Removal of dyes using low cost adsorbents

Abstract

The low cost adsorbents namely Rice Husk Carbon (RHC), Wheat Straw Carbon (WSC) and Saw Dust Carbon (SDC) have been tested for the effectiveness in decolourisation of wastewater containing a mixture of dyes. Three dyes namely crystal violet, direct orange and magenta have been used for imparting colour in the representative samples of wastewater. Effect of various parameters such as agitation time, pH, temperature and adsorbent dosage has been investigated in the study. The adsorption of dyes are best described by pseudo first order mechanism. The rate constants of adsorption (Kad) for the three dyes have been determined for the three adsorbents separately which are found to be 6.8x10⁻³, 8x10⁻³ and 25x10⁻³ min⁻¹ for crystal violet, 8x10⁻³, 12x10⁻³ and 16x10⁻³ min⁻¹ for direct orange and 10x10⁻³, 10.6x10⁻³ and 6x10⁻³ min⁻¹ for magenta when treated with RHC, WSC and SDC respectively.