Studies on auramine dye adsorption on psidium guava leaves

Abstract

Removal of auramine dye from aqueous waste solutions was investigated by using very cheap and bio- sorbent, withered guava tree leaves and activated carbon. Guava leaves are readily available in the western and northern parts of India throughout the year, and hence form a cost effective alternative for removal of dyes from waste waters. The optimum contact time was found to be 120 min. in a pH range of 8-9 for 92-94% removal of the dye from aqueous solutions containing 150 mg/L of auramine dye using 2 g of the adsorbent. The effect of pH, dye concentration, sorbent dosage, temperature and contact time on the dye removal efficiency has been studied. Experimental results were found to fit both Freundlich and Langmuir models. Since the dye contains a cationic species, the removal efficiency was highest in a pH range of 8-9. Continuous adsorption studies in a packed column showed 100% removal efficiency for a flow rate of 10 ml·min −1 . When compared with the activated carbon, it was also found that adsorbent derived from guava leaves is more efficient in removal of dye.