Immobilization of microbes and enzymes for textile wastewater treatment

Given the environmental and health hazards posed by xenobiotic dyes, it is imperative that they be removed from the effluents of the textile industries. Biological treatment of textile dyes employing microbial cells and enzymes emerged as an ecofriendly, easy-to-operate, and cost-effective method. Immobilization of the microbial cells and enzymes can make the method more versatile, robust, and efficient. The immobilization technique has proved to be effective in enhancing the biological removal of textile dyes by providing the microbial cells/enzymes with mechanical strength, protection from high dye concentration, longer viability, a higher degree of degradation capacity, and resilience to adverse environmental conditions such as changes in temperature, salinity, pH. State-of-the-art cell/enzyme immobilization methods for textile dye removal are constantly being developed, and innovations in this arena are anticipated to accelerate in the future. Immobilized microbial cells and/or enzymes can be used conveniently in a continuous reactor such as packed-bed reactors, which enables the possibility of high performance, scalability, process automation, and large-scale wastewater treatment. This chapter summarizes the comprehensive assessment of key cell/enzyme immobilization aspects including the immobilization mechanisms, and conventional and contemporary support matrices for the immobilization of dye-degrading microbes and their enzymes. Furthermore, the feasibility of using the immobilized microbial cells and/or enzymes for a sustainable textile dye remediation approach has been described.