Comparison of membrane bioreactor technology and conventional activated sludge system for treating bleached kraft mill effluent

Abstract

The purpose of this paper was to review the use of membrane bioreactor technology as an alternative for treating the discharged effluent from a bleached kraft mill by comparing and contrasting membrane bioreactors with conventional activated sludge systems for wastewater treatment. There are many water shortage problems currently in the world, some of which are more serious than others. Public concern over health and the environment, combined with increased requirements for municipalities to reuse wastewater, have created a need for new technologies that can treat wastewater to generate high quality reusable water at low cost. In several of these technologies, membrane technology could make a great contribution since membranes have the ability to produce water of exceptional purity that can be recycled for reuse in a variety of places. This reuse of wastewater is already widely practiced in many countries, which reduces net demand on water supply systems. In industry, in particular the pulp and paper industry, large volumes of water are used with a significant amount of wastewater generated. This effluent needs to be treated prior to final disposal or reuse. The commonly used biological treatment methods of aerated lagoons and activated sludge of bleached kraft mill effluent have been found to be inadequate in achieving the desired level of toxicity removal. There is, therefore, the growing demand for greener/sustainable technologies for reuse/recycling of wastewater and the membrane bioreactors treatment of these effluents has shown some greater potential as it is much cleaner and meet stringent discharge requirements than with other techniques.

Key words: Membrane bioreactor, activated sludge, bleached kraft mill effluent, pulp and paper.