KINETICS OF NUTRIENT UPTAKE BY ECONOMICAL VEGETABLE SPECIES GROWN IN CONSTRUCTED WETLANDS
Haq Nawaz Abbasi1,2, Jing Xie1, Jan Vymazal3 and Xiwu Lu1,*
1School of Energy and Environment, SoutheastUniversity, Nanjing, Jiangsu, China
2Department of Environmental Science, FUUAST, Karachi, Sindh, Pakistan
3Department of Applied Ecology, Czech University of Life Sciences Prague, Czech Republic
*Corresponding author: xiwulu@seu.edu.cn; +86-13914753816
ABSTRACT
Constructed wetlands are used to treat wastewater, however, their performance and usage can be improved by selecting a suitable substrate. Various plants may differ in their capacity to assimilate nutrients in a constructed wetland system. In this research, Michaelis-Menten kinetic (Michaelis-Menten constant (Km) and maximum uptake rate (Imax)) provides a useful tool for the identification of plant nutrient uptake efficiency and selection of plants. Six economical plant species (Phyllostachysheteroclada, Medicago hispidaGaertn, Ipomoea aquatica, Brassica junceavar, Colocasiaesculenta L. Schoot, and A. tubersomrottle ex spreng) were selected to investigate the uptake kinetics. I. aquatica showed a higher maximum uptake capacity for all three nutrients (PO4-P, NO3-N and NH4-N). The second highest uptake capacity for PO4-P, NO3-N and NH4-N was found for A. tuberosum, B. juncea and M. hispida. I. aquatica has the highest Imax and lowest Km values for all three nutrients and it has good capabilities to adjust in high PO4-P, NO3-N and NH4-N nutrient condition. Imax and Km of P.heteroclada were relatively small and suitable for the low nutrients concentration environment, whereas the Imax and Km of A. tuberosum, M. hispidaand B. juncea were relatively large, which is suitable for treating wastewater with high nutrient concentration.
Keywords: Uptake kinetics; Michaelis-Menten kinetic; Michaelis-Menten constant (Km); Maximum uptake rate (Imax); Constructed wetland.
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