REMOVAL OF RHODAMINE-B BY BIOGAS WASTE SLURRY FROM AQUEOUS-SOLUTION

The ability of biogas waste slurry to adsorb a basic dye (Rhodamine-B) has been investigated. The parameters include agitation time, initial dye concentration, pH and adsorbent dosage. The rate controlling step is mainly intraparticle diffusion. The adsorption rate constant was found to be 2.9 X 10(-2) min-1 at 20 mg L-1 initial dye concentration. The adsorption conforms with Freundlich isotherm. Removal of the dye was at least 90% in the entire pH range from 2.3 to 11.2. Desorption of the dye in 50% (v/v) acetic acid to the extent of 69.7% indicates that most of the dye is held by the adsorbent by chemisorption.