Removal of Acid Red 88 from Aqueous Solutions by Walnut Shells

Nowadays dyes are considered as major environmental pollutants. In this study, batch adsorption of Acid Red 88 onto walnut shells as a low-cost adsorbent was investigated. The effect of various experimental parameters such as initial dye concentration (25, 50, 100, 150 mg/L), adsorbent dosage (5, 10, 20, 35 g/L) and pH (4, 6, 8) was evaluated on dye adsorption using full factorial experiment design. The adsorption data were collected by means of spectrophotometer. The results showed that walnut shells have the capacity to remove approximately 95 percent of acid red 88 after 90 minute of adsorption process in a batch system at the optimum experimental condition (C = 150 mg/L, Adsorbent dosage = 35 g/L at pH = 4). While the change in pH did not significantly affect the total dye removal, adsorbent dosage showed to be the most effective factor. Equilibrium data were achieved by isotherms namely Langmuir and Freundlich models.

Keywords:

Adsorption , Dye , Acid Red 88 , Walnut Shells