Advances in Green Technologies for the Removal of Effluent Organic Matter from the Urban Wastewater

Effluent organic matter (EfOM) is a blend of organic matter, microbial constituents, biological metabolites, and synthetic chemicals which is originated mainly due to anthropogenic activities and is a matter of emerging environmental concern. The presence of EfOM poses a major challenge in the wastewater treatment processes. This review is aimed to assess the recent progress in developing innovative green approaches for the biotransformation of EfOM into ecofriendly products which is vital to attain the “zero-waste” paradigm to achieve wastewater reclamation and environmental sustainability under the umbrella of circular bioeconomy. Characteristics of EfOM and its impact on wastewater treatment processes have been evaluated. The potential and shortcomings of the traditional, advanced, and biological approaches for the EfOM removal have been described. Recent strategies which are based on the combination of two or more of these technologies (hybrid systems) have been discussed to address the challenges/shortcomings of the standalone technologies and to improve the process efficiency. Microalgae and cyanobacteria-based removal of EfOM along with its subsequent utilization as a soil amender is proposed as a novel trend in the future. Assessment of the previously employed technologies provided an insight into their working mechanisms which have suggested several improvements in the processes. Besides, hybrid systems could be an ecofriendly removal of EfOM via biosorption.