Browsing by Author "Tanaka, N."

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    Effect of external organic matter on nutrient removal and growth of Phragmites australis in a laboratory scale
    (Q IWA Publishing, 2006) Karunarathna, A.K.; Jinadasa, K.B.S.N.; Tanaka, N.
    Coconut dust, which is used intensively in horticultural applications, was tested as an external organic additive in a series of laboratory-scale subsurface-flow constructed wetlands planted with Phragmites australis. The systems were fed with a mixture of NO2 3 -N; NHþ 4 -N, and SRP in tap water to simulate high nutrient loads. In the absence of plants, TN removal efficiency was 66%, and the efficiency increased to .80% in the microcosm wetlands. TN and NO2 3 removal efficiencies were marginally increased by coconut-dust treatment in comparison with sand-bed microcosms. Analysis by ANOVA showed that the TN removal from a coconut dust-supplemented sand-bed microcosm was significantly different from a sand-bed microcosm (0.0437 , p , 0.05). All the systems showed an equal capacity to treat NHþ 4 nitrogen under low influent concentration levels. Phosphorus removal efficiencies were .98% in all three systems, and a difference between planted and unplanted systems was not observed. Shoot height and shoot densities of P. australis grown in the coconut dust-supplemented medium were significantly higher than those grown in the sand-bed medium. The difference in P. australis growth in response to the coconut dust addition revealed that the added material has the potential to create favourable conditions for plant growth.