Innovative sequencing batch reactors for industrial wastewater treatment

Industrial wastewaters are difficult to treat due to their high pollution load and to the presence of recalcitrant compounds. Being biological treatments preferable in terms of cost-competitiveness, technology limitations, eco-friendliness and generation of secondary pollution, research has focused on the development of improved biological reactors. Numerous researchers have investigated sequencing batch reactors (SBRs) as they present several advantages (like better degree of treatment, lower volumes, cost effectiveness, ease of operation, selection of specific populations able to degrade xenobiotic compounds, high rates of substrate removal, flexibility). All these characteristics make SBR ideal for industrial wastewater treatment. Even better performances can be achieved if innovative SBRs are used, such as sequencing batch biofilm reactor, anaerobic sequencing batch reactor and anaerobicaerobic sequencing batch reactor, or if granular sludge is generated after a proper choice of certain operational parameters. In fact, thanks to its regular, dense and strong microbial structure, granular sludge presents good settleability, high biomass retention, great ability to withstand shock loadings and the possibility to decompose toxic wastewater and simultaneously remove organic carbon, nitrogen and phosphorus. However, the relatively high concentrations of suspended solids in the effluent to allow the development of biomass in granular form impose the need for a post-treatment unit for solids removal. Such drawback has been solved with a new technology, namely sequencing batch biofilter granular reactor (SBBGR), which features all the advantages of a granular SBR together with very high filtering capacity and very low sludge production. © 2013 Nova Science Publishers, Inc.