ua cov nplaim hluav taws kub nyhiab, muaj nyob hauv ib puag ncig ntuj. . Cov dej hauv av thiab av ua rau muaj kuab paug loj, uas ua rau muaj kev puas tsuaj loj rau tib neeg lub neej thiab kev noj qab haus huv ntawm lub cev thiab lub hlwb. Ntawm cov khib nyiab PCB, muaj ze li ntawm 20 hom hlau tsis-ferrous thiab cov hlau tsis tshua muaj, uas muaj cov khoom siv rov ua dua tshiab thiab cov nqi lag luam, thiab nws yog kuv qhov tiag tiag tos kom mined.

Yuav ua li cas pov tseg cov PCB Circuit Boards

1 Kev cai lij choj lub cev

Txoj kev siv lub cev yog siv cov cuab yeej cuab tam thiab qhov sib txawv ntawm PCB lub cev kom ua tiav cov khoom siv rov ua dua tshiab.

1.1 Ua tsaug

Lub hom phiaj ntawm crushing yog kom dissociate cov hlau nyob rau hauv lub pov tseg Circuit Court board los ntawm cov organic teeb meem ntau npaum li sai tau los txhim kho kev sib cais efficiency. Txoj kev tshawb nrhiav pom tias thaum cov hlau tawg ntawm 0.6 hli, cov hlau tuaj yeem ncav cuag 100% dissociation, tab sis qhov kev xaiv ntawm crushing txoj kev thiab tus naj npawb ntawm cov theem yog nyob ntawm cov txheej txheem tom ntej.

1.2 Kev txheeb xyuas

Kev sib cais yog ua tiav los ntawm kev siv qhov sib txawv hauv lub cev xws li cov khoom siv ntom ntom, qhov loj me, kev coj ua, sib nqus permeability, thiab cov yam ntxwv saum npoo. Tam sim no dav siv yog cua shaker tshuab, flotation sib cais tshuab, cyclone sib cais tshuab, ntab-sab sib cais thiab eddy tam sim no sib cais tshuab.

2 Supercritical technology kho txoj kev

Supercritical kua extraction technology yog hais txog ib txoj kev purification uas siv lub siab thiab kub ntawm solubility ntawm supercritical kua los ua extraction thiab sib cais yam tsis tau hloov cov tshuaj muaj pes tsawg leeg. Piv nrog rau cov txheej txheem rho tawm ib txwm muaj, cov txheej txheem supercritical CO2 extraction muaj qhov zoo ntawm ib puag ncig tus phooj ywg, kev sib cais yooj yim, tsis muaj tshuaj lom, me me lossis tsis muaj qhov seem, thiab tuaj yeem ua haujlwm ntawm chav tsev kub.

Cov lus qhia kev tshawb fawb tseem ceeb ntawm kev siv cov kua dej supercritical los kho cov khib nyiab PCBs yog tsom rau ob yam: Ua ntej, vim tias cov kua roj carbon dioxide supercritical muaj peev xwm tshem tawm cov resin thiab brominated nplaim taws retardant Cheebtsam nyob rau hauv lub Circuit Court board. Thaum cov khoom sib txuas ntawm cov khoom siv hauv lub rooj tsavxwm luam tawm tau raug tshem tawm los ntawm cov kua dej CO2 supercritical, cov txheej tooj liab thiab cov iav fiber ntau hauv cov ntawv luam tawm tuaj yeem sib cais tau yooj yim, yog li muab qhov ua tau zoo ntawm cov khoom siv hauv cov ntawv luam tawm. pawg thawj coj. 2. ncaj qha siv cov kua dej supercritical los rho tawm cov hlau los ntawm khib nyiab PCBs. Wai et al. tshaj tawm cov extraction ntawm Cd2+, Cu2+, Zn2+, Pb2+, Pd2+, As2+, Au3+, Ga3+ thiab Ga3+ los ntawm simulated cellulose lim ntawv los yog xuab zeb siv lithium fluorinated diethyldithiocarbamate (LiFDDC) ua ib tug complexing neeg sawv cev. Raws li cov txiaj ntsig ntawm Sb3+ kev tshawb fawb, qhov kev ua tau zoo ntawm kev rho tawm yog siab dua 3%.

Supercritical processing thev naus laus zis kuj muaj qhov tsis xws luag xws li: kev xaiv siab ntawm kev rho tawm yuav tsum tau ntxiv cov entrainer, uas ua rau muaj kev phom sij rau ib puag ncig; kuj siab extraction siab yuav tsum tau cov cuab yeej siab; kub kub yog siv nyob rau hauv cov txheej txheem extraction thiab yog li ntawd siab zog noj.

3 Cov txheej txheem tshuaj

Cov cuab yeej siv tshuaj kho mob yog txheej txheem ntawm kev rho tawm siv tshuaj lom neeg ruaj khov ntawm ntau yam khoom hauv PCB.

3.1 Txoj kev kho cua sov

Txoj kev kho cua sov feem ntau yog ib txoj kev sib cais cov organic thiab hlau los ntawm kev kub siab. Nws feem ntau suav nrog txoj kev incineration, lub tshuab nqus tsev tawg, txoj kev microwave thiab lwm yam.

3.1.1 Txoj kev Incineration

Txoj kev incineration yog txhawm rau txhawm rau cov khoom pov tseg hluav taws xob rau qee qhov me me thiab xa mus rau lub tshuab hluav taws xob tseem ceeb rau incineration, decompose cov organic Cheebtsam hauv nws, thiab cais cov roj ntawm cov khoom. Cov seem tom qab incineration yog cov hlau liab los yog nws cov oxide thiab iav fiber ntau, uas tuaj yeem rov qab los ntawm kev siv lub cev thiab tshuaj lom neeg tom qab crushed. Cov roj uas muaj cov khoom siv organic nkag mus rau hauv lub tshuab hluav taws xob thib ob rau kev kho combustion thiab raug tso tawm. Qhov tsis zoo ntawm txoj kev no yog tias nws tsim ntau cov pa khib nyiab thiab tshuaj lom.

3.1.2 Txoj kev Cracking

Pyrolysis tseem hu ua qhuav distillation hauv kev lag luam. Nws yog los ua kom sov cov khoom siv hluav taws xob hauv ib lub thawv nyob rau hauv cov xwm txheej ntawm kev sib cais ntawm huab cua, tswj qhov kub thiab txias, kom cov organic teeb meem nyob rau hauv nws decomposed thiab hloov mus rau hauv roj thiab roj, uas yuav rov qab tau tom qab condensation thiab sau. Tsis zoo li cov khoom siv hluav taws xob hauv hluav taws xob, lub tshuab nqus tsev pyrolysis yog ua raws li cov txheej txheem tsis muaj oxygen, yog li kev tsim cov dioxins thiab furans tuaj yeem raug tshem tawm, cov roj pov tseg uas tsim tawm me me, thiab ib puag ncig muaj kuab paug tsawg.

3.1.3 Microwave processing technology

Txoj kev siv microwave rov ua dua yog thawj zaug tsoo cov khoom siv hluav taws xob, thiab tom qab ntawd siv microwave cua sov kom decompose cov organic teeb meem. Cua sov txog li 1400 ℃ melts iav fiber ntau thiab hlau los ua ib qho vitrified khoom. Tom qab cov khoom no txias lawm, kub, nyiaj thiab lwm yam hlau yog sib cais nyob rau hauv daim ntawv ntawm cov hlaws dai, thiab cov iav uas tseem tshuav tuaj yeem siv los ua cov khoom siv hauv tsev. Txoj kev no yog qhov sib txawv ntawm cov txheej txheem cua sov ib txwm muaj, thiab muaj cov txiaj ntsig zoo xws li kev ua haujlwm siab, ceev ceev, muaj peev xwm rov qab los thiab siv tau, thiab kev siv hluav taws xob tsawg.

3.2 Hydrometallurgy

Hydrometallurgical thev naus laus zis tsuas yog siv cov yam ntxwv ntawm cov hlau uas tuaj yeem yaj hauv cov kua qaub xws li nitric acid, sulfuric acid thiab aqua regia kom tshem tawm cov hlau los ntawm hluav taws xob pov tseg thiab rov qab los ntawm cov kua theem. Tam sim no nws yog txoj kev siv dav tshaj plaws rau kev ua cov khoom siv hluav taws xob. Piv nrog rau pyrometallurgy, hydrometallurgy muaj qhov zoo ntawm cov pa pa tsawg dua, yooj yim pov tseg cov khoom seem tom qab hlau rho tawm, cov txiaj ntsig tseem ceeb ntawm kev lag luam, thiab cov txheej txheem yooj yim ntws.

4 Biotechnology

Biotechnology siv cov adsorption ntawm cov kab mob nyob rau saum npoo ntawm cov zaub mov thiab oxidation ntawm cov kab mob los daws cov teeb meem ntawm cov hlau rov qab. Microbial adsorption tuaj yeem muab faib ua ob hom: kev siv cov microbial metabolites rau immobilize hlau ions thiab siv cov microbes ncaj qha immobilize hlau ions. Tus qub yog siv cov hydrogen sulfide uas tsim los ntawm cov kab mob los kho, thaum lub nto ntawm cov kab mob adsorbs ions kom ncav cuag saturation, nws muaj peev xwm tsim flocs thiab khom; tom kawg siv cov cuab yeej oxidizing ntawm ferric ions los oxidize lwm cov hlau hauv cov hlau muaj txiaj ntsig zoo xws li kub Nws dhau los ua soluble thiab nkag mus rau hauv kev daws teeb meem, nthuav tawm cov hlau zoo nkauj los pab txhawb kev rov zoo. Kev rho tawm ntawm cov hlau muaj txiaj ntsig xws li kub los ntawm biotechnology muaj qhov zoo ntawm cov txheej txheem yooj yim, tus nqi qis, thiab kev ua haujlwm yooj yim, tab sis lub sij hawm leaching yog ntev dua thiab leaching tus nqi qis, yog li nws tsis tau muab tso rau hauv kev siv tam sim no.

Thaum xaus lus

E-pov tseg yog ib qho khoom muaj txiaj ntsig, thiab nws tseem ceeb heev los txhawb kev tshawb fawb thiab kev siv cov cuab yeej siv hlau rov ua dua tshiab rau e-kua pov tseg, ob qho tib si los ntawm kev lag luam thiab ib puag ncig ntawm kev pom. Vim lub complex thiab ntau haiv neeg cov yam ntxwv ntawm e-kua pov tseg, nws yog ib qhov nyuaj rau rov qab cov hlau nyob rau hauv nws nrog tej technology ib leeg. Txoj kev loj hlob yav tom ntej ntawm e-khoom siv thev naus laus zis yuav tsum yog: kev lag luam ntawm cov ntaub ntawv ua tiav, kev siv ntau tshaj plaws ntawm cov peev txheej, thiab kev siv thev naus laus zis. Hauv cov ntsiab lus, kev kawm txog kev rov ua dua tshiab ntawm cov khib nyiab PCB tuaj yeem tsis tsuas yog tiv thaiv ib puag ncig, tiv thaiv kev ua qias tuaj, tab sis kuj pab txhawb kev rov ua dua tshiab, txuag ntau lub zog, thiab txhawb kev txhim kho kev lag luam thiab zej zog.