Feasibility of hybrid bioreactor in the treatment of wastewater containing slowly biodegradable substances

Slowly biodegradable substances and recalcitrant pose a serious threat to the environment owing to their bio-resistant nature. With the increase in industrial activities, more and more quantity of these substances is being discharged through wastewater. The biodegradability potential of such substances can be anticipated from low BOD/COD ratio. Traditionally, the wastewater containing recalcitrant/slowly biodegradable materials is treated by the chemical oxidation followed by biological method. Although chemical oxidation enhances the BOD/COD ratio appreciably in the first step, it has a drawback of forming chemical sludge. In view of that a unique hybrid bioreactor is thought for so that its biofilm segment can perform under inhibitory environment. The present paper reviewed the background and the experiences of treatment of the slowly biodegradable substances and explores the scope of the hybrid bioreactor in this regard. Specific applications of hybrid bioreactor in treating aforesaid wastewater are also highlighted.