Kev siv cov nyhuv ntawm PAC hauv kev kho dej ntawm lub zog hluav taws xob thermal

1. Kev kho dej pleev ua ntej

Cov dej ntuj feem ntau muaj av nplaum, av nplaum, humus thiab lwm yam khoom uas raug tshem tawm thiab cov khoom tsis huv colloidal thiab cov kab mob, cov pwm, algae, cov kab mob thiab lwm yam kab mob me me, lawv muaj qee qhov kev ruaj khov hauv dej, yog qhov ua rau dej tsis huv, xim thiab tsw. Cov organic ntau dhau no nkag mus rau hauv lub tshuab hloov pauv ion, ua rau cov resin paug, txo qhov peev xwm pauv ntawm cov resin, thiab txawm tias cuam tshuam rau qhov zoo ntawm cov dej ntws. Kev kho coagulation, kev ua kom pom tseeb thiab kev lim dej yog lub hom phiaj tseem ceeb los tshem tawm cov khoom tsis huv no, yog li cov ntsiab lus ntawm cov khoom raug tshem tawm hauv dej raug txo kom tsawg dua 5mg / L, uas yog, kom tau txais dej ntshiab. Qhov no hu ua kev kho dej ua ntej. Tom qab kev kho ua ntej, cov dej tsuas yog siv tau ua dej boiler thaum cov ntsev yaj hauv dej raug tshem tawm los ntawm kev pauv ion thiab cov pa roj yaj hauv dej raug tshem tawm los ntawm kev ua kom sov lossis nqus tsev lossis tshuab. Yog tias cov khoom tsis huv no tsis raug tshem tawm ua ntej, kev kho tom qab (desalting) tsis tuaj yeem ua tiav. Yog li ntawd, kev kho coagulation ntawm dej yog qhov txuas tseem ceeb hauv cov txheej txheem kho dej.

Cov txheej txheem ua ntej ntawm lub zog fais fab thermal yog raws li nram no: dej nyoos → coagulation → nag thiab ua kom pom tseeb → lim. Cov coagulants feem ntau siv rau hauv cov txheej txheem coagulation yog polyaluminum chloride, polyferric sulfate, aluminium sulfate, ferric trichloride, thiab lwm yam. Cov hauv qab no feem ntau qhia txog kev siv polyaluminum chloride.

Polyaluminum chloride, hu ua PAC, yog ua los ntawm cov tshauv txhuas lossis cov zaub mov txhuas ua cov khoom siv raw, ntawm qhov kub siab thiab qee qhov siab nrog alkali thiab txhuas cov tshuaj tiv thaiv tsim cov polymer, cov khoom siv raw thiab cov txheej txheem ntau lawm txawv, cov lus qhia ntawm cov khoom tsis zoo ib yam. Cov mis molecular ntawm PAC [Al2(OH)nCI6-n]m, qhov twg n tuaj yeem yog cov lej ntawm 1 thiab 5, thiab m yog cov lej ntawm pawg 10. PAC muaj ob qho tib si khov thiab kua.

2. Txoj kev sib xyaw ua ke

Muaj peb qhov cuam tshuam tseem ceeb ntawm cov coagulants rau cov khoom colloidal hauv dej: hluav taws xob neutralization, adsorption bridging thiab sweeping. Qhov twg ntawm peb qhov cuam tshuam no yog qhov tseem ceeb nyob ntawm hom thiab koob tshuaj ntawm coagulant, qhov xwm txheej thiab cov ntsiab lus ntawm cov khoom colloidal hauv dej, thiab tus nqi pH ntawm dej. Lub tshuab ua haujlwm ntawm polyaluminum chloride zoo ib yam li cov txhuas sulfate, thiab tus cwj pwm ntawm txhuas sulfate hauv dej hais txog cov txheej txheem ntawm Al3 + tsim ntau yam hydrolyzed hom.

Polyaluminum chloride tuaj yeem suav hais tias yog ntau yam khoom nruab nrab hauv cov txheej txheem ntawm hydrolysis thiab polymerization ntawm txhuas chloride rau hauv Al (OH) 3 nyob rau hauv qee qhov xwm txheej. Nws yog tam sim no ncaj qha nyob rau hauv dej nyob rau hauv daim ntawv ntawm ntau yam polymeric hom thiab A1 (OH) a (s), tsis muaj cov txheej txheem hydrolysis ntawm Al3 +.

3. Daim ntawv thov thiab cov yam cuam tshuam

1. Kub ntawm dej

Qhov kub ntawm dej muaj feem cuam tshuam rau qhov kev kho mob coagulation. Thaum qhov kub ntawm dej qis, qhov hydrolysis ntawm cov coagulant nyuaj dua, tshwj xeeb tshaj yog thaum qhov kub ntawm dej qis dua 5 ℃, qhov hydrolysis qeeb, thiab cov flocculant tsim muaj cov qauv xoob, cov dej ntau thiab cov khoom me me. Thaum qhov kub ntawm dej qis, qhov kev yaj ntawm cov khoom colloidal nce ntxiv, lub sijhawm flocculation ntev, thiab qhov kev tso dej qeeb. Kev tshawb fawb qhia tau hais tias qhov kub ntawm dej ntawm 25 ~ 30 ℃ yog qhov tsim nyog dua.

2. Tus nqi pH ntawm dej

Cov txheej txheem hydrolysis ntawm polyaluminum chloride yog ib qho txheej txheem ntawm kev tso tawm H + tas mus li. Yog li ntawd, nyob rau hauv cov xwm txheej pH sib txawv, yuav muaj cov tshuaj hydrolysis sib txawv, thiab qhov zoo tshaj plaws pH nqi ntawm polyaluminum chloride coagulation kev kho mob feem ntau yog ntawm 6.5 thiab 7.5. Cov nyhuv coagulation yog siab dua lub sijhawm no.

3. Kev siv tshuaj coagulant

Thaum cov coagulant ntxiv tsis txaus, qhov seem turbidity hauv cov dej tawm yuav loj dua. Thaum cov khoom loj dhau, vim tias cov khoom me me colloidal hauv dej nqus cov coagulant ntau dhau, qhov khoom them ntawm cov khoom me me colloidal hloov pauv, ua rau cov seem turbidity hauv cov dej ntws rov qab nce ntxiv. Cov txheej txheem coagulation tsis yog ib qho tshuaj yooj yim, yog li qhov xav tau koob tshuaj tsis tuaj yeem txiav txim siab raws li kev xam, tab sis yuav tsum txiav txim siab raws li qhov zoo ntawm dej tshwj xeeb kom txiav txim siab qhov koob tshuaj tsim nyog; Thaum qhov zoo ntawm dej hloov pauv raws caij nyoog, qhov koob tshuaj yuav tsum tau hloov kho raws li.

4. Kev sib txuas lus nruab nrab

Thaum lub sijhawm kho cov dej khov lossis lwm yam kev kho dej nag, yog tias muaj qee cov av nkos hauv dej, cov nyhuv ntawm kev kho cov dej khov tuaj yeem txhim kho tau zoo heev. Nws tuaj yeem muab thaj chaw loj, los ntawm kev nqus, catalysis thiab crystallization core, txhim kho cov nyhuv ntawm kev kho cov dej khov.

Tam sim no, kev siv cov tshuaj coagulation precipitation yog ib txoj kev kho dej uas siv dav heev. Kev lag luam Polyaluminum chloride siv los ua cov tshuaj flocculant kho dej, nrog kev ua haujlwm zoo ntawm coagulant, cov floc loj, cov koob tshuaj tsawg dua, kev ua haujlwm siab, cov nag sai, ntau yam kev siv thiab lwm yam zoo, piv rau cov tshuaj flocculant ib txwm muaj, cov nqi tuaj yeem txo tau 1/3 ~ 1/2, thiab tus nqi tuaj yeem txuag tau 40%. Ua ke nrog kev ua haujlwm ntawm lub lim dej tsis muaj valve thiab lub lim dej carbon activated, qhov turbidity ntawm cov dej nyoos raug txo qis heev, qhov zoo ntawm cov dej khib nyiab ntawm lub kaw lus desalt tau zoo dua, thiab lub peev xwm pauv ntawm cov desalt resin kuj nce ntxiv, thiab tus nqi ua haujlwm raug txo qis.