Bioremediation of Heavy Metal in Paper Mill Effluent

Abstract

The pulp and papermaking industry, being a large consumer of natural resources, i.e., wood and water, has become one of the largest sources of pollution to the environment. Wastewater generated during various stages of the pulp and paper-making process continues to be toxic in nature even after secondary treatment. The effluent water contains not only various toxic chemicals such as volatile organic compounds but also heavy metals like copper, mercury, iron, zinc aluminium, etc. Even at very low concentrations, most of the heavy metals are toxic and deadly in nature. Prolonged exposure to heavy metals causes various diseases in humans and animals either through skin contact, inhalation, or via consuming food materials. Treatment of pulp and paper industry wastewater by conventional methods is not efficient due to its complex nature. These conventional methods, either physical, biological, chemical or a combination of these methods are also not environmentally safe and economically viable. Complete degradation of heavy metals is not possible by the application of a single method. The generation of a huge volume of toxic sludge is an ongoing and major problem. Therefore bioremediation methods are preferred as they are highly efficient, cost effective, eco-friendly in nature, there is no secondary waste created in the environment and metabolize the highly toxic heavy metals into degradable, less toxic components with the help of microbes. This chapter focuses on Micro-Bioremediation methods using algae, fungi, yeasts and bacteria as the most preferred medium to treat wastewater generated by the pulp and paper industry. These are further also used to reduce toxic organic compounds.<br>