Pulp and Paper Mill Wastewater: Ecotoxicological Effects and Bioremediation Approaches for Environmental Safety

Abstract

Pulp and paper industry is one of the important industrial sectors in India, which consume huge amount of water in the papermaking process. The final wastewater is often characterized by high color, BOD (biochemical oxygen demand), COD (chemical oxygen demand), AOX (adsorbable organic halides), SS (suspended solids), TDS (total dissolved solids), phenolics, heavy metals, and plant components like lignin, tannin, resin acids, and extractives. Finally, these compounds are reached to aquatic and terrestrial ecosystem and causing serious environmental pollution. The generated wastewaters are treated by conventional biological treatment like activated sludge process (ASP) after primary treatment. Biological treatment of paper mill effluent significantly removes BOD, COD, SS, and also COD, but it is insufficient in removal of lignin and chlorophenols due to its low biodegradability and toxicity. During last few decades, several physical and chemical methods have been developed with the aim to use as pre- and posttreatment method. However, application of this technology at large scale is costly. Therefore, bioremediation which involve the use of pollutant-specific microorganism for wastewater treatment has been considered as cost-effective and eco-friendly treatment method. Thus, this chapter provides the updated information on paper processing and wastewater generation and their characteristics and toxicity. Processes based on physicochemical and biological methods for the treatment of pulp and paper mill wastewater have been also discussed.