Floating island of plants to clean Mumbai’s river which is 100 times more polluted than safe limit
A 25-square-foot floating island made of plants, which were going to be uprooted for Metro construction, was placed in Poisar river on Sunday as an experiment to see if it could be used to clean the polluted waterbody. The plants were uprooted from a Metro rail construction site in Andheri and were put in 500 discarded plastic bottles which were tied together to create a makeshift ‘mop’.
The Poisar, which flows through Kandivli and Borivli, is polluted with untreated sewage from residential and industrial areas. HT had reported that a study by Environmental Policy and Research India (EPRI) had showed that pollution in the Poisar river was 100 times the safe limit.
Members of River March, a group which aims to revive Mumbai’s four rivers — Poisar, Oshiwara, Mithi and Dahisar — said that they have used a wetland plant species – canna indica – to create the floating wetland. “The plants in the wetland provide a peculiar habitat for beneficial microorganisms in the root-zone (which also pump oxygen from the atmosphere into the bed) and jointly purify the sewage while the plants are automatically nurtured by the nitrogen and phosphorous in the sewage,” said Shyam Asolekar, professor from the Indian Institute of Technology, Bombay.

The floating island uses plants to create a better environment for aquatic life. A group of 15 volunteers spent Sunday creating the floating island and then placed it in the river. “The idea was to recycle the plastic bottles, which would have otherwise ended up at city dumping grounds, and the plants that would have been chopped for the Metro project. However, our goal is to make sure that this wetland bed can absorb pollutants,” said Tejas Shah, a member of River March. “We did this on an experimental basis and will check the results over the next few months.”
Describing the operation, Sagar Vira, a Kandivli resident, said, “We divided our team in two groups. One group collected and cut the plastic bottles from the base to make conical funnels to hold the plants and the other team went to Andheri to get the plants.”
Borivli resident and another volunteer Chetan Gandhi said they used an excavator machine for the work. Pollultion experts said floating islands of vegetation can be used to clean up water bodies.
What is a floating treatment wetland?
A constructed wetland bed is a natural treatment system that does not need energy or chemicals to clean wastewater
It traps the foul odour below the wetland bed and treats sewage through a continuous biotechnological process once the wastewater is released into the wetland bed.
What does it do?
Making use of waste material helps reduce water pollution in river as these floating treatment wetlands remove nutrients, suspended solids, metals like Zinc and Copper and excess ammonia (NH3)
The process helps increase availability of oxygen to protect aquatic life
Floating wetlands have now been approved as a storm-water best management practice (BMP) both within the country and abroad
Proposal to clean Poisar using artificial wetlands
Last week, the River March group submitted a proposal to the storm-water drain (SWD) department of the civic body suggesting that artificial floating islands be made along the entire 1.5 km stretch of the Poisar river
Officials from Brihanmumbai Municipal Corporation’s SWD department said they were interested in using such a technique. “This is a cost-effective measure to reduce water pollution. We will check the results of the pilot project and if positive, sanction it to contractor for all four rivers in the city,” said a senior civic official from SWD department.
-
Ruins of Maharaja Ranjit Singh’s mansion to host religious event on his death anniversary
In an effort to regain the lost splendour of Maharaja Ranjit Singh's historical buildings at his summer capital Dinanagar in Gurdaspur and promote tourism, the district administration, for the first time, will organise a religious event in the ruins of the Sikh ruler's mansion on June 29 to mark his death anniversary. During the religious function, path of Sukhmani Sahib will be held in a pandal.
-
HC allows Jalandhar man to go abroad; says pendency of an FIR no ground to deny him permission
The Punjab and Haryana high court has allowed a Jalandhar man, an accused in a criminal case, to go abroad, observing that pendency of an FIR would not mean that The petitioner, Kanwalpreet Singh Kalra would not return back. The petitioner, Kanwalpreet Singh Kalra, had approached the high court after he was denied permission to fly to Canada to attend the convocation ceremony of his daughter by a Jalandhar court.
-
Two days ahead of its first budget, the Aam Aadmi Party government in Punjab, while painting a grim picture of the state finances, on Saturday tore into the previous Congress government for “reckless spending” and saddling it with “unpaid liability” of ₹24,351 crore besides a colossal debt. Another ₹7,117.86 crore is unpaid power subsidy claimed by Punjab State Power Corporation Limited for supply to agriculture, domestic and industry consumers last year.
-
2 cops booked for helping gangster Duneke obtain passport on forged documents
Moga Amid investigation by the anti-Gangster task force into the gangsters operating from abroad, the district police on Saturday booked two cops for allegedly helping gangster Sukhdul Singh alias Sukha Duneke to obtain a passport by tampering police verification process using forged documents. The case was registered against assistant sub-inspector Prabhdyal Singh and head constable Gurwinder Singh, who were found guilty of helping Duneke.
-
EcoSikh to plant 450 mini forests in Amritsar
To tackle environmental degradation in Amritsar, US-based environmental organisation EcoSikh will plant 450 Guru Nanak Sacred forests comprising 550 trees each in the next five years in the city. The charitable organisation fighting climate crisis will launch the five-year campaign on Monday, the 445th foundation day of its Amritsar chapter. The campaign- Eco Amritsar 450- will culminate on the 450th anniversary of its founding in 2027.