The Pune Municipal Corporation (PMC) is working to develop ‘floating wetlands’ or ‘florafts’ on the lines of the Thane Municipal Corporation (TMC) to clean polluted lakes in the city. Bangalore-based company, JMS Biotech Pvt Ltd, led a presentation on floating wetlands in the PMC environment department on Tuesday.
The TMC in 2015 had developed florafts under the guidance of the National Environmental Engineering Research Institute (NEERI). The florafts involved planting in rafts certain plant varieties that help fight pollution.
Sanjay Shinde, deputy commissioner, environment department, PMC, said, “The floating wetlands’ concept has already been implemented in Bangalore, Thane, and Mira-Bhayander municipal corporations. It is successful and gives good results. We are also working on this concept to implement in the lakes in Pune to clean them. We are facing the problem of polluted water in lakes. One company made a presentation to us. Now, we will carry out the necessary things and take a final call after presenting the concept to the PMC commissioner.”
“After approval of the concept, we will allocate funds and run a pilot project in one of the lakes,” Shinde said.
Currently, the lakes are contaminated with high levels of sewage containing phosphates, nitrates, and other substances that promote the growth of water weeds and water hyacinth. These plants have covered the lakes, and are consuming large amounts of oxygen. This has reduced the level of dissolved oxygen in the water and created obstacles for oxygen to penetrate water. Due to the decrease in oxygen levels, there is no proper aquatic life existing in these lakes.
{{/usCountry}}Currently, the lakes are contaminated with high levels of sewage containing phosphates, nitrates, and other substances that promote the growth of water weeds and water hyacinth. These plants have covered the lakes, and are consuming large amounts of oxygen. This has reduced the level of dissolved oxygen in the water and created obstacles for oxygen to penetrate water. Due to the decrease in oxygen levels, there is no proper aquatic life existing in these lakes.
{{/usCountry}}The TMC is using ‘florafts’ involving wetland plants such as Canna, Scripus, Cyperus, Typha, Phragmites etc. in 10 x 10 feet rafts suspended in lakes. The roots of these plants absorb pollutants from the water such as excess nitrogen and phosphorus. These plants increase dissolved oxygen content and help trap sediments, thus serving as feeding and breeding grounds for dragonflies, birds and fishes.
In Pune city, there are three major lakes at Katraj, Pashan and Jambhulwadi. Currently, all three lakes are facing challenges such as dumping of garbage and untreated sewage, encroachment, and excessive aquatic flora such as water hyacinth during the summers. To stop sewage from flowing directly into the lakes, the PMC is installing sewage treatment plants (STPs) under the union government’s Atal Mission for Rejuvenation and Urban Transformation (AMRUT).
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Floating wetlands
Small artificial platforms for aquatic emergent plants to grow in water
Plants such as Canna, Scripus, Cyperus, Typha, and Phragmites are used in 10 x 10 feet rafts suspended in lakes
The floating mat provides shelter, reducing turbulence and mixing caused by wind and waves
Plants directly absorb nutrients like nitrogen (N) and phosphorus (P) from the water
Plant roots trap and aid in the settling of sediment, larger particles, and associated pollutants
This settling process is essential for reducing total phosphorus and orthophosphate levels in water