Insights into multi-component adsorption of reactive dyes on MIL-101-Cr metal organic framework: Experimental and modeling approach

Abstract

Reactive dyes are frequently applied in textile industries owing to varied color and texture. Treatment of such dye laden wastewater from textile industry is a major problem. Over the last few decades the most convenient removal mechanism adopted was adsorption using conventional adsorbents. Metal organic frameworks (MOFs) are porous compounds with metal ionic network bridged using organic ligands possessing high surface area, adjustable pore size and high stability. In this study, an in depth investigation of adsorption of toxic reactive dyes on MIL-101-Cr MOF was undertaken. Four reactive dyes (reactive yellow 15, reactive black 5, reactive red 24 and reactive blue 2) were adsorbed onto highly porous MIL-101-Cr MOF from their aqueous solution. Real life study with industrial dye laden wastewater was also investigated. The process was simulated using a multi-component modeling derived from first principles to understand the interaction among the dye molecules and between the adsorbate and adsorbent. The adsorbent was characterized using scanning electron microscopy, BET surface area, FTIR, particle size and zeta potential. Reactive dyes were completely adsorbed in pH range 3.0–10.0. Maximum Langmuir adsorption capacities of nascent MIL-101-Cr for above mentioned dyes were in the range of 377–397 mg/g at room temperature (30 °C). Effects of pH, temperature, salt concentration, adsorbent dosing and kinetic study for the adsorbent dosing were investigated. Regeneration efficiency of the spent MIL-101-Cr adsorbent was also envisaged.