ADSORPTION OF MIXTURE OF TWO DYES ON ACTIVATED CARBON

Activated carbon is known as adsorbent of various contaminants from wastewater and air. The aim of the work was to estimate sorptive capacity of activated carbon in the removal of dyes, which are contaminants from textile wastewaters. The mixture of two dyes, methyl blue and naphthol green B was selected for investigations and WDex activated carbon, virgin and regenerated, was chosen as adsorbent. The dye concentration, in both cases, was 200 mg/dm(3). Sorptive capacities of activated carbon were expressed as values of surface sorption, which in case of fresh activated carbon was 60 mg/g, and after regeneration ranged from 8 mg/g to 13 mg/g. The experimental data adsorption isotherms were defined and adsorption theoretical model, such as that of Freundlich or Langmuir, was selected. The highest removal efficiency in case of methyl blue was 94% for virgin carbon, the lowest - 75% (carbon after the fourth regeneration). The highest removal efficiency in case of naphthol green B was 78% for carbon after the fourth regeneration, the lowest - 55% (carbon after the first regeneration). The experimental data show that activated carbon can be used for the decontamination of dyes from textile wastewater. Model tests, however, need to be verified on real wastewater samples.