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Floating Treatment Wetlands - Bioremediation


Today, water pollution has become a serious issue. If left unchecked, it can have severe effects not just on the human population, but also on the entire terrestrial and aquatic biodiversity. The contamination of the water table by lead, cadmium, and mercury poses grave health problems. The agricultural runoff that is washed away into lakes cause eutrophication leading to degradation of water bodies.

Freshwater lakes worldwide, particularly shallow lakes, are at risk. Urbanisation, waste treatment, landscape changes, agriculture, and natural resource extraction all contribute to the flow of nutrients, pollutants, petroleum products, and organic compounds into freshwater lakes worldwide. However, biological treatment is achievable by utilising the natural ability of plants and bacteria to absorb nutrients (such as phosphorus and nitrogen) and degrade toxins through bioremediation.

How Wetlands help?

Widespread globally is the use of wetland bioremediation to absorb and remove pollutants and nutrients. Wetlands rely on natural processes to biologically filter water as it travels through shallow zones of lush aquatic vegetation and permeable soils at the bottom. The primary mechanisms for nutrient removal is transformation and uptake by microbes and plants, assimilation and absorption into organic and inorganic sediments, and converted into gas through volatilization. Aquatic plants absorb and remove these elements from the soil and water column.

How this inspired the idea of Floating treatment Wetlands-

Floating treatment wetland (FTW) is an efficient and sustainable wastewater treatment method. It has been widely adopted for cleaning agricultural runoff, stormwater, industrial effluents, and other types of polluted water.

Floating treatment wetlands (FTWs) or islands are small manmade platforms that allow suspended aquatic plants to flourish in water that is ordinarily too deep. Their roots spread through the floating islands and down into the water creating dense columns of roots with large surface area. FTW operates using a soil-free hydroponics method. Hydroponics allows plants to grow using only water and sunlight. There is no requirement for soil. There are little pores at the bottom of the base that promote the flow of nutrients from the water to the plants via biological uptake. Through microbial decomposition, microorganisms living on FTW and plant root systems of cleaning chemicals decompose and absorb organic debris in water. The root systems filters out sediments and pollutants, reduces concentration of these chemicals from waterbody.

Not only can plants absorb nutrients and toxins, but plant roots and floating island material also provide ample surface area for microorganisms to flourish, resulting in the formation of a slimy biofilm. In an FTW system, the majority of nutrient intake and decomposition happens within the biofilm. By minimising turbulence and mixing by wind and waves, the floating mat also enables silt and other particles to settle by lowering turbulence. The unique ecosystem that develops has the capacity to absorb nutrients and convert typical pollutants that would otherwise plague and destroy our lakes into harmless byproducts.


FTW is a creative and innovative approach that is currently commonly utilised to revitalise dying water bodies. While these remedial steps are being implemented, it is also crucial to take preventative measures before it is too late. Water Pollution must be controlled, and this requires collaboration, cooperation, and combined efforts of not only the central and state governments, but also the active participation of citizens and the joint efforts of Industry and other Private actors.


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