Vai Ma'a & Malohi Ma'a
'Omi 'a e Vai Ma'a Ki he Tuliki Kotoa pe 'o Mamani
Vai Ma'a & Malohi Ma'a
'Omi 'a e Vai Ma'a Ki he Tuliki Kotoa pe 'o Mamani
TDS, pH, SDI, fefeka, boron mo e niʻihi kehe — founga hono lau ʻo ha sivi vai ki he faʻu RO.
ʻOku kamata ʻa e poloseki RO kotoa ʻi ha sivi ʻo e vai fakahū. ʻOku fakamatalaʻi ʻe he tataki ni ʻa e ngaahi fua ʻoku mahuʻinga ki he faʻu ʻo e sisitemi, founga hono fua, mo e ngaahi lahi angamaheni ʻo e maʻuʻanga vai taki taha. Fakataha eni mo e Ngaahi Meʻa Tefito ʻo e RO mo e Tataki Faʻu SWRO ʻi hoʻo ngāue ʻi ha poloseki moʻoni.
Ko e mamafa ʻo e meʻa taʻe-moʻui mo e meʻa ʻōkeniki kuo mole (ʻoku ʻau ʻi he 0.45 µm) ʻi he vai, ʻoku fakahā ʻi he mg/L. ʻOku fakapapauʻi ʻi hono fakamamafa ʻo ha sivi kuo tātā pea fakamōmoa ʻi he 180 °C (APHA 2540C) pe fakafuofua mei he conductivity. Ngaahi lahi angamaheni:
Ko ha fua fakaʻuhinga ʻo e TDS ʻi he ʻau ʻa e ʻuhila. ʻOku fakatatau ʻa e faktā liliu ki he ngaahi ione ʻoku ʻi ai; ko e ngaahi founga vave angamaheni:
TDS [mg/L] ≈ 0.5 to 0.7 × Conductivity [µS/cm]
Ko e ngaahi vai ʻoku lahi ai ʻa e sodium-chloride ʻoku ngāue ʻaki ha faktā māʻolunga ange (~0.65), ko e ngaahi vai ʻoku lahi ai ʻa e bicarbonate ʻoku māʻulalo ange (~0.50). Ki he vai tahi ʻoku ofi ʻa e faktā ki he 0.70 (ko e 35,000 mg/L ʻoku tatau mo e ~50,000 µS/cm). Ki he vai hū TDS māʻulalo (< 50 mg/L), ʻoku ofi ʻa e faktā ki he 0.50.
ʻOku mahuʻinga ʻa e fakatatau ʻo e māfana ki he 25 °C — ʻoku liliu ʻa e conductivity ʻi he ~2% ʻi he °C.
Ko e log fakafoki ʻo e ngāue ʻa e ione hydrogen. ʻOku ne kaunga ki he tatau ʻo e carbonate, tuʻutāmaki ʻo e tānaki fefeka, feʻunga ʻa e naunau ʻo e membrane, mo e ola ʻo e biocide. Angamaheni:
ʻOku kātakiʻi ʻe he ngaahi membrane polyamide ʻa e pH 2–11 ʻi he ngāue mo e pH 1–13 lolotonga ʻa e fakamaʻa. ʻOku faʻa ngāue ʻaki ʻa e fakatonutonu ʻo e pH ke taʻofi ʻa e tānaki fefeka carbonate (vai fakahū ʻesita) pe fakalelei ʻa e taʻofi ʻo e boron (vai fakahū ʻalikalaʻi ʻi he hū tuʻo ua).
Ko e fua fakatuʻunga ʻo e ʻuli ki he ngaahi vai fakahū RO. ʻOku ʻahiʻahiʻi ha tātā 0.45 µm ʻi he mafatukituki fakahū 30 psi, pea fua ʻa e taimi ke tātā ai ʻa e 500 mL ʻi he t = 0, pea toe fai ʻi he hili ʻa e miniti ʻe 5, 10, pe 15 ʻo e tātā taʻetuʻu. ʻOku lau ʻa e SDI ʻo pehē:
SDI₁₅ = 100 × (1 − t₀ / t₁₅) / 15
Ngaahi taumuʻa ʻa e kau ngaohi membrane:
Ko e SDI ʻoku fakatatau ki he sivi pea ʻoku kaunga ki ai ʻa e tokotaha ngāue. Ko e Modified Fouling Index (MFI) ko ha founga kehe.
ʻOku ne fua ʻa e fakamovetevete ʻo e maama ʻe he ngaahi meʻa iiki ʻoku tautau. Ko e vai fakahū RO ʻoku lelei: < 0.2 NTU hili ʻa e tokanga muʻa (ʻoku ala maʻu ʻa e 1 NTU ki he vai vaikeli taʻe ha tātā ka ʻoku ʻikai feʻunga ki he maʻu vai ʻoku ava). ʻE lava ke laka hake ʻa e vai ʻi ʻolunga ʻi he 100 NTU lolotonga ʻa e afā; ʻoku fie maʻu ʻa e fakataha meʻa iiki mo e multimedia pe UF.
Ko e fakakātoa ʻo e ngaahi ione calcium mo e magnesium, ʻoku fakahā ko e mg/L CaCO₃. Ngaahi vahevahe:
ʻOku ne pule ki he tuʻutāmaki ʻo e tānaki fefeka CaCO₃ ʻi he BWRO mo e RO vai paipa. Lau ʻa e Langelier Saturation Index (LSI) mo e Stiff & Davis Stability Index (S&DSI ki he TDS māʻolunga) ke tomuʻa ʻilo ʻa e tānaki fefeka. ʻOku fie maʻu ʻa e fakamahu antiscalant pe ko ha tokanga muʻa fakamolū ʻi he taimi ʻoku fakahā ai ʻe he ngaahi fua ʻa e tānaki fefeka.
ʻOku fakaʻokosisheni ʻa e ngaahi membrane polyamide ʻi he ala ki he kolo. ʻOku tānaki ʻa e kātaki: ~1,000 ppm-houa ʻo e ala kimuʻa peá ne kamata ke mole ha ngāue ʻoku ala fua. Ko e ngataʻanga ngāue moʻoni: < 0.1 ppm taʻetuʻu. Toʻo ʻa e kolo ʻaki:
ʻOku maumau lahi ange ʻa e chloramine (NH₂Cl) ʻi he kolo taʻehaʻi pea ʻoku ʻikai faingofua hono toʻo ʻe he SMBS — faʻu fakatokanga ʻi he taimi ʻoku ʻi ai ʻa e chloramine ʻi he vai ʻa e kolo.
Ko ha meʻa ʻuli faingataʻa ki he SWRO. ʻOku ʻi ai ʻi he vai tahi ʻa e 4–5 ppm boron ko e ʻesiti boric (pKa = 9.2). ʻI he pH fakanatula ʻo e vai tahi (~8.0), ʻoku ʻi ai ʻa e boron ko e H₃BO₃ taʻe-uku, ʻa ia ʻoku toʻo pē ʻe he polyamide ʻa e 50–90% — ʻe lava ke aʻu ʻa e boron ʻi he vai hū ki he 0.5–2 mg/L ʻi he hū tuʻo taha. Ngaahi taumuʻa:
Ngaahi founga: ngaahi membrane taʻofi boron māʻolunga (FilmTec SW30HRLE, Toray TM820), RO hū tuʻo ua ʻi he pH māʻolunga (10–10.5) ʻa ia ʻoku toʻo lelei ai ʻa e boron, pe ko ha fakamaʻa ʻaki ha resin fetongi ione boron (Purolite S108, Lewatit MK51).
Ko e Total Organic Carbon (TOC) ʻa e fua ʻaonga taha. Ko e TOC > 2 mg/L ʻoku fakaʻilonga ʻoku fie maʻu ha tokanga muʻa lahi ange (fakataha meʻa iiki, DAF, UF, pe karapone ngāue). Ko e ngaahi meʻa humic mamafa ʻoku nau fakaʻuli ʻa e membrane pea fakalahi ʻa e ʻuli fakaeʻilo moʻui ʻi hono fafanga ʻo e biofilm.
| Ione | Vai Tahi (mg/L) | Mahuʻinga ki he RO |
|---|---|---|
| Sodium (Na⁺) | 10,800 | Ko e cation tefito; ʻoku fakatatau ʻe he Cl⁻ ke tatau ʻa e uku |
| Chloride (Cl⁻) | 19,400 | ʻOku ne fokotuʻu ʻa e ngāue ʻo e ʻuli metale; ʻoku fie maʻu ʻa e Super Duplex 2507 ki he SWRO |
| Sulfate (SO₄²⁻) | 2,700 | Tuʻutāmaki ʻo e tānaki fefeka BaSO₄ / SrSO₄ / CaSO₄; ʻoku fie maʻu ʻa e antiscalant |
| Magnesium (Mg²⁺) | 1,290 | Fefeka; Mg(OH)₂ ʻi he pH māʻolunga ʻaupito |
| Calcium (Ca²⁺) | 410 | Tānaki fefeka CaCO₃ / CaSO₄; ʻoku fie maʻu ha sivi LSI / S&DSI |
| Potassium (K⁺) | 390 | Siʻi; ʻoku toʻo tatau mo e Na |
| Bicarbonate (HCO₃⁻) | 140 | ʻOku ne fokotuʻu ʻa e ʻalikalaʻi mo e tuʻutāmaki ʻo e tānaki fefeka CaCO₃ |
| Bromide (Br⁻) | 67 | ʻOku faʻu ʻa e bromate kapau ʻe tomuʻa fakaʻokosisheni ʻaki ʻa e ozone |
| Strontium (Sr²⁺) | 8 | Tānaki fefeka SrSO₄ ʻi he BWRO ʻi he fakaakeake māʻolunga |
| Barium (Ba²⁺) | 0.02 | Siʻi ʻaupito, ka ʻoku māʻulalo ʻaupito ʻa e ʻau ʻa e BaSO₄ |
| Silica (SiO₂) | 0.1–10 | Faingataʻa hono fakamaʻa; ʻoku ne fakangatangata ʻa e fakaakeake BWRO |
| Fluoride (F⁻) | 1.3 | ʻE laka hake nai ʻa e ngaahi vaikeli kona siʻi; tānaki fefeka CaF₂ |
| Nitrate (NO₃⁻) | 0.5 | Meʻa hoha ki he vai inu ʻi he ngaahi vaikeli ngoue (> 10 mg/L NO₃-N) |
Ko e HPC (heterotrophic plate count), ngaahi coliform kātoa, mo e ATP (meʻa moʻui) ʻoku nau fakahā ʻa e tuʻutāmaki ʻo e ʻuli fakaeʻilo moʻui. Ko e ngaahi maʻu vai ʻoku ava (tautautefito ʻi he māfana) ʻoku fie maʻu ha founga biocide — kolo ʻi he taimi ki he taimi mo e toʻo kolo, pe fakamahu vave ʻo e DBNPA. Ko e ngaahi fale tātā cartridge mo e ngaahi laine ʻoku tuʻu noa ko e feituʻu ia ʻoku lahi ai ʻa e biofilm.
ʻI hoʻo maʻu ha lipooti mei he fale sivi, ngāue ʻi he hokohoko ni:
Fakahū eni ki he polokalama fakafuofua (DuPont WAVE, Hydranautics IMSDesign, Toray DS2, LG Q+) ki he fili ʻo e membrane mo e fokotuʻutuʻu.
mg/L ÷ equivalent weight = meq/L
hangē, Ca²⁺: 40.08 / 2 = 20.04 g/eq, ko ia ko e 100 mg/L Ca²⁺ = 5.0 meq/L
mg/L ÷ molecular weight = mmol/L
hangē, 100 mg/L Ca²⁺ = 100 / 40.08 = 2.49 mmol/L
1 NTU ≈ 0.5–2.4 mg/L meʻa ʻoku tautau (ʻoku fakatatau ki he maʻuʻanga vai)
1 grain/gallon fefeka = 17.1 mg/L ko e CaCO₃
Founga ngāue ʻa e osimosisi fakafoki.
Fua mo e fokotuʻu ʻo e ngaahi ʻapi RO vai tahi.
Fakamaʻa, siofi, mo e fetongi.
PX pe HPB mo e lau ʻo e SEC.
Fua ʻo e SWRO taʻe ʻi he ʻuhila mo e fakatahaʻi.
ʻOatu mai hoʻo sivi vai fakahū mo e ngaahi taumuʻa ʻo e lahi — te mau fua ʻa e sisitemi mo ʻoatu hono totongi.
Kole ha Fakamatala Totongi