Microbial Electrochemical Dye Degradation: Present State of Art

Dyes are commonly utilised by many industries, for instance, pharmaceuticals, cosmetics, leather and textiles. Out of which, the textile-based industries produce most of the wastewater which is a major source for pollution in the world, as it contains a mixture of dyes, additives and chemicals which were added during textile manufacturing. These dyes are detrimental to the environment as most of the dyes are recalcitrant. Without treatment of dye-containing wastewater, dyes may accumulate in the fishes and other aquatic flora and fauna. It further causes carcinogenic or mutagenic conditions. It can also cause skin irritation, allergies or dermatitis. Microbial fuel cell (MFC) is a promising microbial-mediated electrochemical wastewater treatment tool where electroactive bacteria can be utilised for degrading the dyes with simultaneous electricity generation. Dyes could be removed both in anodic and cathodic chambers using the oxidation and reduction capabilities of bacteria, respectively. This chapter has highlighted principle of MFCs for dye biodegradation, microbes associated with dye degradation along with catabolic pathway responsible for dye degradation. Also, different case studies for cationic, anionic and non-ionic dyes with MFCs, factors affecting dye degradation and challenges in MFC operation are taken into account. Furthermore, it also discusses the materials used in MFCs, the different types of dyes, their structure and effects along with the pros and cons of the dye degradation techniques of MFC compared to other existing processes.