Treatment of dye wastewater using granular activated carbon and zeolite filter

Abstract

Dye wastewater sample contains moderate concentration of chemical oxygen demand (COD), ammonia (NH 3) and color. This work evaluates the removal of COD, ammonia and color in dye wastewater using granular activated carbon (GAC) and zeolite in the column studies. Different surface loading rates, height of adsorbent and empty bed contact time were used to investigate the efficiency of the adsorption process. The maximum removal efficiency was found at the surface loading rate of 2.84 ml/cm 2.min and bed height of 10 cm. Due to the characteristics of GAC and zeolite, a sequence of combination with both adsorbents produces a better removal of contaminants. The best removal of the contaminants among the all adsorption treatment was found using GAC (bottom layer) and zeolite (upper layer) in 6.35 cm diameter column with 59.46% removal of COD, 60.82% removal of ammonia and 58.4% removal of color. For the adsorption with zeolite as the bottom layer and GAC as the upper layer, the data fitted well with the Langmuir model. While for the adsorption with zeolite as the upper layer and GAC as the bottom layer, the data fitted well for both Langmuir and Freundlich isotherms.