Microbiological treatment of distillery wastewater focusing on colorant decolorization and resource recovery: a review

Wastewater generated from distillery industries is a matter of great concern due to its dark brown color, high organic load and resistance to natural biodegradation. Therefore, enormous effort is needed to avoid the discharge of this highly polluted effluent into natural water bodies and their consequent contamination. However, the treatment of the ever-increasing quantities of distillery wastewater in a cost-effective and eco-friendly manner is very challenging. The current physicochemical techniques available are either costly, energy-intensive or involve toxic chemicals. Thus, there is an urgent need to complement the existing knowledge on the biodegradation of distillery effluent with valuable resource recovery to find an appropriate solution for its sustainable management. This review incorporates a summary of the problems associated with distillery wastewater with special attention towards major color-causing components present in it and the challenges they pose. Detailed examination of various bioremediation approaches used by researchers for the treatment of distillery effluent is also provided. Moreover, the review scrutinizes the utilization of distillery wastewater for valuable product recovery to reduce its environmental burden and ascribe value to it. The study might help researchers and policy makers to develop suitable strategies for the microbiological treatment of high organic load and color-containing wastewater generated from various industries along with resource recovery, a beneficial step in the direction of sustainable development and circular economy.