Adsorption behaviour of direct dye on cotton from water bath without any additions

Abstract

Adsorption behaviour of direct dye on cotton ( dyeing) was examined in order to gain data on colour binding mechanism and defining conditions of natural fibres dyeing process without any usual additions - electrolytes and other auxiliaries, as the basic precondition for optimising conventional or alternative, ecological additives. Adsorption was conducted under various conditions. It was determined that it depends upon contact time, initial dye concentration and adsorbent amount. The longer contact time is the more colour transfers on the yarn. Dye concentration in solution descends during the adsorption process. There is continuous growth of removed dye amount along with adsorbents amount. Characteristic illustration gained from Freundlich isotherm has confirmed that this model provides enough precise description of experimental data for direct dye in comparison to Langmuir isotherm.