Rov qab osmosis membrane tshuab ua lub luag haujlwm tseem ceeb tsis yog hauv kev kho dej haus nkaus xwb tab sis kuj tseem nyob hauv kev kho dej khib nyiab, kev tsim tshuaj dej, thiab dej ultrapure rau kev lag luam hluav taws xob. Hauv kev kho dej khib nyiab hauv kev lag luam, rov qab osmosis daim nyias nyias tuaj yeem txo qhov concentration ntawm cov pa phem hauv cov dej khib nyiab, ua kom nws ua tau raws li cov qauv tso tawm lossis rov siv dua. Qhov no tsis yog tsuas yog txo cov pa phem ib puag ncig tab sis kuj ua tiav cov peev txheej dej rov ua dua tshiab, ua raws li lub tswv yim ntawm kev txhim kho kom ruaj khov.
Hauv kev lag luam kws kho mob, rov qab osmosis daim nyias nyias yog siv los tsim cov khoom siv tshuaj siab -purity purity, xws li dej rau kev txhaj tshuaj thiab dej tsis muaj menyuam. Qhov siab - dej purity no ua lub luag haujlwm tseem ceeb hauv kev tsim tshuaj, ua kom zoo thiab kev nyab xeeb ntawm cov tshuaj. Hauv kev lag luam hluav taws xob, thim rov qab osmosis membrane tshuab ua ke nrog kev sib pauv ion tuaj yeem tsim tau siab - dej ntshiab siv rau hauv cov txheej txheem tsim khoom xws li cov khoom siv hluav taws xob thiab cov khoom sib txuas. Kev siv siab - dej purity tsis tsuas yog txhim kho cov khoom zoo thiab kev ntseeg siab xwb tab sis kuj tseem ua rau lub neej ntev ntawm cov khoom siv ntau lawm.