Limits and perspectives of pulp and paper industry wastewater treatment - A review

Every year the pulp and paper industry consumes billions of metres cubed of water and produces huge amounts of highly polluted wastewater that needs to be treated. Conventional techniques of wastewater treatment require a high energy input and their environmental impact is debatable. Thus, the need to find new sustainable, environmentally friendly and efficient treatment techniques is urgent. Microbial fuel cells (MFC) are the technology of the future since they simultaneously treat wastewater and produce clean energy. The historical development of this technology towards its application to wastewater treatment was described. The application of MFCs in pulp and paper wastewater treatment is a new and developing field of investigation that still needs to overcome many limitations before its use on an industrial scale. This article reviews the limits of conventional treatment methods and the current state of the art MFC systems for pulp and paper wastewater treatment. The paper provides an overview of the electrogenic microorganisms able to produce electricity from pulp and paper wastewater. The bacteria, isolated at different stages of pulp and papermaking, are best suited for electrogenic activity in harsh environments. It was shown that MFC technology fully meets the requirements of sustainable pulp and paper wastewater treatment and, in terms of the input-output energy balance, remains energetically and environmentally competitive when compared to conventional treatment methods.