Nitrogen transformation in a coupled high rate-water hyacinth ponds
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Date
2006
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Publisher
University of Dar es Salaam
Abstract
The role of plant biofilm and the effect of high rate pond (HRP) ON Nitrogen transformations and removal was studied in a water hyacinth wetland (WHW) unit. The study was done in two phases, phase I (WHW unit) and Phase ii (coupled HRP-WHW units). A conceptual model was then developed to model various processes in the system using STELLA 6.0.1 software. The study demonstrated the significance of the plant biofilm on nitrogen removal in WHW. Model results in phase I showed that 1.26gNm2.d of nitrogen was removed in presence of biofilm, but in absence of biofilm only 0.89gNm2.d was removed. In phase ii, 1.22gNm2.d and 0.37gNm2.d was removed in presence and absence of biofilm, respectively. The decrease in nitrogen removal in absence of biofilm, demonstrates the importance of biofilm attached onto plants. There was a higher nitrate removal through denitrification in WHW in phase ii WHW denitrification rate was 1.00gnm2.d but decreased slightly to 0.93gNm2.d in phase I WHW, probably because of introduction in WHW unit due to anoxie conditions. From the model results it was recommended that HRP should be incorporated in wetland design for efficient nitrogen removal to improve the performance, residence time for HRP should be increased promote nitrification.
Description
Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF TD746.5.H36)
Keywords
Nitroigen, Water hyacinth, Ponds, Environmental engineering
Citation
Hanai, E. E (2006) Nitrogen transformation in a coupled high rate-water hyacinth ponds, Master dissertation, University of Dar es Salaam. Dar es Salaam.