Fig. 8: Pictorial representation of wastewater treatment by constructed wetlands in East Kolkata, West Bengal, India.

The raw sewage water from different sewage canals (stage 1) enters wetlands (stage 2) utilised for aquaculture activities and then goes into natural streams/rivers (stage 3). The wetlands in stage 2 are purposed as natural treatment systems of urban wastewater. In the study, Sardar Bherry was selected as the model system to investigate the role of microbiome-based bio-treatment and reuse systems of urban wastewater in constructed wetland treatment systems.