Cov dej kais dej feem ntau muaj cov ntsev yaj xws li sodium, calcium, magnesium, chloride, nitrates, thiab silicon. Cov ntsev no yog tsim los ntawm qhov tsis zoo them nyiaj ions (ACs) thiab qhov zoo them ions (Cs). Rov qab osmosis tuaj yeem tshem tawm ntau dua 99% ntawm cov ions no. Cov dej kais dej kuj tseem muaj cov kab hlau, cov roj yaj (xws li CO2), thiab lwm yam tsis muaj zog ionized (xws li silicon thiab boron) uas yuav tsum tau muab tshem tawm hauv kev kho mob.
Cov conductivity ntawm RO rov qab osmosis effluent (EDI pub dej) feem ntau yog 10⁻² μS / cm, nrog rau qhov zoo tshaj tus nqi qis dua 6 μS / cm. Raws li cov kev cai tshwj xeeb, qhov kev tiv thaiv ntawm ultrapure dej tsim los ntawm EDI tuaj yeem ncav cuag 15-18 MΩ·cm. Cov dej tsis txaus tuaj yeem ua rau tsis muaj kev puas tsuaj rau EDI thiab ua rau nws lub neej luv.
Kev sib pauv cov tshuaj tiv thaiv tshwm sim nyob rau hauv lub desalination chamber ntawm lub module, qhov twg anion pauv resins siv lawv hydroxide ions (OH⁻) pauv rau anions (xws li chloride ions, Cl⁻) nyob rau hauv cov ntsev yaj. Ua ke, cation txauv resins siv lawv cov hydrogen ions (H⁺) los pauv rau cations (xws li Na⁺) hauv cov ntsev yaj.
Ib tug raug EDI membrane pawg muaj ntau chav nyob sandwiched ntawm ob electrodes. Txhua chav tsev muaj ib lub desalination chamber thiab ib tug concentrate chamber. Lub desalination chamber yog sau nrog ib tug sib tov ntawm anion thiab cation txauv resins, uas yog positioned ntawm lub cation exchange membrane thiab cov anion exchange membrane.
Ib qho DC hluav taws xob yog siv nruab nrab ntawm anode (+) thiab cathode (-) ntawm ob qho kawg ntawm lub module. Qhov no muaj peev xwm ua rau cov ions sib pauv ntawm cov resin mus rau ntawm qhov chaw ntawm cov resin hais thiab dhau los ntawm daim nyias nyias mus rau hauv cov concentrate chamber. Lub anode attracts anions (xws li OH-, Cl-), uas dhau los ntawm cov anion txauv membrane rau hauv cov concentrate chamber uas nyob ib sab tab sis raug thaiv los ntawm cation exchange membrane, yog li nyob rau hauv lub concentrate chamber. Lub cathode attracts cations (xws li H +, Na +), uas dhau los ntawm cov cation txauv membrane rau hauv cov concentrate chamber uas nyob ib sab tab sis raug thaiv los ntawm anion exchange membrane, yog li nyob rau hauv lub concentrate chamber. Raws li cov dej ntws los ntawm ob qho tib si chamber no, ions raug tshem tawm ntawm lub desalination chamber thiab sib sau ua ke hauv cov concentrate chamber uas nyob ib sab, qhov uas lawv tau nqa tawm ntawm lub module los ntawm cov dej ntws. DC qhov hluav taws xob siv thoob plaws hauv daim nyias nyias tsis tsuas yog tsav ion tsiv teb tsaws tab sis tseem cuam tshuam cov dej molecules, tsim kom muaj ntau H + thiab OH-. Cov H + thiab OH- ions tsiv teb tsaws nyob rau hauv lub zog ntawm ib qho hluav taws xob teb, regenerating deactivated cation exchanges thiab anion exchange resins feem, yog li ua tiav tas li electrochemical regeneration ntawm cov resins yam tsis tas yuav tsum tau rau lwm yam tshuaj. Nyob rau hauv ib tug raug EDI system, kwv yees li 5% -10% ntawm cov dej pub nkag mus rau hauv lub concentrate chamber. Cov concentrate yog circulated los ntawm lub twj tso kua mis ntawm tus nqi siab, uas yuav pab txhim kho desalination efficiency, txhawb dej sib tov, thiab txo qhov kev pheej hmoo ntawm scaling. Concentrated ions raug tso tawm los ntawm lub cev los ntawm kev tso tawm ib feem ntawm cov concentrate.
Txhawm rau kom ruaj khov thiab ua haujlwm tau zoo ntawm EDI system, tsim nyog pretreatment ntawm cov dej pub (xws li rov qab osmosis) yog tsim nyog los tswj nws cov conductivity, hardness, organic teeb meem, thiab tshem tawm cov ntsiab lus. Cov impurities hauv cov dej pub muaj qhov cuam tshuam loj rau ntawm deionization module thiab yuav ua rau nws lub neej luv.
