A comparative adsorption/biosorption for the removal of phenol and lead onto granular activated carbon and dried anaerobic sludge

The potential use of dried anaerobic granular sludge (DAGS) as a substitute for granular activated carbon (GAC) for removing phenol and lead from aqueous solution was examined in a batch system. To make the comparison between adsorption/biosorption process fair, the working sorption pH, temperature, mixing speed and contact time were fixed at 4, 30 degrees C, 250 rpm and 24 h, respectively for both the sorbents. Adsorption/biosorption isotherms were developed for both the single and binary component systems and expressed by four models. Model parameters were estimated by the nonlinear regression method using STATISTICA version 6 and EXCEL 2007 software. The maximum loading capacity (q(m)) of the phenol was 66.8234 and 37.0370 mg/g for lead onto GAC, while it was 70.0183 mg/g for phenol and 89.8783 mg/g for lead onto DAGS in single system. However, in binary system, the loading capacity decreased because of competition between compounds to binding sites of adsorbent/biosorbent.