Removal of Coomassie Brilliant Blue G-250 from Aqueous Solutions Using Cu(II)/Cr(III)-Based Layered Double Hydroxide

Project no. 33439 · Status: Kapanmış · 2026

Summary

<p>In&nbsp;this&nbsp;study,&nbsp;the&nbsp;removal&nbsp;performance&nbsp;of&nbsp;Coomassie&nbsp;Brilliant&nbsp;Blue&nbsp;G-250&nbsp;(CBB)&nbsp;dye&nbsp;from&nbsp;aqueous&nbsp;solutions&nbsp;using&nbsp;Cu(II)/Cr(III)-based&nbsp;layered&nbsp;double&nbsp;hydroxide&nbsp;(Cu/Cr&nbsp;LDH)&nbsp;was&nbsp;investigated.&nbsp;Cu/Cr&nbsp;LDH&nbsp;was&nbsp;synthesized&nbsp;via&nbsp;the&nbsp;co-precipitation&nbsp;method&nbsp;and&nbsp;employed&nbsp;as&nbsp;a&nbsp;sorbent&nbsp;material.&nbsp;Batch&nbsp;experiments&nbsp;were&nbsp;conducted&nbsp;to&nbsp;evaluate&nbsp;the&nbsp;effects&nbsp;of&nbsp;sorbent&nbsp;dosage,&nbsp;initial&nbsp;solution&nbsp;pH,&nbsp;and&nbsp;contact&nbsp;time&nbsp;on&nbsp;CBB&nbsp;removal.&nbsp;In&nbsp;addition,&nbsp;isotherm,&nbsp;kinetic,&nbsp;and&nbsp;thermodynamic&nbsp;studies&nbsp;were&nbsp;performed,&nbsp;while&nbsp;the&nbsp;influence&nbsp;of&nbsp;interfering&nbsp;ions&nbsp;(Cl^–,&nbsp;SO₄^2–&nbsp;and&nbsp;NO₃^–)&nbsp;was&nbsp;assessed&nbsp;through&nbsp;selectivity&nbsp;experiments.&nbsp;FTIR,&nbsp;Raman,&nbsp;XRD,&nbsp;and&nbsp;XPS&nbsp;analyses&nbsp;were&nbsp;carried&nbsp;out&nbsp;to&nbsp;characterize&nbsp;the&nbsp;sorbent&nbsp;structure&nbsp;and&nbsp;elucidate&nbsp;the&nbsp;CBB&nbsp;retention&nbsp;mechanism.&nbsp;CBB&nbsp;concentrations&nbsp;were&nbsp;determined&nbsp;spectrophotometrically&nbsp;at&nbsp;590&nbsp;nm.</p><p></p><p>The&nbsp;results&nbsp;demonstrated&nbsp;that&nbsp;the&nbsp;optimum&nbsp;sorbent&nbsp;dosage&nbsp;for&nbsp;CBB&nbsp;removal&nbsp;was&nbsp;0.025&nbsp;g/25&nbsp;mL,&nbsp;and&nbsp;high&nbsp;removal&nbsp;efficiencies&nbsp;were&nbsp;achieved&nbsp;within&nbsp;the&nbsp;investigated&nbsp;pH&nbsp;range.&nbsp;Kinetic&nbsp;studies&nbsp;revealed&nbsp;that&nbsp;CBB&nbsp;removal&nbsp;by&nbsp;Cu/Cr&nbsp;LDH&nbsp;was&nbsp;rapid&nbsp;and&nbsp;reached&nbsp;equilibrium&nbsp;within&nbsp;approximately&nbsp;60&nbsp;min.&nbsp;The&nbsp;kinetic&nbsp;data&nbsp;were&nbsp;best&nbsp;described&nbsp;by&nbsp;the&nbsp;pseudo-second-order&nbsp;kinetic&nbsp;model.&nbsp;Equilibrium&nbsp;studies&nbsp;indicated&nbsp;that&nbsp;CBB&nbsp;removal&nbsp;followed&nbsp;the&nbsp;Langmuir&nbsp;isotherm&nbsp;model,&nbsp;with&nbsp;maximum&nbsp;sorption&nbsp;capacities&nbsp;ranging&nbsp;from&nbsp;70.6468&nbsp;to&nbsp;192.9716&nbsp;mg/g&nbsp;depending&nbsp;on&nbsp;temperature.&nbsp;Thermodynamic&nbsp;analyses&nbsp;showed&nbsp;that&nbsp;the&nbsp;process&nbsp;occurred&nbsp;spontaneously&nbsp;due&nbsp;to&nbsp;negative&nbsp;ΔG°&nbsp;values,&nbsp;while&nbsp;the&nbsp;positive&nbsp;ΔH°&nbsp;value&nbsp;(30.3&nbsp;kJ/mol)&nbsp;confirmed&nbsp;the&nbsp;endothermic&nbsp;nature&nbsp;of&nbsp;the&nbsp;sorption&nbsp;process.&nbsp;Characterization&nbsp;results&nbsp;suggested&nbsp;that&nbsp;CBB&nbsp;retention&nbsp;occurred&nbsp;through&nbsp;a&nbsp;multi-interaction&nbsp;mechanism&nbsp;involving&nbsp;electrostatic&nbsp;interactions,&nbsp;hydrogen&nbsp;bonding,&nbsp;and&nbsp;coordination/Lewis&nbsp;acid–base&nbsp;interactions&nbsp;between&nbsp;the&nbsp;dye&nbsp;molecule&nbsp;and&nbsp;Cu/Cr&nbsp;LDH.&nbsp;Under&nbsp;optimum&nbsp;conditions,&nbsp;the&nbsp;initial&nbsp;10&nbsp;mg/L&nbsp;CBB&nbsp;concentration&nbsp;was&nbsp;reduced&nbsp;below&nbsp;1&nbsp;mg/L,&nbsp;successfully&nbsp;achieving&nbsp;the&nbsp;project&nbsp;performance&nbsp;target.</p>

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