Page 69 - March 2020 - WT Site

In Tamil Nadu, India, studies have indicated that the coontail, accumulates matter. Plant top-growth provides nutrient uptake,
Ceratophyllum demersum, a submerged macrophyte, is very shade for protection against algal growth and water removal in
efficient at removing ammonia (97%) and phosphorus (96%) the form of transpiration, while the large mass of self-generating
from raw sewage and also removes 95% of the BOD5. The root systems and accumulated material serve as living filters.
basic function of the macrophytes in the latter mechanism is
to assimilate, concentrate and store contaminants on a short- Conclusion
term basis. Subsequent harvest of the plant biomass results in
permanent removal of stored contaminents from the pond Water has a precious value and each drop must be accounted
treatment system. for in water scarce regions. Therefore, wastewater has to be
reclassified as a renewable water resource rather than waste as it
Emergent Macrophyte Treatment Systems helps to increase water availability and at the same time, prevents
environmental pollution.
Natural and artificial wetlands and marshes have been used to
treat raw sewage and partially-treated effluents. Natural wetlands Utilization of this resource requires collection, treatment, and
are usually unmanaged, whereas artificial systems are specially use of all generated wastewater. Although reuse of wastewater is
designed to maximize performance by providing the optimum recognized in most water-scarce countries, the reuse of wastewater
conditions for emergent macrophyte growth. The key features of is still very low. The reuse of the wastewater decreases the money
such reed bed treatment systems are:
spent on fertilizers, and the resulting water is considered safe,
• Rhizomes of the reeds grow vertically and horizontally in the since it has been treated for pathogens. To come to this point, the
soil or gravel bed, opening up ‘hydraulic pathways’. urban areas of many developing countries are growing rapidly,
and ecological sanitation systems that are sustainable and have the
• Wastewater BOD and nitrogen are removed by bacterial ability to adapt and grow with the community’s sanitation needs
activity; aerobic treatment takes place in the rhizosphere, must be developed.
with anoxic and anaerobic treatment taking place in the
surrounding soil. To successfully implement the strategies for wastewater reuse, it
is vitally necessary for institutional and policymaking capacities to
• Oxygen passes from the atmosphere to the rhizosphere be improved, public awareness of related issues to be increased,
via the leaves and stems of the reeds through the hollow and appropriate financial mechanisms to be created.
rhizomes and out through the roots.

• Suspended solids in the sewage are aerobically composted
in the above-ground layer of vegetation formed from dead About the Author
leaves and stems. S.M. Kumar, Director of Vishnu Pumps Coimbatore,
is the Sole Proprietor. He provides complete solutions
Nutrient Film Technique for industrial motors and related components. He is the
manufacturer, trader and supplier of high quality range of products
The nutrient film technique (NFT) is a modification of the which comprises of Electric Motor, Pumping Equipment,
hydroponic plant growth system in which plants are grown Agricultural Equipment, Fuel Pump Set, Power Generator, Bakery
directly on an impermeable surface to which a thin film of Equipment, Chain Saw Machine and many more. He has worked
wastewater is continuously applied. Root production on the on a project at Chennai related to waste water treatment. He can
be reached at kumar26101976@gmail.com.
impermeable surface is high and the large surface area and

Water Today - The Magazine l March 2020 71