Dyeadsorbing

Dyeadsorbing refers to the capacity of a material to remove dye molecules from aqueous solutions through adsorption, typically used in wastewater treatment from textile and dyeing industries.

The process occurs at solid-liquid interfaces; mechanisms include physical adsorption via van der Waals and π-π interactions, and chemical adsorption via covalent or coordinative bonds; electrostatic attraction is important depending on dye charge and surface charge; pore diffusion and surface area influence capacity.

Common dyeadsorbing materials include activated carbon, aluminosilicates like clays and zeolites, silica, graphene-based materials, carbon nanotubes, biochars, chitosan and other biopolymers, metal-organic frameworks, and magnetic nanoparticles enabling easy separation.

Dye properties and solution conditions govern adsorption capacity: dye charge, molecular size, solution pH, ionic strength, temperature. Cationic dyes tend to adsorb strongly onto negatively charged surfaces; conversely anionic dyes may require positively charged surfaces or functional groups.

Adsorption is often described by isotherms such as Langmuir and Freundlich, and kinetics by pseudo-first-order or pseudo-second-order models; intraparticle diffusion can limit rate.

Practical use includes treatment of textile effluents, wastewater polishing, dye recovery, and regeneration and reuse; challenges include selectivity, regeneration efficiency, and competing substances; recent work focuses on composite materials and magnetic separations for easier deployment.

Related topics include adsorption, wastewater treatment, activated carbon, and isotherm models.