Kuwongolera kwa kusanthula kwa COD muzachimbudzi
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1. Chinthu chachikulu-kuimira chitsanzo
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Popeza kuti zitsanzo zamadzi zomwe zimawunikidwa m'zimbudzi zapakhomo ndizosagwirizana kwambiri, chinsinsi chopezera zotsatira zolondola za COD ndikuti zitsanzozo ziyenera kukhala zoimira. Kuti tichite zimenezi, mfundo zotsatirazi ziyenera kuzindikirika.
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1.1 Gwedezani madzi bwino
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Pakuyezera madzi aiwisi ① ndi madzi oyeretsedwa ②, botolo lachitsanzo liyenera kulumikizidwa mwamphamvu ndikugwedezeka bwino musanatenge sampuli kuti limwaza tinthu tating'onoting'ono ndi zolimba zoyimitsidwa mumtsuko wamadzi momwe zingathere kuti chitsanzo chofananira ndi choyimira analandira. Wamadzi. Pazinyalala ③ ndi ④ zomwe zayamba kumveka bwino pambuyo pa mankhwala, zitsanzo zamadzi ziyeneranso kugwedezeka bwino musanatenge zitsanzo zoyezera. Pamene kuyeza COD pa chiwerengero chachikulu cha zitsanzo za m'madzi onyansa a m'nyumba, anapeza kuti pambuyo pa kugwedezeka kokwanira, zotsatira za kuyeza kwa zitsanzo za madzi sizikhala zovuta kwambiri. Zimasonyeza kuti chitsanzocho chikuyimira kwambiri.
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1.2 Tengani chitsanzo mutangogwedeza madzi
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Popeza kuti madzi otayira ali ndi zinthu zambiri zosagwirizana zoyimitsidwa, ngati chitsanzocho sichimatengedwa mwamsanga pambuyo pa kugwedezeka, zolimba zoyimitsidwa zidzamira mofulumira. The madzi chitsanzo ndende, makamaka zikuchokera inaimitsidwa zolimba, analandira pogwiritsa ntchito pipette nsonga kwa zitsanzo pa malo osiyanasiyana pamwamba, pakati ndi pansi pa botolo chitsanzo adzakhala osiyana kwambiri, amene sangakhoze kuimira mkhalidwe weniweni wa zimbudzi, ndi zotsatira zoyezedwa sizoyimira. . Tengani chitsanzo mwamsanga mutagwedeza mofanana. Ngakhale thovu amapangidwa chifukwa cha kugwedezeka (thovu zina zidzatha panthawi yochotsa chitsanzo cha madzi), voliyumu yotsatiridwayo idzakhala ndi zolakwika pang'ono pamtengo wokwanira chifukwa cha kukhalapo kwa thovu lotsalira, koma izi ndi The analytical error chifukwa kuchepa kwa kuchuluka kwathunthu ndi konyozeka poyerekeza ndi cholakwika chomwe chimabwera chifukwa cha kusagwirizana kwa kuyimira zitsanzo.
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Kuyesera kulamulira kuyeza zitsanzo za madzi zomwe zinasiyidwa kwa nthawi zosiyana pambuyo pa kugwedezeka ndi kusanthula mofulumira ndi kusanthula mwamsanga pambuyo pa kugwedeza zitsanzozo kunapeza kuti zotsatira zoyesedwa ndi zakale zinapatuka kwambiri ku mikhalidwe yeniyeni yamadzi.
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1.3 Voliyumu yoyeserera isakhale yaying'ono kwambiri
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Ngati chiwerengero cha sampuli ndi chochepa kwambiri, tinthu tina timene timayambitsa mpweya wambiri m'madzi otayira, makamaka madzi osaphika, sangachotsedwe chifukwa cha kugawidwa kosagwirizana, kotero zotsatira za COD zoyezedwa zidzakhala zosiyana kwambiri ndi zofunikira zenizeni za okosijeni. . Chitsanzo chomwecho chinayesedwa pansi pamikhalidwe yomweyi pogwiritsa ntchito 2.00, 10.00, 20.00, ndi 50.00 mL masampling volumes. Zinapezeka kuti zotsatira za COD zoyezedwa ndi 2.00 mL ya madzi osaphika kapena zotayira zomaliza nthawi zambiri zimakhala zosagwirizana ndi madzi enieni, komanso kukhazikika kwa chiwerengero cha ziwerengero kunalinso kosauka kwambiri; 10.00 inagwiritsidwa ntchito , kukhazikika kwa zotsatira za kuyeza kwa madzi a 20.00mL kwakhala bwino kwambiri; kukhazikika kwa zotsatira za COD za kuyeza kwa madzi a 50.00mL ndizabwino kwambiri.
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Chifukwa chake, pamadzi aiwisi okhala ndi COD yayikulu, njira yochepetsera kuchuluka kwa zitsanzo siziyenera kugwiritsidwa ntchito mwachimbulimbuli kuti zikwaniritse zofunikira za kuchuluka kwa potaziyamu dichromate yowonjezeredwa komanso kuchuluka kwa titrant muyeso. M'malo mwake, ziyenera kutsimikiziridwa kuti chitsanzocho chili ndi voliyumu yokwanira ya sampuli ndipo ndi yoyimira kwathunthu. Cholinga chake ndikusintha kuchuluka kwa dichromate ya potaziyamu yomwe yawonjezeredwa komanso kuchuluka kwa titrant kuti ikwaniritse zofunikira zamtundu wamadzi zachitsanzo, kuti deta yoyezedwa ikhale yolondola.
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1.4 Sinthani pipette ndikuwongolera sikelo
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Popeza tinthu kukula zolimba inaimitsidwa zitsanzo madzi zambiri lalikulu kuposa m'mimba mwake wa chitoliro kubwereketsa wa pipette, nthawi zonse zimakhala zovuta kuchotsa zolimba inaimitsidwa mu chitsanzo madzi pamene ntchito muyezo pipette kusamutsa zitsanzo zimbudzi zoweta. Zomwe zimayesedwa motere ndi mtengo wa COD wa zimbudzi zomwe zachotsa pang'ono zolimba zomwe zayimitsidwa. Komano, ngakhale mbali ya zabwino inaimitsidwa zolimba kuchotsedwa, chifukwa pipette suction doko ndi laling'ono kwambiri, zimatenga nthawi yaitali kuti mudzaze sikelo, ndi zolimba inaimitsidwa amene anagwedezeka wogawana mu zimbudzi pang'onopang'ono kumira. , ndipo zinthu zomwe zachotsedwa ndizosagwirizana kwambiri. , zitsanzo za madzi zomwe sizikuyimira mikhalidwe yeniyeni ya khalidwe la madzi, zotsatira zomwe zimayesedwa motere ziyenera kukhala ndi vuto lalikulu. Chifukwa chake, kugwiritsa ntchito pipette yokhala ndi pakamwa yabwino kuti mutenge zitsanzo za zimbudzi zapanyumba kuti muyese COD sikungapereke zotsatira zolondola. Choncho, pamene pipetting zoweta zimbudzi zitsanzo madzi, makamaka zitsanzo madzi ndi chiwerengero chachikulu cha inaimitsidwa particles lalikulu, pipette ayenera kusinthidwa pang'ono kukulitsa m'mimba mwake pores kuti zolimba inaimitsidwa akhoza mwamsanga pokoka mpweya, ndiyeno sikelo mzere ayenera kukonzedwa. , kupangitsa kuti muyeso ukhale wosavuta.
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2. Sinthani ndende ndi kuchuluka kwa reagents
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Mu njira yowunikira ya COD, kuchuluka kwa potaziyamu dichromate nthawi zambiri kumakhala 0.025mol/L, kuchuluka komwe kumawonjezeredwa pakuyezera kwachitsanzo ndi 5.00mL, ndipo voliyumu yotengera zimbudzi ndi 10.00mL. Pamene COD ndende ya zimbudzi ndi mkulu, njira kutenga zochepa zitsanzo kapena diluting zitsanzo zambiri ntchito kukwaniritsa zolephera experimental pa zinthu pamwamba. Komabe, Lian Huaneng amapereka ma reagents a COD kwa zitsanzo zamitundu yosiyanasiyana. Kuyika kwa ma reagentswa kumasinthidwa, kuchuluka ndi kuchuluka kwa potassium dichromate kumasinthidwa, ndipo pambuyo pa kuyesa kochuluka, amakwaniritsa zofunikira zozindikiritsa COD zamitundu yonse ya moyo.
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Mwachidule, poyang'anira ndi kusanthula khalidwe la madzi COD mu zimbudzi zapakhomo, chinthu chofunika kwambiri chowongolera ndi kuyimira chitsanzo. Ngati izi sizingatsimikizidwe, kapena ulalo uliwonse womwe umakhudza kuyimilira kwaubwino wamadzi umanyalanyazidwa, kuyeza ndi kusanthula zotsatira zidzakhala zolakwika. zolakwika zomwe zimatsogolera kumalingaliro olakwika aukadaulo.
The mofulumiraKuzindikira kwa CODNjira yopangidwa ndi Lianhua mu 1982 imatha kuzindikira zotsatira za COD mkati mwa mphindi 20. Opaleshoniyo imayendetsedwa bwino ndipo chidacho chakhazikitsa kale phokoso, kuchotsa kufunikira kwa titration ndi kutembenuka, zomwe zimachepetsa kwambiri zolakwika zomwe zimachitika chifukwa cha ntchito. Njirayi yatsogolera luso lazopangapanga pankhani ya kuyezetsa madzi ndikupereka thandizo lalikulu.
Nthawi yotumiza: May-11-2024
