Wastewater generation is an explicit factor of urbanization. Urban expansion has imposed a pressure on wastewater management across world and Kolkata is no exception. Wastewater in Kolkata is treated by four Sewage Treatment Plants (STP) and the vast wetlands at the eastern fringe of the city, the East Kolkata Wetlands (EKW). The wastewater treatment by STPs is insufficient both in quality of treatment and quantity of water treated. To compound the problem EKW area is shrinking due to rapid urbanization. To deal with the wastewater management in Kolkata, an effective treatment process is presented in this study. Wastewater treatment by natural process or bioremediation is considered as an efficient and environmentally safe
technology for inexpensive decontamination of polluted water. This study has been designed to understand the efficiency of cyanobacteria treated wastewater compared to the conventional stabilization pond system followed at EKW fish ponds and also to propose for reuse of these important nutrients to return them to the environment. In the course of this study, it has been found that the wastewater treated with blue-green algae Anabaena sp. shows improved water quality than the water treated by conventional system at stabilization pond. Thus bioremediation by blue-green algae offers a good opportunity to deal with the problem of wastewater management in Kolkata.
Comparison in efficiency of treatment between the two systems
Cyanobacteria, stabilization pond, East Kolkata Wetlands, bioremediation, wastewater.