Kuwonongeka kwa methylene blue ndi fotokatalisisi: kutanthauzira zotsatira za kuchotsa

Laboratoriyo imayesa makatalisiti awiri kuti aone kuwonongeka kwa methylene blue mothandizidwa ndi kuwala. Katalisiti A imachotsa 95 peresenti ya mtundu wabuluu mu ola limodzi. Katalisiti B imakwanitsa 60 peresenti yokha. Gulu limalengeza kuti A yapambana, limalemba zimenezi mu lipoti, ndipo limayitanitsa ina yambiri. Patapita miyezi, kuyeza kaboni kumaulula zoona: utoto wambiri umene A inachotsa unali udakali wosasinthika pamwamba pa chinthu cholimba, pamene B inali itaphwanya molekyulu zambiri za utoto. Kusanjako kunali kolakwika chifukwa gululo linayeza chinthu chimodzi koma linachitcha dzina la china.

Kulakwitsa kumeneku n'kofala chifukwa zinthu zinayi zosiyana zimakhala ndi chizindikiro chimodzi chooneka: madzi abuluu amatumbuluka. Kumamatira pamwamba, kutha kwa mtundu, kuwonongeka kwa molekyulu, ndi kusanduka zinthu za mchere zingachititse chotsatira chimenecho, ndipo chilichonse chimafotokoza chosiyana pa zimene zachitikira utotowo. Methylene blue ndi imodzi mwa zinthu zimene zimagwiritsidwa ntchito poyeza zinthu ndi kufufuza za chilengedwe, kumene utotowo umakhala ndi ntchito yodziwika bwino; pano ntchito yake ndi kuimira chinthu choipitsa chimene chikuchotsedwa kapena kusinthidwa. Musanayerekezere makatalisiti kapena kufalitsa peresenti ya zimene zachotsedwa, sankhani chotsatira chimene miyeso yanu ingatsimikizire.

Zotsatira zinayi, matanthauzo anayi osiyana

Ganizirani zimenezi ngati zinthu zinayi zimene zimagwira ntchito m'njira zosiyana. Chilichonse chimayankha funso losiyana, ndipo chilichonse chimafuna umboni wake.

Kumamatira pamwamba kumatanthauza kuti molekyulu za utoto zimachoka m'madzi n'kukhazikika pa chinthu cholimba popanda kusintha kapangidwe kake ka mankhwala. Mayeso ake amachitika mumdima mpaka kuchuluka kwa utoto womamatira kukhale kosasintha kwenikweni, ndipo umboni woyenera umaphatikizapo utoto wobwezeretsedwa kuchokera pa chinthu cholimbacho mwa kuumasula kapena kuutulutsa. Nthawi yokhazikika ya mphindi 30 mumdima si umboni wakuti chinthu chilichonse chafika pa kufanana kwa kumamatira ndi kumasuka, ndipo nkhani yaposachedwa yokhudza njira zoyesera ikusonyeza momwe kudumpha sitepe imeneyi kumachititsira kusanja makatalisiti molakwika pamene kumamatira mumdima kumasiyana pakati pa zinthu.

Kutha kwa mtundu kumatanthauza kutha kwa gawo la molekyulu limene limapereka mtundu wooneka, ndipo nthawi zambiri kumatsatiridwa pafupi ndi gawo lalikulu loyamwa kuwala la pafupifupi 664 nm. Kumamatira pamwamba, kulandira maelekitironi, kuchotsedwa kwa magulu a methyl pa nayitrojeni, ndi kuphwanyika kwa gawo lopereka mtundu zonse zingachepetse muyeso umenewo, motero muyeso wa utali umodzi wa funde sungasonyeze chifukwa chake. Lembani sipekitiramu yonse m'malo mwa nambala imodzi: kusuntha kwa nsonga kupita ku utali waufupi wa funde kumagwirizana ndi zinthu za banja la Azure zimene zachotsedwa magulu a methyl. Chotsatira chotchulidwa kuti kuchotsa 95 peresenti pa 664 nm chiyenera kutchedwa kutha kwa mtundu kwa 95 peresenti, osati kuwonongeka kwa molekyulu kwa 95 peresenti.

Kuwonongeka kwa molekyulu kumatanthauza kuti molekyulu yoyambirira ya methylene blue yasintha kapangidwe kake ka mankhwala. Umboni wake umachokera ku kromatografiya: utoto wosasinthika umachepa pa HPLC kapena UPLC pamene zinthu zopangidwa ndi kusinthako zimaonekera, kenako nazonso zimawonongeka; bwino kwambiri zitadziwika pogwiritsa ntchito LC-MS. Zizindikiro zothandiza zimaphatikizapo ayoni ya molekyulu yoyambirira pafupi ndi m/z 284, ndi mndandanda wa kuchotsedwa kwa magulu a methyl pang'onopang'ono: Azure B pafupi ndi 270, Azure A pafupi ndi 256, Azure C pafupi ndi 242, ndi thionine pafupi ndi 228. Kusintha kwa maayoni mu LC-MS/MS kovomerezedwa poyeza mitundu ya utoto m'madzi kwafalitsidwa.

Kusanduka zinthu za mchere kumatanthauza kuti kaboni wa zinthu za organic wasandulika kukhala zinthu zomaliza za inorganic, makamaka carbon dioxide ndi kaboni wa inorganic, ndipo nayitrojeni ndi sulfure zimathera m'zinthu monga ammonium, nitrate, ndi sulfate. Kuchepa kwa kaboni yense wa organic (TOC) ndi muyeso wa kaboni womwe umagwiritsidwa ntchito kawirikawiri. Kuchepa kwa kuchuluka kwa okosijeni kofunikira posintha zinthu mwa mankhwala (COD) kumasonyeza kuchepa kwa zinthu zimene zingalandire okosijeni, koma si chiwerengero chosonyeza kuchuluka konse kwa kaboni ndipo pakokha sikutsimikizira kusanduka kwathunthu kukhala zinthu za mchere. Kromatografiya ya maayoni poyeza sulfate, nitrate, ndi ammonium imalimbikitsa umboniwo.

Mitundu ya makatalisiti (titania yowonjezeredwa zinthu zina, zinthu zophatikizidwa, zinthu zoikidwa pa kaboni, ndi zina zofanana) iyenera kuyerekezera pamodzi pokhapokha mtundu uliwonse utayesedwa pa zotsatira ndi mayeso oyerekezera omwewo. Chinthu chophatikizidwa chimene chimakopa utoto kwambiri pamwamba pake nthawi zonse chidzaoneka kuti chikugwira ntchito mofulumira pa mayeso a mtundu. Ndi chifukwa chenicheni chimene mndandanda wowunika uli pansipa umasiyanitsira kumamatira ndi kusintha kwa mankhwala musanayambe kusanja.

Mmene methylene blue imawonongekera ndi fotokatalisisi

Njira zovomerezedwa zimene zimayamba pamene kuwala kwadzutsa semikondakita mwachindunji zafotokozedwa mwachidule mu ndemanga yotchulidwa kwambiri yokhudza kuwonongeka kwa utoto ndi fotokatalisisi pogwiritsa ntchito zinthu zopangidwa ndi titania. Mafotoni amene ayamwidwa amapanga maelekitironi mu gawo loyendetsa magetsi ndi mipata ya maelekitironi mu gawo la valence. Mipatayo imatenga maelekitironi kuchokera ku madzi kapena hydroxide yapamwamba, n'kupanga maradikali a hydroxyl, pamene maelekitironi amapatsa okosijeni wosungunuka m'madzi maelekitironi n'kupanga superoxide. Kusintha kwina kudzera mu maradikali a hydroperoxyl ndi hydrogen peroxide kumapanga maradikali ena a hydroxyl. Mitundu imeneyi ya okosijeni yogwira ntchito kwambiri, limodzi ndi mipatayo, kenako imaukira utoto.

Kusintha kwa methylene blue nthawi zambiri kumayamba ndi kuchotsa magulu a methyl pa nayitrojeni motsatizana kudzera mu Azure B, Azure A, ndi Azure C kupita ku thionine, limodzi ndi kusintha kwa gawo lopereka mtundu la phenothiazine mwa kulitengera maelekitironi. Kuukira kwina kwa maradikali kumathyola maulalo a kaboni ndi sulfure komanso a kaboni ndi nayitrojeni, kumatsegula mphete za aromatic, ndipo kumatulutsa zinthu za mtundu wa phenol ndi aniline, aldehyde, ndi maasidi a carboxylic okhala ndi kulemera kochepa kwa molekyulu, zisanafike posanduka zinthu za mchere. Ndemanga yapadera ya makhalidwe a methylene blue ndi njira zake zowonongekera ndi kuwala imafotokoza njira zimenezi mwatsatanetsatane. Kuchuluka kwa zinthu zimene zimatsatira nthambi iliyonse kumadalira katalisiti, pH, kupezeka kwa okosijeni, ndi kuwala kogwiritsidwa ntchito, choncho onani dongosololi ngati gulu la njira zosiyanasiyana osati mndandanda umodzi wokakamizika.

Zinthu ziwiri za mayesero ziyenera kuyang'aniridwa chifukwa zimasintha liwiro looneka la kusintha popanda kusintha makhalidwe enieni a katalisiti. pH imasintha chaji ya pamwamba pa titania ndi kuchuluka kwa magulu a hydroxyl pamenepo, zimene zimasintha kumamatira kwa utoto wa chaji yabwino ndipo motero liwiro limene limaonedwa; yerekezani zinthu pa pH yofanana ndipo lembani miyeso yoyambirira ndi yomaliza. Mchere wosungunuka ndi zinthu zosunga pH zimagwiranso ntchito mofanana: chloride, phosphate, carbonate, ndi sulfate zingatenge malo a pamwamba ndi kusintha mmene maradikali amagwirira ntchito. Kafukufuku wapadera wa mchere wa inorganic mu fotokatalisisi ya titania amafotokoza mwachindunji mmene zimakhudzira methylene blue.

Msampha wa kuwala kooneka

Titania yoyera, yosasintha, imafuna kudzutsidwa ndi kuwala kwapafupi ndi UV, koma malipoti ambiri amasonyeza methylene blue ikutaya mtundu pansi pa nyali zotulutsa kuwala kooneka kokha, ndipo amanena kuti katalisiti imagwira ntchito ndi kuwala kooneka. Njira imene mwina ikuchitika ndi kudzutsidwa mothandizidwa ndi utoto: utoto wodzutsidwa ndi kuwala umalowetsa elekitironi mu semikondakita, ndipo elekitironiyo imapatsa okosijeni maelekitironi, n'kuchititsa mtundu kutha popanda kuwala kudzutsa chinthu cholimbacho kudutsa kusiyana kwa mphamvu pakati pa magawo ake. Mayesero osungidwa a Ohtani ndi anzake okhudza vuto la kuwala kooneka anasonyeza cholakwika chimenechi, ndipo mafotokozedwe a malire a ISO 10678 amaika malirewo momveka bwino: njira yake yoyesera methylene blue ndi ya kuwala kwa UV kokha, osati yotsimikizira kugwira ntchito ndi kuwala kooneka.

Mayeso othandiza ndi osavuta. Bwerezani kuyeserako pogwiritsa ntchito chinthu choyesera chopanda mtundu chimene sichiyamwa kuwala kooneka, ndipo yerekezani mmene liwiro limasinthira ndi utali wa funde ndi sipekitiramu yoyamwa kuwala ya katalisiti. Ngati kugwira ntchito kukutsatira kuyamwa kuwala kwa utoto m'malo mwa kwa katalisiti, chotsatiracho chimatsimikizira kudzutsidwa mothandizidwa ndi utoto, osati fotokatalisisi ya kuwala kooneka yochokera ku katalisiti yeniyeniyo. Kumbukirani mayeso amenewa powerenga zimene ogulitsa amanena za mitundu ya makatalisiti ogwira ntchito ndi kuwala kooneka.

Mndandanda wowunika zotsatira

Gwiritsani ntchito mndandandawu musanasanje makatalisiti kapena kulemba kuti chinthu chachotsedwa. Ndi chida cha patsamba lino chimene mungagwiritse ntchito mobwerezabwereza: kuyesera kulikonse kwa kuwonongeka kwa methylene blue kuyenera kukwaniritsa mfundo iliyonse.

1. Mayeso oyerekezera a kumamatira mumdima: utoto ndi katalisiti, popanda kuwala, zosonkhezeredwa mpaka kufika pa kuchuluka kosasintha koyezedwa, ndi kubwezeretsa utoto kuchokera pa chinthu cholimba, osati kungoganiza motengera nthawi yokhazikika.
2. Mayeso oyerekezera a kuwonongeka ndi kuwala kokha: utoto ndi kuwala, popanda katalisiti, kuti muyeze kutha kwa mtundu kochitika mwachindunji pansi pa nyali yanu ndi kapangidwe ka mayeserowo.
3. Chitsanzo choyezera chopanda utoto: katalisiti ndi kuwala, popanda utoto, kuti muone zizindikiro zochokera ku zinthu zina pa TOC, maayoni, ndi sipekitiramu.
4. Mikhalidwe yokhazikika ya kusintha: sipekitiramu ya nyali, kuchuluka kwa mafotoni odutsa, kutentha, kusakaniza, okosijeni wosungunuka, kapangidwe ka chotengera choyeseramo, kuchuluka koyambirira kwa utoto m'madzi, kuchuluka kwa katalisiti, pH, ndi zinthu zina zonse m'chitsanzo zisakhale zosiyana pakati pa mitundu yoyerekezedwa.
5. Kulekanitsa chinthu cholimba musanayeze ndi sipekitiramu: sefani kapena gwiritsani ntchito makina ozungulira mwachangu kuti kumwazika kwa kuwala kusawerengedwe ngati kuyamwa kuwala.
6. Sipekitiramu zonse, osati utali umodzi wa funde: perekani sikani yonse kuti kusuntha kwa nsonga ndi magawo atsopano zionekebe.
7. Kutsimikizira ndi kromatografiya pa zonena zilizonse za kuwonongeka kwa molekyulu: kuchepa kwa molekyulu yoyambirira yosasinthika, kuphatikizapo kutsatira zinthu zopangidwa.
8. Kuwerengera kaboni pa zonena zilizonse za kusanduka zinthu za mchere: TOC ndi zitsanzo zopanda chinthu choyezedwa, komanso kuwunika kuti kaboni wooneka ngati watha sanangosamukira pa chinthu cholimba.
9. Kuwunika kutuluka kwa zinthu kuchokera pa chinthu cholimba: chotsani chinthu cholimbacho chonse (mayeso a mtundu wa kusefa kutentha), walitsani madzi amene adutsa musefa, ndipo yezani zitsulo zosungunuka; ngati kusintha kukupitirirabe, zimasonyeza kuti zinthu zosungunuka zikuthandizanso.
10. Kutchula moona: tchulani chotsatira cha 664 nm kuti kutha kwa mtundu, cha kromatografiya kuti kuwonongeka kwa molekyulu, ndipo cha TOC kuti kusanduka zinthu za mchere.

Kafukufuku waposachedwa wa chotengera choyeseramo chogwiritsa ntchito UV-LED, chophatikiza mayeso a kumamatira, kulekanitsa katalisiti, UV-vis, ndi TOC amasonyeza momwe zigawo zimenezi zimagwirizanirana m'gawo limodzi lofotokoza njira zoyesera.

Chitsanzo chowerengera kuchuluka kwa zinthu

Tiyerekeze kuti mayeso a 100 mL akuyamba ndi methylene blue ya 10 mg/L, kotero chotengera choyeseramo chili ndi 1.0 mg ya utoto. Pambuyo pofika pa kufanana kwa kumamatira ndi kumasuka mumdima, madziwo amayezedwa kukhala 8.0 mg/L, kutanthauza kuti 0.2 mg ili pa chinthu cholimba ndipo 0.8 mg idakali yosungunuka. Pambuyo pa ola limodzi lowunikira, kuyeza madzi osefedwa ndi kromatografiya kumapereka 2.0 mg/L ya utoto wosasinthika (0.2 mg m'madzi), kumasula utoto kumabwezeretsa 0.1 mg ya utoto wosasinthika kuchokera pa chinthu cholimba, ndipo TOC imasonyeza kuti 40 peresenti ya kaboni wa organic woyambirira wachoka m'gulu lonse la madzi ndi chinthu cholimba n'kukhala kaboni wa inorganic.

Chiwerengero chozikidwa pa kaboni chimati: kaboni woyambirira ndi wofanana ndi utoto woyambirira m'madzi kuphatikiza utoto woyambirira womamatira pamwamba kuphatikiza zinthu zapakati za organic kuphatikiza kaboni wosanduka zinthu za mchere. Pano 20 peresenti ya kulemera koyambirira kwa utoto ikadali ngati molekyulu yoyambirira yosasinthika (0.2 mg m'zigawo zonse ziwiri), 40 peresenti yasanduka zinthu za mchere, ndipo 40 peresenti yotsalayo ndi zinthu za organic zopangidwa ndi kusintha (zinthu zapakati m'madzi kapena pa chinthu cholimba, zotsimikizidwa ndi nsonga za zinthu zopangidwazo). Lipoti loyenera ndi kuwonongeka kwa utoto woyambirira kwa 80 peresenti ndi kusanduka zinthu za mchere kwa 40 peresenti, osati 95 peresenti ya chilichonse. Onani msampha wake: ngati TOC ikanayesedwa pa madzi apamwamba osefedwa okha, zinthu za organic zomamatira zikanawerengedwa ngati zawonongedwa ndipo chiwerengero cha kusanduka zinthu za mchere chikanakwera molakwika. Yezani kaboni m'chosakaniza chonse cha madzi ndi zolimba ngati n'zotheka, kapena onjezerani momveka bwino gawo lomamatira pa chinthu cholimba.

Lamulo lofotokozera zotsatira

Nenani chotsatira chochepa kwambiri chimene umboni wanu umatsimikizira, kenako onjezerani zonena zamphamvu kwambiri pokhapokha muyeso uliwonse wowonjezera wazitsimikizira. Kafukufuku wa kuwonongeka kwa methylene blue amapeza chidaliro mofanana ndi njira zina zogwiritsa ntchito utoto: mwa kufananitsa chotsatira ndi khalidwe limene njirayo imayezadi. Buku lotsagana lofotokoza momwe mungawerengere zonena za kafukufuku wogwiritsa ntchito utoto limagwiritsa ntchito kusamala komweku pa kapangidwe ka kafukufuku, ndipo ndondomeko yothandiza yowunika mikhalidwe ya mayeso imafotokoza zizolowezi zokonza kulondola kwa miyeso zimene zingagwiritsidwe ntchito mwachindunji pa ntchito ya zotengera zoyeseramo zogwiritsa ntchito kuwala.