Ukuthelekisa ngokufanelekileyo ii-adsorbent ze-methylene blue: umthamo, i-kinetics, neemeko zovavanyo

Olunye uphononongo lunika ingxelo ye-58 mg/g. Olunye lunika ingxelo ye-725 mg/g. Kulula ukuhendeka ukuba kuthiwe i-adsorbent yesibini ingcono ngokuphindwe kalishumi elinesibini uze uyeke ukufunda. Olu luhlu ludla ngokungabi nantsingiselo, kuba la manani mabini aveliswe phantsi kweemeko ezahlukeneyo yaye kusenokwenzeka ukuba awamele nohlobo olunye lwenani.

Amaphepha e-adsorption anika ingxelo yezixa ezintathu ezibonakala zifana: ipesenti yokususwa, i-uptake elinganisiweyo, kunye nomthamo ofakwe kwimodeli. Xa kongezwa uluhlu lwezinto ezicetywayo ukubopha idayi kunye neendlela idayi esabela ngazo kwindawo ekuyo, ukuthelekisa kuqala kube yingxaki yokuhambelanisa ngaphambi kokuba kube yingxaki yokubeka kuluhlu.

Isilumkiso sisekelwe kulwakhiwo, hayi kumzekelo omnye. Uhlalutyo lokufunda koomatshini lweemvavanyo ezingama-914 ezivela kumaphepha angama-75 kwi-clay, uthuthu, kunye nezinto ezenziwe zisebenze nge-alkali lwafumanisa ukuba i-uptake enikwe ingxelo yayilawulwa kakhulu ziisetingi zovavanyo, uxinaniso lokuqala lwedayi luyeyona nto inamandla ekuqikeleleni. Uphononongo luka-2024 lwee-adsorbent ezenziwe ngamagqabi lubonisa indlela iiprothokholi ezahluka ngayo kakhulu kwanaphakathi kosapho olunye lwezinto. Akukho namnye kule mithombo oxhasa uluhlu lokuthelekisa olwakhiwe kumaxabiso e-mg/g aphambili kuphela.

Ipesenti yokususwa ayingomthamo

Uninzi lwezintlu ezingalunganga ludibanisa izinto ezintathu. Ipesenti yokususwa iphendula umbuzo wokuba leliphi iqhezu ledayi elisusiweyo kwisisombululo esithile. I-uptake elinganisiweyo iphendula ukuba ingakanani idayi ehleli kwigram nganye ye-adsorbent xa kufikelelwe kwi-equilibrium. Umthamo ofakwe kwimodeli uphendula ukuba leliphi ixabiso le-saturation eliqikelelwa yimodeli ye-isotherm ekhethiweyo kuxinaniso oluphezulu.

I-mass balance idibanisa ezimbini zokuqala:

qe = (C0 minus Ce) times V divided by m

apho qe iyi-equilibrium uptake kwi-mg/g, C0 kunye ne-Ce zinguxinaniso lokuqala nolwe-equilibrium, V ngumthamo, kwaye m bubunzima be-adsorbent.

Isibini samanani sibonisa umgibe. Ukususa 100 percent kwi-0.1 L yedayi eyi-10 mg/L usebenzisa i-1 g ye-adsorbent kunika kuphela i-1 mg/g. Ukususa 80 percent kwi-0.1 L yedayi eyi-1000 mg/L usebenzisa i-0.1 g kunika i-800 mg/g. Isiphumo sokuqala sibonakala sigqibelele njengepesenti kodwa phantse asincedi njengomthamo. Naluphi na uluhlu oludibanisa ezi kholamu zimbini lubeka uvavanyo kuluhlu, hayi into.

I-qmax efakwe kwimodeli yongeza olunye umaleko. I-isotherm ye-methylene blue adsorption ibonisa qe ngokuchasene ne-Ce kuluhlu loxinaniso lokuqala. Ukufakwa kwe-Langmuir kuqikelela igophe lisondela kwindawo ephezulu enomda ebizwa ngokuba yi-qmax; ukufakwa kwe-Freundlich kuchaza i-power law engenandawo iphezulu. I-qmax enikwe ingxelo yiparamitha yemodeli, hayi isixa esilinganisiweyo ngobunzima. Ukuba amanqaku awasondeli kwindawo ephezulu, utshintsho oluncinci kumanqaku okugqibela lunokuyitshintsha kakhulu i-qmax.

Iimeko ezintandathu ezitshintsha inani ngalinye

Idosi. Umgubo omninzi uthetha iindawo ezininzi, ngoko ipesenti yokususwa idla ngokunyuka ngoxa i-uptake kwi-mg/g isihla, kuba idayi ebanjiweyo yahlulwe kubunzima obungakumbi. Amabango e-99 percent yokususwa kwi-10 g/L nakwi-0.2 g/L ahluka ngokuphindwe amashumi amahlanu ekusebenzeni kakuhle kwezinto. Bhala idosi kwi-g/L uze uthelekise i-uptake kwidosi ehambelanayo.

Uxinaniso lokuqala. I-C0 ephezulu inika amandla okuqhuba amakhulu, ngoko qe iyenyuka ngoxa ipesenti yokususwa isihla njengoko iindawo zizala. I-qmax efakwe kuluhlu lwe-100 ukuya ku-400 mg/L ichaza indawo eyahlukileyo yegophe kunaleyo ifakwe kuluhlu lwe-5 ukuya ku-50 mg/L. Funa uluhlu oludibanayo ngaphambi kokubeka kuluhlu.

pH. I-Methylene blue iyi-cationic, ngoko intlawulo yomphezulu ilawula ukutsalana. Ngaphantsi kwe-point of zero charge yawo umphezulu uyayigxotha idayi; ngaphezu kwayo umphezulu uyayitsala. Izifundo ezinika ingxelo ye-pH yokuqala kuphela zishiya umsantsa, kuba i-adsorption iyalitshintsha ixabiso le-equilibrium. Bhala zombini, kunye neetyuwa ezingasemva, kuba i-ionic strength iyawanciphisa la mandla afanayo alawulwa yi-pH. Indlela engqongqo egcina ukulinganisa okusekelwe kwi-absorbance kuchanekile malunga ne-solvent ne-pH iyasebenza nalapha: inani lihamba neemeko zalo.

Ixesha. Ixabiso elithathwe emva kwe-5 minutes ngu-qt, hayi qe. Ukukhawuleza kunye nokuba nomthamo omkhulu ziimpawu ezahlukeneyo: uthotho loncwadi olumalunga nemigubo yamagqabi lunika ingxelo yokufikelela kwi-equilibrium malunga ne-60 minutes phantsi kweprothokholi enye kwaye malunga ne-160 phantsi kwenye. Thelekisa amaxabiso e-equilibrium kuphela emva kokuba igophe le-kinetic lithe tyaba, kwaye unike ingxelo ye-uptake yexesha lokuqala njengesiphumo se-kinetics esahlukileyo.

Ubushushu. I-equilibrium kunye ne-diffusion zombini zisabela kubushushu ngeendlela ezithile kwinkqubo nganye. Kolunye uthotho lwe-date palm, i-Langmuir qmax yenyuka ukusuka malunga ne-43 mg/g kwi-30 C ukuya malunga ne-58 mg/g kwi-60 C, utshintsho lwe-35 percent olubangelwe bubushushu kuphela. Ungaze ubeke kuluhlu imithamo elinganisiwe kubushushu obude kakhulu ukusuka kwenye ngaphandle kokukuphawula oko.

Isiseko sokunika ingxelo. I-Milligrams per gram ithelekiseka kuphela xa i-gram ithetha into efanayo. Ubunzima obomileyo xa kuthelekiswa nobumanzi buyahluka ngokweqhezu lokufuma, kwaye ii-bead eziyimixube zahlukile kwinqanaba elisebenzayo elimsulwa. Chaza idinomineyitha kunye naluphi na ulungiso lokufuma. Kwiifilitha, yongeza umthamo ophindwe nge-bulk density; ekusebenzeni kakuhle komphezulu, yongeza umthamo owahlulwe nge-BET area, uqaphele ukuba ayingawo wonke umphezulu olinganisiweyo ovumela imolekyuli enkulu njenge-methylene blue ukuba ingene. Isazisi se-reagent sifanele sibhalwe kweli nyathelo, yiyo loo nto uhlolo lobunyulu be-reagent kunye ne-specification luhamba kunye nobunzima be-adsorbent.

Oko kuthethwa ngokwenene kukufakwa kwe-isotherm kunye ne-kinetics

Impazamo eqhelekileyo kukuthatha ukufana kakuhle kwemodeli njengobungqina be-mechanism. Uthelekiso lwe-methylene blue Langmuir Freundlich luvavanya ukuba yeyiphi i-equation echaza ngcono imilo yegophe kuluhlu oluvavanyiweyo. Aluqinisekisi i-monolayer coverage, i-homogeneity, okanye ukwakheka kwe-multilayer. Izinto ezine-porous ezingalinganiyo zisenokunika amagophe amile njenge-Langmuir kuluhlu olulinganiselweyo, kwaye ukufana okungcono kwe-Freundlich kuthetha kuphela ukuba idatha iyaqhubeka nokunyuka ngendlela enyuka ngayo loo equation. Qinisekisa i-mechanism ngobungqina obuzimeleyo obufana ne-spectroscopy, i-calorimetry, okanye ukuxhomekeka kwi-ionic strength.

Imikhwa yokuvavanya umgangatho wokufakwa ibalulekile. Khetha i-nonlinear regression, kuba i-linearized transforms zigqwetha iimpazamo kwaye zinokukhetha ngendlela ecwangcisiweyo imodeli enye. Jonga ii-residuals endaweni yokuthemba i-R squared kuphela. Buza ukuba i-qmax ingaphakathi kuluhlu olulinganisiweyo okanye ingaphaya kwalo: indawo ephezulu ekude ngaphezu kwe-qe enkulu elinganisiweyo luqikelelo, kwaye ukungaqiniseki kwayo kufanele kunikwe ingxelo, hayi ixabiso layo kuphela.

Ubulumko obufanayo bulawula i-methylene blue adsorption kinetics. Kuncwadi lwee-adsorbent zamagqabi i-equation ye-pseudo second order yeyona ixhaphakileyo ukunikwa ingxelo njengeyona ifana kakuhle nedatha, kodwa oko akungqini i-chemisorption, kanye njengokuba ukufana kwe-pseudo first order kungangqini i-physisorption. I-diffusion inokulinganisa nayiphi na kwezi equation kuxhomekeke kubungakanani bamasuntswana kunye nokuxovulwa, kwaye i-linearized plots ngokwembali ziye zathambekisela ukhuphiswano kwi-pseudo second order. Chaza i-equation, i-rate constant, i-equilibrium efakiweyo, i-interval, ubungakanani bamasuntswana, kunye nokuxovulwa, uze ugcine isantya nomthamo kwiikholamu ezahlukeneyo zephepha lokusebenzela.

Iphepha lokusebenzela lokuthelekisa izifundo ezipapashiweyo

Khuphela le theyibhile kube kanye kwisifundo ngasinye. Uthelekiso lusebenza kuphela apho iikholamu zokuhlola zihambelana.

Imizekelo emibini yoncwadi ibonisa iphepha lokusebenzela lisebenza. Uthotho lwe-date palm lunika ingxelo ye-equilibrium malunga ne-160 minutes, ixabiso elifanelekileyo kufuphi ne-pH 6.5, i-qmax enyuka nobushushu, kunye ne-Temkin kunye ne-pseudo second order njengeenkcazelo ezikhethwayo. Umgubo wamagqabi e-bamboo onyangiweyo unika ingxelo malunga ne-725 mg/g kunye nokususwa okusondele ekupheleleni, kodwa oku kuvela kwidayi eyi-100 ukuya ku-400 mg/L, idosi eyi-0.2 ukuya ku-1.4 g/L, kunye nexesha elimalunga ne-60 minutes ukuya kwi-equilibrium. Zombini zinokuba zichanekile ngaphakathi kwizifundo zazo kodwa zingenakuthelekiswa kuluhlu de idosi, uxinaniso, i-pH, ubushushu, kunye nesiseko zihambelane.

Isivakalisi esifanelekileyo sinemilo esisigxina: phantsi koluhlu loxinaniso oluhambelanayo, idosi, i-pH, ubushushu, ixesha le-equilibrium, kunye nesiseko sokunika ingxelo, into X ibonisa i-uptake ephezulu kunento Y. Nantoni na emfutshane kunoko libango malunga neemvavanyo ezimbini, hayi izinto ezimbini.