Abstract: Background & Aims of the Study: Textile dyes generally are made of synthetic, organic, and aromatic compounds that may be contain of some heavy metals in their structure. Complex structure and presence of these metals cause toxicity and may be mutagen, teratogen or carcinogen. This study has investigated the ability of peanut shell powder to removal of some reactive dyes (Green 19, Orange 16, and Yellow 14) from aqueous solutions.

Materials & Methods : The effects of contact time, initial concentration of reactive dyes, adsorbent dosage and pH have been reported. The applicability of Langmuir and Freundlich isotherm was tried for the system to completely understand the adsorption isotherm processes.

Results: Batch adsorption studies showed that the peanut shell powder was able to remove the reactive dyes from aqueous solutions in the concentration range 25 to 250 mg/L. The highest percent removal for the Green 19, Orange 16, and Yellow 14 dyes was 84.2%, 87.36% and 88.49%, respectively. The adsorption was favored with maximum adsorption at pH=2. Also the optimum adsorbent dose was obtained 0.4 g/100 mL. By increasing adsorbent dose and initial concentration, removal efficiency was increased considerably. The adsorption isotherm studies clearly indicated that the adsorptive behavior of dyes on peanut shell satisfies only the Freundlich with average R 2 =0.926.

Conclusions: Based on findings, the peanut shell powder was found as a low cost, natural and abundant availability adsorbent to removal of reactive dyes from aqueous solution.