Volume No. 3 Issue No.: 3 Page No.: 695-705 Jan-Mar 2009




G. Baskar*, V.T. Deeptha and A. Abdul Rahaman

School of civil engineering
Faculty of Engineering and Technology, SRM University, Kattankulathur, Chennai (INDIA)


Received on : October 8, 2008




The term root zone encompasses the life interactions of bacteria, the roots of the wetland plants, soil, air, sun and water. Root zone treatment is an engineered method of purifying waste water as it passes through artificially constructed wetland area. It is considered as an effective and reliable secondary and tertiary treatment method. The pollutants are removed by various physical, chemical and biogeochemical processes like sedimentation, absorption, and nitrification as well as through uptake by wetland plants. Root zone systems are reported to be most suitable for schools, hospitals, hotels and for smaller communities. The aim of this research is to study the effectiveness of the wetland plant Phragmites australis in the treatment of waste water generated in the SRM University premises. A pilot wetland unit of size 1.5X0.6X0.3m was constructed in the campus grounds. Phragmites australis species were grown in the field with fresh water. 3X3 rows of plants were transplanted into the pilot unit and subjected to waste water from the hostels and other campus buildings. The raw waste water and treated waste water were collected periodically and tested for quality. It is seen that this pilot unit is reducing the concentrations of TSS, TDS, TN, TP, BOD, COD by 90%, 77%, 85%, 95%, 95%, 69%, respectively on an average. Root zone system achieves standards for tertiary treatment with no operating costs, low maintenance costs, enhances the landscape, provides a natural habitat for birds, and does not have any odour problem.


Keywords : Root Zone, Constructed wetland, Phragmites australis, Sedimentation, Absorption, Nitrification, Uptake