Horizontal-flow anaerobic immobilized sludge (HAIS) reactor for paper industry wastewater treatment

Abstract

Immobilized cell reactors are known to permit the continuous operation without biomass washout and also for increasing the time available for cells` catalytic function in a reaction or in a series of reactions. Several cell immobilization supports have been used in different reactors for anaerobic wastewater treatment, such as: agar gel, acrylamide, porous ceramic, and polyurethane foam besides the self-immobilized biomass from UASB reactors. However, the results are not conclusive as to the advantages of these different reactors with different supports as compared to other anaerobic reactor configurations. This paper describes a new anaerobic attached growth reactor configuration, herein referred as horizontal-flow anaerobic immobilized sludge (HAIS) reactor and presents the results of its performance test treating kraft paper industry wastewater. The reactor configuration was conceived aiming to increase the ratio useful volume/total volume by lowering the volume for gas separation. The HAIS reactor conception would permit also to incorporate the reactor hydrodynamic characteristics in its design criteria if the flow pattern could be approximated as plug-flow.