Removal of dyes from a synthetic textile dye effluent by biosorption on apple pomace and wheat straw

This paper deals with two low-cost, locally available, renewable biosorbents: apple pomace and wheat straw for textile dye removal. Experiments at total dye concentrations of 10, 20, 30, 40, 50, 100, 150, and 200 mg/l were carried out with a synthetic effluent consisting of an equal mixture of five textile dyes. The effect of initial dye concentration. biosorbent particle size, quantity of biosorbent, effective adsorbance, dye removal and the applicability of the Langmuir and Freundlich isotherms were examined. One gram apple pomace was found to be a better biosorbent. removing 81% of dyes from the synthetic effluent at a particle size of 2 mm x 4 mm and 91% at 600 mum. Adsorption of dyes by apple pomace occurred at a faster rate in comparison to wheat straw. Both the isotherms were found to be applicable in the case of dye adsorption using apple pomace. (C) 2002 Elsevier Science Ltd. All rights reserved.