First trials have been carried out in the adapted system for adsorption process based in cheese pilot line already exiting in CTAEX, with fly ash contained in two rotating blades sunken into 80 kg sewage sludge. Laboratory optimal conditions were scale up to this trial: ratio 1/65 ash/sludge and 3 hours agitating.

<p> &nbsp;</p> <p> Heavy metal content was assessed in the original sludge and periodically every 30 min. along the trial.</p> <p> &nbsp;</p> <p> Adsorption capacity data were not as satisfactory (high) as in laboratory scale trial. Excepting Cr, C.A did not overpass 20%.</p> <p> &nbsp;</p> <p> To increase contact surface and improve these results, a previous conditioning of fly as is proposed and tested.</p>