Hauv kev txiav txim siab dav dav, electrochemical oxidation yog hais txog tag nrho cov txheej txheem ntawm electrochemistry, uas cuam tshuam ncaj qha lossis tsis ncaj electrochemical tshwm sim ntawm electrode raws li cov hauv paus ntsiab lus ntawm oxidation-txo cov tshuaj tiv thaiv. Cov tshuaj tiv thaiv no tsom txo lossis tshem tawm cov pa phem ntawm cov dej khib nyiab.
Narrowly txhais, electrochemical oxidation tshwj xeeb yog hais txog cov txheej txheem anodic. Nyob rau hauv cov txheej txheem no, cov organic tov los yog ncua kev kawm ntawv yog nkag mus rau hauv ib tug electrolytic cell, thiab los ntawm daim ntawv thov ntawm ncaj qha tam sim no, electrons raug rho tawm ntawm lub anode, ua rau oxidation ntawm cov organic tebchaw. Xwb, cov hlau tsis tshua muaj siab tuaj yeem oxidized rau high-valence hlau ions ntawm anode, uas tom qab ntawd koom nrog oxidation ntawm cov organic tebchaw. Feem ntau, qee pawg ua haujlwm hauv cov organic tebchaw nthuav tawm cov haujlwm electrochemical. Raws li kev cuam tshuam ntawm hluav taws xob, cov qauv ntawm cov pab pawg ua haujlwm no tau hloov pauv, hloov cov tshuaj lom neeg ntawm cov organic tebchaw, txo lawv cov tshuaj lom, thiab txhim kho lawv cov biodegradability.
Electrochemical oxidation tuaj yeem faib ua ob hom: ncaj qha oxidation thiab indirect oxidation. Direct oxidation (ncaj electrolysis) muaj feem cuam tshuam ncaj qha tshem tawm cov pa phem ntawm cov dej khib nyiab los ntawm oxidizing lawv ntawm electrode. Cov txheej txheem no suav nrog cov txheej txheem anodic thiab cathodic. Cov txheej txheem anodic cuam tshuam nrog oxidation ntawm cov pa phem ntawm qhov chaw anode, hloov lawv mus rau hauv cov tshuaj lom neeg tsawg lossis cov khoom uas muaj biodegradable, yog li txo lossis tshem tawm cov pa phem. Cov txheej txheem cathodic cuam tshuam nrog kev txo cov pa phem ntawm qhov chaw cathode thiab feem ntau yog siv los txo thiab tshem tawm cov halogenated hydrocarbons thiab rov ua kom cov hlau hnyav.
Cov txheej txheem cathodic tuaj yeem raug xa mus rau kev txo qis electrochemical. Nws koom nrog kev hloov ntawm electrons los txo cov hlau hnyav xws li Cr6 + thiab Hg2 + rau hauv lawv cov oxidation qis. Tsis tas li ntawd, nws tuaj yeem txo cov chlorinated organic tebchaw, hloov lawv mus rau hauv cov tshuaj tsis muaj tshuaj lom lossis tsis muaj tshuaj lom, thaum kawg txhim kho lawv cov biodegradability:
R-Cl + H + e → RH + Cl-
Indirect oxidation (indirect electrolysis) yog siv los ntawm electrochemically generated oxidizing los yog txo cov neeg ua hauj lwm reactants los yog catalysts los hloov cov pa phem rau hauv tsawg dua tshuaj lom. Indirect electrolysis tuaj yeem muab faib ntxiv rau hauv cov txheej txheem thim rov qab thiab irreversible. Cov txheej txheem thim rov qab (mediated electrochemical oxidation) koom nrog kev tsim dua tshiab thiab rov ua dua tshiab ntawm hom redox thaum cov txheej txheem electrochemical. Cov txheej txheem irreversible, ntawm qhov tod tes, siv cov khoom tsim los ntawm cov tshuaj tiv thaiv tsis tau electrochemical, xws li cov tshuaj muaj zog oxidizing zoo li Cl2, chlorates, hypochlorites, H2O2, thiab O3, kom oxidize organic compounds. Cov txheej txheem irreversible kuj tuaj yeem tsim cov oxidative intermediates, nrog rau cov hluav taws xob solvated, · HO radicals, · HO2 radicals (hydroperoxyl radicals), thiab · O2- radicals (superoxide anions), uas tuaj yeem siv los degrade thiab tshem tawm cov pa phem xws li cyanide, phenols, COD (Chemical Oxygen Demand), thiab S2- ions, thaum kawg hloov lawv mus rau qhov tsis muaj mob. tshuaj.
Nyob rau hauv cov ntaub ntawv ntawm ncaj qha anodic oxidation, tsawg reactant concentrations yuav txwv tsis pub cov electrochemical nto cov tshuaj tiv thaiv vim huab hwm coj hloov cov kev txwv, thaum qhov kev txwv no tsis muaj nyob rau indirect oxidation txheej txheem. Thaum ob qho tib si ncaj qha thiab tsis ncaj qha oxidation cov txheej txheem, sab cuam tshuam nrog rau tiam H2 lossis O2 roj yuav tshwm sim, tab sis cov kev cuam tshuam sab nraud tuaj yeem tswj tau los ntawm kev xaiv cov khoom siv hluav taws xob thiab kev tswj xyuas muaj peev xwm.
Electrochemical oxidation tau pom tias muaj txiaj ntsig zoo rau kev kho cov dej khib nyiab nrog cov organic ntau ntau, cov khoom sib xyaw ua ke, ntau cov tshuaj refractory, thiab cov xim siab. Los ntawm kev siv anodes nrog electrochemical kev ua haujlwm, cov cuab yeej no tuaj yeem ua kom muaj oxidative hydroxyl radicals zoo heev. Cov txheej txheem no ua rau cov decomposition ntawm cov pa phem tsis tu ncua rau hauv cov khoom tsis muaj tshuaj lom, biodegradable thiab lawv cov ntxhia ua tiav rau hauv cov tebchaw xws li carbon dioxide lossis carbonates.
Post lub sij hawm: Sep-07-2023
