Modes of Enzyme Delivery in Treatment of Wastewater Containing Recalcitrant Pollutants

Water is a precious and dwindling resource. The enormous increase in domestic and industrial water consumption has been accompanied by a commensurate increase in the production of domestic and industrial effluents. Despite the limited availability of water, seas, rivers and lakes have been used as sinks for the disposal of domestic and industrial wastewater. Various effluent treatment methods have been developed to clean effluents and enable their reuse as efforts to conserve water. Some pollutants in wastewater persist in the environment because they are resistant to degradation by conventional treatment methods. The present chapter attempts to explore the use of enzymes as an alternative method for degrading recalcitrant pollutants in wastewater. The aim of the present chapter is to provide an account of various delivery systems that can be used to introduce enzymes into the reaction mixture during wastewater treatment. The chapter discusses different modes, such as the use of microbial or plant cells, cell-free extracts, and nanoparticles, by which enzymes can be delivered to degrade target pollutants in effluents, and it assesses the strengths and drawbacks of each mode. Furthermore, the need for current and future research to prioritize the development of economically feasible and environmentally sustainable wastewater treatment practices is emphasized.