Tshuaj lom neeg thiab cov txheej txheem rau kev tshem tawm ammonia nitrogen ntawm dej
1. Ammonia nitrogen yog dab tsi?
Ammonia nitrogen yog hais txog ammonia nyob rau hauv daim ntawv ntawm ammonia dawb (lossis non-ionic ammonia, NH3) lossis ionic ammonia (NH4 +). pH siab dua thiab qhov sib piv ntawm cov ammonia dawb siab dua; Ntawm qhov tsis sib xws, qhov sib piv ntawm cov ntsev ammonium siab.
Ammonia nitrogen yog ib qho khoom noj khoom haus hauv dej, uas tuaj yeem ua rau dej eutrophication, thiab yog cov pa phem tshaj plaws hauv dej, uas yog lom rau ntses thiab qee cov tsiaj txhu hauv dej.
Qhov teeb meem loj tshaj plaws ntawm ammonia nitrogen rau cov tsiaj txhu hauv dej yog ammonia dawb, uas nws qhov lom yog ntau dua li ntawm ammonium ntsev, thiab nce nrog rau qhov nce ntawm alkalinity. Ammonia nitrogen lom yog ze rau tus nqi pH thiab dej kub ntawm cov dej pas dej, feem ntau, tus nqi pH thiab dej kub siab dua, qhov muaj zog dua qhov lom.
Ob txoj kev ntsuas xim uas siv los txiav txim siab txog ammonia yog txoj kev Nessler reagent thiab txoj kev phenol-hypochlorite. Kev ntsuas thiab cov txheej txheem hluav taws xob kuj siv los txiav txim siab txog ammonia; Thaum cov ntsiab lus ammonia nitrogen siab, txoj kev distillation titration kuj siv tau. (Cov qauv hauv tebchaws suav nrog Nath's reagent method, salicylic acid spectrophotometry, distillation - titration method)
2. Cov txheej txheem tshem tawm nitrogen ntawm lub cev thiab tshuaj lom neeg
① Txoj kev ua dej nag los ntawm tshuaj lom neeg
Txoj kev ua kom dej nag los ntawm tshuaj lom neeg, tseem hu ua MAP precipitation method, yog ntxiv magnesium thiab phosphoric acid lossis hydrogen phosphate rau hauv cov dej khib nyiab uas muaj ammonia nitrogen, kom NH4 + hauv cov dej khib nyiab sib xyaw nrog Mg + thiab PO4- hauv cov kua dej kom tsim cov dej nag los ntawm ammonium magnesium phosphate, cov mis molecular yog MgNH4P04.6H20, kom ua tiav lub hom phiaj ntawm kev tshem tawm ammonia nitrogen. Magnesium ammonium phosphate, feem ntau hu ua struvite, tuaj yeem siv ua compost, av additive lossis hluav taws kub retardant rau kev tsim cov khoom siv. Cov kab zauv teb yog raws li nram no:
Mg++ NH4 + + PO4 – = MgNH4P04
Cov yam tseem ceeb uas cuam tshuam rau kev kho mob ntawm cov tshuaj nag yog pH tus nqi, kub, ammonia nitrogen concentration thiab molar ratio (n(Mg+) : n(NH4+) : n(P04-)). Cov txiaj ntsig qhia tau tias thaum pH tus nqi yog 10 thiab molar ratio ntawm magnesium, nitrogen thiab phosphorus yog 1.2:1:1.2, cov txiaj ntsig kho mob zoo dua.
Siv magnesium chloride thiab disodium hydrogen phosphate ua cov neeg sawv cev ua kom cov av noo, cov txiaj ntsig qhia tau tias cov txiaj ntsig kho mob zoo dua thaum tus nqi pH yog 9.5 thiab qhov piv ntawm magnesium, nitrogen thiab phosphorus yog 1.2: 1: 1.
Cov txiaj ntsig qhia tau tias MgC12 + Na3PO4.12H20 zoo dua li lwm cov tshuaj ua kom dej nag sib xyaw. Thaum tus nqi pH yog 10.0, qhov kub yog 30 ℃, n(Mg+) : n(NH4+) : n(P04-) = 1:1:1, qhov concentration ntawm ammonia nitrogen hauv cov dej khib nyiab tom qab do rau 30 feeb txo qis los ntawm 222mg/L ua ntej kho mus rau 17mg/L, thiab tus nqi tshem tawm yog 92.3%.
Txoj kev siv tshuaj lom neeg los ua kom cov dej khib nyiab ammonia nitrogen uas muaj ntau thiab txoj kev siv kua membrane tau muab ua ke los kho cov dej khib nyiab ammonia nitrogen uas muaj ntau heev. Nyob rau hauv cov xwm txheej ntawm kev ua kom zoo tshaj plaws ntawm cov txheej txheem los ua kom cov dej khib nyiab, qhov kev tshem tawm ntawm ammonia nitrogen tau txog 98.1%, thiab tom qab ntawd kho ntxiv nrog txoj kev siv kua zaj duab xis, qhov kev txo qis ntawm ammonia nitrogen mus rau 0.005g / L, ua tiav tus qauv tso pa phem hauv tebchaws.
Kev tshawb nrhiav txog kev tshem tawm cov nyhuv ntawm cov hlau divalent ions (Ni +, Mn +, Zn +, Cu +, Fe +) uas tsis yog Mg + ntawm ammonia nitrogen nyob rau hauv qhov kev ua ntawm phosphate tau tshawb nrhiav. Ib qho txheej txheem tshiab ntawm CaSO4 precipitation-MAP precipitation tau pom zoo rau ammonium sulfate wastewater. Cov txiaj ntsig qhia tau tias tus neeg tswj hwm NaOH ib txwm tuaj yeem hloov los ntawm txiv qaub ntsuab.
Qhov zoo ntawm txoj kev siv tshuaj lom neeg yog tias thaum cov dej khib nyiab ammonia nitrogen ntau, kev siv lwm txoj kev txwv, xws li txoj kev siv tshuaj lom neeg, txoj kev tawg chlorination, txoj kev sib cais membrane, txoj kev pauv ion, thiab lwm yam. Lub sijhawm no, txoj kev siv tshuaj lom neeg siv tau rau kev kho ua ntej. Kev tshem tawm zoo dua ntawm txoj kev siv tshuaj lom neeg siv tau zoo dua, thiab nws tsis txwv los ntawm qhov kub thiab txias, thiab kev ua haujlwm yooj yim. Cov sludge uas muaj magnesium ammonium phosphate tuaj yeem siv ua cov chiv sib xyaw kom paub txog kev siv cov khib nyiab, yog li them ib feem ntawm tus nqi; Yog tias nws tuaj yeem ua ke nrog qee lub tuam txhab lag luam uas tsim cov dej khib nyiab phosphate thiab cov tuam txhab uas tsim cov ntsev brine, nws tuaj yeem txuag cov nqi tshuaj thiab pab txhawb kev siv loj.
Qhov tsis zoo ntawm txoj kev siv tshuaj lom neeg yog tias vim muaj kev txwv ntawm cov khoom yaj ntawm ammonium magnesium phosphate, tom qab ammonia nitrogen hauv cov dej khib nyiab mus txog qee qhov concentration, qhov kev tshem tawm tsis pom tseeb thiab tus nqi nkag tau nce siab heev. Yog li ntawd, txoj kev siv tshuaj lom neeg yuav tsum tau siv ua ke nrog lwm txoj hauv kev uas tsim nyog rau kev kho mob siab heev. Tus nqi ntawm cov tshuaj reagent siv yog loj, cov sludge tsim tawm yog loj, thiab tus nqi kho mob yog siab. Kev qhia txog chloride ions thiab cov phosphorus seem thaum lub sijhawm siv tshuaj tuaj yeem ua rau muaj kev ua qias tuaj ntxiv.
② txoj kev tshuab tawm
Kev tshem tawm ammonia nitrogen los ntawm txoj kev tshuab yog kho qhov pH kom alkaline, kom cov ammonia ion hauv cov dej khib nyiab hloov mus ua ammonia, yog li nws feem ntau muaj nyob rau hauv daim ntawv ntawm ammonia dawb, thiab tom qab ntawd cov ammonia dawb raug coj tawm ntawm cov dej khib nyiab los ntawm cov roj thauj khoom, kom ua tiav lub hom phiaj ntawm kev tshem tawm ammonia nitrogen. Cov yam tseem ceeb uas cuam tshuam rau kev ua haujlwm ntawm lub tshuab yog pH tus nqi, kub, roj-kua piv, roj ntws tus nqi, qhov pib concentration thiab lwm yam. Tam sim no, txoj kev tshuab dav dav siv rau kev kho cov dej khib nyiab uas muaj cov ammonia nitrogen ntau.
Kev tshawb nrhiav txog kev tshem tawm ammonia nitrogen ntawm cov dej khib nyiab los ntawm kev siv tshuab cua tshuab. Pom tau tias cov yam tseem ceeb uas tswj kev ua haujlwm ntawm kev siv tshuab cua tshuab yog qhov kub, qhov sib piv ntawm roj thiab kua, thiab pH. Thaum qhov kub ntawm dej ntau dua 2590, qhov sib piv ntawm roj thiab kua yog li 3500, thiab pH yog li 10.5, qhov kev tshem tawm tuaj yeem ncav cuag ntau dua 90% rau cov dej khib nyiab nrog cov ammonia nitrogen concentration siab txog 2000-4000mg/L. Cov txiaj ntsig qhia tau tias thaum pH = 11.5, qhov kub ntawm kev tshem tawm yog 80cC thiab lub sijhawm tshem tawm yog 120 feeb, qhov kev tshem tawm ntawm ammonia nitrogen hauv cov dej khib nyiab tuaj yeem ncav cuag 99.2%.
Kev siv lub tshuab cua tshuab tawm ntawm cov dej khib nyiab uas muaj ammonia nitrogen ntau heev tau ua los ntawm lub tshuab cua tshuab tawm. Cov txiaj ntsig tau qhia tias qhov kev ua haujlwm ntawm kev tshuab tawm nce ntxiv nrog rau qhov nce ntawm pH. Qhov piv ntawm cov roj thiab kua loj dua, qhov kev tsav tsheb ntawm kev hloov pauv ntawm ammonia stripping mass ntau dua, thiab qhov kev ua haujlwm ntawm kev stripping kuj nce ntxiv.
Kev tshem tawm ammonia nitrogen los ntawm txoj kev tshuab cua yog qhov zoo, yooj yim rau kev khiav lag luam thiab yooj yim rau kev tswj hwm. Cov ammonia nitrogen uas tshuab cua tuaj yeem siv ua lub nqus nrog sulfuric acid, thiab cov nyiaj sulfuric acid uas tsim tawm tuaj yeem siv ua chiv. Txoj kev tshuab cua yog ib qho thev naus laus zis siv rau kev tshem tawm nitrogen lub cev thiab tshuaj lom neeg tam sim no. Txawm li cas los xij, txoj kev tshuab cua muaj qee qhov tsis zoo, xws li kev nce qib ntau zaus hauv lub pej thuam tshuab cua, kev tshem tawm ammonia nitrogen tsawg ntawm qhov kub qis, thiab kev ua qias tuaj ntawm cov pa roj tshuab cua. Txoj kev tshuab cua feem ntau yog ua ke nrog lwm txoj kev kho dej khib nyiab ammonia nitrogen los kho cov dej khib nyiab ammonia nitrogen uas muaj ntau.
③Kev ua kom cov tshuaj chlorine tawg
Lub tshuab ntawm kev tshem tawm ammonia los ntawm kev tawg chlorination yog tias cov pa roj chlorine cuam tshuam nrog ammonia los tsim cov pa roj nitrogen tsis muaj teeb meem, thiab N2 tawm mus rau hauv huab cua, ua rau qhov chaw ua haujlwm txuas ntxiv mus rau sab xis. Cov mis tshuaj tiv thaiv yog:
HOCl NH4 + + 1.5 – > 0.5 N2 H20 H++ Cl – 1.5 + 2.5 + 1.5)
Thaum cov pa roj chlorine raug xa mus rau hauv cov dej khib nyiab mus rau ib qho chaw, cov ntsiab lus ntawm cov chlorine dawb hauv dej tsawg, thiab qhov concentration ntawm ammonia yog xoom. Thaum cov pa roj chlorine hla dhau qhov chaw, cov chlorine dawb hauv dej yuav nce ntxiv, yog li ntawd, qhov chaw ntawd hu ua qhov tawg, thiab cov chlorination hauv lub xeev no hu ua qhov tawg chlorination.
Txoj kev siv tshuaj chlorine los kho cov dej khib nyiab tom qab siv ammonia nitrogen los kho, thiab cov txiaj ntsig kho tau cuam tshuam ncaj qha los ntawm cov txheej txheem ua ntej siv ammonia nitrogen los kho. Thaum 70% ntawm ammonia nitrogen hauv cov dej khib nyiab raug tshem tawm los ntawm cov txheej txheem tshuab thiab tom qab ntawd kho los ntawm kev siv tshuaj chlorine, qhov concentration ntawm ammonia nitrogen hauv cov dej khib nyiab tsawg dua 15mg / L. Zhang Shengli et al. tau siv cov dej khib nyiab ammonia nitrogen uas muaj qhov concentration ntawm 100mg / L ua lub hom phiaj tshawb fawb, thiab cov txiaj ntsig tshawb fawb qhia tau tias cov yam tseem ceeb thiab cov yam tseem ceeb thib ob uas cuam tshuam rau kev tshem tawm ammonia nitrogen los ntawm kev oxidation ntawm sodium hypochlorite yog qhov sib piv ntawm chlorine rau ammonia nitrogen, lub sijhawm teb, thiab pH.
Txoj kev siv tshuaj chlorine los ntxuav cov dej khib nyiab muaj cov txiaj ntsig zoo ntawm kev tshem tawm cov nitrogen, qhov kev tshem tawm tuaj yeem ncav cuag 100%, thiab cov ammonia concentration hauv cov dej khib nyiab tuaj yeem txo qis rau xoom. Cov nyhuv ruaj khov thiab tsis cuam tshuam los ntawm qhov kub thiab txias; Cov khoom siv tsawg dua, teb sai thiab tiav; Nws muaj cov nyhuv ntawm kev ua kom tsis muaj menyuam thiab tua kab mob rau lub cev dej. Qhov ntau thiab tsawg ntawm kev siv txoj kev siv tshuaj chlorine los ntxuav cov dej khib nyiab yog tias cov ammonia nitrogen uas muaj cov dej khib nyiab tsawg dua 40mg / L, yog li txoj kev siv tshuaj chlorine los ntxuav cov dej khib nyiab feem ntau yog siv rau kev kho cov dej khib nyiab ammonia nitrogen uas muaj cov tshuaj ntau. Qhov yuav tsum tau siv thiab khaws cia kom muaj kev nyab xeeb siab, tus nqi kho mob siab, thiab cov khoom siv chloramines thiab cov organic chlorinated yuav ua rau muaj kuab paug thib ob.
④ txoj kev oxidation catalytic
Txoj kev oxidation catalytic yog los ntawm kev ua haujlwm ntawm catalyst, nyob rau hauv qee qhov kub thiab siab, los ntawm huab cua oxidation, cov organic teeb meem thiab ammonia hauv cov dej phwj tuaj yeem oxidized thiab decomposed rau hauv cov tshuaj tsis muaj teeb meem xws li CO2, N2 thiab H2O, kom ua tiav lub hom phiaj ntawm kev ntxuav.
Cov yam tseem ceeb uas cuam tshuam rau qhov cuam tshuam ntawm catalytic oxidation yog cov yam ntxwv ntawm catalyst, kub, lub sijhawm teb, pH tus nqi, ammonia nitrogen concentration, siab, stirring intensity thiab lwm yam.
Cov txheej txheem rhuav tshem ntawm ozonated ammonia nitrogen tau kawm. Cov txiaj ntsig qhia tau tias thaum pH tus nqi nce, ib hom HO radical nrog lub peev xwm oxidation muaj zog tau tsim, thiab tus nqi oxidation tau nrawm dua. Cov kev tshawb fawb qhia tau tias ozone tuaj yeem oxidize ammonia nitrogen rau nitrite thiab nitrite rau nitrate. Qhov concentration ntawm ammonia nitrogen hauv dej txo qis nrog lub sijhawm nce, thiab tus nqi tshem tawm ntawm ammonia nitrogen yog li 82%. CuO-Mn02-Ce02 tau siv los ua cov tshuaj sib xyaw ua ke los kho cov dej khib nyiab ammonia nitrogen. Cov txiaj ntsig ntawm kev sim qhia tau tias qhov kev ua haujlwm oxidation ntawm cov tshuaj sib xyaw ua ke tshiab tau zoo dua, thiab cov xwm txheej tsim nyog yog 255 ℃, 4.2MPa thiab pH = 10.8. Hauv kev kho cov dej khib nyiab ammonia nitrogen nrog qhov concentration pib ntawm 1023mg / L, tus nqi tshem tawm ntawm ammonia nitrogen tuaj yeem ncav cuag 98% hauv 150 feeb, ncav cuag lub teb chaws theem ob (50mg / L) tus qauv tso tawm.
Kev ua haujlwm catalytic ntawm zeolite txhawb TiO2 photocatalyst tau tshawb xyuas los ntawm kev kawm txog qhov kev puas tsuaj ntawm ammonia nitrogen hauv cov kua sulfuric acid. Cov txiaj ntsig qhia tau tias qhov koob tshuaj zoo tshaj plaws ntawm Ti02 / zeolite photocatalyst yog 1.5g / L thiab lub sijhawm teb yog 4 teev nyob rau hauv ultraviolet irradiation. Tus nqi tshem tawm ntawm ammonia nitrogen los ntawm cov dej khib nyiab tuaj yeem ncav cuag 98.92%. Kev tshem tawm ntawm cov hlau siab thiab nano-chin dioxide nyob rau hauv lub teeb ultraviolet ntawm phenol thiab ammonia nitrogen tau kawm. Cov txiaj ntsig qhia tau tias tus nqi tshem tawm ntawm ammonia nitrogen yog 97.5% thaum pH = 9.0 siv rau cov kua ammonia nitrogen nrog qhov concentration ntawm 50mg / L, uas yog 7.8% thiab siab dua 22.5% dua li ntawm cov hlau siab lossis Chine dioxide ib leeg.
Txoj kev catalytic oxidation muaj qhov zoo ntawm kev ua kom huv siab, cov txheej txheem yooj yim, thaj chaw hauv qab me me, thiab lwm yam, thiab feem ntau siv los kho cov dej khib nyiab ammonia nitrogen uas muaj ntau. Qhov nyuaj ntawm daim ntawv thov yog yuav ua li cas tiv thaiv kev poob ntawm catalyst thiab kev tiv thaiv xeb ntawm cov khoom siv.
⑤Txoj kev oxidation electrochemical
Txoj kev oxidation electrochemical yog hais txog txoj kev tshem tawm cov pa phem hauv dej los ntawm kev siv electrooxidation nrog kev ua haujlwm catalytic. Cov yam ntxwv cuam tshuam yog qhov ceev tam sim no, tus nqi ntws nkag, lub sijhawm tawm thiab lub sijhawm daws teeb meem.
Kev kawm txog kev oxidation electrochemical ntawm ammonia-nitrogen dej khib nyiab hauv lub cell electrolytic uas ntws mus los, qhov zoo yog Ti/Ru02-TiO2-Ir02-SnO2 network hluav taws xob thiab qhov tsis zoo yog Ti network hluav taws xob. Cov txiaj ntsig qhia tau tias thaum qhov concentration ntawm chloride ion yog 400mg/L, qhov concentration ntawm ammonia nitrogen pib yog 40mg/L, qhov nrawm ntawm cov dej ntws yog 600mL/min, qhov ceev tam sim no yog 20mA/cm2, thiab lub sijhawm electrolytic yog 90min, qhov nrawm ntawm ammonia nitrogen tshem tawm yog 99.37%. Nws qhia tau tias kev oxidation electrolytic ntawm ammonia-nitrogen dej khib nyiab muaj kev cia siab zoo rau kev siv.
3. Cov txheej txheem tshem tawm cov pa roj biochemical
① tag nrho cov nitrification thiab denitrification
Tag nrho cov txheej txheem nitrification thiab denitrification yog ib hom kev siv tshuaj lom neeg uas tau siv dav dav rau lub sijhawm ntev tam sim no. Nws hloov ammonia nitrogen hauv cov dej khib nyiab mus rau hauv nitrogen los ntawm ntau yam kev tshuaj tiv thaiv xws li nitrification thiab denitrification nyob rau hauv kev ua ntawm ntau yam kab mob me me, kom ua tiav lub hom phiaj ntawm kev kho dej khib nyiab. Cov txheej txheem ntawm nitrification thiab denitrification kom tshem tawm ammonia nitrogen yuav tsum dhau ob theem:
Cov tshuaj tiv thaiv nitrification: Cov tshuaj tiv thaiv nitrification ua tiav los ntawm cov kab mob aerobic autotrophic. Hauv lub xeev aerobic, cov pa roj carbon dioxide inorganic siv ua qhov chaw nitrogen los hloov NH4 + mus rau hauv NO2-, thiab tom qab ntawd nws raug oxidized rau NO3-. Cov txheej txheem nitrification tuaj yeem faib ua ob theem. Hauv theem ob, nitrite raug hloov mus rau nitrate (NO3-) los ntawm cov kab mob nitrifying, thiab nitrite raug hloov mus rau nitrate (NO3-) los ntawm cov kab mob nitrifying.
Kev tshuaj tiv thaiv Denitrification: Kev tshuaj tiv thaiv Denitrification yog cov txheej txheem uas cov kab mob denitrifying txo cov nitrite nitrogen thiab nitrate nitrogen rau hauv cov pa roj nitrogen (N2) hauv lub xeev hypoxia. Cov kab mob denitrifying yog cov kab mob heterotrophic, feem ntau yog cov kab mob amphictic. Hauv lub xeev hypoxia, lawv siv cov pa oxygen hauv nitrate ua tus txais hluav taws xob thiab cov organic matter (BOD Cheebtsam hauv cov dej phwj) ua tus pub hluav taws xob los muab lub zog thiab raug oxidized thiab stabilized.
Tag nrho cov txheej txheem nitrification thiab denitrification engineering daim ntawv thov feem ntau suav nrog AO, A2O, oxidation ditch, thiab lwm yam, uas yog ib txoj kev paub ntau dua siv hauv kev lag luam tshem tawm nitrogen.
Tag nrho cov txheej txheem nitrification thiab denitrification muaj qhov zoo ntawm cov nyhuv ruaj khov, yooj yim ua haujlwm, tsis muaj kev ua qias tuaj thib ob thiab tus nqi qis. Txoj kev no kuj muaj qee qhov tsis zoo, xws li yuav tsum ntxiv cov pa roj carbon thaum qhov sib piv C / N hauv cov dej khib nyiab qis, qhov kub xav tau nruj heev, qhov ua tau zoo qis ntawm qhov kub qis, thaj chaw loj, qhov xav tau oxygen loj, thiab qee cov tshuaj lom neeg xws li cov hlau hnyav ions muaj cov nyhuv nias rau cov kab mob me me, uas yuav tsum tau tshem tawm ua ntej txoj kev tshawb fawb txog kab mob. Tsis tas li ntawd, qhov concentration siab ntawm ammonia nitrogen hauv cov dej khib nyiab kuj muaj cov nyhuv inhibitory rau cov txheej txheem nitrification. Yog li ntawd, kev kho ua ntej yuav tsum tau ua ua ntej kev kho cov dej khib nyiab ammonia nitrogen siab kom qhov concentration ntawm ammonia nitrogen tsawg dua 500mg / L. Txoj kev tshawb fawb txog kab mob ib txwm muaj rau kev kho cov dej khib nyiab ammonia nitrogen qis uas muaj cov organic teeb meem, xws li cov dej khib nyiab hauv tsev, cov dej khib nyiab tshuaj lom neeg, thiab lwm yam.
② Kev sib xyaw ua ke ntawm nitrification thiab denitrification (SND)
Thaum nitrification thiab denitrification ua ke hauv tib lub reactor, nws hu ua simultaneous digestion denitrification (SND). Cov pa oxygen yaj hauv cov dej khib nyiab raug txwv los ntawm qhov nrawm diffusion los tsim cov pa oxygen yaj hauv thaj chaw microenvironment ntawm microbial floc lossis biofilm, uas ua rau cov pa oxygen yaj ntawm sab nraud ntawm microbial floc lossis biofilm uas ua rau kev loj hlob thiab kev nthuav dav ntawm cov kab mob aerobic nitrifying thiab ammoniating. Qhov tob dua rau hauv floc lossis membrane, qhov concentration ntawm cov pa oxygen yaj qis dua, ua rau thaj chaw anoxic qhov twg cov kab mob denitrifying dominate. Yog li tsim cov txheej txheem zom zaub mov thiab denitrification tib lub sijhawm. Cov yam ntxwv cuam tshuam rau kev zom zaub mov thiab denitrification tib lub sijhawm yog PH tus nqi, kub, alkalinity, organic carbon qhov chaw, cov pa oxygen yaj thiab sludge hnub nyoog.
Muaj nitrification/denitrification tib lub sijhawm nyob rau hauv Carrousel oxidation ditch, thiab qhov concentration ntawm cov pa oxygen yaj ntawm lub impeller aerated hauv Carrousel oxidation ditch maj mam txo qis, thiab cov pa oxygen yaj hauv qab ntawm Carrousel oxidation ditch qis dua li ntawm sab saud. Kev tsim thiab kev siv ntawm nitrate nitrogen hauv txhua qhov ntawm cov channel yuav luag sib npaug, thiab qhov concentration ntawm ammonia nitrogen hauv cov channel yeej ib txwm qis heev, uas qhia tau tias cov tshuaj nitrification thiab denitrification tshwm sim tib lub sijhawm hauv Carrousel oxidation channel.
Cov kev tshawb fawb txog kev kho cov dej phwj hauv tsev qhia tau hais tias CODCr siab dua, qhov denitrification tiav ntau dua thiab qhov kev tshem tawm TN zoo dua. Cov nyhuv ntawm cov pa oxygen yaj rau kev nitrification thiab denitrification tib lub sijhawm zoo heev. Thaum cov pa oxygen yaj raug tswj ntawm 0.5 ~ 2mg / L, tag nrho cov nyhuv tshem tawm nitrogen zoo. Tib lub sijhawm, txoj kev nitrification thiab denitrification txuag lub reactor, luv lub sijhawm teb, muaj kev siv hluav taws xob tsawg, txuag kev nqis peev, thiab yooj yim los tswj cov nqi pH ruaj khov.
③Kev zom zaub mov luv luv thiab denitrification
Hauv tib lub reactor, cov kab mob ammonia oxidizing siv los oxidize ammonia rau nitrite nyob rau hauv cov xwm txheej aerobic, thiab tom qab ntawd nitrite yog denitrified ncaj qha los tsim nitrogen nrog cov organic matter lossis cov pa roj carbon sab nraud ua tus pub electron nyob rau hauv cov xwm txheej hypoxia. Cov yam ntxwv cuam tshuam ntawm luv luv nitrification thiab denitrification yog kub, dawb ammonia, pH tus nqi thiab yaj oxygen.
Qhov cuam tshuam ntawm qhov kub thiab txias rau kev ua kom cov dej phwj hauv nroog tsis muaj dej hiav txwv thiab cov dej phwj hauv nroog nrog 30% dej hiav txwv. Cov txiaj ntsig ntawm kev sim qhia tau tias: rau cov dej phwj hauv nroog tsis muaj dej hiav txwv, kev nce qhov kub thiab txias yog qhov zoo rau kev ua kom cov dej phwj luv luv. Thaum qhov feem pua ntawm cov dej hiav txwv hauv cov dej phwj hauv tsev yog 30%, kev ua kom cov dej phwj luv luv tuaj yeem ua tiav zoo dua nyob rau hauv qhov kub nruab nrab. Delft University of Technology tau tsim cov txheej txheem SHARON, kev siv qhov kub siab (kwv yees li 30-4090) yog qhov zoo rau kev loj hlob ntawm cov kab mob nitrite, yog li cov kab mob nitrite poob kev sib tw, thaum tswj lub hnub nyoog ntawm cov sludge kom tshem tawm cov kab mob nitrite, yog li cov tshuaj tiv thaiv nitrification hauv theem nitrite.
Raws li qhov sib txawv ntawm kev sib raug zoo ntawm cov pa oxygen ntawm cov kab mob nitrite thiab cov kab mob nitrite, Gent Microbial Ecology Laboratory tau tsim cov txheej txheem OLAND los ua kom tiav cov nitrogen nitrite los ntawm kev tswj cov pa oxygen yaj kom tshem tawm cov kab mob nitrite.
Cov txiaj ntsig ntawm kev sim ua ntej ntawm kev kho cov dej khib nyiab coking los ntawm kev ua nitrification luv luv thiab denitrification qhia tau tias thaum cov COD, ammonia nitrogen, TN thiab phenol concentration yog 1201.6,510.4,540.1 thiab 110.4mg/L, qhov nruab nrab ntawm cov dej khib nyiab COD, ammonia nitrogen, TN thiab phenol concentration yog 197.1,14.2,181.5 thiab 0.4mg/L, raws li. Cov nqi tshem tawm sib xws yog 83.6%, 97.2%, 66.4% thiab 99.6%, raws li.
Cov txheej txheem nitrification thiab denitrification luv luv tsis dhau theem nitrate, txuag cov pa roj carbon uas xav tau rau kev tshem tawm cov nitrogen hauv lub cev. Nws muaj qee qhov zoo rau cov dej khib nyiab ammonia nitrogen nrog qhov sib piv C/N qis. Kev nitrification thiab denitrification luv luv muaj qhov zoo ntawm cov sludge tsawg dua, lub sijhawm teb luv luv thiab txuag cov reactor ntim. Txawm li cas los xij, kev nitrification thiab denitrification luv luv xav tau kev sib sau ua ke ntawm nitrite ruaj khov thiab kav ntev, yog li yuav ua li cas thiaj li tiv thaiv tau cov kab mob nitrifying ua haujlwm tau zoo yog qhov tseem ceeb.
④ Kev ua kom tsis muaj pa oxygen hauv cov pa oxygen
Anaerobic ammoxidation yog ib qho txheej txheem ntawm kev oxidation ncaj qha ntawm ammonia nitrogen rau nitrogen los ntawm autotrophic bacteria nyob rau hauv qhov xwm txheej ntawm hypoxia, nrog nitrous nitrogen lossis nitrous nitrogen ua electron acceptor.
Cov teebmeem ntawm qhov kub thiab PH rau kev ua haujlwm ntawm anammoX tau raug kawm. Cov txiaj ntsig tau qhia tias qhov kub zoo tshaj plaws yog 30 ℃ thiab pH tus nqi yog 7.8. Kev siv tau ntawm anaerobic ammoX reactor rau kev kho cov dej ntsev siab thiab cov dej khib nyiab nitrogen siab tau raug kawm. Cov txiaj ntsig tau qhia tias cov ntsev siab ua rau anammoX ua haujlwm tsis zoo, thiab qhov kev txwv no rov qab tau. Cov dej num anaerobic ammox ntawm cov sludge tsis tau acclimated yog 67.5% qis dua li ntawm cov sludge tswj nyob rau hauv cov ntsev ntawm 30g.L-1 (NaC1). Cov dej num anammoX ntawm cov sludge acclimated yog 45.1% qis dua li ntawm cov tswj. Thaum cov sludge acclimated raug hloov los ntawm ib puag ncig salinity siab mus rau ib puag ncig salinity qis (tsis muaj brine), cov dej num anaerobic ammoX tau nce 43.1%. Txawm li cas los xij, lub reactor yuav ua haujlwm poob qis thaum nws khiav hauv salinity siab ntev.
Piv rau cov txheej txheem tshuaj lom neeg ib txwm muaj, anaerobic ammoX yog cov thev naus laus zis tshem tawm cov pa roj nitrogen pheej yig dua uas tsis muaj cov pa roj carbon ntxiv, tsis tas yuav siv cov tshuaj reagents los ua kom tsis muaj zog, thiab tsis tas yuav tsim cov sludge ntau. Qhov tsis zoo ntawm anaerobic ammox yog tias qhov ceev ntawm cov tshuaj tiv thaiv qeeb, qhov ntim ntawm lub reactor loj, thiab qhov chaw carbon tsis zoo rau anaerobic amMOX, uas muaj txiaj ntsig zoo rau kev daws cov dej khib nyiab ammonia nitrogen uas tsis zoo biodegradability.
4. kev sib cais thiab kev nqus cov nitrogen tshem tawm cov txheej txheem
① txoj kev sib cais membrane
Txoj kev sib cais membrane yog siv qhov kev xaiv permeability ntawm daim nyias nyias los xaiv cov khoom hauv cov kua, kom ua tiav lub hom phiaj ntawm kev tshem tawm ammonia nitrogen. Xws li rov qab osmosis, nanofiltration, deammoniating membrane thiab electrodialysis. Cov yam ntxwv cuam tshuam rau kev sib cais membrane yog cov yam ntxwv ntawm daim nyias nyias, siab lossis voltage, pH tus nqi, kub thiab ammonia nitrogen concentration.
Raws li qhov zoo ntawm cov dej ntawm cov dej khib nyiab ammonia nitrogen uas tau tso tawm los ntawm lub chaw ua dej khib nyiab tsis tshua muaj neeg, qhov kev sim rov qab osmosis tau ua tiav nrog NH4C1 thiab NaCI simulated wastewater. Nws tau pom tias nyob rau hauv tib qho xwm txheej, rov qab osmosis muaj qhov tshem tawm ntau dua ntawm NaCI, thaum NHCl muaj qhov tsim dej ntau dua. Tus nqi tshem tawm ntawm NH4C1 yog 77.3% tom qab kev kho rov qab osmosis, uas tuaj yeem siv ua kev kho ua ntej ntawm ammonia nitrogen wastewater. Reverse osmosis technology tuaj yeem txuag hluav taws xob, zoo thermal stability, tab sis chlorine tsis kam, thiab kev ua qias tuaj yeem tsis zoo.
Ib txoj kev sib cais biochemical nanofiltration membrane tau siv los kho cov khib nyiab pov tseg, yog li ntawd 85% ~ 90% ntawm cov kua dej permeable tau raug tso tawm raws li tus qauv, thiab tsuas yog 0% ~ 15% ntawm cov kua dej phwj tuaj thiab av nkos tau rov qab mus rau lub thoob khib nyiab. Ozturki et al. kho cov khib nyiab pov tseg ntawm Odayeri hauv tebchaws Turkey nrog nanofiltration membrane, thiab tus nqi tshem tawm ntawm ammonia nitrogen yog li 72%. Nanofiltration membrane xav tau qhov siab qis dua li rov qab osmosis membrane, yooj yim rau kev khiav lag luam.
Feem ntau, lub tshuab membrane tshem tawm ammonia yog siv rau kev kho cov dej khib nyiab uas muaj ammonia nitrogen ntau. Ammonia nitrogen hauv dej muaj qhov sib npaug hauv qab no: NH4- + OH- = NH3 + H2O ua haujlwm, cov dej khib nyiab uas muaj ammonia ntws mus rau hauv lub plhaub ntawm lub module membrane, thiab cov kua qaub uas nqus tau dej ntws mus rau hauv cov yeeb nkab ntawm lub module membrane. Thaum PH ntawm cov dej khib nyiab nce lossis qhov kub nce, qhov sib npaug yuav hloov mus rau sab xis, thiab ammonium ion NH4- dhau los ua cov roj dawb NH3. Lub sijhawm no, cov roj NH3 tuaj yeem nkag mus rau theem kua qaub nqus hauv cov yeeb nkab los ntawm theem dej khib nyiab hauv lub plhaub los ntawm cov qhov me me ntawm qhov chaw ntawm cov fiber hollow, uas raug nqus los ntawm cov kua qaub thiab tam sim ntawd dhau los ua ionic NH4-. Khaws PH ntawm cov dej khib nyiab kom siab dua 10, thiab qhov kub siab dua 35 ° C (qis dua 50 ° C), yog li NH4 hauv theem dej khib nyiab yuav txuas ntxiv mus ua NH3 mus rau theem kua nqus. Yog li ntawd, qhov concentration ntawm ammonia nitrogen hauv sab dej khib nyiab txo qis txuas ntxiv. Cov kua qaub uas nqus tau, vim tsuas muaj kua qaub thiab NH4- xwb, tsim cov ntsev ammonium ntshiab heev, thiab ncav cuag qee qhov concentration tom qab kev ncig tas mus li, uas tuaj yeem rov ua dua tshiab. Ntawm ib sab tes, kev siv cov thev naus laus zis no tuaj yeem txhim kho qhov kev tshem tawm ntawm ammonia nitrogen hauv cov dej khib nyiab, thiab ntawm qhov tod tes, nws tuaj yeem txo tag nrho cov nqi khiav lag luam ntawm cov txheej txheem kho dej khib nyiab.
② txoj kev electrodialysis
Electrodialysis yog ib txoj kev tshem tawm cov khoom khov uas yaj hauv cov kua dej los ntawm kev siv hluav taws xob ntawm cov khub membrane. Nyob rau hauv qhov kev ua ntawm hluav taws xob, cov ammonia ions thiab lwm cov ions hauv cov dej khib nyiab ammonia-nitrogen raug nplua los ntawm daim nyias nyias hauv cov dej uas muaj ammonia concentrated, kom ua tiav lub hom phiaj ntawm kev tshem tawm.
Txoj kev electrodialysis tau siv los kho cov dej khib nyiab inorganic nrog cov ammonia nitrogen ntau thiab tau txais txiaj ntsig zoo. Rau 2000-3000mg / L ammonia nitrogen wastewater, tus nqi tshem tawm ntawm ammonia nitrogen tuaj yeem ntau dua 85%, thiab cov dej ammonia concentrated tuaj yeem tau txais los ntawm 8.9%. Tus nqi hluav taws xob siv thaum lub sijhawm ua haujlwm ntawm electrodialysis yog proportional rau tus nqi ntawm ammonia nitrogen hauv cov dej khib nyiab. Kev kho dej khib nyiab electrodialysis tsis txwv los ntawm pH tus nqi, kub thiab siab, thiab nws yooj yim rau kev khiav lag luam.
Qhov zoo ntawm kev sib cais daim nyias nyias yog qhov rov qab tau cov ammonia nitrogen ntau, kev ua haujlwm yooj yim, kev kho mob ruaj khov thiab tsis muaj kev ua qias tuaj ntxiv. Txawm li cas los xij, hauv kev kho cov dej khib nyiab ammonia nitrogen uas muaj ntau, tshwj tsis yog daim nyias nyias uas tsis muaj ammonia, lwm cov daim nyias nyias yooj yim rau kev nthuav dav thiab txhaws, thiab kev rov ua dua tshiab thiab rov qab ntxuav dua yog ntau zaus, ua rau tus nqi kho mob nce ntxiv. Yog li ntawd, txoj kev no zoo dua rau kev kho ua ntej lossis cov dej khib nyiab ammonia nitrogen uas muaj tsawg.
③ Txoj kev pauv Ion
Txoj kev pauv ion yog ib txoj kev los tshem tawm ammonia nitrogen ntawm cov dej khib nyiab los ntawm kev siv cov ntaub ntawv uas muaj zog xaiv adsorption ntawm ammonia ions. Cov ntaub ntawv adsorption feem ntau siv yog activated carbon, zeolite, montmorillonite thiab exchange resin. Zeolite yog ib hom silico-aluminate nrog peb-dimensional spatial qauv, ib txwm pore qauv thiab qhov, ntawm cov uas clinoptilolite muaj zog xaiv adsorption peev xwm rau ammonia ions thiab tus nqi qis, yog li nws feem ntau siv ua cov khoom adsorption rau ammonia nitrogen dej khib nyiab hauv engineering. Cov yam ntxwv cuam tshuam rau kev kho mob ntawm clinoptilolite suav nrog qhov loj me ntawm cov khoom me me, kev cuam tshuam ammonia nitrogen concentration, lub sijhawm sib cuag, pH tus nqi thiab lwm yam.
Qhov cuam tshuam ntawm zeolite rau ammonia nitrogen yog qhov pom tseeb, ua raws li ranite, thiab cov nyhuv ntawm av thiab ceramisite tsis zoo. Txoj hauv kev tseem ceeb los tshem tawm ammonia nitrogen ntawm zeolite yog kev sib pauv ion, thiab cov nyhuv adsorption lub cev me me heev. Cov nyhuv pauv ion ntawm ceramite, av thiab ranite zoo ib yam li cov nyhuv adsorption lub cev. Lub peev xwm adsorption ntawm plaub qhov fillers txo qis nrog qhov nce ntawm qhov kub thiab txias hauv qhov ntau ntawm 15-35 ℃, thiab nce nrog qhov nce ntawm pH hauv qhov ntau ntawm 3-9. Qhov sib npaug adsorption tau mus txog tom qab 6 teev oscillation.
Kev siv zeolite adsorption los tshem tawm ammonia nitrogen ntawm cov av khib nyiab tau raug kawm. Cov txiaj ntsig ntawm kev sim qhia tau tias txhua gram ntawm zeolite muaj peev xwm adsorption tsawg ntawm 15.5mg ammonia nitrogen, thaum qhov loj ntawm zeolite yog 30-16 mesh, qhov kev tshem tawm ntawm ammonia nitrogen ncav cuag 78.5%, thiab nyob rau tib lub sijhawm adsorption, koob tshuaj thiab qhov loj ntawm zeolite, qhov siab dua ntawm ammonia nitrogen concentration, qhov siab dua ntawm adsorption, thiab nws yog qhov ua tau rau zeolite ua adsorbent kom tshem tawm ammonia nitrogen ntawm leachate. Tib lub sijhawm, nws tau taw qhia tias qhov adsorption ntawm ammonia nitrogen los ntawm zeolite yog qis, thiab nws nyuaj rau zeolite kom ncav cuag saturation adsorption peev xwm hauv kev ua haujlwm.
Kev tshawb nrhiav txog kev tshem tawm cov teebmeem ntawm lub txaj zeolite rau nitrogen, COD thiab lwm yam kuab paug hauv cov dej phwj hauv zos uas tau ua qauv. Cov txiaj ntsig qhia tau tias tus nqi tshem tawm ammonia nitrogen los ntawm lub txaj zeolite yog ntau dua 95%, thiab kev tshem tawm nitrate nitrogen raug cuam tshuam loj heev los ntawm lub sijhawm nyob hydraulic.
Txoj kev pauv ion muaj qhov zoo ntawm kev nqis peev me me, cov txheej txheem yooj yim, kev ua haujlwm yooj yim, tsis muaj kev cuam tshuam rau tshuaj lom thiab kub, thiab rov siv dua zeolite los ntawm kev rov ua dua tshiab. Txawm li cas los xij, thaum kho cov dej khib nyiab ammonia nitrogen uas muaj ntau qhov concentration, kev rov ua dua tshiab yog ntau zaus, uas coj kev tsis yooj yim rau kev ua haujlwm, yog li nws yuav tsum tau ua ke nrog lwm txoj kev kho ammonia nitrogen, lossis siv los kho cov dej khib nyiab ammonia nitrogen uas muaj qhov concentration tsawg.
Chaw Tsim Khoom thiab Chaw Muag Khoom Zeolite 4A Lag Luam Wholesale | EVERBRIGHT (cnchemist.com)