46.Yini i-oxygen encibilikile?
I-Oxygen encibilikile DO (isifinyezo se-Dissolved Oxygen ngesiNgisi) imelela inani le-molecule ye-oxygen encibilike emanzini, futhi iyunithi ingu-mg/L.Okuqukethwe okugcwele komoyampilo oncibilikisiwe emanzini kuhlobene nezinga lokushisa lamanzi, ukucindezela komkhathi kanye nokwakheka kwamakhemikhali kwamanzi.Ngomfutho owodwa womkhathi, okuqukethwe komoyampilo lapho i-oksijini encibilikisiwe emanzini acwengekile kufinyelela ku-saturation ku-0oC kungu-14.62mg/L, futhi ku-20oC kungu-9.17mg/L.Ukwenyuka kwezinga lokushisa lamanzi, ukwanda kosawoti, noma ukuncipha komfutho womoya kuzobangela ukuthi okuqukethwe komoyampilo okuncibilikisiwe emanzini kunciphe.
I-oxygen encibilikisiwe iyinto ebalulekile ekusindeni nasekukhiqizeni kabusha izinhlanzi kanye namabhaktheriya e-aerobic.Uma umoya-mpilo oncibilikisiwe ungaphansi kuka-4mg/L, kuzoba nzima ngezinhlanzi ukuthi ziphile.Uma amanzi engcoliswe izinto eziphilayo, ukufakwa kwe-oxidation yento ephilayo nge-aerobic microorganisms kuzodla umoya-mpilo oncibilikisiwe emanzini.Uma ingakwazi ukugcwaliswa emoyeni ngesikhathi, i-oxygen encibilikisiwe emanzini izokwehla kancane kancane ize isondele ku-0, okwenza inani elikhulu lama-anaerobic microorganisms liphindaphindeke.Yenza amanzi abe mnyama futhi anuke.
47. Yiziphi izindlela ezivame ukusetshenziswa zokukala umoya-mpilo oncibilikile?
Kunezindlela ezimbili ezivame ukusetshenziswa zokulinganisa umoya-mpilo oncibilikisiwe, enye indlela ye-iodometric kanye nendlela yokulungisa (GB 7489–87), kanti enye iyindlela yokuhlola i-electrochemical (GB11913–89).Indlela ye-iodometric ifanele ukukala amasampula amanzi ngomoya-mpilo oncibilikisiwe omkhulu kuno-0.2 mg/L.Ngokuvamile, indlela ye-iodometric ifaneleka kuphela ukulinganisa i-oxygen encibilikile emanzini ahlanzekile.Lapho ukala i-oxygen encibilikile emanzini angcolile ezimbonini noma izinyathelo zezinqubo ezihlukahlukene zezitshalo zokuhlanza indle, kufanele kusetshenziswe i-iodine elungisiwe.indlela ye-quantitative noma indlela ye-electrochemical.Umkhawulo ophansi wokunquma wendlela ye-electrochemical probe uhlobene nethuluzi elisetshenzisiwe.Ngokuyinhloko kunezinhlobo ezimbili: indlela ye-membrane electrode kanye nendlela ye-electrode engenalwelwesi.Ngokuvamile afaneleka ukulinganisa amasampuli amanzi ngomoya-mpilo oncibilikisiwe omkhulu kuno-0.1mg/L.Imitha ye-DO eku-inthanethi efakwe futhi isetshenziswe emathangini okungenisa umoya nakwezinye izindawo ezikhungweni zokuhlanza indle isebenzisa indlela ye-electrode ye-membrane noma indlela ye-electrode engaphansi kwe-membrane.
Umgomo oyisisekelo wendlela ye-iodometric ukufaka i-manganese sulfate ne-alkaline potassium iodide kusampula yamanzi.I-oxygen encibilikisiwe emanzini yenza i-manganese ene-valent ephansi ibe yi-high-valent manganese, ikhiqize imvula ensundu ye-tetravalent manganese hydroxide.Ngemva kokwengeza i-asidi, i-precipitate ensundu iyancibilika bese Ihlangana nama-ion e-iodide ukuze ikhiqize iodine yamahhala, bese isebenzisa isitashi njengenkomba bese ishintshanisa i-iodine yamahhala nge-sodium thiosulfate ukubala okuqukethwe komoyampilo oncibilikisiwe.
Uma isampula yamanzi inombala noma iqukethe izinto eziphilayo ezingasabela nge-iodine, ayifaneleki ukusebenzisa indlela ye-iodometric kanye nendlela yayo yokulungisa ukukala umoya-mpilo oncibilikisiwe emanzini.Esikhundleni salokho, i-electrode yefilimu ezwela umoya-mpilo noma i-electrode engaphansi kwe-membrane ingasetshenziselwa ukulinganisa.I-electrode ezwela umoya-mpilo iqukethe ama-electrode amabili ensimbi axhumene ne-electrolyte esekelayo kanye nolwelwesi olukhethiwe olukwazi ukungena ngaphakathi.I-membrane ingadlula umoya-mpilo kanye namanye amagesi, kodwa amanzi nezinto ezincibilikayo kuwo azikwazi ukudlula.I-oksijeni edlula kulwelwesi iyancipha ku-electrode.Kukhiqizwa amandla asakazwayo abuthakathaka, futhi usayizi wamanje ulingana nokuqukethwe komoyampilo okuncibilikisiwe ezingeni lokushisa elithile.I-electrode engenafilimu yakhiwe i-cathode ekhethekile ye-alloy yesiliva kanye ne-iron (noma i-zinc) anode.Ayisebenzisi ifilimu noma i-electrolyte, futhi akukho voltage ye-polarization eyengezwe phakathi kwezigxobo ezimbili.Ixhumana kuphela nezigxobo ezimbili ngokusebenzisa isixazululo samanzi esilinganisiwe ukuze kwakhiwe ibhethri eliyinhloko, futhi ama-molecule e-oksijini emanzini Ukuncishiswa kwenziwa ngokuqondile ku-cathode, futhi ukuncipha kwamanje okukhiqizwayo kuhambisana nokuqukethwe komoya-mpilo esixazululweni esilinganiswayo. .
48. Kungani inkomba ye-oxygen encibilikile ingenye yezinkomba ezibalulekile zokusebenza okujwayelekile kohlelo lokuhlanza amanzi angcolile?
Ukugcina inani elithile le-oxygen encibilikile emanzini kuyisimo esiyisisekelo sokusinda nokukhiqizwa kabusha kwezinto eziphilayo zasemanzini ezi-aerobic.Ngakho-ke, inkomba ye-oxygen encibilikisiwe nayo ingenye yezinkomba ezibalulekile zokusebenza okujwayelekile kohlelo lokwelashwa kwe-biological ye-sewage.
Idivayisi yokwelapha yebhayoloji ye-aerobic idinga umoya-mpilo oncibilikisiwe emanzini ukuthi ube ngaphezu kuka-2 mg/L, futhi idivayisi yokwelapha yebhayoloji ye-anaerobic idinga umoya-mpilo oncibilikisiwe ukuthi ube ngaphansi kuka-0.5 mg/L.Uma ufuna ukungena esigabeni esikahle se-methanogenesis, kungcono ungabi nawo umoya-mpilo otholakalayo oncibilikisiwe (ku-0), futhi uma isigaba A senqubo ye-A/O sisesimweni esibucayi, umoya-mpilo oncibilikisiwe ungcono kakhulu u-0.5~1mg/L. .Uma amanzi angcolile aphuma ethangini lesibili le-sedimentation lendlela yebhayoloji yebhayoloji efaneleka, okuqukethwe kwawo komoyampilo okuncibilikisiwe ngokuvamile kungabi ngaphansi kuka-1mg/L.Uma iphansi kakhulu (<0.5mg/L) noma phezulu kakhulu (indlela yokufaka umoya >2mg/L), izodala ukuchitheka kwamanzi.Izinga lamanzi liyawohloka noma lidlule ngisho namazinga.Ngakho-ke, ukunakekela okugcwele kufanele kukhokhwe ekuqapheni okuqukethwe komoyampilo oncibilikisiwe ngaphakathi kwensiza yokwelapha yebhayoloji kanye namanzi angcolile ethangi layo lenhlabathi.
I-Iodometric titration ayifanele ukuhlolwa endaweni, futhi ayikwazi ukusetshenziselwa ukuqapha okuqhubekayo noma ukunqunywa kwendawo komoya-mpilo oncibilikisiwe.Ekuqaphelweni okuqhubekayo kwe-oksijini ehlakazekile ezinhlelweni zokuhlanza indle, indlela ye-membrane electrode endleleni ye-electrochemical isetshenziswa.Ukuze ubambe ngokuqhubekayo izinguquko ku-DO yoketshezi oluxubile ethangini lokungenisa umoya phakathi nenqubo yokuhlanza indle ngesikhathi sangempela, imitha ye-DO ye-electrochemical probe ngokuvamile isetshenziswa.Ngesikhathi esifanayo, imitha ye-DO nayo iyingxenye ebalulekile yokulawula okuzenzakalelayo kanye nesistimu yokulungisa ye-oxygen encibilikile ku-aeration tank.Ngokuba uhlelo lokulungiswa nokulawula ludlala indima ebalulekile ekusebenzeni kwayo okujwayelekile.Ngesikhathi esifanayo, futhi kuyisisekelo esibalulekile sabaqhubi bezinqubo ukulungisa nokulawula ukusebenza okuvamile kokwelashwa kwe-biological ye-sewage.
49. Yiziphi izinyathelo zokuphepha zokukala umoya-mpilo oncibilikisiwe nge-iodometric titration?
Ukunakekelwa okukhethekile kufanele kuthathwe lapho kuqoqwa amasampula amanzi okulinganisa umoya-mpilo oncibilikisiwe.Amasampula amanzi akufanele axhumane nomoya isikhathi eside futhi akufanele anyakaze.Lapho wenza amasampula ethangini lokuqoqa amanzi, sebenzisa ibhodlela le-oxygen elifakwe ingilazi elingu-300 ml elinomlomo omncane oncibilikisiwe, bese ukala futhi urekhode izinga lokushisa lamanzi ngesikhathi esifanayo.Ngaphezu kwalokho, uma usebenzisa i-titration ye-iodometric, ngaphezu kokukhetha indlela ethile yokuqeda ukuphazamiseka ngemva kwesampula, isikhathi sokugcina kufanele sifinyezwe ngangokunokwenzeka, futhi kungcono ukuhlaziya ngokushesha.
Ngokuthuthukiswa kwezobuchwepheshe kanye nemishini kanye nosizo lwe-instrumentation, i-iodometric titration ihlala iyindlela enembile futhi enokwethenjelwa yokuhlaziya i-oxygen encibilikile.Ukuze kuqedwe ithonya lezinto ezihlukahlukene eziphazamisayo kumasampuli amanzi, kunezindlela ezimbalwa eziqondile zokulungiswa kwe-titration ye-iodometric.
Ama-oksidi, ama-reductants, izinto eziphilayo, njll. ezikhona kumasampula amanzi zizophazamisa ukulinganiswa kwe-iodometric.Amanye ama-oxidants angahlukanisa i-iodide ibe yi-iodine (ukuphazamiseka okuhle), kanti amanye ama-ejenti anciphisayo anganciphisa i-iodine ibe iodide (ukuphazamiseka okungekuhle).Ukuphazamiseka), lapho imvula ye-manganese ene-oxidized yenziwa i-asidi, izinto eziningi eziphilayo zingafakwa i-oxidized ngokwengxenye, zikhiqize amaphutha amabi.Indlela yokulungiswa kwe-azide ingaqeda ngempumelelo ukuphazanyiswa kwe-nitrite, futhi lapho isampula yamanzi iqukethe insimbi ene-valent ephansi, indlela yokulungiswa kwe-potassium permanganate ingasetshenziswa ukuqeda ukuphazamiseka.Uma isampula lamanzi liqukethe umbala, ulwelwe, nezinto eziqinile ezimisiwe, indlela yokulungiswa kwe-alum flocculation kufanele isetshenziswe, futhi indlela yokulungisa i-copper sulfate-sulfamic acid flocculation isetshenziswa ukuze kutholwe umoya-mpilo oncibilikisiwe wengxube ye-sludge ecushiwe.
50. Yiziphi izinyathelo zokuphepha zokukala i-oxygen encibilikile usebenzisa indlela yefilimu encane ye-electrode?
I-electrode ye-membrane iqukethe i-cathode, i-anode, i-electrolyte ne-membrane.I-electrode cavity igcwele isisombululo se-KCl.Ulwelwesi luhlukanisa i-electrolyte kusampula yamanzi ukuze ikalwe, bese umoya-mpilo oncibilikisiwe ungene futhi usakazeke kulwelwesi.Ngemva kokuba i-DC fixed polarization voltage ye-0.5 kuya ku-1.0V isetshenziswe phakathi kwezigxobo ezimbili, i-oksijeni encibilikisiwe emanzini akalwayo idlula ifilimu futhi incishiswe ku-cathode, ikhiqize ukusabalalisa kwamanje ngokulingana nokuhlushwa komoya-mpilo.
Amafilimu asetshenziswa kakhulu yi-polyethylene kanye namafilimu e-fluorocarbon angavumela ama-molecule e-oksijini ukuba adlule futhi abe nezinto ezinzile.Ngenxa yokuthi ifilimu ingangena kumagesi ahlukahlukene, amanye amagesi (afana ne-H2S, SO2, CO2, NH3, njll.) aku-electrode ebonisayo.Akulula ukuhlehlisa, okuzonciphisa ukuzwela kwe-electrode futhi kuholele ekuphambukeni emiphumeleni yokulinganisa.Amafutha namafutha emanzini akaliwe kanye nama-microorganisms ku-aeration tank ngokuvamile anamathela kulwelwesi, okuthinta kakhulu ukunemba kokulinganisa, ngakho-ke ukuhlanza nokulinganisa okuvamile kuyadingeka.
Ngakho-ke, i-membrane electrode encibilikisiwe i-oxygen analyzers esetshenziswa ezinhlelweni zokuhlanza indle kumele isetshenziswe ngokuhambisana ngokuqinile nezindlela zokulinganisa zomenzi, futhi ukuhlanza okuvamile, ukulinganisa, ukugcwalisa i-electrolyte, kanye nokushintshwa kwe-electrode membrane kuyadingeka.Lapho ushintsha ifilimu, kufanele ukwenze ngokucophelela.Okokuqala, kufanele uvimbele ukungcoliswa kwezingxenye ezibucayi.Okwesibili, qaphela ukuthi ungashiyi ama-bubbles amancane ngaphansi kwefilimu.Uma kungenjalo, umsinga osele uzokwanda futhi uthinte imiphumela yokulinganisa.Ukuze kuqinisekiswe idatha enembile, ukugeleza kwamanzi endaweni yokulinganisa i-electrode ye-membrane kufanele kube nezinga elithile lesiyaluyalu, okungukuthi, isisombululo sokuhlola esidlula ebusweni be-membrane kufanele sibe nesilinganiso sokugeleza esanele.
Ngokuvamile, umoya noma amasampula anokugxiliswa kwe-DO okwaziwayo namasampuli angenayo i-DO angasetshenziswa ukulawula ukulinganisa.Yiqiniso, kungcono ukusebenzisa isampula yamanzi ngaphansi kokuhlolwa ukuze kulinganiswe.Ngaphezu kwalokho, iphuzu elilodwa noma amabili kufanele ahlolwe njalo ukuze kuqinisekiswe idatha yokulungiswa kwezinga lokushisa.
Isikhathi sokuthumela: Nov-14-2023
