Pehea ka loaʻa ʻana o ka membrane RO i ka 99.9% paʻakai hōʻole?

Hoʻohana ʻia ka membrane reverse osmosis (RO membrane) ma ke kumu kumu o ka pale ʻana i ke kaʻina osmotic kūlohelohe. Eia ka ʻike hohonu o kāna ʻano hana.

ʻO ka hoʻohālikelike kino o Natural Osmosis a me Reverse Osmosis

ʻO ka Natural Osmosis Phenomenon ka wā e loaʻa ai ka ʻokoʻa ʻokoʻa ma nā ʻaoʻao ʻelua o ka membrane semipermeable (e like me ka wai hou a me ka wai paʻakai), e kahe wale nā ​​mole wai mai ka ʻaoʻao haʻahaʻa a i ka ʻaoʻao kiʻekiʻe a hiki i ke kaulike ʻana o nā ʻaoʻao ma nā ʻaoʻao ʻelua. I kēia manawa, ʻo ke kaomi i hana ʻia e ka ʻokoʻa kiʻekiʻe o ka ʻili wai ka osmotic pressure.

ʻO ke kaomi osmotic π o kahi hoʻoheheʻe dilute ʻo ia: π = iCRT (kahi i ka helu o nā ion i hana ʻia e ka electrolysis o nā molekole solute; ʻO C ka ʻike mola o ka solute; ʻO R ke kinoea molar mau; ʻO T ka wela piha.)
No ka laʻana, ʻoi aku ke kiʻekiʻe o ke kaomi osmotic o ke kai e like me ka 28 bar, e koi ana i ke kaomi nui aʻe e hoʻohuli i ke kahe wai.

Ke hoʻohana nei ʻo "High-Pressure Counter-Flow" o Reverse Osmosis i ke kaomi i ka ʻaoʻao paʻakai (>osmotic pressure) e hoʻoikaika i nā molekele wai e kahe i hope, e loaʻa ana i ka neʻe ʻana i ka neʻe ʻana i ka neʻe ʻana mai ka "wai saline → wai maʻemaʻe."

I loko o ka osmosis hoʻohuli, ʻo ka wikiwiki osmotic o ka mea hoʻoheheʻe, ʻo ia hoʻi, ka ikehu kahe wai N, ʻo ia: N=Kh(Δp－Δπ) (kahi ʻo Kh ka pākēneki permeability hydraulic, e piʻi iki ana me ka mahana; ʻo Δp ka ʻokoʻa kaomi paʻa ma waena o ka membrane; ʻo Δπ ka ʻokoʻa osmotic pressure ma waena o ka membrane).

I kēia manawa: Ma ka ʻaoʻao wai maʻemaʻe: ʻO ka ʻohi ʻana i nā molekala wai e hele i loko (permete), Ma ka ʻaoʻao wai i hoʻopaʻa ʻia: E mālama ana i ka paʻakai, nā metala kaumaha, a me nā mea haumia ʻē aʻe (concentrate).

ʻOi loa ka pololei o ke kūkulu ʻana i ka membrane

ʻO ka hana Sandwich:

Kākoʻo kākoʻo: ʻO ka lole i ulana ʻole ʻia (ka mānoanoa ≈ 120 μm) - ka "paʻa kila" e kū nei i ke kaomi kiʻekiʻe.

Papa poha: ʻO nā mea polysulfone (ka nui o ka pore 0.01-0.1 μm) - ka "laina mua o ka pale" e hoʻopili i ka lepo, ke one, a me ka ʻōpala.

Papa hana: ʻO ke kiʻiʻoniʻoni polyamide (ka mānoanoa ≈ 200 nm) - ka "molecular referee" maoli me ka nui o ka pore he 0.1-1 nm wale nō (≈ ʻelua ka nui o nā molekele wai).

ʻIkepili hoʻohālikelike:

Virus anawaena (0.02-0.3 μm) > Membrane pore nui 3000 manawa.

Ka nui o ka bacteria (0.5-5 μm) > Ka nui o ka membrane pore 5000 manawa.

Ka manaʻo kumu hoʻohālike

• Hoʻohālikelike-Diffusion Model

Manaʻo kumu: ʻO ka membrane he ʻano like ʻole me ka ʻole o nā pores, a ua hoʻoneʻe ʻia ka solute a me ka solvent ma o ka hoʻoheheʻe ʻana i ka mea membrane a me ka diffusion.

Kaʻina hoʻouna:

Dissolution: Hoʻopili nā molekala wai a me nā solutes ma ka ʻili o ka membrane a hoʻoheheʻe ʻia i loko o ka mea membrane;
Hoʻopuehu: Ma lalo o ka ikaika hoʻokele o ka gradient hiki kemika (ka ʻokoʻa o ke kaomi), ʻoi aku ka maikaʻi o nā molekole wai ma o ka membrane;

Desorption: Hoʻokuʻu ʻia e like me ka wai maʻemaʻe ma kēlā ʻaoʻao o ka membrane.

Manaʻo makemakika: Ka wai kahe Jw = A(ΔP − Dp), inā ʻo A ʻo ia ke koena o ka membrane permeability coefficient, ʻO DʻO P ke kaomi i hoʻohana ʻia, a ʻO Dp ʻo ka ʻokoʻa osmotic pressure.

• Hoʻohālike Adsorption-Capilary Flow Model

Manaʻo kumu: Aia nā kahawai nanoscale i ka ʻili o ka membrane, kahi e hoʻopili ai i nā molekele wai e hana i kahi monolayer o "wai paʻa," aʻo nā solutes e hoʻihoʻi ʻia.

ʻAno hoʻouna:

Hoʻopili koho: Hoʻopili koho ka ʻili o ka membrane i nā molekele wai ma o nā paʻa hydrogen (e laʻa, carbonyl oxygen i cellulose acetate);

Ka lawe ʻana i ke kahawai: Ma lalo o ke kaomi kiʻekiʻe, hele ka wai i hoʻopaʻa ʻia ma nā kahawai ma o ka "lele ʻana i ka paʻa hydrogen," ʻoiai e mālama ʻia nā solutes ma muli o ka wehe ʻana o ka nui.

Hana:

Laki hōʻole paʻakai: 98%-99.9% (TDS

Laki hoʻoneʻe metala kaumaha: >99.9% (lead, arsenic, etc.).

ʻO nā kumu hoʻoikaika nui

Pumi Hana
Pono ʻo > solution osmotic pressure, maʻamau 60-80 bar no nā hana ʻoihana (desalination), a me 2-4 bar no ka hoʻohana ʻana i ka hale.

Ka wela: 5-45 ℃ (ke wela kiʻekiʻe ke kumu o ka deformation pore membrane)

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

ʻAno haumia

Ka hoʻonui ʻia ʻana (e laʻa, CaCO₃): Pono ka hoʻomaʻemaʻe ʻana i ka waikawa citric ma ka pH=2

ʻO ka hoʻohaumia olaola (e laʻa, nā kiʻiʻoniʻoni bacterial): mālama ʻia me DBNPA sanitizer.

ʻO nā hiʻohiʻona noiʻi a me ke koho ʻano membrane

ʻO ka hoʻoheheʻe ʻana i ka wai kai ʻo Polyamide composite membrane (TFC) Ke kūʻē i ke kaomi kiʻekiʻe (＞60 bar), 99% desalination rate

ʻO ka hoʻomaʻemaʻe wai home Spiral composite membrane ʻO ka hana haʻahaʻa haʻahaʻa (2-4 bar), mālama i ka ikehu 30%.

ʻO ka wai maʻemaʻe ʻoihana (nā ʻāpana uila) ʻO ka membrane composite puʻe haʻahaʻa haʻahaʻa.