Coagulation yog ib kauj ruam tseem ceeb hauv kev kho dej. Nws cuam tshuam ncaj qha rau kev tshem tawm cov teeb meem tshem tawm thiab cov colloidal impurities hauv dej, thiab tseem cuam tshuam rau kev ruaj ntseg thiab kev lag luam ntawm cov txheej txheem tom ntej xws li pom, softening, thiab desalination. Txawm li cas los xij, cov nyhuv coagulation tsis tsuas yog txiav txim siab los ntawm qhov ntau npaum li cas ntawm cov reagent, tab sis yog cuam tshuam los ntawm kev sib xyaw ua ke nrog rau cov xwm txheej hydraulic, dej kub, pH nqi, dej hardness, thiab alkalinity. Kab lus no tau txheeb xyuas cov xwm txheej cuam tshuam rau coagulation efficiency los ntawm ob qho tib si engineering xyaum thiab theoretical foundations, thiab siv cov tshuaj tiv thaiv kab zauv sib npaug thiab xam cov qauv los pab cov nyeem kom nkag siab tob txog cov txheej txheem tseem ceeb no.
I. Qhov cuam tshuam ntawm Hydraulic Conditions ntawm Coagulation Efficiency
Lub ntsiab lus ntawm cov txheej txheem coagulation yog kev sib ntsib thiab cov tshuaj tiv thaiv ntawm reagents nrog impurity hais nyob rau hauv dej, thaum kawg tsim loj thiab ruaj khov flocs. Yog tias cov xwm txheej hydraulic tsis txaus, cov reagents tsis tuaj yeem sib xyaw nrog dej, ua rau cov tshuaj tiv thaiv qis; Txawm li cas los xij, yog tias cov xwm txheej hydraulic muaj zog dhau lawm, cov flocs twb tsim lawm yuav tawg. Yog li ntawd, qhov sib zog sib zog yuav tsum tau tswj nyob rau hauv qhov tsim nyog ntau yam. Ib qho kev qhia siv hydraulic feem ntau yog qhov sib xyaw siv gradient G tus nqi, xam raws li hauv qab no.
Hauv cov mis: G yog qhov sib xyaw siv gradient, s⁻¹; yog qhov ntom ntom ntawm cov dej, N / m³ lossis kg / m³; h yog lub taub hau poob hauv cov khoom siv coagulation, m; μ yog dynamic viscosity ntawm dej, Pa·s lossis N·s/m³; T yog lub sijhawm nyob nruab nrab ntawm cov dej ntws los ntawm cov khoom siv, s.
Hauv kev ua haujlwm tiag tiag, qhov tsim nyog G tus nqi ntau rau cov theem sib xyaw feem ntau yog 600-1000 s⁻¹; Qhov tsim nyog G tus nqi ntau rau theem flocculation feem ntau yog 20-70 s⁻¹.
II. Kev cuam tshuam ntawm Dej Kub ntawm Coagulation Efficiency
Dej kub yog lwm yam tseem ceeb cuam tshuam rau coagulation efficiency. Thaum qhov kub thiab txias txo, qhov viscosity ntawm cov dej nce, lub sijhawm rau kev sib tsoo ntawm cov khoom txo qis, thiab floc tsim tus nqi qeeb zuj zus; Nyob rau tib lub sijhawm, qhov kub thiab txias kuj tseem cuam tshuam cov tshuaj tiv thaiv hydrolysis ntawm cov reagents, ua rau txo qis hauv coagulation efficiency. Thaum cov dej kub siab tshaj 15 degree, cov tshuaj tiv thaiv hydrolysis accelerates, floc loj hlob sai, thiab sedimentation yog zoo. Thaum cov dej kub qis dua 10 degree, lub hydrolysis ntawm tus neeg sawv cev yog qhov nyuaj, lub zog interparticle khi tsis muaj zog, floc yog xoob, thiab sedimentation nyuaj. Thaum cov dej kub qis dua 5 degree, qhov ntau npaum ntawm coagulant yuav tsum tau nce ntxiv, thiab kev hloov alkalinity kuj tseem tsim nyog los xyuas kom meej cov nyhuv.
Yog li ntawd, nyob rau hauv lub caij ntuj no kev ua hauj lwm, nws yog ib qhov tsim nyog yuav tau siv ntau npaum li cas ntawm cov tshuaj ntawm tus neeg sawv cev thiab ua rau kom lub stirring siv kom them nyiaj rau qhov tsis zoo ntawm qhov kub thiab txias.
III. Kev cuam tshuam ntawm pH tus nqi ntawm Coagulation nyhuv
Cov tshuaj tiv thaiv hydrolysis ntawm coagulants hauv dej yog ze ze rau tus nqi pH ntawm cov tshuaj. Noj cov ntsev txhuas thiab cov ntsev hlau ua piv txwv, lawv cov khoom siv hydrolysis thiab nag lossis daus yuav hloov pauv nrog cov pH sib txawv.
1. Aluminium ntsev Coagulant Reaction
Nyob rau hauv cov xwm txheej zoo pH, txhuas ntsev tuaj yeem tsim aluminium hydroxide precipitate, raws li qhia hauv qab no.
Cov nyhuv coagulation yog qhov zoo tshaj plaws thaum pH tus nqi ntawm cov dej nyob hauv thaj tsam ntawm 5.5 txog 7.5.
2. Cov tshuaj tiv thaiv ntawm Ferrous ntsev Coagulants
Lub hydrolysis ntawm ferric ntsev nyob rau hauv dej yog complex, feem ntau nrog rau cov nram qab no cov tshuaj:
Qhov zoo pH ntau yog 6.0-8.0. Yog tias pH qis dua 3, ferric ntsev tsis tuaj yeem tsim ferric hydroxide flocs; Yog hais tias pH siab tshaj 9, Fe³⁺ yuav hloov mus rau ntau soluble complex ions, txo cov coagulation nyhuv. Nyob rau hauv high alkalinity tej yam kev mob, ferric ntsev tau txais cov nram qab no cov tshuaj tiv thaiv.
Yog li ntawd, cov nyhuv coagulation ntawm ferric ntsev yog qhov zoo tshaj plaws nyob rau hauv nruab nrab lossis me ntsis alkaline tej yam kev mob.
IV. Cov teebmeem ntawm Dej Hardness thiab Alkalinity
Bicarbonate, calcium, thiab magnesium ions nyob rau hauv dej tuaj yeem cuam tshuam rau hydrolysis ntawm coagulants thiab floc tsim vim yog cov nram qab no tshwm sim.
Tsim nyog alkalinity yog qhov zoo rau cov tshuaj tiv thaiv. Yog tias cov dej alkalinity tsawg dhau lawm, cov txiv qaub ntxiv (CaO) lossis dej qab zib tshauv yuav tsum tau ntxiv kom ntseeg tau tias muaj cov hydroxide flocs txaus. Cov mis hauv qab no tuaj yeem siv los kwv yees cov nyiaj alkalinity them ntau npaum li cas.
Hauv cov mis: [CaO] yog qhov ntau npaum ntawm cov txiv qaub ntshiab (CaO), mg sib npaug / L; [a] yog qhov ntau npaum ntawm coagulant, mg sib npaug / L; [z] yog alkalinity ntawm cov dej nyoos, mg sib npaug / L; [δ] yog qhov seem alkalinity, feem ntau yog 0.5-1.0 mg sib npaug / L.
Cov ntsiab lus: Coagulation tsis yog ib qho tshuaj tiv thaiv ib leeg, tab sis cov txheej txheem dav dav uas cuam tshuam nrog kev sib xyaw ua ke ntawm lub cev, tshuaj, thiab hydraulic. Kev hloov pauv hauv txhua yam, los ntawm kev sib zog siv rau dej kub, los ntawm pH mus rau alkalinity, tuaj yeem ua rau muaj qhov sib txawv ntawm qhov kawg tshwm sim. Yog li ntawd, tsuas yog los ntawm kev nkag siab tob txog cov txheej txheem no tuaj yeem ua tiav cov txiaj ntsig kev kho dej zoo los ntawm kev hloov mus rau cov xwm txheej hauv zos. Nyob rau hauv lub neej yav tom ntej, raws li kev kho dej kev lag luam nrhiav kev txuag hluav taws xob, emission txo, thiab kev ua haujlwm tau zoo, kev tswj xyuas kom zoo ntawm cov txheej txheem coagulation yuav dhau los ua qhov tseem ceeb, thiab kev nkag siab txog nws cov kev cuam tshuam yuav dhau los ua ib qho tseem ceeb ntawm cov engineers.