Water 2016, 8(11), 514; doi:10.3390/w8110514
Nitrogen Removal in a Horizontal Subsurface Flow Constructed Wetland Estimated Using the First-Order Kinetic Model
1
Institute of Wetland Research, Chinese Academy of Forestry, Beijing 100091, China
2
Beijing Hanshiqiao National Wetland Ecosystem Research Station, Beijing 101399, China
3
The Beijing Key Laboratory of Wetland Ecological Function and Restoration, Beijing 100091, China
4
School of Natural Resources, West Virginia University, Morgantown, WV 26506, USA
†
These authors contributed equally to this work.
*
Author to whom correspondence should be addressed.
Academic Editors: Hans Brix, Carlos A. Arias and Pedro N. Carvalho
Received: 25 August 2016 / Revised: 26 October 2016 / Accepted: 2 November 2016 / Published: 7 November 2016
(This article belongs to the Special Issue Constructed Wetlands for Water Treatment: New Developments)
Abstract
We monitored the water quality and hydrological conditions of a horizontal subsurface constructed wetland (HSSF-CW) in Beijing, China, for two years. We simulated the area-based constant and the temperature coefficient with the first-order kinetic model. We examined the relationships between the nitrogen (N) removal rate, N load, seasonal variations in the N removal rate, and environmental factors—such as the area-based constant, temperature, and dissolved oxygen (DO). The effluent ammonia (NH4+-N) and nitrate (NO3−-N) concentrations were significantly lower than the influent concentrations (p < 0.01, n = 38). The NO3−-N load was significantly correlated with the removal rate (R2 = 0.96, p < 0.01), but the NH4+-N load was not correlated with the removal rate (R2 = 0.02, p > 0.01). The area-based constants of NO3−-N and NH4+-N at 20 °C were 27 ± 26 (mean ± SD) and 14 ± 10 m∙year−1, respectively. The temperature coefficients for NO3−-N and NH4+-N were estimated at 1.004 and 0.960, respectively. The area-based constants for NO3−-N and NH4+-N were not correlated with temperature (p > 0.01). The NO3−-N area-based constant was correlated with the corresponding load (R2 = 0.96, p < 0.01). The NH4+-N area rate was correlated with DO (R2 = 0.69, p < 0.01), suggesting that the factors that influenced the N removal rate in this wetland met Liebig’s law of the minimum. View Full-Text
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
Share & Cite This Article
MDPI and ACS Style
Cui, L.; Li, W.; Zhang, Y.; Wei, J.; Lei, Y.; Zhang, M.; Pan, X.; Zhao, X.; Li, K.; Ma, W. Nitrogen Removal in a Horizontal Subsurface Flow Constructed Wetland Estimated Using the First-Order Kinetic Model. Water 2016, 8, 514.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.