Rov qab osmosis, tseem hu ua thim rov qab osmosis, yog cov txheej txheem sib cais membrane uas siv qhov sib txawv ntawm qhov sib txawv raws li lub zog tsav los cais cov kuab tshuaj los ntawm kev daws.
Lub siab yog siv rau cov tshuaj pub rau ntawm ib sab ntawm daim nyias nyias. Thaum lub siab tshaj nws osmotic siab, cov kuab tshuaj yuav permeate nyob rau hauv opposite kev taw qhia ntawm ntuj osmosis. Yog li, cov kuab tshuaj permeated, piv txwv li, permeate, tau txais ntawm qhov qis - siab ntawm daim nyias nyias, thaum cov tshuaj concentrated, piv txwv li, concentrate, tau txais ntawm siab - siab. Yog tias rov qab osmosis yog siv los kho cov dej hiav txwv, cov dej tshiab tau txais ntawm qhov qis - siab ntawm daim nyias nyias, thiab brine tau txais nyob rau sab siab - siab.
Thaum lub sij hawm rov qab osmosis, qhov hnyav permeation tus nqi, piv txwv li, cov kua ntws zog N, yog: N=Kh (Δp - Δπ), qhov twg Kh yog hydraulic permeability coefficient, uas nce me ntsis nrog nce kub; Δp yog qhov sib txawv ntawm qhov sib txawv hydrostatic nyob rau hauv daim nyias nyias; thiab Δπ yog qhov sib txawv osmotic siab ntawm cov tshuaj nyob rau hauv daim nyias nyias. Lub siab osmotic π ntawm dilute tov yog: π=iCRT, qhov twg kuv yog tus naj npawb ntawm ions generated los ntawm ionization ntawm cov kua molecule; C yog molar concentration ntawm cov kuab tshuaj; R yog molar gas tas li; thiab T yog qhov kub thiab txias. Rov qab osmosis feem ntau siv cov asymmetric membranes thiab cov ntaub ntawv sib xyaw. Cov cuab yeej siv rau rov qab osmosis feem ntau yog hollow fiber lossis kauv qhov txhab membrane cais cov khoom.
Rov qab osmosis daim nyias nyias muaj peev xwm khaws tau ntau yam inorganic ions, colloidal tshuaj, thiab loj molecular solutes hauv dej, yog li tau txais cov dej huv. Nws kuj tseem tuaj yeem siv rau ua ntej - kev sib xyaw ntawm cov kev daws teeb meem uas muaj cov khoom loj molecular organic. Vim nws txoj kev yooj yim thiab kev siv hluav taws xob tsawg, rov qab osmosis tau tsim kho sai hauv 20 xyoo dhau los. Nws yog tam sim no dav siv hauv dej hiav txwv thiab dej brackish (saib brine) desalination, boiler dej softening, thiab kev kho dej khib nyiab. Ua ke nrog kev sib pauv ion, nws yog siv los tsim cov dej huv siab - purity, thiab nws daim ntawv thov tau nthuav dav, tam sim no suav nrog cov ntsiab lus ntawm cov khoom siv mis nyuj thiab kua txiv hmab txiv ntoo, nrog rau kev sib cais thiab concentration ntawm biochemical thiab cov tshuaj lom neeg.