Yuav Ua Li Cas RO Membrane Ua tiav 99.9% Kev Tsis Txaus Ntsig?

Rov qab osmosis membrane (RO membrane) ua haujlwm ntawm lub hauv paus ntsiab lus ntawm kev tiv thaiv cov txheej txheem osmotic. Ntawm no yog ib qho kev ntsuam xyuas qhov tob ntawm nws cov txheej txheem ua haujlwm:

Lub cev sib piv ntawm Natural Osmosis thiab Reverse Osmosis

Ntuj Osmosis Phenomenon yog thaum muaj qhov sib txawv ntawm qhov sib txawv ntawm ob sab ntawm ib lub semipermeable membrane (xws li dej tshiab thiab dej ntsev), dej molecules yuav spontaneously ntws los ntawm qhov tsawg concentration sab mus rau siab concentration sab kom txog rau thaum cov concentrations ntawm ob sab yog sib npaug. Lub sijhawm no, lub siab tsim los ntawm qhov siab sib txawv ntawm cov kua dej yog lub siab osmotic.

Lub siab osmotic π ntawm dilute tov yog: π = iCRT (qhov twg kuv yog tus naj npawb ntawm ions tsim los ntawm electrolysis ntawm cov kua molecules; C yog molar concentration ntawm cov kua; R yog molar gas tas li; T yog qhov kub thiab txias.)
Piv txwv li, lub osmotic siab ntawm seawater siab li 28 bar, yuav tsum tau ntau dua siab rov qab cov dej ntws.

"High-Pressure Counter-Flow" ntawm Reverse Osmosis yog siv lub siab rau sab saline (> osmotic siab) yuam cov dej molecules kom ntws rov qab, ua tiav qhov rov qab concentration gradient tsiv teb tsaws los ntawm "dej ntsev → dej ntshiab."

Thaum rov qab osmosis, osmotic tus nqi ntawm cov kuab tshuaj, piv txwv li, cov kua ntws zog N, yog: N = Kh (Δp-Δπ) (qhov twg Kh yog hydraulic permeability coefficient, uas me ntsis nce nrog kub; Δp yog qhov sib txawv ntawm qhov sib txawv ntawm daim nyias nyias; Δπ yog qhov sib txawv osmotic siab nyob rau hauv daim nyias nyias).

Ntawm no: Nyob rau sab dej ntshiab: Sau cov dej molecules uas dhau mus (permeate), Nyob rau sab dej concentrated: khaws ntsev, hnyav hlau, thiab lwm yam impurities (concentrate).

Extreme Precision ntawm Membrane Structure

Sandwich qauv:

Kev them nyiaj yug txheej: Non-woven npuag (thickness ≈ 120 μm) - "steel thav duab" uas tiv taus siab.

Porous txheej: Polysulfone cov khoom (pore loj 0.01-0.1 μm) - "thawj kab ntawm kev tiv thaiv" uas cuam tshuam cov av nkos, xuab zeb, thiab xeb.

Txheej txheej: Polyamide zaj duab xis (thickness ≈ 200 nm) - qhov tseeb "molecular referee," nrog lub pore loj ntawm tsuas yog 0.1-1 nm (≈ ob npaug ntawm qhov loj ntawm cov dej molecules).

Cov ntaub ntawv sib piv:

Tus kab mob txoj kab uas hla (0.02-0.3 μm) > Membrane pore loj 3000 zaug.

Cov kab mob loj (0.5-5 μm) > Membrane pore loj 5000 zaug.

Classical qauv kev tshawb xav

• Solution-Diffusion Model

Core Assumption: Lub membrane yog homogeneous qauv tsis muaj qhov hws, thiab cov kuab tshuaj thiab cov kuab tshuaj raug xa mus los ntawm kev tawg mus rau hauv cov ntaub ntawv membrane thiab diffusion.

Txheej txheem kis:

Dissolution: Dej molecules thiab solutes adsorb rau ntawm daim nyias nyias thiab yaj rau hauv cov khoom siv membrane;
Diffusion: Nyob rau hauv lub zog tsav ntawm cov tshuaj muaj peev xwm gradient (siab txawv), dej molecules nyiam diffuse los ntawm daim nyias nyias;

Desorption: Tso tawm raws li cov dej ntshiab nyob rau sab nraud ntawm daim nyias nyias.

Mathematical expression: Dej ntws Jw = A(ΔP -Dp), qhov twg A yog cov membrane permeability coefficient, DP yog lub siab thov, thiab Dp yog qhov sib txawv osmotic siab.

• Preferential Adsorption-Capillary Flow Model

Cov kev xav hauv nruab nrab: Lub membrane nto muaj nanoscale raws, uas nyiam adsorb dej molecules los tsim ib lub monolayer ntawm "kua dej", thaum cov kua dej yog repelled.

Kis mechanism:

Selective adsorption: Lub membrane nto xaiv adsorbs dej molecules ntawm hydrogen bonds (xws li, carbonyl oxygen hauv cellulose acetate);

Kev thauj mus los ntawm Channel: Nyob rau hauv qhov siab siab, cov dej khis dhau los ntawm cov kab ntawm "hydrogen bond jumping," thaum cov kua nplaum khaws cia vim qhov loj me me.

Kev ua tau zoo:

Kev tsis lees txais ntsev: 98% -99.9% (TDS

Hnyav hlau tshem tawm tus nqi:> 99.9% (cov hlau lead, arsenic, thiab lwm yam).

Yam tseem ceeb cuam tshuam

Kev Ua Haujlwm Siab
Yuav tsum yog> daws osmotic siab, feem ntau 60-80 bar rau kev siv (desalination), thiab 2-4 bar rau tsev neeg siv.

Kub: 5-45 ℃ (siab kub ua rau daim nyias nyias pore deformation)

pH ntau: 4-11 (polyamide membrane), 5-6 (cellulose acetate membrane).

Hom pa phem

Inorganic scaling (piv txwv li, CaCO₃): Yuav tsum tau citric acid ntxuav ntawm pH = 2

Kev kis kab mob lom (xws li cov kab mob kab mob): kho nrog DBNPA tshuaj tua kab mob.

Daim Ntawv Thov Scenarios thiab Membrane Hom Xaiv

Seawater desalination Polyamide Composite Membrane (TFC) Siab-siab tsis kam (＞60 bar), 99% desalination tus nqi

Kev lim dej hauv tsev Kauv puas daim nyias nyias Tsis tshua muaj siab ua haujlwm (2-4 bar), txuag hluav taws xob 30%.

Muaj dej ntshiab (suav hluav taws xob) Ultra-low pressure composite membrane Khoom dej resistivity 18 MΩ·cm.