SISTEMA A BIOMASSA GRANULARE INTEGRATO CON OZONO PER IL TRATTAMENTO ESAUSTIVO DEI REFLUI BIOREFRATTARI (PROGETTO EU LIFE PERBIOF)

This paper reports the results of an investigation carried out at demonstrative scale aimed at evaluating the performances of an innovative process for treating wastewater containing refractory compounds (i.e., tannery wastewater). In such a process the biological degradation, carried out in a periodic biofilter with granular biomass (SBBGR - Sequencing Batch Biofilter Granule Reactor), is integrated with chemical oxidation by ozone used with the aim to render biodegradable the recalcitrant compounds. The obtained results showed high removal efficiencies for COD, total suspended solids, nitrogen and surfactants with residual concentrations in the effluent much lower than Italian limits. Moreover, the process was characterised by very low sludge production (i.e., 0.1 kg of dry sludge/m3 of treated wastewater) with interesting repercussions on treatment costs (i.e., about 1 euro/m3).