Immobilization as a powerful bioremediation tool for abatement of dye pollution: a review

Abstract

Dyes are xenobiotic compounds widely used by textile, leather, paper, printing, food, pharmaceutical, and cosmetic industries. Decolorization and dye degradation in the effluents is a prime hurdle in its treatment, and there is still a shortage of economically attractive and easy-to-operate treatments that can eliminate dye pollution. In recent years, chemical-based treatments are being replaced by greener technologies at the laboratory and industrial scale to combat dye pollution. It is noteworthy that immobilization is a biotechnological tool that greatly enhances bioremediation’s potential. The present review has covered the basic concepts of immobilization, including the different immobilization techniques and the various carriers used for immobilization. The efficient immobilization of a biocatalyst depends on the proper choice of a carrier combined with a suitable immobilization technique. Hence, this review provides a comparative analysis of the different immobilization techniques and carriers used. Further, there is an in-depth discussion on the potential of immobilized enzymes and cells as bioremediation agents for dye degradation. Nearly all the studies indicated that immobilization enhanced the biodecolorization of colored wastewater compared with free systems. Further, the potential of immobilized systems for large scale industrial implementation was also examined. The article ends with a note on the loopholes of research on immobilization and future scopes of this technique.