Adsorption kinetic and equilibrium studies for maxilon blue GRL dye by cotton fiber in aqueous solutions

The adsorption interaction between cotton fibers and dye maxilon blue GRL was systematically investigated under varying contact times, initial dye concentrations, pH, agitation speeds and temperatures; and the adsorption capacity of dyes increases with the increase of those five parameters. The kinetic and isotherm results showed that the saturated adsorption capacity qm and adsorption capacity KF exhibited temperature-dependent enhancement; both the equilibrium adsorption amount qe and the apparent rate constant k2 increase with elevated agitation speeds and temperatures. Thermodynamic analysis indicated a non-spontaneous endothermic process. The low activation energy and adsorption enthalpy change confirmed physical adsorption mechanisms. Understanding the interaction between fiber and dye is helpful for optimizing dye utilization in industrial processes and engineering modified cotton fibers for wastewater decolorization.